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Osuna-Lopez F, Herrera-Zamora JM, Reyes-Méndez ME, Aguilar-Roblero RA, Sánchez-Pastor EA, Navarro-Polanco RA, Moreno-Galindo EG, Alamilla J. Age-, region-, and day/night-related variation of the chloride reversal potential in the rat suprachiasmatic nucleus. J Neurosci Res 2024; 102:e25373. [PMID: 39101281 DOI: 10.1002/jnr.25373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 06/06/2024] [Accepted: 07/21/2024] [Indexed: 08/06/2024]
Abstract
The master control of mammalian circadian rhythms is the suprachiasmatic nucleus (SCN), which is formed by the ventral and dorsal regions. In SCN neurons, GABA has an important function and even excitatory actions in adulthood. However, the physiological role of this neurotransmitter in the developing SCN is unknown. Here, we recorded GABAergic postsynaptic currents (in the perforated-patch configuration using gramicidin) to determine the chloride reversal potential (ECl) and also assessed the immunological expression of the Na-K-Cl cotransporter 1 (NKCC1) at early ages of the rat (postnatal days (P) 3 to 25), during the day and night, in the two SCN regions. We detected that ECl greatly varied with age and depending on the SCN region and time of day. Broadly speaking, ECl was more hyperpolarized with age, except for the oldest age studied (P20-25) in both day and night in the ventral SCN, where it was less negative. Likewise, ECl was more hyperpolarized in the dorsal SCN both during the day and at night; while ECl was more negative at night both in the ventral and the dorsal SCN. Moreover, the total NKCC1 fluorescent expression was higher during the day than at night. These results imply that NKCC1 regulates the circadian and developmental fluctuations in the [Cl-]i to fine-tune ECl, which is crucial for either excitatory or inhibitory GABAergic actions to occur in the SCN.
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Affiliation(s)
- Fernando Osuna-Lopez
- Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Mexico
| | | | - Miriam E Reyes-Méndez
- Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Mexico
| | - Raúl A Aguilar-Roblero
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de Mexico, Mexico
| | | | | | - Eloy G Moreno-Galindo
- Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Mexico
| | - Javier Alamilla
- Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Mexico
- Consejo Nacional de Humanidades, Ciencia y Tecnología (CONAHCYT)-Universidad de Colima, Colima, Mexico
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2
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Raut S, Singh K, Sanghvi S, Loyo-Celis V, Varghese L, Singh E, Gururaja Rao S, Singh H. Chloride ions in health and disease. Biosci Rep 2024; 44:BSR20240029. [PMID: 38573803 PMCID: PMC11065649 DOI: 10.1042/bsr20240029] [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: 01/09/2024] [Revised: 03/26/2024] [Accepted: 04/04/2024] [Indexed: 04/06/2024] Open
Abstract
Chloride is a key anion involved in cellular physiology by regulating its homeostasis and rheostatic processes. Changes in cellular Cl- concentration result in differential regulation of cellular functions such as transcription and translation, post-translation modifications, cell cycle and proliferation, cell volume, and pH levels. In intracellular compartments, Cl- modulates the function of lysosomes, mitochondria, endosomes, phagosomes, the nucleus, and the endoplasmic reticulum. In extracellular fluid (ECF), Cl- is present in blood/plasma and interstitial fluid compartments. A reduction in Cl- levels in ECF can result in cell volume contraction. Cl- is the key physiological anion and is a principal compensatory ion for the movement of the major cations such as Na+, K+, and Ca2+. Over the past 25 years, we have increased our understanding of cellular signaling mediated by Cl-, which has helped in understanding the molecular and metabolic changes observed in pathologies with altered Cl- levels. Here, we review the concentration of Cl- in various organs and cellular compartments, ion channels responsible for its transportation, and recent information on its physiological roles.
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Affiliation(s)
- Satish K. Raut
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | - Kulwinder Singh
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | - Shridhar Sanghvi
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
- Department of Molecular Cellular and Developmental Biology, The Ohio State University, Columbus, OH, U.S.A
| | - Veronica Loyo-Celis
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | - Liyah Varghese
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | - Ekam R. Singh
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | | | - Harpreet Singh
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
- Department of Molecular Cellular and Developmental Biology, The Ohio State University, Columbus, OH, U.S.A
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Vishnevetskii DV, Andrianova YV, Polyakova EE, Ivanova AI, Mekhtiev AR. Fluoride-Ion-Responsive Sol-Gel Transition in an L-Cysteine/AgNO 3 System: Self-Assembly Peculiarities and Anticancer Activity. Gels 2024; 10:332. [PMID: 38786249 PMCID: PMC11121661 DOI: 10.3390/gels10050332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/02/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
Supramolecular hydrogels based on low-molecular-weight compounds are a unique class of so-called "soft" materials, formed by weak non-covalent interactions between precursors at their millimolar concentrations. Due to the variety of structures that can be formed using different low-molecular-weight gelators, they are widely used in various fields of technology and medicine. In this study, we report for the first time an unusual self-assembly process of mixing a hydrosol obtained from L-cysteine and silver nitrate (cysteine-silver sol-CSS) with sodium halides. Modern instrumental techniques such as viscosimetry, UV spectroscopy, dynamic light scattering, zeta potential measurements, SEM and EDS identified that adding fluoride anions to CSS is able to form stable hydrogels of a thixotropic nature, while Cl-, Br- and I- lead to precipitation. The self-assembly process proceeds using a narrow concentration range of F-. An increase in the fluoride anion content in the system leads to a change in the gel network morphology from elongated structures to spherical ones. This fact is reflected in a decrease in the gel viscosity and a number of gel-sol-gel transition cycles. The mechanism of F-'s interaction with hydrosol includes the condensation of anions on the positive surface of the CSS nanoparticles, their binding via electrostatic forces and the formation of a resulting gel carcass. In vitro analysis showed that the hydrogels suppressed human squamous carcinoma cells at a micromolar sample concentration. The obtained soft gels could have potential applications against cutaneous malignancy and as carriers for fluoride anion and other bioactive substance delivery.
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Affiliation(s)
- Dmitry V. Vishnevetskii
- Department of Physical Chemistry, Tver State University, Building 33, Zhelyabova Str., Tver 170100, Russia; (Y.V.A.); (E.E.P.)
- Institute of Biomedical Chemistry, 10 Building 8, Pogodinskaya Str., Moscow 191121, Russia
| | - Yana V. Andrianova
- Department of Physical Chemistry, Tver State University, Building 33, Zhelyabova Str., Tver 170100, Russia; (Y.V.A.); (E.E.P.)
| | - Elizaveta E. Polyakova
- Department of Physical Chemistry, Tver State University, Building 33, Zhelyabova Str., Tver 170100, Russia; (Y.V.A.); (E.E.P.)
| | - Alexandra I. Ivanova
- Department of Applied Physics, Tver State University, Building 33, Zhelyabova Str., Tver 170100, Russia;
| | - Arif R. Mekhtiev
- Institute of Biomedical Chemistry, 10 Building 8, Pogodinskaya Str., Moscow 191121, Russia
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Ott S, Xu S, Lee N, Hong I, Anns J, Suresh DD, Zhang Z, Zhang X, Harion R, Ye W, Chandramouli V, Jesuthasan S, Saheki Y, Claridge-Chang A. Kalium channelrhodopsins effectively inhibit neurons. Nat Commun 2024; 15:3480. [PMID: 38658537 PMCID: PMC11043423 DOI: 10.1038/s41467-024-47203-w] [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: 08/02/2023] [Accepted: 03/18/2024] [Indexed: 04/26/2024] Open
Abstract
The analysis of neural circuits has been revolutionized by optogenetic methods. Light-gated chloride-conducting anion channelrhodopsins (ACRs)-recently emerged as powerful neuron inhibitors. For cells or sub-neuronal compartments with high intracellular chloride concentrations, however, a chloride conductance can have instead an activating effect. The recently discovered light-gated, potassium-conducting, kalium channelrhodopsins (KCRs) might serve as an alternative in these situations, with potentially broad application. As yet, KCRs have not been shown to confer potent inhibitory effects in small genetically tractable animals. Here, we evaluated the utility of KCRs to suppress behavior and inhibit neural activity in Drosophila, Caenorhabditis elegans, and zebrafish. In direct comparisons with ACR1, a KCR1 variant with enhanced plasma-membrane trafficking displayed comparable potency, but with improved properties that include reduced toxicity and superior efficacy in putative high-chloride cells. This comparative analysis of behavioral inhibition between chloride- and potassium-selective silencing tools establishes KCRs as next-generation optogenetic inhibitors for in vivo circuit analysis in behaving animals.
