1
|
Kok M, Brodsky JL. The biogenesis of potassium transporters: implications of disease-associated mutations. Crit Rev Biochem Mol Biol 2024:1-45. [PMID: 38946646 DOI: 10.1080/10409238.2024.2369986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 06/16/2024] [Indexed: 07/02/2024]
Abstract
The concentration of intracellular and extracellular potassium is tightly regulated due to the action of various ion transporters, channels, and pumps, which reside primarily in the kidney. Yet, potassium transporters and cotransporters play vital roles in all organs and cell types. Perhaps not surprisingly, defects in the biogenesis, function, and/or regulation of these proteins are linked to range of catastrophic human diseases, but to date, few drugs have been approved to treat these maladies. In this review, we discuss the structure, function, and activity of a group of potassium-chloride cotransporters, the KCCs, as well as the related sodium-potassium-chloride cotransporters, the NKCCs. Diseases associated with each of the four KCCs and two NKCCs are also discussed. Particular emphasis is placed on how these complex membrane proteins fold and mature in the endoplasmic reticulum, how non-native forms of the cotransporters are destroyed in the cell, and which cellular factors oversee their maturation and transport to the cell surface. When known, we also outline how the levels and activities of each cotransporter are regulated. Open questions in the field and avenues for future investigations are further outlined.
Collapse
Affiliation(s)
- Morgan Kok
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| |
Collapse
|
2
|
Wang Y, Zhang Y, Yu W, Dong M, Cheng P, Wang Y. Sevoflurane-induced regulation of NKCC1/KCC2 phosphorylation through activation of Spak/OSR1 kinase and cognitive impairment in ischemia-reperfusion injury in rats. Heliyon 2024; 10:e32481. [PMID: 38975218 PMCID: PMC11226796 DOI: 10.1016/j.heliyon.2024.e32481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/30/2024] [Accepted: 06/04/2024] [Indexed: 07/09/2024] Open
Abstract
The occurrence of excitotoxic damage caused by cerebral ischemia-reperfusion (I/R) injury is closely linked to a decrease in central inhibitory function, in which the concentration of chloride inside the cells ([Cl-]i) plays a crucial role. The outflow and inflow of [Cl-]i are controlled by KCC2 and NKCC1, which are cellular cotransporters for K+/Cl- and Na+/K+/Cl-, respectively. NKCC1/KCC2 is regulated by upstream regulators such as SPAK and OSR1, whose activity is influenced by I/R. Sevoflurane is the most commonly used and controversial general anesthetic. To elucidate the impact of sevoflurane on cerebral ischemia-reperfusion (I/R) injury and its underlying mechanism, we investigated its influence on cognitive function and the mechanism of action utilizing a rat model of I/R. By activating the kinase Spak/OSR1, we discovered that I/R damage enhanced the function of NKCC1 and inhibited the function of KCC2, which triggered an imbalance of [Cl-]i concentration, leading to neurological dysfunction and cognitive dysfunction. At the beginning of reperfusion, administration of 1.3 MAC sevoflurane for 3 h increased activation of Spak/OSR1 kinases on day 7 post-perfusion, resulting in an additional dysregulation of NKCC1 and KCC2 activity, which disappeared on day 14. Administration of Closantel, a Spak/OSR1 kinase inhibitor, to animals treated with sevoflurane reverses the additional stimulation. The research revealed that sevoflurane modified the functioning of NKCC1 and KCC2, resulting in cognitive decline by activating Spak/OSR1 kinase. However, this issue could be resolved by inhibiting Spak/OSR1. The research revealed that sevoflurane transiently alters the function of NKCC1 and KCC2, resulting in exacerbating cognitive decline. However, this can be fixed by suppressing Spak/OSR1.
Collapse
Affiliation(s)
- Yuefeng Wang
- Department of Anesthesiology, Yijishan Hospital, First Affiliated Hospital of Wannan Medical College, Wuhu, 241004, China
| | - Yuanyu Zhang
- Department of Health Manageent Center, Yijishan Hospital, First Affiliated Hospital of Wannan Medical College, Wuhu, 241004, China
| | - Wei Yu
- Department of Anesthesiology, Yijishan Hospital, First Affiliated Hospital of Wannan Medical College, Wuhu, 241004, China
| | - Mengjuan Dong
- Department of Anesthesiology, Yijishan Hospital, First Affiliated Hospital of Wannan Medical College, Wuhu, 241004, China
| | - Pingping Cheng
- Department of Anesthesiology, Yijishan Hospital, First Affiliated Hospital of Wannan Medical College, Wuhu, 241004, China
| | - Ye Wang
- Department of Anesthesiology, Yijishan Hospital, First Affiliated Hospital of Wannan Medical College, Wuhu, 241004, China
| |
Collapse
|
3
|
Hamze M, Brier C, Buhler E, Zhang J, Medina I, Porcher C. Regulation of Neuronal Chloride Homeostasis by Pro- and Mature Brain-Derived Neurotrophic Factor (BDNF) via KCC2 Cation-Chloride Cotransporters in Rat Cortical Neurons. Int J Mol Sci 2024; 25:6253. [PMID: 38892438 PMCID: PMC11172813 DOI: 10.3390/ijms25116253] [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: 05/17/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 06/21/2024] Open
Abstract
The strength of inhibitory neurotransmission depends on intracellular neuronal chloride concentration, primarily regulated by the activity of cation-chloride cotransporters NKCC1 (Sodium-Potassium-Chloride Cotransporter 1) and KCC2 (Potassium-Chloride Cotransporter 2). Brain-derived neurotrophic factor (BDNF) influences the functioning of these co-transporters. BDNF is synthesized from precursor proteins (proBDNF), which undergo proteolytic cleavage to yield mature BDNF (mBDNF). While previous studies have indicated the involvement of BDNF signaling in the activity of KCC2, its specific mechanisms are unclear. We investigated the interplay between both forms of BDNF and chloride homeostasis in rat hippocampal neurons and in utero electroporated cortices of rat pups, spanning the behavioral, cellular, and molecular levels. We found that both pro- and mBDNF play a comparable role in immature neurons by inhibiting the capacity of neurons to extrude chloride. Additionally, proBDNF increases the endocytosis of KCC2 while maintaining a depolarizing shift of EGABA in maturing neurons. Behaviorally, proBDNF-electroporated rat pups in the somatosensory cortex exhibit sensory deficits, delayed huddling, and cliff avoidance. These findings emphasize the role of BDNF signaling in regulating chloride transport through the modulation of KCC2. In summary, this study provides valuable insights into the intricate interplay between BDNF, chloride homeostasis, and inhibitory synaptic transmission, shedding light on the underlying cellular mechanisms involved.
