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Watanabe M, Sinha AS, Shinmyo Y, Fukuda A. Early establishment of chloride homeostasis in CRH neurons is altered by prenatal stress leading to fetal HPA axis dysregulation. Front Mol Neurosci 2024; 17:1373337. [PMID: 38577026 PMCID: PMC10994000 DOI: 10.3389/fnmol.2024.1373337] [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: 01/19/2024] [Accepted: 03/05/2024] [Indexed: 04/06/2024] Open
Abstract
Corticotropin-releasing hormone (CRH) neurons play an important role in the regulation of neuroendocrine responses to stress. The excitability of CRH neurons is regulated by inhibitory GABAergic inputs. However, it is unclear when GABAergic regulation of CRH neurons is established during fetal brain development. Furthermore, the exact progression of the developmental shift of GABA action from depolarization to hyperpolarization remains unelucidated. Considering the importance of CRH neuron function in subsequent hypothalamic-pituitary-adrenal (HPA) axis regulation during this critical phase of development, we investigated the ontogeny of GABAergic inputs to CRH neurons and consequent development of chloride homeostasis. Both CRH neuron soma in the paraventricular nucleus (PVN) and axons projecting to the median eminence could be identified at embryonic day 15 (E15). Using acute slices containing the PVN of CRF-VenusΔNeo mice, gramicidin perforated-patch clamp-recordings of CRH neurons at E15, postnatal day 0 (P0), and P7 were performed to evaluate the developmental shift of GABA action. The equilibrium potential of GABA (EGABA) was similar between E15 and P0 and showed a further hyperpolarizing shift between P0 and P7 that was comparable to EGABA values in adult CRH neurons. GABA primarily acted as an inhibitory signal at E15 and KCC2 expression was detected in CRH neurons at this age. Activation of the HPA axis has been proposed as the primary mechanism through which prenatal maternal stress shapes fetal development and subsequent long-term disease risk. We therefore examined the impact of maternal food restriction stress on the development of chloride homeostasis in CRH neurons. We observed a depolarization shift of EGABA in CRH neurons of pups exposed to maternal food restriction stress. These results suggest that Cl- homeostasis in early developmental CRH neurons attains mature intracellular Cl- levels, GABA acts primarily as inhibitory, and CRH neurons mature and function early compared with neurons in other brain regions, such as the cortex and hippocampus. Maternal food restriction stress alters chloride homeostasis in CRH neurons of pups, reducing their inhibitory control by GABA. This may contribute to increased CRH neuron activity and cause activation of the HPA axis in pups.
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Affiliation(s)
| | | | - Yohei Shinmyo
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
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Zhang M, Chen Y, Xu T, Jiang J, Zhang D, Huang H, Kurth CD, Yuan I, Wang R, Liu J, Zhu T, Zhou C. γ-Aminobutyric Acid-Ergic Development Contributes to the Enhancement of Electroencephalogram Slow-Delta Oscillations Under Volatile Anesthesia in Neonatal Rats. Anesth Analg 2024; 138:198-209. [PMID: 36753442 DOI: 10.1213/ane.0000000000006396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
BACKGROUND General anesthetics (eg, propofol and volatile anesthetics) enhance the slow-delta oscillations of the cortical electroencephalogram (EEG), which partly results from the enhancement of (γ-aminobutyric acid [GABA]) γ-aminobutyric acid-ergic (GABAergic) transmission. There is a GABAergic excitatory-inhibitory shift during postnatal development. Whether general anesthetics can enhance slow-delta oscillations in the immature brain has not yet been unequivocally determined. METHODS Perforated patch-clamp recording was used to confirm the reversal potential of GABAergic currents throughout GABAergic development in acute brain slices of neonatal rats. The power density of the electrocorticogram and the minimum alveolar concentrations (MAC) of isoflurane and/or sevoflurane were measured in P4-P21 rats. Then, the effects of bumetanide, an inhibitor of the Na + -K + -2Cl - cotransporter (NKCC1) and K + -Cl - cotransporter (KCC2) knockdown on the potency of volatile anesthetics and the power density of the EEG were determined in vivo. RESULTS Reversal potential of GABAergic currents were gradually hyperpolarized from P4 to P21 in cortical pyramidal neurons. Bumetanide enhanced the hypnotic effects of volatile anesthetics at P5 (for MAC LORR , isoflurane: 0.63% ± 0.07% vs 0.81% ± 0.05%, 95% confidence interval [CI], -0.257 to -0.103, P < .001; sevoflurane: 1.46% ± 0.12% vs 1.66% ± 0.09%, 95% CI, -0.319 to -0.081, P < .001); while knockdown of KCC2 weakened their hypnotic effects at P21 in rats (for MAC LORR , isoflurane: 0.58% ± 0.05% to 0.77% ± 0.20%, 95% CI, 0.013-0.357, P = .003; sevoflurane: 1.17% ± 0.04% to 1.33% ± 0.04%, 95% CI, 0.078-0.244, P < .001). For cortical EEG, slow-delta oscillations were the predominant components of the EEG spectrum in neonatal rats. Isoflurane and/or sevoflurane suppressed the power density of slow-delta oscillations rather than enhancement of it until GABAergic maturity. Enhancement of slow-delta oscillations under volatile anesthetics was simulated by preinjection of bumetanide at P5 (isoflurane: slow-delta changed ratio from -0.31 ± 0.22 to 1.57 ± 1.15, 95% CI, 0.67-3.08, P = .007; sevoflurane: slow-delta changed ratio from -0.46 ± 0.25 to 0.95 ± 0.97, 95% CI, 0.38-2.45, P = .014); and suppressed by KCC2-siRNA at P21 (isoflurane: slow-delta changed ratio from 16.13 ± 5.69 to 3.98 ± 2.35, 95% CI, -18.50 to -5.80, P = .002; sevoflurane: slow-delta changed ratio from 0.13 ± 2.82 to 3.23 ± 2.49, 95% CI, 3.02-10.79, P = .003). CONCLUSIONS Enhancement of cortical EEG slow-delta oscillations by volatile anesthetics may require mature GABAergic inhibitory transmission during neonatal development.
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Affiliation(s)
- Mingyue Zhang
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Yali Chen
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Ting Xu
- Department of Anesthesiology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Jingyao Jiang
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Donghang Zhang
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Han Huang
- Department of Anesthesiology, West China Second Hospital of Sichuan University, Chengdu, China
| | - Charles D Kurth
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Ian Yuan
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Rurong Wang
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Jin Liu
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Tao Zhu
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Cheng Zhou
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
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Rahati Quchani M, Farmanesh E, Esmaili A, Moghimi A, Fereidoni M, Rahati Quchani S. Behavioral and electrophysiological (ECoG) effects of haplophyllum robustum and TRPA1 antagonist in adult male wistar rats. Toxicon 2023; 233:107233. [PMID: 37541601 DOI: 10.1016/j.toxicon.2023.107233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 07/20/2023] [Accepted: 08/01/2023] [Indexed: 08/06/2023]
Abstract
This article aimed to investigate the effects of Haplophyllum robustum hydroalcoholic extract on animals' behavioral and electrocorticographic changes. This plant is mainly found in Turkey, Iran, and Central Asia, and is reported to have convulsive effects. In this article, we worked on the effects of its hydroalcoholic extract on electrocorticography (ECoG), along with changes induced by intracerebroventricular administration of GABAA antagonists. Furthermore, the effects of low doses of this extract on behavioral depression were examined. Four animal sets were used to compare ECoG in Wistar rats. A group of negative control, a group of positive control (PTZ), and two groups received an injection of plant extract (500 mg/kg, ip), with or without administration of Diazepam (5 mg/kg). Also, three sets were applied to compare receiving and not receiving intracerebroventricular (icv) injection of Transient receptor potential ankyrin 1 antagonist (HC-030031) (2 μg/kg) on plant-induced seizure delay and animal death. Two groups of control and a group with plant extract together with TRPA1 antagonist were administrated. Furthermore, in the present study, the forced swimming test (FST) was used as a model of depression. The behaviors of animals in three groups of negative control and positive control (Fluoxetine) and plant extract (200 mg/kg, ip) were compared. According to the ECoG, high doses of extract of plants led to seizures similar to PTZ, which were then reduced by diazepam injection. At this dose, injection of TRPA1 antagonist did not significantly delay the onset of seizures or the death of the animals. Further, a subconvulsive dose of hydroalcoholic plant extracts was equally effective in treating depression as Fluoxetine injections.
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Affiliation(s)
- Maedeh Rahati Quchani
- Rayan Research Center for Neuroscience & Behavior, Dept of Biology, Faculty of Science, Ferdowsi University of Mashhad, Iran
| | - Elham Farmanesh
- Rayan Research Center for Neuroscience & Behavior, Dept of Biology, Faculty of Science, Ferdowsi University of Mashhad, Iran
| | - Asieh Esmaili
- Rayan Research Center for Neuroscience & Behavior, Dept of Biology, Faculty of Science, Ferdowsi University of Mashhad, Iran
| | - Ali Moghimi
- Rayan Research Center for Neuroscience & Behavior, Dept of Biology, Faculty of Science, Ferdowsi University of Mashhad, Iran.
| | - Masoud Fereidoni
- Rayan Research Center for Neuroscience & Behavior, Dept of Biology, Faculty of Science, Ferdowsi University of Mashhad, Iran
| | - Saeed Rahati Quchani
- Dept of Biomedical Engineering, Faculty of Engineering, Islamic Azad University, Central Tehran Branch, Iran
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Pressey JC, de Saint-Rome M, Raveendran VA, Woodin MA. Chloride transporters controlling neuronal excitability. Physiol Rev 2023; 103:1095-1135. [PMID: 36302178 DOI: 10.1152/physrev.00025.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Synaptic inhibition plays a crucial role in regulating neuronal excitability, which is the foundation of nervous system function. This inhibition is largely mediated by the neurotransmitters GABA and glycine that activate Cl--permeable ion channels, which means that the strength of inhibition depends on the Cl- gradient across the membrane. In neurons, the Cl- gradient is primarily mediated by two secondarily active cation-chloride cotransporters (CCCs), NKCC1 and KCC2. CCC-mediated regulation of the neuronal Cl- gradient is critical for healthy brain function, as dysregulation of CCCs has emerged as a key mechanism underlying neurological disorders including epilepsy, neuropathic pain, and autism spectrum disorder. This review begins with an overview of neuronal chloride transporters before explaining the dependent relationship between these CCCs, Cl- regulation, and inhibitory synaptic transmission. We then discuss the evidence for how CCCs can be regulated, including by activity and their protein interactions, which underlie inhibitory synaptic plasticity. For readers who may be interested in conducting experiments on CCCs and neuronal excitability, we have included a section on techniques for estimating and recording intracellular Cl-, including their advantages and limitations. Although the focus of this review is on neurons, we also examine how Cl- is regulated in glial cells, which in turn regulate neuronal excitability through the tight relationship between this nonneuronal cell type and synapses. Finally, we discuss the relatively extensive and growing literature on how CCC-mediated neuronal excitability contributes to neurological disorders.