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Affiliation(s)
- Stanislav Ott
- Program in Neuroscience and Behavioral Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Sangyu Xu
- Institute for Molecular and Cell Biology, A*STAR Agency for Science, Technology and Research, Singapore, Singapore
| | - Nicole Lee
- Program in Neuroscience and Behavioral Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Ivan Hong
- Program in Neuroscience and Behavioral Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Jonathan Anns
- Institute for Molecular and Cell Biology, A*STAR Agency for Science, Technology and Research, Singapore, Singapore
- School of Biological Sciences and Institute for Life Sciences, University of Southampton, Southampton, UK
| | - Danesha Devini Suresh
- Program in Neuroscience and Behavioral Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Zhiyi Zhang
- Program in Neuroscience and Behavioral Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Xianyuan Zhang
- Program in Neuroscience and Behavioral Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Raihanah Harion
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Weiying Ye
- Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Vaishnavi Chandramouli
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Suresh Jesuthasan
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Yasunori Saheki
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Adam Claridge-Chang
- Program in Neuroscience and Behavioral Disorders, Duke-NUS Medical School, Singapore, Singapore.
- Institute for Molecular and Cell Biology, A*STAR Agency for Science, Technology and Research, Singapore, Singapore.
- Department of Physiology, National University of Singapore, Singapore, Singapore.
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Pethe A, Hamze M, Giannaki M, Heimrich B, Medina I, Hartmann AM, Roussa E. K +/Cl - cotransporter 2 (KCC2) and Na +/ HCO3- cotransporter 1 (NBCe1) interaction modulates profile of KCC2 phosphorylation. Front Cell Neurosci 2023; 17:1253424. [PMID: 37881493 PMCID: PMC10595033 DOI: 10.3389/fncel.2023.1253424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/07/2023] [Indexed: 10/27/2023] Open
Abstract
K+/Cl- cotransporter 2 (KCC2) is a major Cl- extruder in mature neurons and is responsible for the establishment of low intracellular [Cl-], necessary for fast hyperpolarizing GABAA-receptor mediated synaptic inhibition. Electrogenic sodium bicarbonate cotransporter 1 (NBCe1) is a pH regulatory protein expressed in neurons and glial cells. An interactome study identified NBCe1 as a possible interaction partner of KCC2. In this study, we investigated the putative effect of KCC2/NBCe1 interaction in baseline and the stimulus-induced phosphorylation pattern and function of KCC2. Primary mouse hippocampal neuronal cultures from wildtype (WT) and Nbce1-deficient mice, as well as HEK-293 cells stably transfected with KCC2WT, were used. The results show that KCC2 and NBCe1 are interaction partners in the mouse brain. In HEKKCC2 cells, pharmacological inhibition of NBCs with S0859 prevented staurosporine- and 4-aminopyridine (4AP)-induced KCC2 activation. In mature cultures of hippocampal neurons, however, S0859 completely inhibited postsynaptic GABAAR and, thus, could not be used as a tool to investigate the role of NBCs in GABA-dependent neuronal networks. In Nbce1-deficient immature hippocampal neurons, baseline phosphorylation of KCC2 at S940 was downregulated, compared to WT, and exposure to staurosporine failed to reduce pKCC2 S940 and T1007. In Nbce1-deficient mature neurons, baseline levels of pKCC2 S940 and T1007 were upregulated compared to WT, whereas after 4AP treatment, pKCC2 S940 was downregulated, and pKCC2 T1007 was further upregulated. Functional experiments showed that the levels of GABAAR reversal potential, baseline intracellular [Cl-], Cl- extrusion, and baseline intracellular pH were similar between WT and Nbce1-deficient neurons. Altogether, our data provide a primary description of the properties of KCC2/NBCe1 protein-protein interaction and implicate modulation of stimulus-mediated phosphorylation of KCC2 by NBCe1/KCC2 interaction-a mechanism with putative pathophysiological relevance.
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Affiliation(s)
- Abhishek Pethe
- Department of Molecular Embryology, Faculty of Medicine, Institute for Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Mira Hamze
- INMED, INSERM, Aix-Marseille University, Marseille, France
| | - Marina Giannaki
- Department of Molecular Embryology, Faculty of Medicine, Institute for Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Bernd Heimrich
- Department of Neuroanatomy, Faculty of Medicine, Institute for Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Igor Medina
- INMED, INSERM, Aix-Marseille University, Marseille, France
| | - Anna-Maria Hartmann
- Division of Neurogenetics, Faculty VI, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Eleni Roussa
- Department of Molecular Embryology, Faculty of Medicine, Institute for Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
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Feng Y, Chang P, Kang Y, Liao P, Li CY, Liu J, Zhang WS. Etomidate-Induced Myoclonus in Sprague-Dawley Rats Involves Neocortical Glutamate Accumulation and N -Methyl- d -Aspartate Receptor Activity. Anesth Analg 2023; 137:221-233. [PMID: 36607803 DOI: 10.1213/ane.0000000000006292] [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: 01/07/2023]
Abstract
BACKGROUND Etomidate-induced myoclonus, a seizure-like movement, is of interest to anesthetists. However, its origin in the brain and its underlying mechanism remain unclear. METHODS Adult male Sprague-Dawley rats were anesthetized with etomidate, propofol, or lidocaine plus etomidate. We assessed the incidence of myoclonus, behavioral scores, and levels of glutamate and γ-aminobutyric acid (GABA) in the neocortex and hippocampus. To determine the origin and how N -methyl- d -aspartate receptors (NMDARs) modulate etomidate-induced neuroexcitability, the local field potential and muscular tension were monitored. Calcium imaging in vitro and immunoblotting in vivo were conducted to investigate the mechanisms underlying myoclonus. RESULTS The incidence of etomidate (1.5 mg/kg in vivo)-induced myoclonus was higher than that of propofol (90% vs 10%, P = .0010) and lidocaine plus etomidate (90% vs 20%, P = .0050). Etomidate at doses of 3.75 and 6 mg/kg decreased the mean behavioral score at 1 (mean difference [MD]: 1.80, 95% confidence interval [CI], 0.58-3.02; P = .0058 for both), 2 (MD: 1.60, 95% CI, 0.43-2.77; P = .0084 and MD: 1.70, 95% CI, 0.54-2.86; P = .0060), 3 (MD: 1.60, 95% CI, 0.35-2.85; P = .0127 and MD: 1.70, 95% CI, 0.46-2.94; P = .0091) minutes after administration compared to etomidate at a dose of 1.5 mg/kg. In addition, 0.5 and 1 µM etomidate in vitro increased neocortical intracellular calcium signaling; this signaling decreased when the concentration increased to 5 and 10 μM. Etomidate increased the glutamate level compared to propofol (mean rank difference: 18.20; P = .003), and lidocaine plus etomidate (mean rank difference: 21.70; P = .0002). Etomidate in vivo activated neocortical ripple waves and was positively correlated with muscular tension amplitude (Spearman's r = 0.785, P < .0001). Etomidate at 1.5 mg/kg decreased the K-Cl cotransporter isoform 2 (KCC2) level compared with propofol (MD: -1.15, 95% CI, -1.47 to -0.83; P < .0001) and lidocaine plus etomidate (MD: -0.64, 95% CI, -0.96 to -0.32; P = .0002), DL-2-amino-5-phosphopentanoic acid (AP5) suppressed these effects, while NMDA enhanced them. CONCLUSIONS Etomidate-induced myoclonus or neuroexcitability is concentration dependent. Etomidate-induced myoclonus originates in the neocortex. The underlying mechanism involves neocortical glutamate accumulation and NMDAR modulation and myoclonus correlates with NMDAR-induced downregulation of KCC2 protein expression.