Collapse
Affiliation(s)
- Mira Hamze
- INMED, INSERM, Aix-Marseille University, 13273 Marseille, France; (M.H.); (C.B.); (E.B.); (I.M.)
- INSERM (Institut National de la Santé et de la Recherche Médicale), Unité 1249, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| | - Cathy Brier
- INMED, INSERM, Aix-Marseille University, 13273 Marseille, France; (M.H.); (C.B.); (E.B.); (I.M.)
- INSERM (Institut National de la Santé et de la Recherche Médicale), Unité 1249, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| | - Emmanuelle Buhler
- INMED, INSERM, Aix-Marseille University, 13273 Marseille, France; (M.H.); (C.B.); (E.B.); (I.M.)
- INSERM (Institut National de la Santé et de la Recherche Médicale), Unité 1249, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| | - Jinwei Zhang
- Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Ling Ling Road, Shanghai 200032, China;
| | - Igor Medina
- INMED, INSERM, Aix-Marseille University, 13273 Marseille, France; (M.H.); (C.B.); (E.B.); (I.M.)
- INSERM (Institut National de la Santé et de la Recherche Médicale), Unité 1249, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| | - Christophe Porcher
- INMED, INSERM, Aix-Marseille University, 13273 Marseille, France; (M.H.); (C.B.); (E.B.); (I.M.)
- INSERM (Institut National de la Santé et de la Recherche Médicale), Unité 1249, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| |
Collapse
|
4
|
Nascimento AA, Pereira-Figueiredo D, Borges-Martins VP, Kubrusly RC, Calaza KC. GABAergic system and chloride cotransporters as potential therapeutic targets to mitigate cell death in ischemia. J Neurosci Res 2024; 102:e25355. [PMID: 38808645 DOI: 10.1002/jnr.25355] [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: 08/25/2023] [Revised: 04/17/2024] [Accepted: 05/06/2024] [Indexed: 05/30/2024]
Abstract
Gamma aminobutyric acid (GABA) is a critical inhibitory neurotransmitter in the central nervous system that plays a vital role in modulating neuronal excitability. Dysregulation of GABAergic signaling, particularly involving the cotransporters NKCC1 and KCC2, has been implicated in various pathologies, including epilepsy, schizophrenia, autism spectrum disorder, Down syndrome, and ischemia. NKCC1 facilitates chloride influx, whereas KCC2 mediates chloride efflux via potassium gradient. Altered expression and function of these cotransporters have been associated with excitotoxicity, inflammation, and cellular death in ischemic events characterized by reduced cerebral blood flow, leading to compromised tissue metabolism and subsequent cell death. NKCC1 inhibition has emerged as a potential therapeutic approach to attenuate intracellular chloride accumulation and mitigate neuronal damage during ischemic events. Similarly, targeting KCC2, which regulates chloride efflux, holds promise for improving outcomes and reducing neuronal damage under ischemic conditions. This review emphasizes the critical roles of GABA, NKCC1, and KCC2 in ischemic pathologies and their potential as therapeutic targets. Inhibiting or modulating the activity of these cotransporters represents a promising strategy for reducing neuronal damage, preventing excitotoxicity, and improving neurological outcomes following ischemic events. Furthermore, exploring the interactions between natural compounds and NKCC1/KCC2 provides additional avenues for potential therapeutic interventions for ischemic injury.
Collapse
Affiliation(s)
- A A Nascimento
- Neurobiology of the Retina Laboratory, Department of Neurobiology and Graduate Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, Brazil
| | - D Pereira-Figueiredo
- Graduate Program in Biomedical Sciences (Physiology and Pharmacology), Fluminense Federal University, Niterói, Brazil
| | - V P Borges-Martins
- Laboratory of Neuropharmacology, Department of Physiology and Pharmacology, Biomedical Institute, Fluminense Federal University, Niterói, Brazil
| | - R C Kubrusly
- Laboratory of Neuropharmacology, Department of Physiology and Pharmacology, Biomedical Institute, Fluminense Federal University, Niterói, Brazil
| | - K C Calaza
- Neurobiology of the Retina Laboratory, Department of Neurobiology and Graduate Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, Brazil
- Graduate Program in Biomedical Sciences (Physiology and Pharmacology), Fluminense Federal University, Niterói, Brazil
| |
Collapse
|
5
|
Hershfinkel M. Cross-talk between zinc and calcium regulates ion transport: A role for the zinc receptor, ZnR/GPR39. J Physiol 2024; 602:1579-1594. [PMID: 37462604 DOI: 10.1113/jp283834] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 06/26/2023] [Indexed: 04/21/2024] Open
Abstract
Zinc is essential for many physiological functions, with a major role in digestive system, skin health, and learning and memory. On the cellular level, zinc is involved in cell proliferation and cell death. A selective zinc sensing receptor, ZnR/GPR39 is a Gq-coupled receptor that acts via the inositol trisphosphate pathway to release intracellular Ca2+. The ZnR/GPR39 serves as a mediator between extracellular changes in Zn2+ concentration and cellular Ca2+ signalling. This signalling pathway regulates ion transporters activity and thereby controls the formation of transepithelial gradients or neuronal membrane potential, which play a fundamental role in the physiological function of these tissues. This review focuses on the role of Ca2+ signalling, and specifically ZnR/GPR39, with respect to the regulation of the Na+/H+ exchanger, NHE1, and of the K+/Cl- cotransporters, KCC1-3, and also describes the physiological implications of this regulation.