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Affiliation(s)
- Jessica C Pressey
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Miranda de Saint-Rome
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Vineeth A Raveendran
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Melanie A Woodin
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
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Zhao Y, Cao E. Structural Pharmacology of Cation-Chloride Cotransporters. MEMBRANES 2022; 12:1206. [PMID: 36557113 PMCID: PMC9784483 DOI: 10.3390/membranes12121206] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/20/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
Loop and thiazide diuretics have been cornerstones of clinical management of hypertension and fluid overload conditions for more than five decades. The hunt for their molecular targets led to the discovery of cation-chloride cotransporters (CCCs) that catalyze electroneutral movement of Cl- together with Na+ and/or K+. CCCs consist of two 1 Na+-1 K+-2 Cl- (NKCC1-2), one 1 Na+-1 Cl- (NCC), and four 1 K+-1 Cl- (KCC1-4) transporters in human. CCCs are fundamental in trans-epithelia ion secretion and absorption, homeostasis of intracellular Cl- concentration and cell volume, and regulation of neuronal excitability. Malfunction of NKCC2 and NCC leads to abnormal salt and water retention in the kidney and, consequently, imbalance in electrolytes and blood pressure. Mutations in KCC2 and KCC3 are associated with brain disorders due to impairments in regulation of excitability and possibly cell volume of neurons. A recent surge of structures of CCCs have defined their dimeric architecture, their ion binding sites, their conformational changes associated with ion translocation, and the mechanisms of action of loop diuretics and small molecule inhibitors. These breakthroughs now set the stage to expand CCC pharmacology beyond loop and thiazide diuretics, developing the next generation of diuretics with improved potency and specificity. Beyond drugging renal-specific CCCs, brain-penetrable therapeutics are sorely needed to target CCCs in the nervous system for the treatment of neurological disorders and psychiatric conditions.
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Miles KD, Doll CA. Chloride imbalance in Fragile X syndrome. Front Neurosci 2022; 16:1008393. [PMID: 36312023 PMCID: PMC9596984 DOI: 10.3389/fnins.2022.1008393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/20/2022] [Indexed: 11/26/2022] Open
Abstract
Developmental changes in ionic balance are associated with crucial hallmarks in neural circuit formation, including changes in excitation and inhibition, neurogenesis, and synaptogenesis. Neuronal excitability is largely mediated by ionic concentrations inside and outside of the cell, and chloride (Cl-) ions are highly influential in early neurodevelopmental events. For example, γ-aminobutyric acid (GABA) is the main inhibitory neurotransmitter of the mature central nervous system (CNS). However, during early development GABA can depolarize target neurons, and GABAergic depolarization is implicated in crucial neurodevelopmental processes. This developmental shift of GABAergic neurotransmission from depolarizing to hyperpolarizing output is induced by changes in Cl- gradients, which are generated by the relative expression of Cl- transporters Nkcc1 and Kcc2. Interestingly, the GABA polarity shift is delayed in Fragile X syndrome (FXS) models; FXS is one of the most common heritable neurodevelopmental disorders. The RNA binding protein FMRP, encoded by the gene Fragile X Messenger Ribonucleoprotein-1 (Fmr1) and absent in FXS, appears to regulate chloride transporter expression. This could dramatically influence FXS phenotypes, as the syndrome is hypothesized to be rooted in defects in neural circuit development and imbalanced excitatory/inhibitory (E/I) neurotransmission. In this perspective, we summarize canonical Cl- transporter expression and investigate altered gene and protein expression of Nkcc1 and Kcc2 in FXS models. We then discuss interactions between Cl- transporters and neurotransmission complexes, and how these links could cause imbalances in inhibitory neurotransmission that may alter mature circuits. Finally, we highlight current therapeutic strategies and promising new directions in targeting Cl- transporter expression in FXS patients.
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Affiliation(s)
| | - Caleb Andrew Doll
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Children’s Hospital Colorado, Aurora, CO, United States
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Oernbo EK, Steffensen AB, Razzaghi Khamesi P, Toft-Bertelsen TL, Barbuskaite D, Vilhardt F, Gerkau NJ, Tritsaris K, Simonsen AH, Lolansen SD, Andreassen SN, Hasselbalch SG, Zeuthen T, Rose CR, Kurtcuoglu V, MacAulay N. Membrane transporters control cerebrospinal fluid formation independently of conventional osmosis to modulate intracranial pressure. Fluids Barriers CNS 2022; 19:65. [PMID: 36038945 PMCID: PMC9422132 DOI: 10.1186/s12987-022-00358-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 07/13/2022] [Indexed: 11/23/2022] Open
Abstract
Background Disturbances in the brain fluid balance can lead to life-threatening elevation in the intracranial pressure (ICP), which represents a vast clinical challenge. Nevertheless, the details underlying the molecular mechanisms governing cerebrospinal fluid (CSF) secretion are largely unresolved, thus preventing targeted and efficient pharmaceutical therapy of cerebral pathologies involving elevated ICP. Methods Experimental rats were employed for in vivo determinations of CSF secretion rates, ICP, blood pressure and ex vivo excised choroid plexus for morphological analysis and quantification of expression and activity of various transport proteins. CSF and blood extractions from rats, pigs, and humans were employed for osmolality determinations and a mathematical model employed to determine a contribution from potential local gradients at the surface of choroid plexus. Results We demonstrate that CSF secretion can occur independently of conventional osmosis and that local osmotic gradients do not suffice to support CSF secretion. Instead, the CSF secretion across the luminal membrane of choroid plexus relies approximately equally on the Na+/K+/2Cl− cotransporter NKCC1, the Na+/HCO3− cotransporter NBCe2, and the Na+/K+-ATPase, but not on the Na+/H+ exchanger NHE1. We demonstrate that pharmacological modulation of CSF secretion directly affects the ICP. Conclusions CSF secretion appears to not rely on conventional osmosis, but rather occur by a concerted effort of different choroidal transporters, possibly via a molecular mode of water transport inherent in the proteins themselves. Therapeutic modulation of the rate of CSF secretion may be employed as a strategy to modulate ICP. These insights identify new promising therapeutic targets against brain pathologies associated with elevated ICP. Supplementary Information The online version contains supplementary material available at 10.1186/s12987-022-00358-4.
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Affiliation(s)
- Eva K Oernbo
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Annette B Steffensen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Pooya Razzaghi Khamesi
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Trine L Toft-Bertelsen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Dagne Barbuskaite
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Frederik Vilhardt
- Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Niklas J Gerkau
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225, Düsseldorf, Germany
| | - Katerina Tritsaris
- Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Anja H Simonsen
- Danish Dementia Research Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Sara D Lolansen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Søren N Andreassen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Steen G Hasselbalch
- Danish Dementia Research Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Zeuthen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Christine R Rose
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225, Düsseldorf, Germany
| | - Vartan Kurtcuoglu
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Nanna MacAulay
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark.
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Gonzalez-Marrero I, Hernández-Abad LG, Castañeyra-Ruiz L, Carmona-Calero EM, Castañeyra-Perdomo A. Changes in the choroid plexuses and brain barriers associated with high blood pressure and ageing. Neurologia 2022; 37:371-382. [PMID: 30060976 DOI: 10.1016/j.nrl.2018.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/29/2018] [Accepted: 06/11/2018] [Indexed: 01/12/2023] Open
Abstract
INTRODUCTION The choroid plexuses, blood vessels, and brain barriers are closely related both in terms of morphology and function. Hypertension causes changes in cerebral blood flow and in small vessels and capillaries of the brain. This review studies the effects of high blood pressure (HBP) on the choroid plexuses and brain barriers. DEVELOPMENT The choroid plexuses (ChP) are structures located in the cerebral ventricles, and are highly conserved both phylogenetically and ontogenetically. The ChPs develop during embryogenesis, forming a functional barrier during the first weeks of gestation. They are composed of highly vascularised epithelial tissue covered by microvilli, and their main function is cerebrospinal fluid (CSF) production. The central nervous system (CNS) is protected by the blood-brain barrier (BBB) and the blood-CSF barrier (BCSFB). While the BBB is formed by endothelial cells of the microvasculature of the CNS, the BCSFB is formed by epithelial cells of the choroid plexuses. Chronic hypertension induces vascular remodelling. This prevents hyperperfusion at HBPs, but increases the risk of ischaemia at low blood pressures. In normotensive individuals, in contrast, cerebral circulation is self-regulated, blood flow remains constant, and the integrity of the BBB is preserved. CONCLUSIONS HBP induces changes in the choroid plexuses that affect the stroma, blood vessels, and CSF production. HBP also exacerbates age-related ChP dysfunction and causes alterations in the brain barriers, which are more marked in the BCSFB than in the BBB. Brain barrier damage may be determined by quantifying blood S-100β and TTRm levels.
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Affiliation(s)
- I Gonzalez-Marrero
- Departamento de Anatomía, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, España
| | - L G Hernández-Abad
- Instituto de Investigación y Ciencias de Puerto de Rosario, Puerto del Rosario, Fuerteventura, España
| | - L Castañeyra-Ruiz
- Departamento de Anatomía, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, España; Departamento de Farmacología, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, España
| | - E M Carmona-Calero
- Departamento de Anatomía, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, España; Instituto de Investigación y Ciencias de Puerto de Rosario, Puerto del Rosario, Fuerteventura, España
| | - A Castañeyra-Perdomo
- Departamento de Anatomía, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, España; Instituto de Investigación y Ciencias de Puerto de Rosario, Puerto del Rosario, Fuerteventura, España.
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Serranilla M, Woodin MA. Striatal Chloride Dysregulation and Impaired GABAergic Signaling Due to Cation-Chloride Cotransporter Dysfunction in Huntington’s Disease. Front Cell Neurosci 2022; 15:817013. [PMID: 35095429 PMCID: PMC8795088 DOI: 10.3389/fncel.2021.817013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 12/24/2021] [Indexed: 11/13/2022] Open
Abstract
Intracellular chloride (Cl–) levels in mature neurons must be tightly regulated for the maintenance of fast synaptic inhibition. In the mature central nervous system (CNS), synaptic inhibition is primarily mediated by gamma-amino butyric acid (GABA), which binds to Cl– permeable GABAA receptors (GABAARs). The intracellular Cl– concentration is primarily maintained by the antagonistic actions of two cation-chloride cotransporters (CCCs): Cl–-importing Na+-K+-Cl– co-transporter-1 (NKCC1) and Cl– -exporting K+-Cl– co-transporter-2 (KCC2). In mature neurons in the healthy brain, KCC2 expression is higher than NKCC1, leading to lower levels of intracellular Cl–, and Cl– influx upon GABAAR activation. However, in neurons of the immature brain or in neurological disorders such as epilepsy and traumatic brain injury, impaired KCC2 function and/or enhanced NKCC1 expression lead to intracellular Cl– accumulation and GABA-mediated excitation. In Huntington’s disease (HD), KCC2- and NKCC1-mediated Cl–-regulation are also altered, which leads to GABA-mediated excitation and contributes to the development of cognitive and motor impairments. This review summarizes the role of Cl– (dys)regulation in the healthy and HD brain, with a focus on the basal ganglia (BG) circuitry and CCCs as potential therapeutic targets in the treatment of HD.
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Kilb W. When Are Depolarizing GABAergic Responses Excitatory? Front Mol Neurosci 2021; 14:747835. [PMID: 34899178 PMCID: PMC8651619 DOI: 10.3389/fnmol.2021.747835] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/28/2021] [Indexed: 11/13/2022] Open
Abstract
The membrane responses upon activation of GABA(A) receptors critically depend on the intracellular Cl− concentration ([Cl−]i), which is maintained by a set of transmembrane transporters for Cl−. During neuronal development, but also under several pathophysiological conditions, the prevailing expression of the Cl− loader NKCC1 and the low expression of the Cl− extruder KCC2 causes elevated [Cl−]i, which result in depolarizing GABAergic membrane responses. However, depolarizing GABAergic responses are not necessarily excitatory, as GABA(A) receptors also reduces the input resistance of neurons and thereby shunt excitatory inputs. To summarize our knowledge on the effect of depolarizing GABA responses on neuronal excitability, this review discusses theoretical considerations and experimental studies illustrating the relation between GABA conductances, GABA reversal potential and neuronal excitability. In addition, evidences for the complex spatiotemporal interaction between depolarizing GABAergic and glutamatergic inputs are described. Moreover, mechanisms that influence [Cl−]i beyond the expression of Cl− transporters are presented. And finally, several in vitro and in vivo studies that directly investigated whether GABA mediates excitation or inhibition during early developmental stages are summarized. In summary, these theoretical considerations and experimental evidences suggest that GABA can act as inhibitory neurotransmitter even under conditions that maintain substantial depolarizing membrane responses.