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Affiliation(s)
- Yan Feng
- From the Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, People's Republic of China
- National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, People's Republic of China
| | - Pan Chang
- From the Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, People's Republic of China
- National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, People's Republic of China
| | - Yi Kang
- From the Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, People's Republic of China
- National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, People's Republic of China
| | - Ping Liao
- From the Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, People's Republic of China
- National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, People's Republic of China
| | - Chen-Yang Li
- From the Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, People's Republic of China
- National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, People's Republic of China
| | - Jin Liu
- From the Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, People's Republic of China
- National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, People's Republic of China
| | - Wen-Sheng Zhang
- From the Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, People's Republic of China
- National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, People's Republic of China
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Yan L, Yun-Lin L, Yong-Ling L, Wei-Wei Z, Yue-Shan P. Alteration of GABAergic neurons and abnormality of NKCC1/KCC2 in focal cortical dysplasia (FCD) type Ⅱ lesions. Epilepsy Res 2023; 194:107180. [PMID: 37352729 DOI: 10.1016/j.eplepsyres.2023.107180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 05/09/2023] [Accepted: 06/13/2023] [Indexed: 06/25/2023]
Abstract
BACKGROUND The current conclusions of molecular genetics still cannot satisfactorily explain the pathogenesis of focal cortical dysplasia (FCD) and the reason for drug resistance. The interneurons of GABA deserve attention. To observe the distribution and changes of GABAergic neurons and to explore the expression of cation chloride cotransporter NKCC1/KCC2 in focal cortical dysplasia (FCD) type II lesions is a highly significant job. METHODS The expressions of GAD67(a marker of active GABAergic neuron), NKCC1 and KCC2 were detected by immunohistochemistry and immunohistochemistry double staining in 10 cases of FCD Ⅱa and 10 cases of FCD Ⅱb. The number of GAD67 positive neurons was counted, and the average absorbance (IA) of NKCC1 positive expression was measured, using Image Pro-Plus7.0 software. The data were statistically analyzed. RESULTS The density of GABAergic neuron in focal dysplastic regions was significantly lower than that in the histologically "normal" cerebral cortex, regions from the same specimen (p < 0.0001, t-test). Compared to the NKCC1 staining intensity of neurons in the control group (measuring 1000 cells each), the IA value of dysmorphic neurons was significantly increased (p < 0.05, t'-test Cochran & Cox method). Intracytoplasmic concentration of KCC2 was evident in dysmorphic neurons but not in the other mature neurons. Most of the balloon cells were negative for NKCC1, except for few balloon cells showing sparse colored particles. The expression of KCC2 was negative in all balloon cells. CONCLUSIONS The changes in the expression of NKCC1 and KCC2 may indicate that dysmorphic neurons were in a state similar to that of immature neurons. This state may be related to the abnormal electrophysiology of epilepsy. The difference between the number of GAD67 positive cells in the lesion site and the remote site of the same case may be an evaluation index of the effectiveness of surgery.
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Affiliation(s)
- Li Yan
- Department of Pathology, Haidian Hospital, Haidian District of Peking University Third Hospital, Beijing, China
| | - Li Yun-Lin
- Department of Neurosurgery, Children's Hospital, Capital Institute of Pediatrics, Beijing, China
| | - Liu Yong-Ling
- Department of Pathology, Haidian Hospital, Haidian District of Peking University Third Hospital, Beijing, China
| | - Zhang Wei-Wei
- Department of Pathology, Beijing Tiantan Hospital Affiliated to Capital Medical University, Beijing, China
| | - Piao Yue-Shan
- Department of Pathology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China; Clinical Research Center for Epilepsy, Capital Medical University, Beijing 100053, China; National Center for Neurological Disorders, Beijing 100053, China.
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Menzikov SA, Zaichenko DM, Moskovtsev AA, Morozov SG, Kubatiev AA. Zinc Inhibits the GABA AR/ATPase during Postnatal Rat Development: The Role of Cysteine Residue. Int J Mol Sci 2023; 24:ijms24032764. [PMID: 36769085 PMCID: PMC9917249 DOI: 10.3390/ijms24032764] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/24/2023] [Accepted: 01/26/2023] [Indexed: 02/04/2023] Open
Abstract
Zinc ions (Zn2+) are concentrated in various brain regions and can act as a neuromodulator, targeting a wide spectrum of postsynaptic receptors and enzymes. Zn2+ inhibits the GABAARs, and its potency is profoundly affected by the subunit composition and neuronal developmental stage. Although the extracellular amino acid residues of the receptor's hetero-oligomeric structure are preferred for Zn2+ binding, there are intracellular sites that, in principle, could coordinate its potency. However, their role in modulating the receptor function during postembryonic development remains unclear. The GABAAR possesses an intracellular ATPase that enables the energy-dependent anion transport via a pore. Here, we propose a mechanistic and molecular basis for the inhibition of intracellular GABAAR/ATPase function by Zn2+ in neonatal and adult rats. The enzymes within the scope of GABAAR performance as Cl-ATPase and then as Cl-, HCO3-ATPase form during the first week of postnatal rat development. In addition, we have shown that the Cl-ATPase form belongs to the β1 subunit, whereas the β3 subunit preferably possesses the Cl-, HCO3-ATPase activity. We demonstrated that a Zn2+ with variable efficacy inhibits the GABAAR as well as the ATPase activities of immature or mature neurons. Using fluorescence recording in the cortical synaptoneurosomes (SNs), we showed a competitive association between Zn2+ and NEM in parallel changes both in the ATPase activity and the GABAAR-mediated Cl- and HCO3- fluxes. Finally, by site-directed mutagenesis, we identified in the M3 domain of β subunits the cysteine residue (C313) that is essential for the manifestation of Zn2+ potency.
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Wang Z, Choi K. Pharmacological modulation of chloride channels as a therapeutic strategy for neurological disorders. Front Physiol 2023; 14:1122444. [PMID: 36935741 PMCID: PMC10017882 DOI: 10.3389/fphys.2023.1122444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 02/09/2023] [Indexed: 03/06/2023] Open
Abstract
Chloride homeostasis is critical in the physiological functions of the central nervous system (CNS). Its concentration is precisely regulated by multiple ion-transporting proteins such as chloride channels and transporters that are widely distributed in the brain cells, including neurons and glia. Unlike ion transporters, chloride channels provide rapid responses to efficiently regulate ion flux. Some of chloride channels are also permeable to selected organic anions such as glutamate and γ-aminobutyric acid, suggesting neuroexcitatory and neuroinhibitory functions while gating. Dysregulated chloride channels are implicated in neurological disorders, e.g., ischemia and neuroinflammation. Modulation of chloride homeostasis through chloride channels has been suggested as a potential therapeutic approach for neurological disorders. The drug design for CNS diseases is challenging because it requires the therapeutics to traverse the blood-brain-barrier. Small molecules are a well-established modality with better cell permeability due to their lower molecular weight and flexibility for structure optimization compared to biologics. In this article, we describe the important roles of chloride homeostasis in each type of brain cells and introduce selected chloride channels identified in the CNS. We then discuss the contribution of their dysregulations towards the pathogenesis of neurological disorders, emphasizing the potential of targeting chloride channels as a therapeutic strategy for CNS disease treatment. Along with this literature survey, we summarize the small molecules that modulate chloride channels and propose the potential strategy of optimizing existing drugs to brain-penetrants to support future CNS drug discovery.
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10
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The mechanisms of chromogranin B-regulated Cl- homeostasis. Biochem Soc Trans 2022; 50:1659-1672. [PMID: 36511243 DOI: 10.1042/bst20220435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/25/2022] [Accepted: 12/01/2022] [Indexed: 12/15/2022]
Abstract
Chloride is the most abundant inorganic anions in almost all cells and in human circulation systems. Its homeostasis is therefore important for systems physiology and normal cellular activities. This topic has been extensively studied with chloride loaders and extruders expressed in both cell surfaces and intracellular membranes. With the newly discovered, large-conductance, highly selective Cl- channel formed by membrane-bound chromogranin B (CHGB), which differs from all other known anion channels of conventional transmembrane topology, and is distributed in plasma membranes, endomembrane systems, endosomal, and endolysosomal compartments in cells expressing it, we will discuss the potential physiological importance of the CHGB channels to Cl- homeostasis, cellular excitability and volume control, and cation uptake or release at the cellular and subcellular levels. These considerations and CHGB's association with human diseases make the CHGB channel a possible druggable target for future molecular therapeutics.