Collapse
Affiliation(s)
- Michal Hershfinkel
- Department of Physiology and Cell Biology and the School of Brain Sciences and Cognition, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| |
Collapse
|
6
|
Watanabe M, Sinha AS, Shinmyo Y, Fukuda A. Early establishment of chloride homeostasis in CRH neurons is altered by prenatal stress leading to fetal HPA axis dysregulation. Front Mol Neurosci 2024; 17:1373337. [PMID: 38577026 PMCID: PMC10994000 DOI: 10.3389/fnmol.2024.1373337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/05/2024] [Indexed: 04/06/2024] Open
Abstract
Corticotropin-releasing hormone (CRH) neurons play an important role in the regulation of neuroendocrine responses to stress. The excitability of CRH neurons is regulated by inhibitory GABAergic inputs. However, it is unclear when GABAergic regulation of CRH neurons is established during fetal brain development. Furthermore, the exact progression of the developmental shift of GABA action from depolarization to hyperpolarization remains unelucidated. Considering the importance of CRH neuron function in subsequent hypothalamic-pituitary-adrenal (HPA) axis regulation during this critical phase of development, we investigated the ontogeny of GABAergic inputs to CRH neurons and consequent development of chloride homeostasis. Both CRH neuron soma in the paraventricular nucleus (PVN) and axons projecting to the median eminence could be identified at embryonic day 15 (E15). Using acute slices containing the PVN of CRF-VenusΔNeo mice, gramicidin perforated-patch clamp-recordings of CRH neurons at E15, postnatal day 0 (P0), and P7 were performed to evaluate the developmental shift of GABA action. The equilibrium potential of GABA (EGABA) was similar between E15 and P0 and showed a further hyperpolarizing shift between P0 and P7 that was comparable to EGABA values in adult CRH neurons. GABA primarily acted as an inhibitory signal at E15 and KCC2 expression was detected in CRH neurons at this age. Activation of the HPA axis has been proposed as the primary mechanism through which prenatal maternal stress shapes fetal development and subsequent long-term disease risk. We therefore examined the impact of maternal food restriction stress on the development of chloride homeostasis in CRH neurons. We observed a depolarization shift of EGABA in CRH neurons of pups exposed to maternal food restriction stress. These results suggest that Cl- homeostasis in early developmental CRH neurons attains mature intracellular Cl- levels, GABA acts primarily as inhibitory, and CRH neurons mature and function early compared with neurons in other brain regions, such as the cortex and hippocampus. Maternal food restriction stress alters chloride homeostasis in CRH neurons of pups, reducing their inhibitory control by GABA. This may contribute to increased CRH neuron activity and cause activation of the HPA axis in pups.
Collapse
Affiliation(s)
| | | | - Yohei Shinmyo
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| |
Collapse
|
7
|
Kok M, Hartnett-Scott K, Happe CL, MacDonald ML, Aizenman E, Brodsky JL. The expression system influences stability, maturation efficiency, and oligomeric properties of the potassium-chloride co-transporter KCC2. Neurochem Int 2024; 174:105695. [PMID: 38373478 PMCID: PMC10923169 DOI: 10.1016/j.neuint.2024.105695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/21/2024]
Abstract
The neuron-specific K+/Cl- co-transporter 2, KCC2, which is critical for brain development, regulates γ-aminobutyric acid-dependent inhibitory neurotransmission. Consistent with its function, mutations in KCC2 are linked to neurodevelopmental disorders, including epilepsy, schizophrenia, and autism. KCC2 possesses 12 transmembrane spans and forms an intertwined dimer. Based on its complex architecture and function, reduced cell surface expression and/or activity have been reported when select disease-associated mutations are present in the gene encoding the protein, SLC12A5. These data suggest that KCC2 might be inherently unstable, as seen for other complex polytopic ion channels, thus making it susceptible to cellular quality control pathways that degrade misfolded proteins. To test these hypotheses, we examined KCC2 stability and/or maturation in five model systems: yeast, HEK293 cells, primary rat neurons, and rat and human brain synaptosomes. Although studies in yeast revealed that KCC2 is selected for endoplasmic reticulum-associated degradation (ERAD), experiments in HEK293 cells supported a more subtle role for ERAD in maintaining steady-state levels of KCC2. Nevertheless, this system allowed for an analysis of KCC2 glycosylation in the ER and Golgi, which serves as a read-out for transport through the secretory pathway. In turn, KCC2 was remarkably stable in primary rat neurons, suggesting that KCC2 folds efficiently in more native systems. Consistent with these data, the mature glycosylated form of KCC2 was abundant in primary rat neurons as well as in rat and human brain. Together, this work details the first insights into the influence that the cellular and membrane environments have on several fundamental KCC2 properties, acknowledges the advantages and disadvantages of each system, and helps set the stage for future experiments to assess KCC2 in a normal or disease setting.
Collapse
Affiliation(s)
- Morgan Kok
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Karen Hartnett-Scott
- Department of Neurobiology and the Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Cassandra L Happe
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Matthew L MacDonald
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Elias Aizenman
- Department of Neurobiology and the Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
8
|
Zhu H, Dalvi U, Cazenave W, Cattaert D, Branchereau P. Excitatory action of low frequency depolarizing GABA/glycine synaptic inputs is prevalent in prenatal spinal SOD1 G93A motoneurons. J Physiol 2024; 602:913-932. [PMID: 38345477 DOI: 10.1113/jp285105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 01/24/2024] [Indexed: 03/09/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal adult-onset neurodegenerative disease characterized by progressive motor neuron degeneration and muscle paralysis. Recent evidence suggests the dysfunction of inhibitory signalling in ALS motor neurons. We have shown that embryonic day (E)17.5 spinal motoneurons (MNs) of the SOD1G93A mouse model of ALS exhibit an altered chloride homeostasis. At this prenatal stage, inhibition of spinal motoneurons (MNs) is mediated by depolarizing GABAergic/glycinergic postsynaptic potentials (dGPSPs). Here, using an ex vivo preparation and patch clamp recording from MNs with a chloride equilibrium set below spike threshold, we report that low input resistance (Rin ) E17.5 MNs from the SOD1G93A ALS mouse model do not correctly integrate dGPSPs evoked by electrical stimulations of GABA/glycine inputs at different frequencies. Indeed, firing activity of most wild-type (WT) MNs with low Rin was inhibited by incoming dGPSPs, whereas low Rin SOD1G93A MNs were excited or exhibited a dual response (excited by low frequency dGPSPs and inhibited by high frequency dGPSPs). Simulation highlighted the importance of the GABA/glycine input density and showed that pure excitation could be obtained in SOD-like MNs by moving GABA/glycine input away from the cell body to dendrites. This was in agreement with confocal imaging showing a lack of peri-somatic inhibitory terminals in SOD1G93A MNs compared to WT littermates. Putative fast ALS-vulnerable MNs with low Rin are therefore lacking functional inhibition at the near-term prenatal stage. KEY POINTS: We analysed the integration of GABAergic/glycinergic synaptic events by embryonic spinal motoneurons (MNs) in a mouse model of the amyotrophic lateral sclerosis (ALS) neurodegenerative disease. We found that GABAergic/glycinergic synaptic events do not properly inhibit ALS MNs with low input resistance, most probably corresponding to future vulnerable MNs. We used a neuron model to highlight the importance of the GABA/glycine terminal location and density in the integration of the GABAergic/glycinergic synaptic events. Confocal imaging showed a lack of GABA/glycine terminals on the cell body of ALS MNs. The present study suggests that putative ALS vulnerable MNs with low Rin lack functional inhibition at the near-term stage.