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Affiliation(s)
- Werner Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
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11
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Human stem cell-derived GABAergic neurons functionally integrate into human neuronal networks. Sci Rep 2021; 11:22050. [PMID: 34764308 PMCID: PMC8585944 DOI: 10.1038/s41598-021-01270-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 10/26/2021] [Indexed: 02/03/2023] Open
Abstract
Gamma-aminobutyric acid (GABA)-releasing interneurons modulate neuronal network activity in the brain by inhibiting other neurons. The alteration or absence of these cells disrupts the balance between excitatory and inhibitory processes, leading to neurological disorders such as epilepsy. In this regard, cell-based therapy may be an alternative therapeutic approach. We generated light-sensitive human embryonic stem cell (hESC)-derived GABAergic interneurons (hdIN) and tested their functionality. After 35 days in vitro (DIV), hdINs showed electrophysiological properties and spontaneous synaptic currents comparable to mature neurons. In co-culture with human cortical neurons and after transplantation (AT) into human brain tissue resected from patients with drug-resistant epilepsy, light-activated channelrhodopsin-2 (ChR2) expressing hdINs induced postsynaptic currents in human neurons, strongly suggesting functional efferent synapse formation. These results provide a proof-of-concept that hESC-derived neurons can integrate and modulate the activity of a human host neuronal network. Therefore, this study supports the possibility of precise temporal control of network excitability by transplantation of light-sensitive interneurons.
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12
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The Alteration of Chloride Homeostasis/GABAergic Signaling in Brain Disorders: Could Oxidative Stress Play a Role? Antioxidants (Basel) 2021; 10:antiox10081316. [PMID: 34439564 PMCID: PMC8389245 DOI: 10.3390/antiox10081316] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 12/22/2022] Open
Abstract
In neuronal precursors and immature neurons, the depolarizing (excitatory) effect of γ-Aminobutyric acid (GABA) signaling is associated with elevated [Cl−]i; as brain cells mature, a developmental switch occurs, leading to the decrease of [Cl−]i and to the hyperpolarizing (inhibitory) effect of GABAergic signaling. [Cl−]i is controlled by two chloride co-transporters: NKCC1, which causes Cl− to accumulate into the cells, and KCC2, which extrudes it. The ontogenetic upregulation of the latter determines the above-outlined switch; however, many other factors contribute to the correct [Cl−]i in mature neurons. The dysregulation of chloride homeostasis is involved in seizure generation and has been associated with schizophrenia, Down’s Syndrome, Autism Spectrum Disorder, and other neurodevelopmental disorders. Recently, much effort has been put into developing new drugs intended to inhibit NKCC1 activity, while no attention has been paid to the origin of [Cl−]i dysregulation. Our study examines the pathophysiology of Cl− homeostasis and focuses on the impact of oxidative stress (OS) and inflammation on the activity of Cl− co-transporters, highlighting the relevance of OS in numerous brain abnormalities and diseases. This hypothesis supports the importance of primary prevention during pregnancy. It also integrates the therapeutic framework addressed to restore normal GABAergic signaling by counteracting the alteration in chloride homeostasis in central nervous system (CNS) cells, aiming at limiting the use of drugs that potentially pose a health risk.
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13
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Doi A, Miyazaki T, Mihara T, Ikeda M, Niikura R, Andoh T, Goto T. CLP290 promotes the sedative effects of midazolam in neonatal rats in a KCC2-dependent manner: A laboratory study in rats. PLoS One 2021; 16:e0248113. [PMID: 33711029 PMCID: PMC7954344 DOI: 10.1371/journal.pone.0248113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 02/22/2021] [Indexed: 11/25/2022] Open
Abstract
Immature neurons dominantly express the Na+-K+-2Cl- cotransporter isoform 1 (NKCC1) rather than the K+-Cl- cotransporter isoform 2 (KCC2). The intracellular chloride ion concentration ([Cl-]i) is higher in immature neurons than in mature neurons; therefore, γ-aminobutyric acid type A (GABAA) receptor activation in immature neurons does not cause chloride ion influx and subsequent hyperpolarization. In our previous work, we found that midazolam, benzodiazepine receptor agonist, causes less sedation in neonatal rats compared to adult rats and that NKCC1 blockade by bumetanide enhances the midazolam-induced sedation in neonatal, but not in adult, rats. These results suggest that GABA receptor activation requires the predominance of KCC2 over NKCC1 to exert sedative effects. In this study, we focused on CLP290, a novel KCC2-selective activator, and found that midazolam administration at 20 mg/kg after oral CLP290 intake significantly prolonged the righting reflex latency even in neonatal rats at postnatal day 7. By contrast, CLP290 alone did not exert sedative effects. Immunohistochemistry showed that midazolam combined with CLP290 decreased the number of phosphorylated cAMP response element-binding protein-positive cells in the cerebral cortex, suggesting that CLP290 reverted the inhibitory effect of midazolam. Moreover, the sedative effect of combined CLP290 and midazolam treatment was inhibited by the administration of the KCC2-selective inhibitor VU0463271, suggesting indirectly that the sedation-promoting effect of CLP290 was mediated by KCC2 activation. To our knowledge, this study is the first report showing the sedation-promoting effect of CLP290 in neonates and providing behavioral and histological evidence that CLP290 reverted the sedative effect of GABAergic drugs through the activation of KCC2. Our data suggest that the clinical application of CLP290 may provide a breakthrough in terms of midazolam-resistant sedation.
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Affiliation(s)
- Akiko Doi
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomoyuki Miyazaki
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Takahiro Mihara
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Maiko Ikeda
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Ryo Niikura
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomio Andoh
- Department of Anesthesiology, Mizonokuchi Hospital, Teikyo University School of Medicine, Kawasaki, Japan
| | - Takahisa Goto
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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14
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Smalley JL, Kontou G, Choi C, Ren Q, Albrecht D, Abiraman K, Santos MAR, Bope CE, Deeb TZ, Davies PA, Brandon NJ, Moss SJ. Isolation and Characterization of Multi-Protein Complexes Enriched in the K-Cl Co-transporter 2 From Brain Plasma Membranes. Front Mol Neurosci 2020; 13:563091. [PMID: 33192291 PMCID: PMC7643010 DOI: 10.3389/fnmol.2020.563091] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 09/14/2020] [Indexed: 12/17/2022] Open
Abstract
Kcc2 plays a critical role in determining the efficacy of synaptic inhibition, however, the cellular mechanisms neurons use to regulate its membrane trafficking, stability and activity are ill-defined. To address these issues, we used affinity purification to isolate stable multi-protein complexes of K-Cl Co-transporter 2 (Kcc2) from the plasma membrane of murine forebrain. We resolved these using blue-native polyacrylamide gel electrophoresis (BN-PAGE) coupled to LC-MS/MS and label-free quantification. Data are available via ProteomeXchange with identifier PXD021368. Purified Kcc2 migrated as distinct molecular species of 300, 600, and 800 kDa following BN-PAGE. In excess of 90% coverage of the soluble N- and C-termini of Kcc2 was obtained. In total we identified 246 proteins significantly associated with Kcc2. The 300 kDa species largely contained Kcc2, which is consistent with a dimeric quaternary structure for this transporter. The 600 and 800 kDa species represented stable multi-protein complexes of Kcc2. We identified a set of novel structural, ion transporting, immune related and signaling protein interactors, that are present at both excitatory and inhibitory synapses, consistent with the proposed localization of Kcc2. These included spectrins, C1qa/b/c and the IP3 receptor. We also identified interactors more directly associated with phosphorylation; Akap5, Akap13, and Lmtk3. Finally, we used LC-MS/MS on the same purified endogenous plasma membrane Kcc2 to detect phosphorylation sites. We detected 11 sites with high confidence, including known and novel sites. Collectively our experiments demonstrate that Kcc2 is associated with components of the neuronal cytoskeleton and signaling molecules that may act to regulate transporter membrane trafficking, stability, and activity.
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Affiliation(s)
- Joshua L Smalley
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Georgina Kontou
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States.,AstraZeneca Tufts Lab for Basic and Translational Neuroscience, Boston, MA, United States
| | - Catherine Choi
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Qiu Ren
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - David Albrecht
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States.,AstraZeneca Tufts Lab for Basic and Translational Neuroscience, Boston, MA, United States
| | - Krithika Abiraman
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States.,AstraZeneca Tufts Lab for Basic and Translational Neuroscience, Boston, MA, United States
| | | | - Christopher E Bope
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Tarek Z Deeb
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States.,AstraZeneca Tufts Lab for Basic and Translational Neuroscience, Boston, MA, United States
| | - Paul A Davies
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Nicholas J Brandon
- AstraZeneca Tufts Lab for Basic and Translational Neuroscience, Boston, MA, United States.,Neuroscience, IMED Biotech Unit, AstraZeneca, Boston, MA, United States
| | - Stephen J Moss
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States.,Department of Neuroscience, Physiology, and Pharmacology, University College London, London, United Kingdom
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15
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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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16
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Environmental regulation of the chloride transporter KCC2: switching inflammation off to switch the GABA on? Transl Psychiatry 2020; 10:349. [PMID: 33060559 PMCID: PMC7562743 DOI: 10.1038/s41398-020-01027-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 09/08/2020] [Accepted: 09/14/2020] [Indexed: 12/15/2022] Open
Abstract
Chloride homeostasis, the main determinant factor for the dynamic tuning of GABAergic inhibition during development, has emerged as a key element altered in a wide variety of brain disorders. Accordingly, developmental disorders such as schizophrenia, Autism Spectrum Disorder, Down syndrome, epilepsy, and tuberous sclerosis complex (TSC) have been associated with alterations in the expression of genes codifying for either of the two cotransporters involved in the excitatory-to-inhibitory GABA switch, KCC2 and NKCC1. These alterations can result from environmental insults, including prenatal stress and maternal separation which share, as common molecular denominator, the elevation of pro-inflammatory cytokines. In this review we report and systemize recent research articles indicating that different perinatal environmental perturbations affect the expression of chloride transporters, delaying the developmental switch of GABA signaling, and that inflammatory cytokines, in particular interleukin 1β, may represent a key causal factor for this phenomenon. Based on literature data, we provide therefore a unifying conceptual framework, linking environmental hits with the excitatory-to-inhibitory GABA switch in the context of brain developmental disorders.
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17
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Changes in the choroid plexuses and brain barriers associated with high blood pressure and ageing. NEUROLOGÍA (ENGLISH EDITION) 2020; 37:371-382. [DOI: 10.1016/j.nrleng.2020.05.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/11/2018] [Indexed: 01/04/2023] Open
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18
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Duy PQ, He M, He Z, Kahle KT. Preclinical insights into therapeutic targeting of KCC2 for disorders of neuronal hyperexcitability. Expert Opin Ther Targets 2020; 24:629-637. [PMID: 32336175 DOI: 10.1080/14728222.2020.1762174] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
INTRODUCTION Epilepsy is a common neurological disorder of neuronal hyperexcitability that begets recurrent and unprovoked seizures. The lack of a truly satisfactory pharmacotherapy for epilepsy highlights the clinical urgency for the discovery of new drug targets. To that end, targeting the electroneutral K+/Cl- cotransporter KCC2 has emerged as a novel therapeutic strategy for the treatment of epilepsy. AREAS COVERED We summarize the roles of KCC2 in the maintenance of synaptic inhibition and the evidence linking KCC2 dysfunction to epileptogenesis. We also discuss preclinical proof-of-principle studies that demonstrate that augmentation of KCC2 function can reduce seizure activity. Moreover, potential strategies to modulate KCC2 activity for therapeutic benefit are highlighted. EXPERT OPINION Although KCC2 is a promising drug target, questions remain before clinical translation. It is unclear whether increasing KCC2 activity can reverse epileptogenesis, the ultimate curative goal for epilepsy therapy that extends beyond seizure reduction. Furthermore, the potential adverse effects associated with increased KCC2 function have not been studied. Continued investigations into the neurobiology of KCC2 will help to translate promising preclinical insights into viable therapeutic avenues that leverage fundamental properties of KCC2 to treat medically intractable epilepsy and other disorders of failed synaptic inhibition with attendant neuronal hyperexcitability.