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Sinha M, Zabini D, Guntur D, Nagaraj C, Enyedi P, Olschewski H, Kuebler WM, Olschewski A. Chloride channels in the lung: Challenges and perspectives for viral infections, pulmonary arterial hypertension, and cystic fibrosis. Pharmacol Ther 2022; 237:108249. [PMID: 35878810 DOI: 10.1016/j.pharmthera.2022.108249] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 07/06/2022] [Accepted: 07/11/2022] [Indexed: 10/16/2022]
Abstract
Fine control over chloride homeostasis in the lung is required to maintain membrane excitability, transepithelial transport as well as intra- and extracellular ion and water homeostasis. Over the last decades, a growing number of chloride channels and transporters have been identified in the cells of the pulmonary vasculature and the respiratory tract. The importance of these proteins is underpinned by the fact that impairment of their physiological function is associated with functional dysregulation, structural remodeling, or hereditary diseases of the lung. This paper reviews the field of chloride channels and transporters in the lung and discusses chloride channels in disease processes such as viral infections including SARS-CoV- 2, pulmonary arterial hypertension, cystic fibrosis and asthma. Although chloride channels have become a hot research topic in recent years, remarkably few of them have been targeted by pharmacological agents. As such, we complement the putative pathophysiological role of chloride channels here with a summary of their therapeutic potential.
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Affiliation(s)
- Madhushri Sinha
- Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Auenbruggerplatz 5, 8036 Graz, Austria.
| | - Diana Zabini
- Department of Physiology, Neue Stiftingtalstrasse 6/V, 8010 Graz, Austria.
| | - Divya Guntur
- Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Auenbruggerplatz 5, 8036 Graz, Austria.
| | - Chandran Nagaraj
- Ludwig Boltzmann Institute for Lung Vascular Research, Neue Stiftingtalstraße 6, 8010 Graz, Austria.
| | - Peter Enyedi
- Department of Physiology, Semmelweis University, Tűzoltó utca 37-47, 1094 Budapest, Hungary.
| | - Horst Olschewski
- Department of Internal Medicine, Division of Pulmonology, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria.
| | - Wolfgang M Kuebler
- Institute of Physiology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
| | - Andrea Olschewski
- Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Auenbruggerplatz 5, 8036 Graz, Austria; Ludwig Boltzmann Institute for Lung Vascular Research, Neue Stiftingtalstraße 6, 8010 Graz, Austria.
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12
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Proskurina EY, Zaitsev AV. Regulation of Potassium and Chloride Concentrations in Nervous Tissue as a Method of Anticonvulsant Therapy. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022050015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abstract
Under some pathological conditions, such as pharmacoresistant
epilepsy, status epilepticus or certain forms of genetic abnormalities,
spiking activity of GABAergic interneurons may enhance excitation
processes in neuronal circuits and provoke the generation of ictal
discharges. As a result, anticonvulsants acting on the GABAergic
system may be ineffective or even increase seizure activity. This
paradoxical effect of the inhibitory system is due to ionic imbalances
in nervous tissue. This review addresses the mechanisms of ictal
discharge initiation in neuronal networks due to the imbalance of
chloride and potassium ions, as well as possible ways to regulate
ionic concentrations. Both the enhancement (or attenuation) of the
activity of certain neuronal ion transporters and ion pumps and
their additional expression via gene therapy can be effective in
suppressing seizure activity caused by ionic imbalances. The Na+–K+-pump,
NKCC1 and KCC2 cotransporters are important for maintaining proper
K+ and Cl– concentrations
in nervous tissue, having been repeatedly considered as pharmacological
targets for antiepileptic exposures. Further progress in this direction
is hampered by the lack of sufficiently selective pharmacological
tools and methods for providing effective drug delivery to the epileptic
focus. The use of the gene therapy techniques, such as overexpressing
of the KCC2 transporter in the epileptic focus, seems to be a more promising
approach. Another possible direction could be the use of optogenetic
tools, namely specially designed light-activated ion pumps or ion
channels. In this case, photon energy can be used to create the
required gradients of chloride and potassium ions, although these
methods also have significant limitations which complicate their
rapid introduction into medicine.
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13
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Qiao J, Wu ZM, Ye QP, Dai M, Dai Y, He ZT, Dou ZL. Characteristics of dysphagia among different lesion sites of stroke: A retrospective study. Front Neurosci 2022; 16:944688. [PMID: 36090270 PMCID: PMC9449127 DOI: 10.3389/fnins.2022.944688] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 08/01/2022] [Indexed: 02/05/2023] Open
Abstract
Objective This study aims to compare the characteristics of dysphagia among different lesion sites and explore the possible risk factors that are relevant to penetration and aspiration after stroke. Materials and methods Data on patients with post-stroke dysphagia were collected. Major measures of the videofluoroscopic swallowing study included pharyngeal transit duration (PTD), pharyngeal response duration (PRD), soft palate elevation duration (SED), stage transition duration (STD), hyoid bone anterior-horizontal displacement (HAD), hyoid bone superior-horizontal displacement (HSD), upper esophageal sphincter opening (UESO), Pharyngeal Residual Grade (PRG), and Penetration Aspiration Scale (PAS). Included patients were divided into supratentorial (deep or lobar intracerebral) and infratentorial stroke groups. The Kruskal–Wallis test, Spearman’s correlation analysis, and multivariate logistic regression analyses were used to test the difference and the correlation between those measures. Time-to-event endpoints (oral feeding) were analyzed by the Kaplan–Meier method. Results A total of 75 patients were included in this study. Significant differences were demonstrated in PTD, PRD, SED, STD, HAD, HSD, UESO, PAS, and PRG between supratentorial and infratentorial stroke groups (p < 0.05). The PRG score of the lobar intracerebral subgroup was significantly higher (p < 0.05) than that of the deep intracerebral and lobar + deep intracerebral stroke subgroups, while HSD was significantly shorter (p < 0.01). Spearman’s correlation analysis revealed that PAS was related to PTD, PRG, HAD, and UESO (p < 0.05). Multivariate logistic regression analysis demonstrated that HAD and PRG may be risk factors for penetration and aspiration (p < 0.05). Kaplan–Meier survival plot showed that there was a significant difference in time to oral feeding between supratentorial and infratentorial stroke groups (p < 0.01). Conclusion Infratentorial stroke may lead to worse swallowing function as compared with supratentorial stroke, and lobar intracerebral stroke may be worse than deep intracerebral stroke. Suitable preventive measures may be considered for patients with higher PRG scores and shorter HSD to avoid penetration and aspiration.
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Affiliation(s)
- Jia Qiao
- Department of Rehabilitation Medicine, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Zhi-min Wu
- Department of Neurosurgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Qiu-ping Ye
- Department of Rehabilitation Medicine, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Meng Dai
- Department of Rehabilitation Medicine, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Yong Dai
- Clinical Medical College of Acupuncture, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zi-tong He
- Department of Rehabilitation Medicine, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Zu-lin Dou
- Department of Rehabilitation Medicine, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- *Correspondence: Zu-lin Dou,
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14
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Hartmann AM, Nothwang HG. NKCC1 and KCC2: Structural insights into phospho-regulation. Front Mol Neurosci 2022; 15:964488. [PMID: 35935337 PMCID: PMC9355526 DOI: 10.3389/fnmol.2022.964488] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/06/2022] [Indexed: 11/13/2022] Open
Abstract
Inhibitory neurotransmission plays a fundamental role in the central nervous system, with about 30–50% of synaptic connections being inhibitory. The action of both inhibitory neurotransmitter, gamma-aminobutyric-acid (GABA) and glycine, mainly relies on the intracellular Cl– concentration in neurons. This is set by the interplay of the cation chloride cotransporters NKCC1 (Na+, K+, Cl– cotransporter), a main Cl– uptake transporter, and KCC2 (K+, Cl– cotransporter), the principle Cl– extruder in neurons. Accordingly, their dysfunction is associated with severe neurological, psychiatric, and neurodegenerative disorders. This has triggered great interest in understanding their regulation, with a strong focus on phosphorylation. Recent structural data by cryogenic electron microscopy provide the unique possibility to gain insight into the action of these phosphorylations. Interestingly, in KCC2, six out of ten (60%) known regulatory phospho-sites reside within a region of 134 amino acid residues (12% of the total residues) between helices α8 and α9 that lacks fixed or ordered three-dimensional structures. It thus represents a so-called intrinsically disordered region. Two further phospho-sites, Tyr903 and Thr906, are also located in a disordered region between the ß8 strand and the α8 helix. We make the case that especially the disordered region between helices α8 and α9 acts as a platform to integrate different signaling pathways and simultaneously constitute a flexible, highly dynamic linker that can survey a wide variety of distinct conformations. As each conformation can have distinct binding affinities and specificity properties, this enables regulation of [Cl–]i and thus the ionic driving force in a history-dependent way. This region might thus act as a molecular processor underlying the well described phenomenon of ionic plasticity that has been ascribed to inhibitory neurotransmission. Finally, it might explain the stunning long-range effects of mutations on phospho-sites in KCC2.