Collapse
Affiliation(s)
- Hongmei Zhu
- University Bordeaux, CNRS, INCIA, UMR 5287, Bordeaux, France
| | - Urvashi Dalvi
- University Bordeaux, CNRS, INCIA, UMR 5287, Bordeaux, France
| | | | - Daniel Cattaert
- University Bordeaux, CNRS, INCIA, UMR 5287, Bordeaux, France
| | | |
Collapse
|
9
|
Grau JW, Hudson KE, Johnston DT, Partipilo SR. Updating perspectives on spinal cord function: motor coordination, timing, relational processing, and memory below the brain. Front Syst Neurosci 2024; 18:1184597. [PMID: 38444825 PMCID: PMC10912355 DOI: 10.3389/fnsys.2024.1184597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 01/29/2024] [Indexed: 03/07/2024] Open
Abstract
Those studying neural systems within the brain have historically assumed that lower-level processes in the spinal cord act in a mechanical manner, to relay afferent signals and execute motor commands. From this view, abstracting temporal and environmental relations is the province of the brain. Here we review work conducted over the last 50 years that challenges this perspective, demonstrating that mechanisms within the spinal cord can organize coordinated behavior (stepping), induce a lasting change in how pain (nociceptive) signals are processed, abstract stimulus-stimulus (Pavlovian) and response-outcome (instrumental) relations, and infer whether stimuli occur in a random or regular manner. The mechanisms that underlie these processes depend upon signal pathways (e.g., NMDA receptor mediated plasticity) analogous to those implicated in brain-dependent learning and memory. New data show that spinal cord injury (SCI) can enable plasticity within the spinal cord by reducing the inhibitory effect of GABA. It is suggested that the signals relayed to the brain may contain information about environmental relations and that spinal cord systems can coordinate action in response to descending signals from the brain. We further suggest that the study of stimulus processing, learning, memory, and cognitive-like processing in the spinal cord can inform our views of brain function, providing an attractive model system. Most importantly, the work has revealed new avenues of treatment for those that have suffered a SCI.
Collapse
Affiliation(s)
- James W. Grau
- Lab of Dr. James Grau, Department of Psychological and Brain Sciences, Cellular and Behavioral Neuroscience, Texas A&M University, College Station, TX, United States
| | | | | | | |
Collapse
|
10
|
McMoneagle E, Zhou J, Zhang S, Huang W, Josiah SS, Ding K, Wang Y, Zhang J. Neuronal K +-Cl - cotransporter KCC2 as a promising drug target for epilepsy treatment. Acta Pharmacol Sin 2024; 45:1-22. [PMID: 37704745 PMCID: PMC10770335 DOI: 10.1038/s41401-023-01149-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 08/02/2023] [Indexed: 09/14/2023] Open
Abstract
Epilepsy is a prevalent neurological disorder characterized by unprovoked seizures. γ-Aminobutyric acid (GABA) serves as the primary fast inhibitory neurotransmitter in the brain, and GABA binding to the GABAA receptor (GABAAR) regulates Cl- and bicarbonate (HCO3-) influx or efflux through the channel pore, leading to GABAergic inhibition or excitation, respectively. The neuron-specific K+-Cl- cotransporter 2 (KCC2) is essential for maintaining a low intracellular Cl- concentration, ensuring GABAAR-mediated inhibition. Impaired KCC2 function results in GABAergic excitation associated with epileptic activity. Loss-of-function mutations and altered expression of KCC2 lead to elevated [Cl-]i and compromised synaptic inhibition, contributing to epilepsy pathogenesis in human patients. KCC2 antagonism studies demonstrate the necessity of limiting neuronal hyperexcitability within the brain, as reduced KCC2 functioning leads to seizure activity. Strategies focusing on direct (enhancing KCC2 activation) and indirect KCC2 modulation (altering KCC2 phosphorylation and transcription) have proven effective in attenuating seizure severity and exhibiting anti-convulsant properties. These findings highlight KCC2 as a promising therapeutic target for treating epilepsy. Recent advances in understanding KCC2 regulatory mechanisms, particularly via signaling pathways such as WNK, PKC, BDNF, and its receptor TrkB, have led to the discovery of novel small molecules that modulate KCC2. Inhibiting WNK kinase or utilizing newly discovered KCC2 agonists has demonstrated KCC2 activation and seizure attenuation in animal models. This review discusses the role of KCC2 in epilepsy and evaluates its potential as a drug target for epilepsy treatment by exploring various strategies to regulate KCC2 activity.
Collapse
Affiliation(s)
- Erin McMoneagle
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Hatherly Laboratories, Streatham Campus, Exeter, EX4 4PS, UK
| | - Jin Zhou
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Shiyao Zhang
- Institute of Cardiovascular Diseases, Xiamen Cardiovascular Hospital Xiamen University, School of Medicine, Xiamen University, Xiang'an Nan Lu, Xiamen, 361102, China
| | - Weixue Huang
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Sunday Solomon Josiah
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Hatherly Laboratories, Streatham Campus, Exeter, EX4 4PS, UK
| | - Ke Ding
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China.
| | - Yun Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
| | - Jinwei Zhang
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Hatherly Laboratories, Streatham Campus, Exeter, EX4 4PS, UK.
- Institute of Cardiovascular Diseases, Xiamen Cardiovascular Hospital Xiamen University, School of Medicine, Xiamen University, Xiang'an Nan Lu, Xiamen, 361102, China.