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Affiliation(s)
- Phan Q Duy
- Department of Neurosurgery, Yale University School of Medicine , New Haven, CT, USA.,Medical Scientist Training Program, Yale University School of Medicine , New Haven, CT, USA
| | - Miao He
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School , Boston, MA, USA
| | - Zhigang He
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School , Boston, MA, USA
| | - Kristopher T Kahle
- Department of Neurosurgery, Yale University School of Medicine , New Haven, CT, USA.,Department of Genetics, Yale University School of Medicine , New Haven, CT, USA.,Departments of Pediatrics and Cellular & Molecular Physiology, Yale University School of Medicine , New Haven, CT, USA.,Yale-Rockefeller NIH Centers for Mendelian Genomics, Yale University , New Haven, CT, USA.,Yale Stem Cell Center, Yale School of Medicine , New Haven, CT, USA
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19
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Fukuda A. Chloride homeodynamics underlying modal shifts in cellular and network oscillations. Neurosci Res 2020; 156:14-23. [PMID: 32105770 DOI: 10.1016/j.neures.2020.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 11/22/2019] [Accepted: 02/21/2020] [Indexed: 11/16/2022]
Abstract
γ-Aminobutyric acid (GABA) generally induces hyperpolarization and inhibition in the adult brain, but causes depolarization (and can be excitatory) in the immature brain. Depolarizing GABA actions are necessary for neurogenesis, differentiation, migration, and synaptogenesis. Additionally, the conversion of GABA responses from inhibition to excitation can be induced in adults by pathological conditions. Because GABAA receptors are Cl- channels, alternating GABA actions between hyperpolarization (Cl- influx) and depolarization (Cl- efflux) are induced by changes in the Cl- gradient, which is regulated by C- transporters. Thus, the dynamics of neural functions are modulated by active Cl- homeostasis (Cl- homeodynamics), alternating inhibition and excitation, and could underlie the modal shifts in cellular and network oscillations. Such a modal shift in GABA actions is required for normal development. Thus disturbances in this developmental GABA modal shift and/or the induction of excitatory GABA action in adult could underlie the pathogenesis of diverse neurological diseases (so-called network diseases).
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Affiliation(s)
- Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan; Advanced Research Facilities and Services, Preeminent Medical Photonics Education and Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan.
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20
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Auer T, Schreppel P, Erker T, Schwarzer C. Impaired chloride homeostasis in epilepsy: Molecular basis, impact on treatment, and current treatment approaches. Pharmacol Ther 2020; 205:107422. [DOI: 10.1016/j.pharmthera.2019.107422] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 10/07/2019] [Indexed: 12/14/2022]
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21
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Hsing HW, Zhuang ZH, Niou ZX, Chou SJ. Temporal Differences in Interneuron Invasion of Neocortex and Piriform Cortex during Mouse Cortical Development. Cereb Cortex 2019; 30:3015-3029. [PMID: 31838488 DOI: 10.1093/cercor/bhz291] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 10/06/2019] [Accepted: 10/31/2019] [Indexed: 12/28/2022] Open
Abstract
Establishing a balance between excitation and inhibition is critical for brain functions. However, how inhibitory interneurons (INs) generated in the ventral telencephalon integrate with the excitatory neurons generated in the dorsal telencephalon remains elusive. Previous studies showed that INs migrating tangentially to enter the neocortex (NCx), remain in the migratory stream for days before invading the cortical plate during late corticogenesis. Here we show that in developing mouse cortices, INs in the piriform cortex (PCx; the major olfactory cortex) distribute differently from those in the NCx. We provide evidence that during development INs invade and mature earlier in PCx than in NCx, likely owing to the lack of CXCR4 expression in INs from PCx compared to those in NCx. We analyzed IN distribution patterns in Lhx2 cKO mice, where projection neurons in the lateral NCx are re-fated to generate an ectopic PCx (ePCx). The PCx-specific IN distribution patterns found in ePCx suggest that properties of PCx projection neurons regulate IN distribution. Collectively, our results show that the timing of IN invasion in the developing PCx fundamentally differs from what is known in the NCx. Further, our results suggest that projection neurons instruct the PCx-specific pattern of IN distribution.
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Affiliation(s)
- Hsiang-Wei Hsing
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529 Taiwan
| | - Zi-Hui Zhuang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529 Taiwan
| | - Zhen-Xian Niou
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529 Taiwan
| | - Shen-Ju Chou
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529 Taiwan
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22
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Duy PQ, David WB, Kahle KT. Identification of KCC2 Mutations in Human Epilepsy Suggests Strategies for Therapeutic Transporter Modulation. Front Cell Neurosci 2019; 13:515. [PMID: 31803025 PMCID: PMC6873151 DOI: 10.3389/fncel.2019.00515] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 11/01/2019] [Indexed: 11/28/2022] Open
Abstract
Epilepsy is a common neurological disorder characterized by recurrent and unprovoked seizures thought to arise from impaired balance between neuronal excitation and inhibition. Our understanding of the neurophysiological mechanisms that render the brain epileptogenic remains incomplete, reflected by the lack of satisfactory treatments that can effectively prevent epileptic seizures without significant drug-related adverse effects. Type 2 K+-Cl− cotransporter (KCC2), encoded by SLC12A5, is important for chloride homeostasis and neuronal excitability. KCC2 dysfunction attenuates Cl− extrusion and impairs GABAergic inhibition, and can lead to neuronal hyperexcitability. Converging lines of evidence from human genetics have secured the link between KCC2 dysfunction and the development of epilepsy. Here, we review KCC2 mutations in human epilepsy and discuss potential therapeutic strategies based on the functional impact of these mutations. We suggest that a strategy of augmenting KCC2 activity by antagonizing its critical inhibitory phosphorylation sites may be a particularly efficacious method of facilitating Cl− extrusion and restoring GABA inhibition to treat medication-refractory epilepsy and other seizure disorders.
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Affiliation(s)
- Phan Q Duy
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, United States.,Medical Scientist Training Program, Yale University School of Medicine, New Haven, CT, United States
| | - Wyatt B David
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, United States
| | - Kristopher T Kahle
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, United States.,Department of Genetics, Yale University School of Medicine, New Haven, CT, United States.,Departments of Pediatrics and Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, CT, United States.,Yale-Rockefeller NIH Centers for Mendelian Genomics, Yale University, New Haven, CT, United States.,Yale Stem Cell Center, Yale School of Medicine, New Haven, CT, United States
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23
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Watanabe M, Zhang J, Mansuri MS, Duan J, Karimy JK, Delpire E, Alper SL, Lifton RP, Fukuda A, Kahle KT. Developmentally regulated KCC2 phosphorylation is essential for dynamic GABA-mediated inhibition and survival. Sci Signal 2019; 12:eaaw9315. [PMID: 31615901 PMCID: PMC7219477 DOI: 10.1126/scisignal.aaw9315] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Despite its importance for γ-aminobutyric acid (GABA) inhibition and involvement in neurodevelopmental disease, the regulatory mechanisms of the K+/Cl- cotransporter KCC2 (encoded by SLC12A5) during maturation of the central nervous system (CNS) are not entirely understood. Here, we applied quantitative phosphoproteomics to systematically map sites of KCC2 phosphorylation during CNS development in the mouse. KCC2 phosphorylation at Thr906 and Thr1007, which inhibits KCC2 activity, underwent dephosphorylation in parallel with the GABA excitatory-inhibitory sequence in vivo. Knockin mice expressing the homozygous phosphomimetic KCC2 mutations T906E/T1007E (Kcc2E/E ), which prevented the normal developmentally regulated dephosphorylation of these sites, exhibited early postnatal death from respiratory arrest and a marked absence of cervical spinal neuron respiratory discharges. Kcc2E/E mice also displayed disrupted lumbar spinal neuron locomotor rhythmogenesis and touch-evoked status epilepticus associated with markedly impaired KCC2-dependent Cl- extrusion. These data identify a previously unknown phosphorylation-dependent KCC2 regulatory mechanism during CNS development that is essential for dynamic GABA-mediated inhibition and survival.
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Affiliation(s)
- Miho Watanabe
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Jinwei Zhang
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, Hatherly Laboratories, Exeter EX4 4PS, UK
| | - M Shahid Mansuri
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT 06510, USA
| | - Jingjing Duan
- Human Aging Research Institute, School of Life Sciences, Nanchang University, Nanchang, Jiangxi 330031, China
| | - Jason K Karimy
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT 06510, USA
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Seth L Alper
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
- The Broad Institute of Harvard and the Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Richard P Lifton
- Laboratory of Human Genetics and Genomics, The Rockefeller University, New York, NY, USA
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan.
- Advanced Research Facilities and Services, Preeminent Medical Photonics Education and Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Kristopher T Kahle
- Departments of Neurosurgery, Pediatrics, and Cellular and Molecular Physiology, Centers for Mendelian Genomics, Yale School of Medicine, New Haven, CT 06510, USA.
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24
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Ghali MGZ, Beshay S. Role of fast inhibitory synaptic transmission in neonatal respiratory rhythmogenesis and pattern formation. Mol Cell Neurosci 2019; 100:103400. [PMID: 31472222 DOI: 10.1016/j.mcn.2019.103400] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 07/31/2019] [Accepted: 08/25/2019] [Indexed: 10/26/2022] Open
Abstract
Several studies have investigated the general role of chloride-based neurotransmission (GABAA and glycinergic signaling) in respiratory rhythmogenesis and pattern formation. In several brain regions, developmental alterations in these signaling pathways have been shown to be mediated by changes in cation-chloride cotransporter (CC) expression. For instance, CC expression changes during the course of neonatal development in medullary respiratory nuclei and other brain/spinal cord regions in a manner which decreases the cellular import, and increases the export, of chloride ions, shifting reversal potentials for chloride to progressively more negative values with maturation. In slice preparations of the same, this is related to an excitatory-to-inhibitory shift of GABAA- and glycinergic signaling. In medullary slices, GABAA-/glycinergic signaling in the early neonatal period is excitatory, becoming inhibitory over time. Additionally, blockade of the Na+/K+/2Cl- cotransporter, which imports these ions via secondary active transport, converts excitatory response to inhibitory ones. These effects have not yet been demonstrated at the individual respiratory-related neuron level to occur in intact (in vivo or in situ) animal preparations, which in contrast to slices, possess normal network connectivity and natural sources of tonic drive. Developmental changes in respiratory rhythm generating and pattern forming pontomedullary respiratory circuitry may contribute to critical periods, during which there exist increased risk for perinatal respiratory disturbances of central, obstructive, or hypoxia/hypercapnia-induced origin, including the sudden infant death syndrome. Thus, better characterizing the neurochemical maturation of the central respiratory network will enhance our understanding of these conditions, which will facilitate development of targeted therapies for respiratory disturbances in neonates and infants.