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Affiliation(s)
- Anna-Maria Hartmann
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- *Correspondence: Anna-Maria Hartmann,
| | - Hans Gerd Nothwang
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Center of Excellence Hearing4all, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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Scalise S, Zannino C, Lucchino V, Lo Conte M, Scaramuzzino L, Cifelli P, D’Andrea T, Martinello K, Fucile S, Palma E, Gambardella A, Ruffolo G, Cuda G, Parrotta EI. Human iPSC Modeling of Genetic Febrile Seizure Reveals Aberrant Molecular and Physiological Features Underlying an Impaired Neuronal Activity. Biomedicines 2022; 10:biomedicines10051075. [PMID: 35625812 PMCID: PMC9138645 DOI: 10.3390/biomedicines10051075] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 04/29/2022] [Accepted: 05/03/2022] [Indexed: 02/01/2023] Open
Abstract
Mutations in SCN1A gene, encoding the voltage-gated sodium channel (VGSC) NaV1.1, are widely recognized as a leading cause of genetic febrile seizures (FS), due to the decrease in the Na+ current density, mainly affecting the inhibitory neuronal transmission. Here, we generated induced pluripotent stem cells (iPSCs)-derived neurons (idNs) from a patient belonging to a genetically well-characterized Italian family, carrying the c.434T > C mutation in SCN1A gene (hereafter SCN1AM145T). A side-by-side comparison of diseased and healthy idNs revealed an overall maturation delay of SCN1AM145T cells. Membranes isolated from both diseased and control idNs were injected into Xenopus oocytes and both GABA and AMPA currents were successfully recorded. Patch-clamp measurements on idNs revealed depolarized action potential for SCN1AM145T, suggesting a reduced excitability. Expression analyses of VGSCs and chloride co-transporters NKCC1 and KCC2 showed a cellular “dysmaturity” of mutated idNs, strengthened by the high expression of SCN3A, a more fetal-like VGSC isoform, and a high NKCC1/KCC2 ratio, in mutated cells. Overall, we provide strong evidence for an intrinsic cellular immaturity, underscoring the role of mutant NaV1.1 in the development of FS. Furthermore, our data are strengthening previous findings obtained using transfected cells and recordings on human slices, demonstrating that diseased idNs represent a powerful tool for personalized therapy and ex vivo drug screening for human epileptic disorders.
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Affiliation(s)
- Stefania Scalise
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Clara Zannino
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Valeria Lucchino
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Michela Lo Conte
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Luana Scaramuzzino
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Pierangelo Cifelli
- Department of Biotechnological and Applied Clinical Sciences (DISCAB), University of Aquila, 67100 Aquila, Italy;
| | - Tiziano D’Andrea
- Department of Physiology and Pharmacology, University of Rome, Sapienza, P.le Aldo Moro, 5, 00185 Rome, Italy; (T.D.); (S.F.); (E.P.)
| | | | - Sergio Fucile
- Department of Physiology and Pharmacology, University of Rome, Sapienza, P.le Aldo Moro, 5, 00185 Rome, Italy; (T.D.); (S.F.); (E.P.)
- IRCCS Neuromed, Via Atinense, 86077 Pozzilli, Italy;
| | - Eleonora Palma
- Department of Physiology and Pharmacology, University of Rome, Sapienza, P.le Aldo Moro, 5, 00185 Rome, Italy; (T.D.); (S.F.); (E.P.)
| | - Antonio Gambardella
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (A.G.); (E.I.P.)
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, University of Rome, Sapienza, P.le Aldo Moro, 5, 00185 Rome, Italy; (T.D.); (S.F.); (E.P.)
- IRCCS San Raffaele Roma, Via della Pisana, 00163 Rome, Italy
- Correspondence: (G.R.); (G.C.)
| | - Giovanni Cuda
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
- Correspondence: (G.R.); (G.C.)
| | - Elvira Immacolata Parrotta
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (A.G.); (E.I.P.)
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16
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Diaz JR, Martá-Ariza M, Khodadadi-Jamayran A, Heguy A, Tsirigos A, Pankiewicz JE, Sullivan PM, Sadowski MJ. Apolipoprotein E4 Effects a Distinct Transcriptomic Profile and Dendritic Arbor Characteristics in Hippocampal Neurons Cultured in vitro. Front Aging Neurosci 2022; 14:845291. [PMID: 35572125 PMCID: PMC9099260 DOI: 10.3389/fnagi.2022.845291] [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: 12/29/2021] [Accepted: 04/06/2022] [Indexed: 11/13/2022] Open
Abstract
The APOE gene is diversified by three alleles ε2, ε3, and ε4 encoding corresponding apolipoprotein (apo) E isoforms. Possession of the ε4 allele is signified by increased risks of age-related cognitive decline, Alzheimer's disease (AD), and the rate of AD dementia progression. ApoE is secreted by astrocytes as high-density lipoprotein-like particles and these are internalized by neurons upon binding to neuron-expressed apoE receptors. ApoE isoforms differentially engage neuronal plasticity through poorly understood mechanisms. We examined here the effects of native apoE lipoproteins produced by immortalized astrocytes homozygous for ε2, ε3, and ε4 alleles on the maturation and the transcriptomic profile of primary hippocampal neurons. Control neurons were grown in the presence of conditioned media from Apoe -/- astrocytes. ApoE2 and apoE3 significantly increase the dendritic arbor branching, the combined neurite length, and the total arbor surface of the hippocampal neurons, while apoE4 fails to produce similar effects and even significantly reduces the combined neurite length compared to the control. ApoE lipoproteins show no systemic effect on dendritic spine density, yet apoE2 and apoE3 increase the mature spines fraction, while apoE4 increases the immature spine fraction. This is associated with opposing effects of apoE2 or apoE3 and apoE4 on the expression of NR1 NMDA receptor subunit and PSD95. There are 1,062 genes differentially expressed across neurons cultured in the presence of apoE lipoproteins compared to the control. KEGG enrichment and gene ontology analyses show apoE2 and apoE3 commonly activate expression of genes involved in neurite branching, and synaptic signaling. In contrast, apoE4 cultured neurons show upregulation of genes related to the glycolipid metabolism, which are involved in dendritic spine turnover, and those which are usually silent in neurons and are related to cell cycle and DNA repair. In conclusion, our work reveals that lipoprotein particles comprised of various apoE isoforms differentially regulate various neuronal arbor characteristics through interaction with neuronal transcriptome. ApoE4 produces a functionally distinct transcriptomic profile, which is associated with attenuated neuronal development. Differential regulation of neuronal transcriptome by apoE isoforms is a newly identified biological mechanism, which has both implication in the development and aging of the CNS.