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China.
| |
Collapse
|
11
|
Radulovic T, Rajaram E, Ebbers L, Pagella S, Winklhofer M, Kopp-Scheinpflug C, Nothwang HG, Milenkovic I, Hartmann AM. Serine 937 phosphorylation enhances KCC2 activity and strengthens synaptic inhibition. Sci Rep 2023; 13:21660. [PMID: 38066086 PMCID: PMC10709408 DOI: 10.1038/s41598-023-48884-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 11/30/2023] [Indexed: 12/18/2023] Open
Abstract
The potassium chloride cotransporter KCC2 is crucial for Cl- extrusion from mature neurons and thus key to hyperpolarizing inhibition. Auditory brainstem circuits contain well-understood inhibitory projections and provide a potent model to study the regulation of synaptic inhibition. Two peculiarities of the auditory brainstem are (i) posttranslational activation of KCC2 during development and (ii) extremely negative reversal potentials in specific circuits. To investigate the role of the potent phospho-site serine 937 therein, we generated a KCC2 Thr934Ala/Ser937Asp double mutation, in which Ser937 is replaced by aspartate mimicking the phosphorylated state, and the neighbouring Thr934 arrested in the dephosphorylated state. This double mutant showed a twofold increased transport activity in HEK293 cells, raising the hypothesis that auditory brainstem neurons show lower [Cl-]i. and increased glycinergic inhibition. This was tested in a mouse model carrying the same KCC2 Thr934Ala/Ser937Asp mutation by the use of the CRISPR/Cas9 technology. Homozygous KCC2 Thr934Ala/Ser937Asp mice showed an earlier developmental onset of hyperpolarisation in the auditory brainstem. Mature neurons displayed stronger glycinergic inhibition due to hyperpolarized ECl-. These data demonstrate that phospho-regulation of KCC2 Ser937 is a potent way to interfere with the excitation-inhibition balance in neural circuits.
Collapse
Affiliation(s)
- Tamara Radulovic
- Division of Physiology School of Medicine and Health Sciences, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
- Research Center Neurosensory Science, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
| | - Ezhilarasan Rajaram
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany
| | - Lena Ebbers
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
| | - Sara Pagella
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany
| | - Michael Winklhofer
- Research Center Neurosensory Science, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
- Institute for Biology and Environmental Sciences IBU, Carl Von Ossietzky University of Oldenburg, 26111, Oldenburg, Germany
| | - Conny Kopp-Scheinpflug
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany
| | - Hans Gerd Nothwang
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
- Research Center Neurosensory Science, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
- Center of Excellence Hearing4all, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
| | - Ivan Milenkovic
- Division of Physiology School of Medicine and Health Sciences, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
- Research Center Neurosensory Science, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
| | - Anna-Maria Hartmann
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany.
- Research Center Neurosensory Science, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany.
| |
Collapse
|
12
|
Zhang S, Meor Azlan NF, Josiah SS, Zhou J, Zhou X, Jie L, Zhang Y, Dai C, Liang D, Li P, Li Z, Wang Z, Wang Y, Ding K, Wang Y, Zhang J. The role of SLC12A family of cation-chloride cotransporters and drug discovery methodologies. J Pharm Anal 2023; 13:1471-1495. [PMID: 38223443 PMCID: PMC10785268 DOI: 10.1016/j.jpha.2023.09.002] [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: 03/04/2023] [Revised: 06/20/2023] [Accepted: 09/05/2023] [Indexed: 09/12/2023] Open
Abstract
The solute carrier family 12 (SLC12) of cation-chloride cotransporters (CCCs) comprises potassium chloride cotransporters (KCCs, e.g. KCC1, KCC2, KCC3, and KCC4)-mediated Cl- extrusion, and sodium potassium chloride cotransporters (N[K]CCs, NKCC1, NKCC2, and NCC)-mediated Cl- loading. The CCCs play vital roles in cell volume regulation and ion homeostasis. Gain-of-function or loss-of-function of these ion transporters can cause diseases in many tissues. In recent years, there have been considerable advances in our understanding of CCCs' control mechanisms in cell volume regulations, with many techniques developed in studying the functions and activities of CCCs. Classic approaches to directly measure CCC activity involve assays that measure the transport of potassium substitutes through the CCCs. These techniques include the ammonium pulse technique, radioactive or nonradioactive rubidium ion uptake-assay, and thallium ion-uptake assay. CCCs' activity can also be indirectly observed by measuring γ-aminobutyric acid (GABA) activity with patch-clamp electrophysiology and intracellular chloride concentration with sensitive microelectrodes, radiotracer 36Cl-, and fluorescent dyes. Other techniques include directly looking at kinase regulatory sites phosphorylation, flame photometry, 22Na+ uptake assay, structural biology, molecular modeling, and high-throughput drug screening. This review summarizes the role of CCCs in genetic disorders and cell volume regulation, current methods applied in studying CCCs biology, and compounds developed that directly or indirectly target the CCCs for disease treatments.
Collapse
Affiliation(s)
- Shiyao Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Nur Farah Meor Azlan
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Sunday Solomon Josiah
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Jing Zhou
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Xiaoxia Zhou
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Lingjun Jie
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Yanhui Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Cuilian Dai
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Dong Liang
- Aurora Discovery Inc., Foshan, Guangdong, 528300, China
| | - Peifeng Li
- Institute for Translational Medicine, Qingdao University, Qingdao, Shandong, 266021, China
| | - Zhengqiu Li
- School of Pharmacy, Jinan University, Guangzhou, 510632, China
| | - Zhen Wang
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yun Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Ke Ding
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yan Wang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Jinwei Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4PS, UK
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
| |
Collapse
|
13
|
Tomita K, Kuwahara Y, Igarashi K, Kitanaka J, Kitanaka N, Takashi Y, Tanaka KI, Roudkenar MH, Roushandeh AM, Kurimasa A, Nishitani Y, Sato T. Therapeutic potential for KCC2-targeted neurological diseases. JAPANESE DENTAL SCIENCE REVIEW 2023; 59:431-438. [PMID: 38022385 PMCID: PMC10665825 DOI: 10.1016/j.jdsr.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 11/01/2023] [Accepted: 11/05/2023] [Indexed: 12/01/2023] Open
Abstract
Patients with neurological diseases, such as schizophrenia, tend to show low K+-Cl- co-transporter 2 (KCC2) levels in the brain. The cause of these diseases has been associated with stress and neuroinflammation. However, since the pathogenesis of these diseases is not yet fully investigated, drug therapy is still limited to symptomatic therapy. Targeting KCC2, which is mainly expressed in the brain, seems to be an appropriate approach in the treatment of these diseases. In this review, we aimed to discuss about stress and inflammation, KCC2 and Gamma-aminobutyric acid (GABA) function, diseases which decrease the KCC2 levels in the brain, factors that regulate KCC2 activity, and the possibility to overcome neuronal dysfunction targeting KCC2. We also aimed to discuss the relationships between neurological diseases and LPS caused by Porphyromonas gingivalis (P. g), which is a type of oral bacterium. Clinical trials on oxytocin, sirtuin 1 (SIRT1) activator, and transient receptor potential cation channel subfamily V Member 1 activator have been conducted to develop effective treatment methods. We believe that KCC2 modulators that regulate mitochondria, such as oxytocin, glycogen synthase kinase 3β (GSK3β), and SIRT1, can be potential targets for neurological diseases.