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Affiliation(s)
- Michael George Zaki Ghali
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America.
| | - Sarah Beshay
- Department of Pulmonology and Critical Care Medicine, Houston Methodist Hospital, Houston, TX 77030, United States of America
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25
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Moore YE, Conway LC, Wobst HJ, Brandon NJ, Deeb TZ, Moss SJ. Developmental Regulation of KCC2 Phosphorylation Has Long-Term Impacts on Cognitive Function. Front Mol Neurosci 2019; 12:173. [PMID: 31396048 PMCID: PMC6664008 DOI: 10.3389/fnmol.2019.00173] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 07/01/2019] [Indexed: 01/04/2023] Open
Abstract
GABAA receptor-mediated currents shift from excitatory to inhibitory during postnatal brain development in rodents. A postnatal increase in KCC2 protein expression is considered to be the sole mechanism controlling the developmental onset of hyperpolarizing synaptic transmission, but here we identify a key role for KCC2 phosphorylation in the developmental EGABA shift. Preventing phosphorylation of KCC2 in vivo at either residue serine 940 (S940), or at residues threonine 906 and threonine 1007 (T906/T1007), delayed or accelerated the postnatal onset of KCC2 function, respectively. Several models of neurodevelopmental disorders including Rett syndrome, Fragile × and Down's syndrome exhibit delayed postnatal onset of hyperpolarizing GABAergic inhibition, but whether the timing of the onset of hyperpolarizing synaptic inhibition during development plays a role in establishing adulthood cognitive function is unknown; we have used the distinct KCC2-S940A and KCC2-T906A/T1007A knock-in mouse models to address this issue. Altering KCC2 function resulted in long-term abnormalities in social behavior and memory retention. Tight regulation of KCC2 phosphorylation is therefore required for the typical timing of the developmental onset of hyperpolarizing synaptic inhibition, and it plays a fundamental role in the regulation of adulthood cognitive function.
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Affiliation(s)
- Yvonne E. Moore
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Leslie C. Conway
- AstraZeneca-Tufts University Laboratory for Basic and Translational Neuroscience Research, Tufts University School of Medicine, Boston, MA, United States
| | - Heike J. Wobst
- Neuroscience, R&D Biopharmaceuticals, AstraZeneca, Boston, MA, United States
| | - Nicholas J. Brandon
- Neuroscience, R&D Biopharmaceuticals, AstraZeneca, Boston, MA, United States
| | - Tarek Z. Deeb
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Stephen J. Moss
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
- AstraZeneca-Tufts University Laboratory for Basic and Translational Neuroscience Research, Tufts University School of Medicine, Boston, MA, United States
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
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26
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Kharod SC, Kang SK, Kadam SD. Off-Label Use of Bumetanide for Brain Disorders: An Overview. Front Neurosci 2019; 13:310. [PMID: 31068771 PMCID: PMC6491514 DOI: 10.3389/fnins.2019.00310] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 03/19/2019] [Indexed: 01/17/2023] Open
Abstract
Bumetanide (BTN or BUM) is a FDA-approved potent loop diuretic (LD) that acts by antagonizing sodium-potassium-chloride (Na-K-Cl) cotransporters, NKCC1 (SLc12a2) and NKCC2. While NKCC1 is expressed both in the CNS and in systemic organs, NKCC2 is kidney-specific. The off-label use of BTN to modulate neuronal transmembrane Cl− gradients by blocking NKCC1 in the CNS has now been tested as an anti-seizure agent and as an intervention for neurological disorders in pre-clinical studies with varying results. BTN safety and efficacy for its off-label use has also been tested in several clinical trials for neonates, children, adolescents, and adults. It failed to meet efficacy criteria for hypoxic-ischemic encephalopathy (HIE) neonatal seizures. In contrast, positive outcomes in temporal lobe epilepsy (TLE), autism, and schizophrenia trials have been attributed to BTN in studies evaluating its off-label use. NKCC1 is an electroneutral neuronal Cl− importer and the dominance of NKCC1 function has been proposed as the common pathology for HIE seizures, TLE, autism, and schizophrenia. Therefore, the use of BTN to antagonize neuronal NKCC1 with the goal to lower internal Cl− levels and promote GABAergic mediated hyperpolarization has been proposed. In this review, we summarize the data and results for pre-clinical and clinical studies that have tested off-label BTN interventions and report variable outcomes. We also compare the data underlying the developmental expression profile of NKCC1 and KCC2, highlight the limitations of BTN’s brain-availability and consider its actions on non-neuronal cells.
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Affiliation(s)
- Shivani C Kharod
- Neuroscience Laboratory, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, United States
| | - Seok Kyu Kang
- Neuroscience Laboratory, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, United States
| | - Shilpa D Kadam
- Neuroscience Laboratory, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, United States.,Department of Neurology and Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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27
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Lee-Hotta S, Uchiyama Y, Kametaka S. Role of the BDNF-TrkB pathway in KCC2 regulation and rehabilitation following neuronal injury: A mini review. Neurochem Int 2019; 128:32-38. [PMID: 30986502 DOI: 10.1016/j.neuint.2019.04.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/04/2019] [Accepted: 04/08/2019] [Indexed: 02/08/2023]
Abstract
In most mature neurons, low levels of intracellular Cl- concentrations ([Cl-]i) are maintained by channels and transporters, particularly the K+-Cl- cotransporter 2 (KCC2), which is the only Cl- extruder in most neurons. Recent studies have implicated KCC2 expression in the molecular mechanisms underlying neuronal disorders, such as spasticity, epilepsy and neuropathic pain. Alterations in KCC2 expression have been associated with brain-derived neurotrophic factor (BDNF) and its receptor tropomyosin-related kinase B (TrkB). The present review summarizes recent progress regarding the roles of Cl- regulators in immature and mature neurons. Moreover, we focus on the role of KCC2 regulation via the BDNF-TrkB pathway in spinal cord injury and rehabilitation, as prior studies have shown that the BDNF-TrkB pathway can affect both the pathological development and functional amelioration of spinal cord injuries. Evidence suggests that rehabilitation using active exercise and mechanical stimulation can attenuate spasticity and neuropathic pain in animal models, likely due to the upregulation of KCC2 expression via the BDNF-TrkB pathway. Moreover, research suggests that such rehabilitation efforts may recover KCC2 expression without the use of exogenous BDNF.
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Affiliation(s)
- Sachiko Lee-Hotta
- Department of Rehabilitation Sciences, Graduate School of Medicine, Nagoya University, 1-1-20, Daiko-minami Higashi-ku, Nagoya-shi, Aichi, 461-8673, Japan.
| | - Yasushi Uchiyama
- Department of Rehabilitation Sciences, Graduate School of Medicine, Nagoya University, 1-1-20, Daiko-minami Higashi-ku, Nagoya-shi, Aichi, 461-8673, Japan.
| | - Satoshi Kametaka
- Department of Rehabilitation Sciences, Graduate School of Medicine, Nagoya University, 1-1-20, Daiko-minami Higashi-ku, Nagoya-shi, Aichi, 461-8673, Japan.
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28
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Côme E, Heubl M, Schwartz EJ, Poncer JC, Lévi S. Reciprocal Regulation of KCC2 Trafficking and Synaptic Activity. Front Cell Neurosci 2019; 13:48. [PMID: 30842727 PMCID: PMC6391895 DOI: 10.3389/fncel.2019.00048] [Citation(s) in RCA: 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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29
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Spoljaric I, Spoljaric A, Mavrovic M, Seja P, Puskarjov M, Kaila K. KCC2-Mediated Cl - Extrusion Modulates Spontaneous Hippocampal Network Events in Perinatal Rats and Mice. Cell Rep 2019; 26:1073-1081.e3. [PMID: 30699338 PMCID: PMC6352714 DOI: 10.1016/j.celrep.2019.01.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 11/30/2018] [Accepted: 01/02/2019] [Indexed: 01/22/2023] Open
Abstract
It is generally thought that hippocampal neurons of perinatal rats and mice lack transport-functional K-Cl cotransporter KCC2, and that Cl- regulation is dominated by Cl- uptake via the Na-K-2Cl cotransporter NKCC1. Here, we demonstrate a robust enhancement of spontaneous hippocampal network events (giant depolarizing potentials [GDPs]) by the KCC2 inhibitor VU0463271 in neonatal rats and late-gestation, wild-type mouse embryos, but not in their KCC2-null littermates. VU0463271 increased the depolarizing GABAergic synaptic drive onto neonatal CA3 pyramidal neurons, increasing their spiking probability and synchrony during the rising phase of a GDP. Our data indicate that Cl- extrusion by KCC2 is involved in modulation of GDPs already at their developmental onset during the perinatal period in mice and rats.
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Affiliation(s)
- Inkeri Spoljaric
- Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, 00014 Helsinki, Finland
| | - Albert Spoljaric
- Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, 00014 Helsinki, Finland
| | - Martina Mavrovic
- Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, 00014 Helsinki, Finland
| | - Patricia Seja
- Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, 00014 Helsinki, Finland
| | - Martin Puskarjov
- Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, 00014 Helsinki, Finland
| | - Kai Kaila
- Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, 00014 Helsinki, Finland.
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30
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Amadeo A, Coatti A, Aracri P, Ascagni M, Iannantuoni D, Modena D, Carraresi L, Brusco S, Meneghini S, Arcangeli A, Pasini ME, Becchetti A. Postnatal Changes in K +/Cl - Cotransporter-2 Expression in the Forebrain of Mice Bearing a Mutant Nicotinic Subunit Linked to Sleep-Related Epilepsy. Neuroscience 2018; 386:91-107. [PMID: 29949744 DOI: 10.1016/j.neuroscience.2018.06.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 06/14/2018] [Accepted: 06/18/2018] [Indexed: 12/13/2022]
Abstract
The Na+/K+/Cl- cotransporter-1 (NKCC1) and the K+/Cl- cotransporter-2 (KCC2) set the transmembrane Cl- gradient in the brain, and are implicated in epileptogenesis. We studied the postnatal distribution of NKCC1 and KCC2 in wild-type (WT) mice, and in a mouse model of sleep-related epilepsy, carrying the mutant β2-V287L subunit of the nicotinic acetylcholine receptor (nAChR). In WT neocortex, immunohistochemistry showed a wide distribution of NKCC1 in neurons and astrocytes. At birth, KCC2 was localized in neuronal somata, whereas at subsequent stages it was mainly found in the somatodendritic compartment. The cotransporters' expression was quantified by densitometry in the transgenic strain. KCC2 expression increased during the first postnatal weeks, while the NKCC1 amount remained stable, after birth. In mice expressing β2-V287L, the KCC2 amount in layer V of prefrontal cortex (PFC) was lower than in the control littermates at postnatal day 8 (P8), with no concomitant change in NKCC1. Consistently, the GABAergic excitatory to inhibitory switch was delayed in PFC layer V of mice carrying β2-V287L. At P60, the amount of KCC2 was instead higher in mice bearing the transgene. Irrespective of genotype, NKCC1 and KCC2 were abundantly expressed in the neuropil of most thalamic nuclei since birth. However, KCC2 expression decreased by P60 in the reticular nucleus, and more so in mice expressing β2-V287L. Therefore, a complex regulatory interplay occurs between heteromeric nAChRs and KCC2 in postnatal forebrain. The pathogenetic effect of β2-V287L may depend on altered KCC2 amounts in PFC during synaptogenesis, as well as in mature thalamocortical circuits.
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Affiliation(s)
- Alida Amadeo
- Department of Biosciences, University of Milano, Via Celoria, 26, 20133 Milano, Italy.
| | - Aurora Coatti
- Department of Biotechnology and Biosciences, and NeuroMI-Milan Center of Neuroscience, University of Milano-Bicocca, Piazza della Scienza, 2, 20126 Milano, Italy.
| | - Patrizia Aracri
- Department of Biotechnology and Biosciences, and NeuroMI-Milan Center of Neuroscience, University of Milano-Bicocca, Piazza della Scienza, 2, 20126 Milano, Italy.
| | - Miriam Ascagni
- Department of Biosciences, University of Milano, Via Celoria, 26, 20133 Milano, Italy.
| | - Davide Iannantuoni
- Department of Biosciences, University of Milano, Via Celoria, 26, 20133 Milano, Italy.
| | - Debora Modena
- Department of Biosciences, University of Milano, Via Celoria, 26, 20133 Milano, Italy.
| | - Laura Carraresi
- Dival Toscana Srl, Via Madonna del Piano, 6 - 50019 Sesto Fiorentino, Firenze, Italy.
| | - Simone Brusco
- Department of Biotechnology and Biosciences, and NeuroMI-Milan Center of Neuroscience, University of Milano-Bicocca, Piazza della Scienza, 2, 20126 Milano, Italy.
| | - Simone Meneghini
- Department of Biotechnology and Biosciences, and NeuroMI-Milan Center of Neuroscience, University of Milano-Bicocca, Piazza della Scienza, 2, 20126 Milano, Italy.
| | - Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, University of Florence, Largo Brambilla, 3, 50134 Firenze, Italy.
| | - Maria Enrica Pasini
- Department of Biosciences, University of Milano, Via Celoria, 26, 20133 Milano, Italy.
| | - Andrea Becchetti
- Department of Biotechnology and Biosciences, and NeuroMI-Milan Center of Neuroscience, University of Milano-Bicocca, Piazza della Scienza, 2, 20126 Milano, Italy.