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Affiliation(s)
- Jenny R. Diaz
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Mitchell Martá-Ariza
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | | | - Adriana Heguy
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, United States
| | - Aristotelis Tsirigos
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, United States
| | - Joanna E. Pankiewicz
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Biochemistry and Pharmacology, New York University Grossman School of Medicine, New York, NY, United States
| | - Patrick M. Sullivan
- Department of Medicine (Geriatrics), Duke University School of Medicine, Durham, NC, United States
- Durham VA Medical Center’s, Geriatric Research Education and Clinical Center, Durham, NC, United States
| | - Martin J. Sadowski
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Biochemistry and Pharmacology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, United States
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Phillips RA, Tuscher JJ, Black SL, Andraka E, Fitzgerald ND, Ianov L, Day JJ. An atlas of transcriptionally defined cell populations in the rat ventral tegmental area. Cell Rep 2022; 39:110616. [PMID: 35385745 PMCID: PMC10888206 DOI: 10.1016/j.celrep.2022.110616] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 12/28/2021] [Accepted: 03/11/2022] [Indexed: 01/06/2023] Open
Abstract
The ventral tegmental area (VTA) is a complex brain region that is essential for reward function and frequently implicated in neuropsychiatric disease. While decades of research on VTA function have focused on dopamine neurons, recent evidence has identified critical roles for GABAergic and glutamatergic neurons in reward processes. Additionally, although subsets of VTA neurons express genes involved in the synthesis and transport of multiple neurotransmitters, characterization of these combinatorial populations has largely relied on low-throughput methods. To comprehensively define the molecular architecture of the VTA, we performed single-nucleus RNA sequencing on 21,600 cells from the rat VTA. Analysis of neuronal subclusters identifies selective markers for dopamine and combinatorial neurons, reveals expression profiles for receptors targeted by drugs of abuse, and demonstrates population-specific enrichment of gene sets linked to brain disorders. These results highlight the heterogeneity of the VTA and provide a resource for further exploration of VTA gene expression.
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Affiliation(s)
- Robert A Phillips
- Department of Neurobiology & Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jennifer J Tuscher
- Department of Neurobiology & Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Samantha L Black
- Department of Neurobiology & Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Emma Andraka
- Department of Neurobiology & Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - N Dalton Fitzgerald
- Department of Neurobiology & Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Lara Ianov
- Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jeremy J Day
- Department of Neurobiology & Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL 35294, USA; Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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Klett NJ, Cravetchi O, Allen CN. Long-Term Imaging Reveals a Circadian Rhythm of Intracellular Chloride in Neurons of the Suprachiasmatic Nucleus. J Biol Rhythms 2022; 37:110-123. [PMID: 34994231 DOI: 10.1177/07487304211059770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Both inhibitory and excitatory GABA transmission exist in the mature suprachiasmatic nucleus (SCN), the master pacemaker of circadian physiology. Whether GABA is inhibitory or excitatory depends on the intracellular chloride concentration ([Cl-]i). Here, using the genetically encoded ratiometric probe Cl-Sensor, we investigated [Cl-]i in AVP and VIP-expressing SCN neurons for several days in culture. The chloride ratio (RCl) demonstrated circadian rhythmicity in AVP + neurons and VIP + neurons, but was not detected in GFAP + astrocytes. RCl peaked between ZT 7 and ZT 8 in both AVP + and VIP + neurons. RCl rhythmicity was not dependent on the activity of several transmembrane chloride carriers, action potential generation, or the L-type voltage-gated calcium channels, but was sensitive to GABA antagonists. We conclude that [Cl-]i is under circadian regulation in both AVP + and VIP + neurons.
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Affiliation(s)
- Nathan J Klett
- Neuroscience Graduate Program, Oregon Health & Science University, Portland, Oregon, USA.,Oregon Institute for Occupational Health Sciences, Oregon Health & Science University, Portland, Oregon, USA.,Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Olga Cravetchi
- Oregon Institute for Occupational Health Sciences, Oregon Health & Science University, Portland, Oregon, USA
| | - Charles N Allen
- Oregon Institute for Occupational Health Sciences, Oregon Health & Science University, Portland, Oregon, USA.,Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, Oregon, USA
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19
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Branchereau P, Cattaert D. Chloride Homeostasis in Developing Motoneurons. ADVANCES IN NEUROBIOLOGY 2022; 28:45-61. [PMID: 36066820 DOI: 10.1007/978-3-031-07167-6_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Maturation of GABA/Glycine chloride-mediated synaptic inhibitions is crucial for the establishment of a balance between excitation and inhibition. GABA and glycine are excitatory neurotransmitters on immature neurons that exhibit elevated [Cl-]i. Later in development [Cl-]i drops leading to the occurrence of inhibitory synaptic activity. This ontogenic change is closely correlated to a differential expression of two cation-chloride cotransporters that are the Cl- channel K+/Cl- co-transporter type 2 (KCC2) that extrudes Cl- ions and the Na+-K+-2Cl- cotransporter NKCC1 that accumulates Cl- ions. The classical scheme built from studies performed on cortical and hippocampal networks proposes that immature neurons display high [Cl-]i because NKCC1 is overexpressed compared to KCC2 and that the co-transporters ratio reverses in mature neurons, lowering [Cl-]i. In this chapter, we will see that this classical scheme is not true in motoneurons (MNs) and that an early alteration of the chloride homeostasis may be involved in pathological conditions.
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Affiliation(s)
- Pascal Branchereau
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), Univ. Bordeaux, UMR 5287, CNRS, Bordeaux, France.
| | - Daniel Cattaert
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), Univ. Bordeaux, UMR 5287, CNRS, Bordeaux, France
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20
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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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21
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Imenez Silva PH, Unwin R, Hoorn EJ, Ortiz A, Trepiccione F, Nielsen R, Pesic V, Hafez G, Fouque D, Massy ZA, De Zeeuw CI, Capasso G, Wagner CA. Acidosis, cognitive dysfunction and motor impairments in patients with kidney disease. Nephrol Dial Transplant 2021; 37:ii4-ii12. [PMID: 34718761 PMCID: PMC8713149 DOI: 10.1093/ndt/gfab216] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Indexed: 12/20/2022] Open
Abstract
Metabolic acidosis, defined as a plasma or serum bicarbonate concentration <22 mmol/L, is a frequent consequence of chronic kidney disease (CKD) and occurs in ~10–30% of patients with advanced stages of CKD. Likewise, in patients with a kidney transplant, prevalence rates of metabolic acidosis range from 20% to 50%. CKD has recently been associated with cognitive dysfunction, including mild cognitive impairment with memory and attention deficits, reduced executive functions and morphological damage detectable with imaging. Also, impaired motor functions and loss of muscle strength are often found in patients with advanced CKD, which in part may be attributed to altered central nervous system (CNS) functions. While the exact mechanisms of how CKD may cause cognitive dysfunction and reduced motor functions are still debated, recent data point towards the possibility that acidosis is one modifiable contributor to cognitive dysfunction. This review summarizes recent evidence for an association between acidosis and cognitive dysfunction in patients with CKD and discusses potential mechanisms by which acidosis may impact CNS functions. The review also identifies important open questions to be answered to improve prevention and therapy of cognitive dysfunction in the setting of metabolic acidosis in patients with CKD.