Collapse
Affiliation(s)
- Kazuo Tomita
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
- Division of Pharmacology, Department of Pharmacy, School of Pharmacy, Hyogo Medical University, Hyogo 650–8530, Japan
| | - Yoshikazu Kuwahara
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
- Division of Radiation Biology and Medicine, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Miyagi, 983-8536, Japan
| | - Kento Igarashi
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
- Division of Pharmacology, Department of Pharmacy, School of Pharmacy, Hyogo Medical University, Hyogo 650–8530, Japan
| | - Junichi Kitanaka
- Laboratory of Drug Addiction and Experimental Therapeutics, Schoolof Pharmacy, Hyogo Medical University, Hyogo 650-8530, Japan
| | - Nobue Kitanaka
- Laboratory of Drug Addiction and Experimental Therapeutics, Schoolof Pharmacy, Hyogo Medical University, Hyogo 650-8530, Japan
- Department of Pharmacology, School of Medicine, Hyogo Medical University, Hyogo 663-8501, Japan
| | - Yuko Takashi
- Department of Restorative Dentistry and Endodontology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
| | - Koh-ichi Tanaka
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
- Division of Pharmacology, Department of Pharmacy, School of Pharmacy, Hyogo Medical University, Hyogo 650–8530, Japan
| | - Mehryar Habibi Roudkenar
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
- Burn and Regenerative Medicine Research Center, Velayat Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht 41937–13194, Iran
| | - Amaneh Mohammadi Roushandeh
- Department of Anatomy, School of Biomedical Sciences, Medicine & Health, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Akihiro Kurimasa
- Division of Radiation Biology and Medicine, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Miyagi, 983-8536, Japan
| | - Yoshihiro Nishitani
- Department of Restorative Dentistry and Endodontology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
| | - Tomoaki Sato
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Byvaltcev E, Behbood M, Schleimer JH, Gensch T, Semyanov A, Schreiber S, Strauss U. KCC2 reverse mode helps to clear postsynaptically released potassium at glutamatergic synapses. Cell Rep 2023; 42:112934. [PMID: 37537840 PMCID: PMC10480490 DOI: 10.1016/j.celrep.2023.112934] [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: 05/21/2023] [Revised: 07/09/2023] [Accepted: 07/18/2023] [Indexed: 08/05/2023] Open
Abstract
Extracellular potassium [K+]o elevation during synaptic activity retrogradely modifies presynaptic release and astrocytic uptake of glutamate. Hence, local K+ clearance and replenishment mechanisms are crucial regulators of glutamatergic transmission and plasticity. Based on recordings of astrocytic inward rectifier potassium current IKir and K+-sensitive electrodes as sensors of [K+]o as well as on in silico modeling, we demonstrate that the neuronal K+-Cl- co-transporter KCC2 clears local perisynaptic [K+]o during synaptic excitation by operating in an activity-dependent reversed mode. In reverse mode, KCC2 replenishes K+ in dendritic spines and complements clearance of [K+]o, therewith attenuating presynaptic glutamate release and shortening LTP. We thus demonstrate a physiological role of KCC2 in neuron-glial interactions and regulation of synaptic signaling and plasticity through the uptake of postsynaptically released K+.
Collapse
Affiliation(s)
- Egor Byvaltcev
- Charité - Universitätsmedizin Berlin, Institute of Cell- and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Mahraz Behbood
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Jan-Hendrik Schleimer
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Thomas Gensch
- Institute of Biological Information Processing 1 (IBI-1, Molecular and Cellular Physiology), Forschungszentrum Jülich, Wilhem-Jonen Straße, 52428 Jülich, Germany
| | - Alexey Semyanov
- Department of Physiology, Jiaxing University College of Medicine, Zhejiang Pro, Jiaxing 314033, China
| | - Susanne Schreiber
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Ulf Strauss
- Charité - Universitätsmedizin Berlin, Institute of Cell- and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany.
| |
Collapse
|
16
|
van van Hugte EJH, Schubert D, Nadif Kasri N. Excitatory/inhibitory balance in epilepsies and neurodevelopmental disorders: Depolarizing γ-aminobutyric acid as a common mechanism. Epilepsia 2023; 64:1975-1990. [PMID: 37195166 DOI: 10.1111/epi.17651] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 05/13/2023] [Accepted: 05/15/2023] [Indexed: 05/18/2023]
Abstract
Epilepsy is one of the most common neurological disorders. Although many factors contribute to epileptogenesis, seizure generation is mostly linked to hyperexcitability due to alterations in excitatory/inhibitory (E/I) balance. The common hypothesis is that reduced inhibition, increased excitation, or both contribute to the etiology of epilepsy. Increasing evidence shows that this view is oversimplistic, and that increased inhibition through depolarizing γ-aminobutyric acid (GABA) similarly contributes to epileptogenisis. In early development, GABA signaling is depolarizing, inducing outward Cl- currents due to high intracellular Cl- concentrations. During maturation, the mechanisms of GABA action shift from depolarizing to hyperpolarizing, a critical event during brain development. Altered timing of this shift is associated with both neurodevelopmental disorders and epilepsy. Here, we consider the different ways that depolarizing GABA contributes to altered E/I balance and epileptogenesis, and discuss that alterations in depolarizing GABA could be a common denominator underlying seizure generation in neurodevelopmental disorders and epilepsies.