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31
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Steffensen AB, Oernbo EK, Stoica A, Gerkau NJ, Barbuskaite D, Tritsaris K, Rose CR, MacAulay N. Cotransporter-mediated water transport underlying cerebrospinal fluid formation. Nat Commun 2018; 9:2167. [PMID: 29867199 PMCID: PMC5986890 DOI: 10.1038/s41467-018-04677-9] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 05/14/2018] [Indexed: 12/20/2022] Open
Abstract
Cerebrospinal fluid (CSF) production occurs at a rate of 500 ml per day in the adult human. Conventional osmotic forces do not suffice to support such production rate and the molecular mechanisms underlying this fluid production remain elusive. Using ex vivo choroid plexus live imaging and isotope flux in combination with in vivo CSF production determination in mice, we identify a key component in the CSF production machinery. The Na+/K+/2Cl− cotransporter (NKCC1) expressed in the luminal membrane of choroid plexus contributes approximately half of the CSF production, via its unusual outward transport direction and its unique ability to directly couple water transport to ion translocation. We thereby establish the concept of cotransport of water as a missing link in the search for molecular pathways sustaining CSF production and redefine the current model of this pivotal physiological process. Our results provide a rational pharmacological target for pathologies involving disturbed brain fluid dynamics. Osmotic forces do not suffice to explain the rate of cerebrospinal fluid (CSF) production. Here, the authors show that the Na+/K+/2Cl− cotransporter in the choroid plexus contributes substantially to CSF production via its inherent ability to cotransport water.
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Affiliation(s)
- Annette B Steffensen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Noerre Allé 14, 2200, Copenhagen, Denmark
| | - Eva K Oernbo
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Noerre Allé 14, 2200, Copenhagen, Denmark
| | - Anca Stoica
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Noerre Allé 14, 2200, Copenhagen, Denmark
| | - Niklas J Gerkau
- Institute of Neurobiology, Heinrich Heine University Duesseldorf, Universitaetsstrasse 1, 40225, Duesseldorf, Germany
| | - Dagne Barbuskaite
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Noerre Allé 14, 2200, Copenhagen, Denmark
| | - Katerina Tritsaris
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Noerre Allé 14, 2200, Copenhagen, Denmark
| | - Christine R Rose
- Institute of Neurobiology, Heinrich Heine University Duesseldorf, Universitaetsstrasse 1, 40225, Duesseldorf, Germany
| | - Nanna MacAulay
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Noerre Allé 14, 2200, Copenhagen, Denmark.
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32
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Rahmati N, Hoebeek FE, Peter S, De Zeeuw CI. Chloride Homeostasis in Neurons With Special Emphasis on the Olivocerebellar System: Differential Roles for Transporters and Channels. Front Cell Neurosci 2018; 12:101. [PMID: 29765304 PMCID: PMC5938380 DOI: 10.3389/fncel.2018.00101] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 03/28/2018] [Indexed: 12/14/2022] Open
Abstract
The intraneuronal ionic composition is an important determinant of brain functioning. There is growing evidence that aberrant homeostasis of the intracellular concentration of Cl- ([Cl-]i) evokes, in addition to that of Na+ and Ca2+, robust impairments of neuronal excitability and neurotransmission and thereby neurological conditions. More specifically, understanding the mechanisms underlying regulation of [Cl-]i is crucial for deciphering the variability in GABAergic and glycinergic signaling of neurons, in both health and disease. The homeostatic level of [Cl-]i is determined by various regulatory mechanisms, including those mediated by plasma membrane Cl- channels and transporters. This review focuses on the latest advances in identification, regulation and characterization of Cl- channels and transporters that modulate neuronal excitability and cell volume. By putting special emphasis on neurons of the olivocerebellar system, we establish that Cl- channels and transporters play an indispensable role in determining their [Cl-]i and thereby their function in sensorimotor coordination.
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Affiliation(s)
- Negah Rahmati
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, Netherlands
| | - Freek E. Hoebeek
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, Netherlands
- NIDOD Institute, Wilhelmina Children's Hospital, University Medical Center Utrecht and Brain Center Rudolf Magnus, Utrecht, Netherlands
| | - Saša Peter
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, Netherlands
| | - Chris I. De Zeeuw
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, Netherlands
- Netherlands Institute for Neuroscience, Royal Dutch Academy for Arts and Sciences, Amsterdam, Netherlands
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33
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Vaaga CE, Miller KE, Bodor ÁL, Perkel DJ. Expression of the potassium-chloride co-transporter, KCC2, within the avian song system. J Comp Neurol 2018; 526:944-956. [PMID: 29218745 DOI: 10.1002/cne.24372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 11/29/2017] [Accepted: 11/30/2017] [Indexed: 11/06/2022]
Abstract
Songbirds learn to produce vocalizations early in life by listening to, then copying the songs of conspecific males. The anterior forebrain pathway, homologous to a basal ganglia-forebrain circuit, is essential for song learning. The projection between the striato-pallidal structure, Area X, and the medial portion of the dorsolateral thalamic nucleus (DLM) is strongly hyperpolarizing in adults, due to a very negative chloride reversal potential (Person & Perkel, Neuron 46:129-140, 2005). The chloride reversal potential is determined, in part, by the expression level of a neuron-specific potassium-chloride cotransporter, KCC2, which is developmentally upregulated in mammals. To determine whether a similar upregulation in KCC2 expression occurs at the Area X to DLM synapse during development, we examined the expression level of KCC2 in adult zebra finches across the song system as well as during development in the Area X - DLM synapse. We demonstrate that KCC2 is expressed in a subset of neurons throughout the song system, including HVC (used as a proper name), robust nucleus of the arcopallium (RA), lateral magnocellular nucleus of the anterior nidopallium (LMAN), Area X, and DLM. The majority of pallidal-like projection neurons in Area X showed KCC2 immunoreactivity. In adults, KCC2 expression was robust within DLM, and was upregulated between 14 and 24 days post hatching, before the onset of song learning. Light and electron microscopic analysis indicated that KCC2 immunoreactivity is strongly associated with the plasma membrane. Thus, in the song system as in the mammalian brain, KCC2 expression is well placed to modulate the GABAA reversal potential.
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Affiliation(s)
- Christopher E Vaaga
- Departments of Biology and Otolaryngology, University of Washington, Seattle, Washington
| | - Kimberly E Miller
- Departments of Biology and Otolaryngology, University of Washington, Seattle, Washington
| | - Ágnes L Bodor
- Departments of Biology and Otolaryngology, University of Washington, Seattle, Washington
| | - David J Perkel
- Departments of Biology and Otolaryngology, University of Washington, Seattle, Washington
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34
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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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35
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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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Molecular features and physiological roles of K +-Cl - cotransporter 4 (KCC4). Biochim Biophys Acta Gen Subj 2017; 1861:3154-3166. [PMID: 28935604 DOI: 10.1016/j.bbagen.2017.09.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 09/15/2017] [Indexed: 12/27/2022]
Abstract
A K+-Cl- cotransport system was documented for the first time during the mid-seventies in sheep and goat red blood cells. It was then described as a Na+-independent and ouabain-insensitive ion carrier that could be stimulated by cell swelling and N-ethylmaleimide (NEM), a thiol-reacting agent. Twenty years later, this system was found to be dispensed by four different isoforms in animal cells. The first one was identified in the expressed sequence tag (EST) database by Gillen et al. based on the assumption that it would be homologous to the Na+-dependent K+-Cl- cotransport system for which the molecular identity had already been uncovered. Not long after, the three other isoforms were once again identified in the EST databank. Among those, KCC4 has generated much interest a few years ago when it was shown to sustain distal renal acidification and hearing development in mouse. As will be seen in this review, many additional roles were ascribed to this isoform, in keeping with its wide distribution in animal species. However, some of them have still not been confirmed through animal models of gene inactivation or overexpression. Along the same line, considerable knowledge has been acquired on the mechanisms by which KCC4 is regulated and the environmental cues to which it is sensitive. Yet, it is inferred to some extent from historical views and extrapolations.
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Moore YE, Kelley MR, Brandon NJ, Deeb TZ, Moss SJ. Seizing Control of KCC2: A New Therapeutic Target for Epilepsy. Trends Neurosci 2017; 40:555-571. [PMID: 28803659 DOI: 10.1016/j.tins.2017.06.008] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 06/20/2017] [Accepted: 06/22/2017] [Indexed: 11/17/2022]
Abstract
Deficits in GABAergic inhibition result in the abnormal neuronal activation and synchronization that underlies seizures. However, the molecular mechanisms responsible for transforming a normal brain into an epileptic one remain largely unknown. Hyperpolarizing inhibition mediated by type A GABA (GABAA) receptors is dependent on chloride extrusion by the neuron-specific type 2K+-Cl- cotransporter (KCC2). Loss-of-function mutations in KCC2 are a known cause of infantile epilepsy in humans and KCC2 dysfunction is present in patients with both idiopathic and acquired epilepsy. Here we discuss the growing evidence that KCC2 dysfunction has a central role in the development and severity of the epilepsies.
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Affiliation(s)
- Yvonne E Moore
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK; Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Matt R Kelley
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Nicholas J Brandon
- AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, MA 02111, USA; AstraZeneca Neuroscience, Innovative Medicines and Early Development Biotech Unit, R&D Boston, Waltham, MA 024515, USA
| | - Tarek Z Deeb
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA; AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, MA 02111, USA
| | - Stephen J Moss
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK; Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA; AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, MA 02111, USA.
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Holló K, Ducza L, Hegyi Z, Dócs K, Hegedűs K, Bakk E, Papp I, Kis G, Mészár Z, Bardóczi Z, Antal M. Interleukin-1 receptor type 1 is overexpressed in neurons but not in glial cells within the rat superficial spinal dorsal horn in complete Freund adjuvant-induced inflammatory pain. J Neuroinflammation 2017. [PMID: 28645297 PMCID: PMC5482961 DOI: 10.1186/s12974-017-0902-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Background All known biological functions of the pro-inflammatory cytokine interleukin-1β (IL-1β) are mediated by type 1 interleukin receptor (IL-1R1). IL-1β–IL-1R1 signaling modulates various neuronal functions including spinal pain processing. Although the role of IL-1β in pain processing is generally accepted, there is a discussion in the literature whether IL-1β exerts its effect on spinal pain processing by activating neuronal or glial IL-1R1. To contribute to this debate, here we investigated the expression and cellular distribution of IL-1R1 in the superficial spinal dorsal horn in control animals and also in inflammatory pain. Methods Experiments were performed on rats and wild type as well as IL-1R1-deficient mice. Inflammatory pain was evoked by unilateral intraplantar injection of complete Freund adjuvant (CFA). The nociceptive responsiveness of control and CFA-treated animals were tested daily for withdrawal responses to mechanical and thermal stimuli before and after CFA injection. Changes in the expression of 48 selected genes/mRNAs and in the quantity of IL-1R1 protein during the first 3 days after CFA injection were measured with the TaqMan low-density array method and Western blot analysis, respectively. The cellular localization of IL-1R1 protein was investigated with single and double staining immunocytochemical methods. Results We found a six times and two times increase in IL-1R1 mRNA and protein levels, respectively, in the dorsal horn of CFA-injected animals 3 days after CFA injection, at the time of the summit of mechanical and thermal allodynia. Studying the cellular distribution of IL-1R1, we found an abundant expression of IL-1R1 on the somatodendritic compartment of neurons and an enrichment of the receptor in the postsynaptic membranes of some excitatory synapses. In contrast to the robust neuronal localization, we observed only a moderate expression of IL-1R1 on astrocytes and a negligible one on microglial cells. CFA injection into the hind paw caused a remarkable increase in the expression of IL-1R1 in neurons, but did not alter the glial expression of the receptor. Conclusion The results suggest that IL-1β exerts its effect on spinal pain processing primarily through neuronal IL-1R1, but it can also interact in some extent with IL-1R1 expressed by astrocytes.