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Affiliation(s)
- Pedro H Imenez Silva
- Institute of Physiology, University of Zurich, Zürich, Switzerland.,National Center of Competence in Research NCCR Kidney.CH, Zürich, Switzerland
| | - Robert Unwin
- Department of Renal Medicine, Royal Free Hospital, University College London, London, UK
| | - Ewout J Hoorn
- Department of Internal Medicine, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Alberto Ortiz
- Department of Nephrology and Hypertension, IIS-Fundacion Jimenez Diaz, Universidad Autonoma de Madrid, Madrid, Spain
| | - Francesco Trepiccione
- Biogem Institute of Molecular Biology and Genetics, Ariano Irpino, Italy.,Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - Rikke Nielsen
- Department of Biomedicine-Anatomy, University of Aarhus, Aarhus, Denmark
| | - Vesna Pesic
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
| | - Gaye Hafez
- Department of Pharmacology, Faculty of Pharmacy, Altinbas University, Istanbul, Turkey
| | - Denis Fouque
- CarMeN, INSERM 1060, Université Claude Bernard Lyon 1, Lyon, France.,Service de Néphrologie, Lyon-Sud Hospital, Pierre-Bénite, France
| | - Ziad A Massy
- Department of Nephrology, Ambroise Paré University Hospital, Assistance Publique Hôpitaux de Paris, Boulogne-Billancourt, France.,Centre de Recherche en Epidémiologie et Santé des Populations, Institut National de la Santé et de la Recherche Médicale U1018-Team 5, Université de Versailles Saint-Quentin-en-Yvelines, University Paris Saclay, Villejuif, France
| | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.,Netherlands Institute for Neuroscience, Royal Dutch Academy of Art and Science, Amsterdam, The Netherlands
| | - Giovambattista Capasso
- Biogem Institute of Molecular Biology and Genetics, Ariano Irpino, Italy.,Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, Zürich, Switzerland.,National Center of Competence in Research NCCR Kidney.CH, Zürich, Switzerland
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22
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Auer F, Franco Taveras E, Klein U, Kesenheimer C, Fleischhauer D, Möhrlen F, Frings S. Anoctamin 2-chloride channels reduce simple spike activity and mediate inhibition at elevated calcium concentration in cerebellar Purkinje cells. PLoS One 2021; 16:e0247801. [PMID: 33651839 PMCID: PMC7924762 DOI: 10.1371/journal.pone.0247801] [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: 11/09/2020] [Accepted: 02/12/2021] [Indexed: 11/19/2022] Open
Abstract
Modulation of neuronal excitability is a prominent way of shaping the activity of neuronal networks. Recent studies highlight the role of calcium-activated chloride currents in this context, as they can both increase or decrease excitability. The calcium-activated chloride channel Anoctamin 2 (ANO2 alias TMEM16B) has been described in several regions of the mouse brain, including the olivo-cerebellar system. In inferior olivary neurons, ANO2 was proposed to increase excitability by facilitating the generation of high-threshold calcium spikes. An expression of ANO2 in cerebellar Purkinje cells was suggested, but its role in these neurons remains unclear. In the present study, we confirmed the expression of Ano2 mRNA in Purkinje cells and performed electrophysiological recordings to examine the influence of ANO2-chloride channels on the excitability of Purkinje cells by comparing wildtype mice to mice lacking ANO2. Recordings were performed in acute cerebellar slices of adult mice, which provided the possibility to study the role of ANO2 within the cerebellar cortex. Purkinje cells were uncoupled from climbing fiber input to assess specifically the effect of ANO2 channels on Purkinje cell activity. We identified an attenuating effect of ANO2-mediated chloride currents on the instantaneous simple spike activity both during strong current injections and during current injections close to the simple spike threshold. Moreover, we report a reduction of inhibitory currents from GABAergic interneurons upon depolarization, lasting for several seconds. Together with the role of ANO2-chloride channels in inferior olivary neurons, our data extend the evidence for a role of chloride-dependent modulation in the olivo-cerebellar system that might be important for proper cerebellum-dependent motor coordination and learning.
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Affiliation(s)
- Friederike Auer
- Department of Animal Physiology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Eliana Franco Taveras
- Department of Animal Physiology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Uli Klein
- Department of Animal Physiology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Céline Kesenheimer
- Department of Animal Physiology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Dana Fleischhauer
- Department of Animal Physiology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Frank Möhrlen
- Department of Animal Physiology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Stephan Frings
- Department of Animal Physiology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- * E-mail:
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23
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Intricacies of GABA A Receptor Function: The Critical Role of the β3 Subunit in Norm and Pathology. Int J Mol Sci 2021; 22:ijms22031457. [PMID: 33535681 PMCID: PMC7867123 DOI: 10.3390/ijms22031457] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 12/23/2022] Open
Abstract
Neuronal intracellular chloride ([Cl−]i) is a key determinant in γ-aminobutyric acid type A (GABA)ergic signaling. γ-Aminobutyric acid type A receptors (GABAARs) mediate both inhibitory and excitatory neurotransmission, as the passive fluxes of Cl− and HCO3− via pores can be reversed by changes in the transmembrane concentration gradient of Cl−. The cation–chloride co-transporters (CCCs) are the primary systems for maintaining [Cl−]i homeostasis. However, despite extensive electrophysiological data obtained in vitro that are supported by a wide range of molecular biological studies on the expression patterns and properties of CCCs, the presence of ontogenetic changes in [Cl−]i—along with the consequent shift in GABA reversal potential—remain a subject of debate. Recent studies showed that the β3 subunit possesses properties of the P-type ATPase that participates in the ATP-consuming movement of Cl− via the receptor. Moreover, row studies have demonstrated that the β3 subunit is a key player in GABAAR performance and in the appearance of serious neurological disorders. In this review, we discuss the properties and driving forces of CCCs and Cl−, HCO3−ATPase in the maintenance of [Cl−]i homeostasis after changes in upcoming GABAAR function. Moreover, we discuss the contribution of the β3 subunit in the manifestation of epilepsy, autism, and other syndromes.
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24
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Juvale IIA, Hassan Z, Has ATC. The Emerging Roles of π Subunit-Containing GABA A Receptors in Different Cancers. Int J Med Sci 2021; 18:3851-3860. [PMID: 34790061 PMCID: PMC8579298 DOI: 10.7150/ijms.60928] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 10/10/2021] [Indexed: 01/15/2023] Open
Abstract
Cancer is one of the leading causes of death in both developed and developing countries. Due to its heterogenous nature, it occurs in various regions of the body and often goes undetected until later stages of disease progression. Feasible treatment options are limited because of the invasive nature of cancer and often result in detrimental side-effects and poor survival rates. Therefore, recent studies have attempted to identify aberrant expression levels of previously undiscovered proteins in cancer, with the hope of developing better diagnostic tools and pharmaceutical options. One class of such targets is the π-subunit-containing γ-aminobutyric acid type A receptors. Although these receptors were discovered more than 20 years ago, there is limited information available. They possess atypical functional properties and are expressed in several non-neuronal tissues. Prior studies have highlighted the role of these receptors in the female reproductive system. New research focusing on the higher expression levels of these receptors in ovarian, breast, gastric, cervical, and pancreatic cancers, their physiological function in healthy individuals, and their pro-tumorigenic effects in these cancer types is reviewed here.
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Affiliation(s)
- Iman Imtiyaz Ahmed Juvale
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Zurina Hassan
- Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
| | - Ahmad Tarmizi Che Has
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
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25
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Koster AK, Reese AL, Kuryshev Y, Wen X, McKiernan KA, Gray EE, Wu C, Huguenard JR, Maduke M, Du Bois J. Development and validation of a potent and specific inhibitor for the CLC-2 chloride channel. Proc Natl Acad Sci U S A 2020; 117:32711-32721. [PMID: 33277431 PMCID: PMC7768775 DOI: 10.1073/pnas.2009977117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
CLC-2 is a voltage-gated chloride channel that is widely expressed in mammalian tissues. In the central nervous system, CLC-2 appears in neurons and glia. Studies to define how this channel contributes to normal and pathophysiological function in the central nervous system raise questions that remain unresolved, in part due to the absence of precise pharmacological tools for modulating CLC-2 activity. Herein, we describe the development and optimization of AK-42, a specific small-molecule inhibitor of CLC-2 with nanomolar potency (IC50 = 17 ± 1 nM). AK-42 displays unprecedented selectivity (>1,000-fold) over CLC-1, the closest CLC-2 homolog, and exhibits no off-target engagement against a panel of 61 common channels, receptors, and transporters expressed in brain tissue. Computational docking, validated by mutagenesis and kinetic studies, indicates that AK-42 binds to an extracellular vestibule above the channel pore. In electrophysiological recordings of mouse CA1 hippocampal pyramidal neurons, AK-42 acutely and reversibly inhibits CLC-2 currents; no effect on current is observed on brain slices taken from CLC-2 knockout mice. These results establish AK-42 as a powerful tool for investigating CLC-2 neurophysiology.