Collapse
Affiliation(s)
- Eline J H van van Hugte
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, the Netherlands
- Department of Epileptology, Academic Centre for Epileptology (ACE) Kempenhaeghe, Heeze, the Netherlands
| | - Dirk Schubert
- Department of Cognitive Neuroscience, Radboud University Medical Center, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, the Netherlands
| | - Nael Nadif Kasri
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, the Netherlands
- Department of Epileptology, Academic Centre for Epileptology (ACE) Kempenhaeghe, Heeze, the Netherlands
| |
Collapse
|
17
|
Calvo PM, de la Cruz RR, Pastor AM, Alvarez FJ. Preservation of KCC2 expression in axotomized abducens motoneurons and its enhancement by VEGF. Brain Struct Funct 2023; 228:967-984. [PMID: 37005931 PMCID: PMC10428176 DOI: 10.1007/s00429-023-02635-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: 11/08/2022] [Accepted: 03/23/2023] [Indexed: 04/04/2023]
Abstract
The potassium chloride cotransporter 2 (KCC2) is the main Cl- extruder in neurons. Any alteration in KCC2 levels leads to changes in Cl- homeostasis and, consequently, in the polarity and amplitude of inhibitory synaptic potentials mediated by GABA or glycine. Axotomy downregulates KCC2 in many different motoneurons and it is suspected that interruption of muscle-derived factors maintaining motoneuron KCC2 expression is in part responsible. In here, we demonstrate that KCC2 is expressed in all oculomotor nuclei of cat and rat, but while trochlear and oculomotor motoneurons downregulate KCC2 after axotomy, expression is unaltered in abducens motoneurons. Exogenous application of vascular endothelial growth factor (VEGF), a neurotrophic factor expressed in muscle, upregulated KCC2 in axotomized abducens motoneurons above control levels. In parallel, a physiological study using cats chronically implanted with electrodes for recording abducens motoneurons in awake animals, demonstrated that inhibitory inputs related to off-fixations and off-directed saccades in VEGF-treated axotomized abducens motoneurons were significantly higher than in control, but eye-related excitatory signals in the on direction were unchanged. This is the first report of lack of KCC2 regulation in a motoneuron type after injury, proposing a role for VEGF in KCC2 regulation and demonstrating the link between KCC2 and synaptic inhibition in awake, behaving animals.
Collapse
Affiliation(s)
- Paula M Calvo
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012, Seville, Spain
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA
| | - Rosa R de la Cruz
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012, Seville, Spain
| | - Angel M Pastor
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012, Seville, Spain
| | | |
Collapse
|
18
|
Pressey JC, de Saint-Rome M, Raveendran VA, Woodin MA. Chloride transporters controlling neuronal excitability. Physiol Rev 2023; 103:1095-1135. [PMID: 36302178 DOI: 10.1152/physrev.00025.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Synaptic inhibition plays a crucial role in regulating neuronal excitability, which is the foundation of nervous system function. This inhibition is largely mediated by the neurotransmitters GABA and glycine that activate Cl--permeable ion channels, which means that the strength of inhibition depends on the Cl- gradient across the membrane. In neurons, the Cl- gradient is primarily mediated by two secondarily active cation-chloride cotransporters (CCCs), NKCC1 and KCC2. CCC-mediated regulation of the neuronal Cl- gradient is critical for healthy brain function, as dysregulation of CCCs has emerged as a key mechanism underlying neurological disorders including epilepsy, neuropathic pain, and autism spectrum disorder. This review begins with an overview of neuronal chloride transporters before explaining the dependent relationship between these CCCs, Cl- regulation, and inhibitory synaptic transmission. We then discuss the evidence for how CCCs can be regulated, including by activity and their protein interactions, which underlie inhibitory synaptic plasticity. For readers who may be interested in conducting experiments on CCCs and neuronal excitability, we have included a section on techniques for estimating and recording intracellular Cl-, including their advantages and limitations. Although the focus of this review is on neurons, we also examine how Cl- is regulated in glial cells, which in turn regulate neuronal excitability through the tight relationship between this nonneuronal cell type and synapses. Finally, we discuss the relatively extensive and growing literature on how CCC-mediated neuronal excitability contributes to neurological disorders.
Collapse
Affiliation(s)
- Jessica C Pressey
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Miranda de Saint-Rome
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Vineeth A Raveendran
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Melanie A Woodin
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
19
|
Jarvis R, Josephine Ng SF, Nathanson AJ, Cardarelli RA, Abiraman K, Wade F, Evans-Strong A, Fernandez-Campa MP, Deeb TZ, Smalley JL, Jamier T, Gurrell IK, McWilliams L, Kawatkar A, Conway LC, Wang Q, Burli RW, Brandon NJ, Chessell IP, Goldman AJ, Maguire JL, Moss SJ. Direct activation of KCC2 arrests benzodiazepine refractory status epilepticus and limits the subsequent neuronal injury in mice. Cell Rep Med 2023; 4:100957. [PMID: 36889319 PMCID: PMC10040380 DOI: 10.1016/j.xcrm.2023.100957] [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: 09/07/2022] [Revised: 11/17/2022] [Accepted: 02/06/2023] [Indexed: 03/09/2023]
Abstract
Hyperpolarizing GABAAR currents, the unitary events that underlie synaptic inhibition, are dependent upon efficient Cl- extrusion, a process that is facilitated by the neuronal specific K+/Cl- co-transporter KCC2. Its activity is also a determinant of the anticonvulsant efficacy of the canonical GABAAR-positive allosteric: benzodiazepines (BDZs). Compromised KCC2 activity is implicated in the pathophysiology of status epilepticus (SE), a medical emergency that rapidly becomes refractory to BDZ (BDZ-RSE). Here, we have identified small molecules that directly bind to and activate KCC2, which leads to reduced neuronal Cl- accumulation and excitability. KCC2 activation does not induce any overt effects on behavior but prevents the development of and terminates ongoing BDZ-RSE. In addition, KCC2 activation reduces neuronal cell death following BDZ-RSE. Collectively, these findings demonstrate that KCC2 activation is a promising strategy to terminate BDZ-resistant seizures and limit the associated neuronal injury.