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Affiliation(s)
- Krisztina Holló
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary
| | - László Ducza
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary
| | - Zoltán Hegyi
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary
| | - Klaudia Dócs
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary
| | - Krisztina Hegedűs
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary
| | - Erzsébet Bakk
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary
| | - Ildikó Papp
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary.,Department of Anatomy, Histology and Embryology, Faculty of Pharmacy, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary
| | - Gréta Kis
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary
| | - Zoltán Mészár
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary
| | - Zsuzsanna Bardóczi
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Miklós Antal
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary. .,MTA-DE Neuroscience Research Group, Nagyerdei krt. 98, 4012, Debrecen, Hungary.
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Role of choroid plexus in cerebrospinal fluid hydrodynamics. Neuroscience 2017; 354:69-87. [DOI: 10.1016/j.neuroscience.2017.04.025] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 04/19/2017] [Accepted: 04/19/2017] [Indexed: 12/24/2022]
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Praetorius J, Damkier HH. Transport across the choroid plexus epithelium. Am J Physiol Cell Physiol 2017; 312:C673-C686. [PMID: 28330845 DOI: 10.1152/ajpcell.00041.2017] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 03/17/2017] [Accepted: 03/17/2017] [Indexed: 11/22/2022]
Abstract
The choroid plexus epithelium is a secretory epithelium par excellence. However, this is perhaps not the most prominent reason for the massive interest in this modest-sized tissue residing inside the brain ventricles. Most likely, the dominant reason for extensive studies of the choroid plexus is the identification of this epithelium as the source of the majority of intraventricular cerebrospinal fluid. This finding has direct relevance for studies of diseases and conditions with deranged central fluid volume or ionic balance. While the concept is supported by the vast majority of the literature, the implication of the choroid plexus in secretion of the cerebrospinal fluid was recently challenged once again. Three newer and promising areas of current choroid plexus-related investigations are as follows: 1) the choroid plexus epithelium as the source of mediators necessary for central nervous system development, 2) the choroid plexus as a route for microorganisms and immune cells into the central nervous system, and 3) the choroid plexus as a potential route for drug delivery into the central nervous system, bypassing the blood-brain barrier. Thus, the purpose of this review is to highlight current active areas of research in the choroid plexus physiology and a few matters of continuous controversy.
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Affiliation(s)
- Jeppe Praetorius
- Department of Biomedicine, Health, Aarhus University, Aarhus, Denmark; and
| | - Helle Hasager Damkier
- Department of Biomedicine, Health, Aarhus University, Aarhus, Denmark; and.,Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Sedmak G, Jovanov-Milošević N, Puskarjov M, Ulamec M, Krušlin B, Kaila K, Judaš M. Developmental Expression Patterns of KCC2 and Functionally Associated Molecules in the Human Brain. Cereb Cortex 2016; 26:4574-4589. [PMID: 26428952 DOI: 10.1093/cercor/bhv218] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Work on rodents demonstrated that steep upregulation of KCC2, a neuron-specific Cl- extruder of cation-chloride cotransporter (CCC) family, commences in supraspinal structures at around birth, leading to establishment of hyperpolarizing GABAergic responses. We describe spatiotemporal expression profiles of the entire CCC family in human brain. KCC2 mRNA was observed already at 10th postconceptional week (PCW) in amygdala, cerebellum, and thalamus. KCC2-immunoreactive (KCC2-ir) neurons were abundant in subplate at 18 PCW. By 25 PCW, numerous subplate and cortical plate neurons became KCC2-ir. The mRNA expression profiles of α- and β-isoforms of Na-K ATPase, which fuels cation-chloride cotransport, as well of tropomyosin receptor kinase B (TrkB), which promotes developmental upregulation of KCC2, were consistent with data from studies on rodents about their interactions with KCC2. Thus, in human brain, expression of KCC2 and its functionally associated proteins begins in early fetal period. Our work facilitates translation of results on CCC functions from animal studies to human and refutes the view that poor efficacy of anticonvulsants in the term human neonate is attributable to the lack of KCC2. We propose that perinatally low threshold for activation of Ca2+-dependent protease calpain renders neonates susceptible to downregulation of KCC2 by traumatic events, such as perinatal hypoxia ischemia.
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Affiliation(s)
| | | | - Martin Puskarjov
- Department of Biosciences and Neuroscience Center, University of Helsinki, Viikinkaari 1, Helsinki FI-00014, Finland
| | - Monika Ulamec
- Department of Pathology, Clinical Hospital Center Sisters of Mercy, University of Zagreb School of Medicine, Zagreb 10 000, Croatia
| | - Božo Krušlin
- Department of Pathology, Clinical Hospital Center Sisters of Mercy, University of Zagreb School of Medicine, Zagreb 10 000, Croatia
| | - Kai Kaila
- Department of Biosciences and Neuroscience Center, University of Helsinki, Viikinkaari 1, Helsinki FI-00014, Finland
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Magalhães AC, Rivera C. NKCC1-Deficiency Results in Abnormal Proliferation of Neural Progenitor Cells of the Lateral Ganglionic Eminence. Front Cell Neurosci 2016; 10:200. [PMID: 27582690 PMCID: PMC4987357 DOI: 10.3389/fncel.2016.00200] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/02/2016] [Indexed: 12/14/2022] Open
Abstract
The proliferative pool of neural progenitor cells is maintained by exquisitely controlled mechanisms for cell cycle regulation. The Na-K-Cl cotransporter (NKCC1) is important for regulating cell volume and the proliferation of different cell types in vitro. NKCC1 is expressed in ventral telencephalon of embryonic brains suggesting a potential role in neural development of this region. The ventral telencephalon is a major source for both interneuron and oligodendrocyte precursor cells. Whether NKCC1 is involved in the proliferation of these cell populations remains unknown. In order to assess this question, we monitored several markers for neural, neuronal, and proliferating cells in wild-type (WT) and NKCC1 knockout (KO) mouse brains. We found that NKCC1 was expressed in neural progenitor cells from the lateral ganglionic eminence (LGE) at E12.5. Mice lacking NKCC1 expression displayed reduced phospho-Histone H3 (PH3)-labeled mitotic cells in the ventricular zone (VZ) and reduced cell cycle reentry. Accordingly, we found a significant reduction of Sp8-labeled immature interneurons migrating from the dorsal LGE in NKCC1-deficient mice at a later developmental stage. Interestingly, at E14.5, NKCC1 regulated also the formation of Olig2-labeled oligodendrocyte precursor cells. Collectively, these findings show that NKCC1 serves in vivo as a modulator of the cell cycle decision in the developing ventral telencephalon at the early stage of neurogenesis. These results present a novel mechanistic avenue to be considered in the recent proposed involvement of chloride transporters in a number of developmentally related diseases, such as epilepsy, autism, and schizophrenia.
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Affiliation(s)
| | - Claudio Rivera
- Neuroscience Center, University of HelsinkiHelsinki, Finland; Aix-Marseille University, UMR S901Marseille, France; INSERM U901, Institut de Neurobiologie de la Méditerranée (INMED)Marseille, France
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43
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Götz M, Nakafuku M, Petrik D. Neurogenesis in the Developing and Adult Brain-Similarities and Key Differences. Cold Spring Harb Perspect Biol 2016; 8:cshperspect.a018853. [PMID: 27235475 DOI: 10.1101/cshperspect.a018853] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Adult neurogenesis in the mammalian brain is often viewed as a continuation of neurogenesis at earlier, developmental stages. Here, we will critically review the extent to which this is the case highlighting similarities as well as key differences. Although many transcriptional regulators are shared in neurogenesis at embryonic and adult stages, recent findings on the molecular mechanisms by which these neuronal fate determinants control fate acquisition and maintenance have revealed profound differences between development and adulthood. Importantly, adult neurogenesis occurs in a gliogenic environment, hence requiring adult-specific additional and unique mechanisms of neuronal fate specification and maintenance. Thus, a better understanding of the molecular logic for continuous adult neurogenesis provides important clues to develop strategies to manipulate endogenous stem cells for the purpose of repair.
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Affiliation(s)
- Magdalena Götz
- Institute of Stem Cell Research, Helmholtz Center Munich, 85764 Neuherberg, Munich, Germany Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, 80336 Munich, Germany Synergy, Munich Cluster for Systems Neurology, 81377 Munich, Germany
| | - Masato Nakafuku
- Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45140 Departments of Pediatrics and Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
| | - David Petrik
- Institute of Stem Cell Research, Helmholtz Center Munich, 85764 Neuherberg, Munich, Germany Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, 80336 Munich, Germany
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Juif PE, Salio C, Zell V, Melchior M, Lacaud A, Petit-Demouliere N, Ferrini F, Darbon P, Hanesch U, Anton F, Merighi A, Lelièvre V, Poisbeau P. Peripheral and central alterations affecting spinal nociceptive processing and pain at adulthood in rats exposed to neonatal maternal deprivation. Eur J Neurosci 2016; 44:1952-62. [DOI: 10.1111/ejn.13294] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 05/24/2016] [Accepted: 06/07/2016] [Indexed: 12/13/2022]
Affiliation(s)
- Pierre-Eric Juif
- Institute of Cellular and Integrative Neurosciences (INCI); Centre National de la Recherche Scientifique; University of Strasbourg; 5 Rue Blaise Pascal F-67084 Strasbourg France
| | - Chiara Salio
- Department of Veterinary Sciences; Università degli Studi di Torino; Torino Italy
| | - Vivien Zell
- Institute of Cellular and Integrative Neurosciences (INCI); Centre National de la Recherche Scientifique; University of Strasbourg; 5 Rue Blaise Pascal F-67084 Strasbourg France
| | - Meggane Melchior
- Institute of Cellular and Integrative Neurosciences (INCI); Centre National de la Recherche Scientifique; University of Strasbourg; 5 Rue Blaise Pascal F-67084 Strasbourg France
| | - Adrien Lacaud
- Institute of Cellular and Integrative Neurosciences (INCI); Centre National de la Recherche Scientifique; University of Strasbourg; 5 Rue Blaise Pascal F-67084 Strasbourg France
| | - Nathalie Petit-Demouliere
- Institute of Cellular and Integrative Neurosciences (INCI); Centre National de la Recherche Scientifique; University of Strasbourg; 5 Rue Blaise Pascal F-67084 Strasbourg France
| | - Francesco Ferrini
- Department of Veterinary Sciences; Università degli Studi di Torino; Torino Italy
| | - Pascal Darbon
- Institute of Cellular and Integrative Neurosciences (INCI); Centre National de la Recherche Scientifique; University of Strasbourg; 5 Rue Blaise Pascal F-67084 Strasbourg France
| | - Ulrike Hanesch
- Laboratory of Neurophysiology and Psychobiology; University of Luxembourg; Luxembourg Luxembourg
| | - Fernand Anton
- Laboratory of Neurophysiology and Psychobiology; University of Luxembourg; Luxembourg Luxembourg
| | - Adalberto Merighi
- Department of Veterinary Sciences; Università degli Studi di Torino; Torino Italy
| | - Vincent Lelièvre
- Institute of Cellular and Integrative Neurosciences (INCI); Centre National de la Recherche Scientifique; University of Strasbourg; 5 Rue Blaise Pascal F-67084 Strasbourg France
| | - Pierrick Poisbeau
- Institute of Cellular and Integrative Neurosciences (INCI); Centre National de la Recherche Scientifique; University of Strasbourg; 5 Rue Blaise Pascal F-67084 Strasbourg France
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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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Watanabe M, Fukuda A. Development and regulation of chloride homeostasis in the central nervous system. Front Cell Neurosci 2015; 9:371. [PMID: 26441542 PMCID: PMC4585146 DOI: 10.3389/fncel.2015.00371] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 09/04/2015] [Indexed: 12/22/2022] Open
Abstract
γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter of the mature central nervous system (CNS). The developmental switch of GABAergic transmission from excitation to inhibition is induced by changes in Cl− gradients, which are generated by cation-Cl− co-transporters. An accumulation of Cl− by the Na+-K+-2Cl− co-transporter (NKCC1) increases the intracellular Cl− concentration ([Cl−]i) such that GABA depolarizes neuronal precursors and immature neurons. The subsequent ontogenetic switch, i.e., upregulation of the Cl−-extruder KCC2, which is a neuron-specific K+-Cl− co-transporter, with or without downregulation of NKCC1, results in low [Cl−]i levels and the hyperpolarizing action of GABA in mature neurons. Development of Cl− homeostasis depends on developmental changes in NKCC1 and KCC2 expression. Generally, developmental shifts (decreases) in [Cl−]i parallel the maturation of the nervous system, e.g., early in the spinal cord, hypothalamus and thalamus, followed by the limbic system, and last in the neocortex. There are several regulators of KCC2 and/or NKCC1 expression, including brain-derived neurotrophic factor (BDNF), insulin-like growth factor (IGF), and cystic fibrosis transmembrane conductance regulator (CFTR). Therefore, regionally different expression of these regulators may also contribute to the regional developmental shifts of Cl− homeostasis. KCC2 and NKCC1 functions are also regulated by phosphorylation by enzymes such as PKC, Src-family tyrosine kinases, and WNK1–4 and their downstream effectors STE20/SPS1-related proline/alanine-rich kinase (SPAK)-oxidative stress responsive kinase-1 (OSR1). In addition, activation of these kinases is modulated by humoral factors such as estrogen and taurine. Because these transporters use the electrochemical driving force of Na+ and K+ ions, topographical interaction with the Na+-K+ ATPase and its modulators such as creatine kinase (CK) should modulate functions of Cl− transporters. Therefore, regional developmental regulation of these regulators and modulators of Cl− transporters may also play a pivotal role in the development of Cl− homeostasis.