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Affiliation(s)
- Anna K Koster
- Department of Chemistry, Stanford University, Stanford, CA 94305
- Department of Molecular & Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
| | - Austin L Reese
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305
| | - Yuri Kuryshev
- Charles River Laboratories Cleveland, Inc., Cleveland, OH 44128
| | - Xianlan Wen
- Department of Molecular & Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
| | - Keri A McKiernan
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Erin E Gray
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Caiyun Wu
- Charles River Laboratories Cleveland, Inc., Cleveland, OH 44128
| | - John R Huguenard
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305;
| | - Merritt Maduke
- Department of Molecular & Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305;
| | - J Du Bois
- Department of Chemistry, Stanford University, Stanford, CA 94305;
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26
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Wirth MJ, Ackels T, Kriebel A, Kriebel K, Mey J, Kuenzel T, Wagner H. Expression patterns of chloride transporters in the auditory brainstem of developing chicken. Hear Res 2020; 393:108013. [PMID: 32554128 DOI: 10.1016/j.heares.2020.108013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 04/29/2020] [Accepted: 05/29/2020] [Indexed: 01/23/2023]
Abstract
GABAergic transmission changes from depolarization to hyperpolarization in most vertebrate brain regions during development. By contrast, in the auditory brainstem of chicken a depolarizing effect of GABA persists after hatching. Since auditory brainstem neurons that receive GABAergic input have a Cl- reversal potential above resting membrane potential, a specifically tuned activity of Cl- transporters is likely. We here present a developmental study of the expression patterns of several members of the SLC12 family (NKCC1, NKCC2, KCC1, KCC2, KCC4, CCC6, CCC9) and of AE3 at developmental ages E7, E10, E12, E15, E17, and P1 with quantitative RT-PCR. NKCC2 and CCC9 were not detected in auditory brainstem (positive control: kidney). KCC1, CCC6 and AE3 were expressed, but not regulated, while NKCC1, KCC2 and KCC4 were regulated. The expression of the latter transporters increased, with KCC2 exhibiting the strongest expression at all time points. Biochemical analysis of the protein expression of NKCC1, KCC2 and KCC4 corroborated the findings on the mRNA level. All three transporters showed a localization at the outer rim of the cells, with NKCC1 and KCC2 expressed in neurons, and KCC4 predominantly in glia. The comparison of the published chloride reversal potential and expression of transporter proteins suggest strong differences in the efficiency of the three transporters. Further, the strong KCC2 expression could reflect a role in the structural development of auditory brainstem synapses that might lead to changes in the physiological properties.
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Affiliation(s)
- Marcus J Wirth
- Department for Chemosensation, RWTH Aachen University, Aachen, Germany.
| | - Tobias Ackels
- Neurophysiology of Behaviour Lab, The Francis Crick Institute, London, United Kingdom; Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Andreas Kriebel
- Department for Zoology and Animal Physiology, RWTH Aachen University, Aachen, Germany
| | - Katharina Kriebel
- Department for Zoology and Animal Physiology, RWTH Aachen University, Aachen, Germany
| | - Jörg Mey
- Department for Chemosensation, RWTH Aachen University, Aachen, Germany; Hospital Nacional de Parapléjicos, Toledo, Spain
| | - Thomas Kuenzel
- Department for Chemosensation, RWTH Aachen University, Aachen, Germany
| | - Hermann Wagner
- Department for Zoology and Animal Physiology, RWTH Aachen University, Aachen, Germany
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27
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Liu R, Wang J, Liang S, Zhang G, Yang X. Role of NKCC1 and KCC2 in Epilepsy: From Expression to Function. Front Neurol 2020; 10:1407. [PMID: 32010056 PMCID: PMC6978738 DOI: 10.3389/fneur.2019.01407] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 12/23/2019] [Indexed: 01/21/2023] Open
Abstract
As a main inhibitory neurotransmitter in the central nervous system, γ-aminobutyric acid (GABA) activates chloride-permeable GABAa receptors (GABAa Rs) and induces chloride ion (Cl−) flow, which relies on the intracellular chloride concentration ([Cl−]i) of the postsynaptic neuron. The Na-K-2Cl cotransporter isoform 1 (NKCC1) and the K-Cl cotransporter isoform 2 (KCC2) are two main cation-chloride cotransporters (CCCs) that have been implicated in human epilepsy. NKCC1 and KCC2 reset [Cl−]i by accumulating and extruding Cl−, respectively. Previous studies have shown that the profile of NKCC1 and KCC2 in neonatal neurons may reappear in mature neurons under some pathophysiological conditions, such as epilepsy. Although increasing studies focusing on the expression of NKCC1 and KCC2 have suggested that impaired chloride plasticity may be closely related to epilepsy, additional neuroelectrophysiological research aimed at studying the functions of NKCC1 and KCC2 are needed to understand the exact mechanism by which they induce epileptogenesis. In this review, we aim to briefly summarize the current researches surrounding the expression and function of NKCC1 and KCC2 in epileptogenesis and its implications on the treatment of epilepsy. We will also explore the potential for NKCC1 and KCC2 to be therapeutic targets for the development of novel antiepileptic drugs.
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Affiliation(s)
- Ru Liu
- Neuroelectrophysiological Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China.,Center of Epilepsy, Center for Brain Disorders Research, Capital Medical University, Beijing, China.,Center of Epilepsy, Beijing Institute of Brain Disorders, Beijing, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
| | - Junling Wang
- Neuroelectrophysiological Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China.,Center of Epilepsy, Center for Brain Disorders Research, Capital Medical University, Beijing, China.,Center of Epilepsy, Beijing Institute of Brain Disorders, Beijing, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
| | - Shuli Liang
- Department of Functional Neurosurgery, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Guojun Zhang
- Department of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xiaofeng Yang
- Neuroelectrophysiological Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China.,Center of Epilepsy, Center for Brain Disorders Research, Capital Medical University, Beijing, China.,Center of Epilepsy, Beijing Institute of Brain Disorders, Beijing, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
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28
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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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29
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Abstract
Cl- is the major extracellular (Cl-out) and intracellular (Cl-in) anion whose concentration is actively regulated by multiple transporters. These transporters generate Cl- gradients across the plasma membrane and between the cytoplasm and intracellular organelles. [Cl-]in changes rapidly in response to cell stimulation and influences many physiological functions, as well as cellular and systemic homeostasis. However, less appreciated is the signaling function of Cl-. Cl- interacts with multiple proteins to directly modify their activity. This review highlights the signaling function of Cl- and argues that Cl- is a bona fide signaling ion, a function deserving extensive exploration.
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Affiliation(s)
- Benjamin P Lüscher
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Laura Vachel
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Ehud Ohana
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
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30
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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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31
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Schmidt T, Ghaffarian N, Philippot C, Seifert G, Steinhäuser C, Pape HC, Blaesse P. Differential regulation of chloride homeostasis and GABAergic transmission in the thalamus. Sci Rep 2018; 8:13929. [PMID: 30224811 PMCID: PMC6141474 DOI: 10.1038/s41598-018-31762-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 08/23/2018] [Indexed: 01/09/2023] Open
Abstract
The thalamus is important for sensory integration with the ventrobasal thalamus (VB) as relay controlled by GABAergic projections from the nucleus reticularis thalami (NRT). Depending on the [Cl-]i primarily set by cation-chloride-cotransporters, GABA is inhibitory or excitatory. There is evidence that VB and NRT differ in terms of GABA action, with classical hyperpolarization in VB due to the expression of the Cl- extruder KCC2 and depolarizing/excitatory GABA action in the NRT, where KCC2 expression is low and Cl- accumulation by the Cl- inward transporter NKCC1 has been postulated. However, data on NKCC1 expression and functional analysis of both transporters are missing. We show that KCC2-mediated Cl- extrusion set the [Cl-]i in VB, while NKCC1 did not contribute substantially to Cl- accumulation and depolarizing GABA action in the NRT. The finding that NKCC1 did not play a major role in NRT neurons is of high relevance for ongoing studies on the therapeutic use of NKCC1 inhibitors trying to compensate for a disease-induced up-regulation of NKCC1 that has been described for various brain regions and disease states like epilepsy and chronic pain. These data suggest that NKCC1 inhibitors might have no major effect on healthy NRT neurons due to limited NKCC1 function.
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Affiliation(s)
- Tobias Schmidt
- Institute of Physiology I, University Hospital Münster, Münster, Germany
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Münster, Münster, Germany
| | - Nikoo Ghaffarian
- Institute of Physiology I, University Hospital Münster, Münster, Germany
| | - Camille Philippot
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Gerald Seifert
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | | | - Peter Blaesse
- Institute of Physiology I, University Hospital Münster, Münster, Germany.
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