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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
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Javdani F, Holló K, Hegedűs K, Kis G, Hegyi Z, Dócs K, Kasugai Y, Fukazawa Y, Shigemoto R, Antal M. Differential expression patterns of K(+) /Cl(-) cotransporter 2 in neurons within the superficial spinal dorsal horn of rats. J Comp Neurol 2015; 523:1967-83. [PMID: 25764511 DOI: 10.1002/cne.23774] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 03/03/2015] [Accepted: 03/03/2015] [Indexed: 01/21/2023]
Abstract
γ-Aminobutyric acid (GABA)- and glycine-mediated hyperpolarizing inhibition is associated with a chloride influx that depends on the inwardly directed chloride electrochemical gradient. In neurons, the extrusion of chloride from the cytosol primarily depends on the expression of an isoform of potassium-chloride cotransporters (KCC2s). KCC2 is crucial in the regulation of the inhibitory tone of neural circuits, including pain processing neural assemblies. Thus we investigated the cellular distribution of KCC2 in neurons underlying pain processing in the superficial spinal dorsal horn of rats by using high-resolution immunocytochemical methods. We demonstrated that perikarya and dendrites widely expressed KCC2, but axon terminals proved to be negative for KCC2. In single ultrathin sections, silver deposits labeling KCC2 molecules showed different densities on the surface of dendritic profiles, some of which were negative for KCC2. In freeze fracture replicas and tissue sections double stained for the β3-subunit of GABAA receptors and KCC2, GABAA receptors were revealed on dendritic segments with high and also with low KCC2 densities. By measuring the distances between spots immunoreactive for gephyrin (a scaffolding protein of GABAA and glycine receptors) and KCC2 on the surface of neurokinin 1 (NK1) receptor-immunoreactive dendrites, we found that gephyrin-immunoreactive spots were located at various distances from KCC2 cotransporters; 5.7 % of them were recovered in the middle of 4-10-µm-long dendritic segments that were free of KCC2 immunostaining. The variable local densities of KCC2 may result in variable postsynaptic potentials evoked by the activation of GABAA and glycine receptors along the dendrites of spinal neurons.
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Affiliation(s)
- Fariba Javdani
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Krisztina Holló
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Krisztina Hegedűs
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Gréta Kis
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Zoltán Hegyi
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Klaudia Dócs
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Yu Kasugai
- Department of Pharmacology, Innsbruck Medical University, Innsbruck 6020, Austria
| | - Yugo Fukazawa
- Division of Cell Biology and Neuroscience, Faculty of Medical Sciences, University of Fukui, Yoshida, 910-1193, Japan
| | - Ryuichi Shigemoto
- Institute of Science and Technology Austria, Klosterneuburg, 3400, Austria
| | - Miklós Antal
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
- MTA-DE Neuroscience Research Group, Debrecen, 4012, Hungary
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Kim J, Takayama C, Park C, Ahn M, Moon C, Shin T. Immunohistochemical localization of GABAergic key molecules in the main olfactory bulb of the Korean roe deer, Capreolus pygargus. Acta Histochem 2015; 117:642-8. [PMID: 26115600 DOI: 10.1016/j.acthis.2015.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 05/14/2015] [Accepted: 06/10/2015] [Indexed: 10/23/2022]
Abstract
Gamma-amino butyric acid (GABA) negatively regulates the excitatory activity of neurons and is a predominant neurotransmitter in the nervous system. The olfactory bulb, the main center in the olfactory system, is modulated by inhibitory interneurons that use GABA as their main neurotransmitter. The present study aimed to evaluate GABAergic transmission in the main olfactory bulb (MOB) of the Korean roe deer (Capreolus pygargus) by examining the immunohistochemical localization of GABAergic key molecules, including glutamic acid decarboxylase (GAD), vesicular GABA transporter (VGAT), GABA transporters (GATs; GAT-1 and GAT-3), and potassium sodium chloride co-transporter 2 (KCC2). GAD, VGAT, and KCC2 were expressed in the glomerular layer (GL), external plexiform layer (ePL), mitral cell layer (ML), and granule cell layer (GrL). Intense GAT-1 expression was observed in the GL; GAT-1 expression was discernible in the ePL, ML, and GrL. However, intense GAT-3 expression was extensively observed in all layers of the MOB. These results suggest that substantial GABAergic synapses are present in the GL, ePL, ML, and GrL. Furthermore, the released GABA may be removed by GAT-1 and GAT-3 in the GL, and the majority of GABA, which is present in the ePL to GrL, may undergo reuptake by GAT-3. This is the first morphological and descriptive study of GABAergic transmission in the MOB of Korean roe deer.
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Affiliation(s)
- Jeongtae Kim
- Department of Molecular Anatomy, Faculty of Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa 903 0215, Japan
| | - Chitoshi Takayama
- Department of Molecular Anatomy, Faculty of Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa 903 0215, Japan
| | - Changnam Park
- Department of Veterinary Anatomy, College of Veterinary Medicine, Jeju National University, Jeju 690 756, Republic of Korea
| | - Meejung Ahn
- School of Medicine, Jeju National University, Jeju 690 756, Republic of Korea
| | - Changjong Moon
- Department of Veterinary Anatomy, College of Veterinary Medicine, Chonnam National University, 300 Yongbong-Dong, Buk-Gu, Gwangju 500 757, Republic of Korea.
| | - Taekyun Shin
- Department of Veterinary Anatomy, College of Veterinary Medicine, Jeju National University, Jeju 690 756, Republic of Korea.
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Chabwine JN, Talavera K, Van Den Bosch L, Callewaert G. NKCC1 downregulation induces hyperpolarizing shift of GABA responsiveness at near term fetal stages in rat cultured dorsal root ganglion neurons. BMC Neurosci 2015; 16:41. [PMID: 26169500 PMCID: PMC4501047 DOI: 10.1186/s12868-015-0180-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 07/08/2015] [Indexed: 11/10/2022] Open
Abstract
Background GABAA receptor-mediated neurotransmission is greatly influenced by cation-chloride cotransporter activity during developmental stages. In embryonic neurons Na–K–2Cl (NKCC1) cotransporters mediate active chloride uptake, thus increasing the intracellular chloride concentration associated with GABA-induced depolarization. At fetal stages near term, oxytocin-induced NKCC1 downregulation has been implicated in the developmental shift from depolarizing to hyperpolarizing GABA action. Mature dorsal root ganglion neurons (DRGN), however, express high NKCC1 levels and maintain high intracellular chloride levels with consequent GABA-induced depolarization. Results Gramicidin-perforated patch-clamp recordings were used to assess the developmental change in chloride homeostasis in rat cultured small DRGN at the embryonic day 16 (E16) and 19 (E19). The results were compared to data previously obtained in fetal DRGN at E14 and in mature cells. A significant NKCC1 downregulation, leading to reduction in excitatory GABAergic transmission, was observed at E16 and E19. Conclusion These results indicate that NKCC1 activity transiently decreases in DRGN at fetal stages near term. This developmental shift in GABAergic transmission may contribute to fetal analgesia and neuroprotection at birth.
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Affiliation(s)
- Joelle N Chabwine
- Department of Cellular and Molecular Medicine, Katholieke Universiteit Leuven (KU Leuven), Louvain, Belgium. .,Neurology Unit, Department of Medicine, Faculty of Sciences, University of Fribourg, Chemin du Musée, 5, Fribourg, 1700, Switzerland.
| | - Karel Talavera
- Laboratory of Ion Channel Research and TRP Channel Research Platform (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, Louvain, Belgium.
| | - Ludo Van Den Bosch
- Laboratory of Neurobiology, Experimental Neurology and Leuven Research Institute for Neuroscience and Disease (LIND), KU Leuven, Louvain, Belgium. .,VIB, Vesalius Research Center, KU Leuven, Louvain, Belgium.
| | - Geert Callewaert
- Department of Cellular and Molecular Medicine, Katholieke Universiteit Leuven (KU Leuven), Louvain, Belgium.
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Kaila K, Price TJ, Payne JA, Puskarjov M, Voipio J. Cation-chloride cotransporters in neuronal development, plasticity and disease. Nat Rev Neurosci 2014; 15:637-54. [PMID: 25234263 DOI: 10.1038/nrn3819] [Citation(s) in RCA: 498] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Electrical activity in neurons requires a seamless functional coupling between plasmalemmal ion channels and ion transporters. Although ion channels have been studied intensively for several decades, research on ion transporters is in its infancy. In recent years, it has become evident that one family of ion transporters, cation-chloride cotransporters (CCCs), and in particular K(+)-Cl(-) cotransporter 2 (KCC2), have seminal roles in shaping GABAergic signalling and neuronal connectivity. Studying the functions of these transporters may lead to major paradigm shifts in our understanding of the mechanisms underlying brain development and plasticity in health and disease.
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Affiliation(s)
- Kai Kaila
- 1] Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland. [2] Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland
| | - Theodore J Price
- University of Texas at Dallas, School of Behavior and Brain Sciences, Dallas, Texas 75093, USA
| | - John A Payne
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, California 95616, USA
| | - Martin Puskarjov
- 1] Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland. [2] Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland
| | - Juha Voipio
- Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland
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