Collapse
Affiliation(s)
- Rebecca Jarvis
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Shu Fun Josephine Ng
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Anna J Nathanson
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Ross A Cardarelli
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Krithika Abiraman
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Fergus Wade
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Aidan Evans-Strong
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Marina P Fernandez-Campa
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Tarek Z Deeb
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Joshua L Smalley
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Tanguy Jamier
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Ian K Gurrell
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Lisa McWilliams
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
| | - Aarti Kawatkar
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Boston, MA, USA
| | - Leslie C Conway
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Qi Wang
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Boston, MA, USA
| | - Roland W Burli
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Nicholas J Brandon
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Boston, MA, USA
| | - Iain P Chessell
- Discovery, Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Aaron J Goldman
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Jamie L Maguire
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Stephen J Moss
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA; Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1 6BT, UK.
| |
Collapse
|
20
|
Zhang H, Xu L, Xiong J, Li X, Yang Y, Liu Y, Zhang C, Wang Q, Wang J, Wang P, Wu X, Wang X, Zhu X, Guan Y. Role of KCC2 in the Regulation of Brain-Derived Neurotrophic Factor on Ethanol Consumption in Rats. Mol Neurobiol 2023; 60:1040-1049. [PMID: 36401060 DOI: 10.1007/s12035-022-03126-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 11/04/2022] [Indexed: 11/21/2022]
Abstract
Alcohol use disorder (AUD) is a common and complex disorder resulting from repetitive alcohol drinking. The mesocorticolimbic dopamine (DA) system, originating from the ventral tegmental area (VTA) in the midbrain, is involved in the rewarding effect of ethanol. The γ-aminobutyric acid (GABA) neurons in VTA appear to be key substrates of acute and chronic ethanol, which regulates DA neurotransmission indirectly in the mesocorticolimbic system. Despite significant research on the relationship between brain-derived neurotrophic factor (BDNF) and reduced alcohol consumption in male rats involving tropomyosin-related kinase B (TrkB), the mechanisms of BDNF-TrkB regulating alcohol behavior remain scarce. K+-Cl- cotransporter 2 (KCC2) plays a crucial role in synaptic function in GABAergic neurons by modulating intracellular chlorine homeostasis. Here, we found that 4-week intermittent alcohol exposure impaired the function of KCC2 in VTA, evidenced by a lower expression level of phosphorylated KCC2 and decreased ratio of phosphorylated KCC2 to total KCC2, especially 72 h after withdrawal from 4-week ethanol exposure in male rats. CLP290 (a KCC2 activator) reduced excessive alcohol consumption after alcohol withdrawal, whereas VU0240551 (a specific KCC2 inhibitor) further enhanced alcohol intake. Importantly, VU0240551 reversed the attenuating effects of BDNF and 7,8-dihydroxyflavone (7,8-DHF) on alcohol consumption after withdrawal. Moreover, intraperitoneal injection of 7,8-DHF upregulated KCC2 expression and phosphorylated KCC2 in VTA 72 h after withdrawal from ethanol exposure in male rats. Collectively, our data indicate that KCC2 may be critical in the regulating action of BDNF-TrkB on ethanol consumption in AUD.
Collapse
Affiliation(s)
- Hongyan Zhang
- Department of Physiology & Neurobiology, Mudanjiang Medical University, Mudanjiang, 157011, China
| | - Lulu Xu
- Department of Physiology & Neurobiology, Mudanjiang Medical University, Mudanjiang, 157011, China
| | - Junwei Xiong
- Department of Physiology & Neurobiology, Mudanjiang Medical University, Mudanjiang, 157011, China
| | - Xinxin Li
- Department of Physiology & Neurobiology, Mudanjiang Medical University, Mudanjiang, 157011, China
| | - Yindong Yang
- Department of Neurology, the Affiliated Hongqi Hospital of Mudanjiang Medical University, Mudanjiang, China
| | - Yong Liu
- Department of Physiology & Neurobiology, Mudanjiang Medical University, Mudanjiang, 157011, China
| | - Chunfeng Zhang
- Institute of Vocational and Technical Education, Heilongjiang Agricultural Economy Vocational College, Mudanjiang, 157011, China
| | - Qiyu Wang
- Department of Physiology & Neurobiology, Mudanjiang Medical University, Mudanjiang, 157011, China
| | - Jiajia Wang
- Department of Physiology & Neurobiology, Mudanjiang Medical University, Mudanjiang, 157011, China
| | - Pengyu Wang
- Department of Physiology & Neurobiology, Mudanjiang Medical University, Mudanjiang, 157011, China
| | - Xiaobin Wu
- Department of Physiology & Neurobiology, Mudanjiang Medical University, Mudanjiang, 157011, China
| | - Xue Wang
- Department of Physiology & Neurobiology, Mudanjiang Medical University, Mudanjiang, 157011, China
| | - Xiaofeng Zhu
- Department of Physiology & Neurobiology, Mudanjiang Medical University, Mudanjiang, 157011, China.
| | - Yanzhong Guan
- Department of Physiology & Neurobiology, Mudanjiang Medical University, Mudanjiang, 157011, China.
| |
Collapse
|
21
|
Talifu Z, Pan Y, Gong H, Xu X, Zhang C, Yang D, Gao F, Yu Y, Du L, Li J. The role of KCC2 and NKCC1 in spinal cord injury: From physiology to pathology. Front Physiol 2022; 13:1045520. [PMID: 36589461 PMCID: PMC9799334 DOI: 10.3389/fphys.2022.1045520] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
The balance of ion concentrations inside and outside the cell is an essential homeostatic mechanism in neurons and serves as the basis for a variety of physiological activities. In the central nervous system, NKCC1 and KCC2, members of the SLC12 cation-chloride co-transporter (CCC) family, participate in physiological and pathophysiological processes by regulating intracellular and extracellular chloride ion concentrations, which can further regulate the GABAergic system. Over recent years, studies have shown that NKCC1 and KCC2 are essential for the maintenance of Cl- homeostasis in neural cells. NKCC1 transports Cl- into cells while KCC2 transports Cl- out of cells, thereby regulating chloride balance and neuronal excitability. An imbalance of NKCC1 and KCC2 after spinal cord injury will disrupt CI- homeostasis, resulting in the transformation of GABA neurons from an inhibitory state into an excitatory state, which subsequently alters the spinal cord neural network and leads to conditions such as spasticity and neuropathic pain, among others. Meanwhile, studies have shown that KCC2 is also an essential target for motor function reconstruction after spinal cord injury. This review mainly introduces the physiological structure and function of NKCC1 and KCC2 and discusses their pathophysiological roles after spinal cord injury.
Collapse
Affiliation(s)
- Zuliyaer Talifu
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China,School of Rehabilitation Sciences and Engineering, University of Health and Rehabilitation Sciences, Qingdao, China
| | - Yunzhu Pan
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China,School of Rehabilitation Sciences and Engineering, University of Health and Rehabilitation Sciences, Qingdao, China
| | - Han Gong
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Xin Xu
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Chunjia Zhang
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Degang Yang
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Feng Gao
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Yan Yu
- School of Rehabilitation, Capital Medical University, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Liangjie Du
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China,*Correspondence: Liangjie Du, ; Jianjun Li,
| | - Jianjun Li
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China,School of Rehabilitation Sciences and Engineering, University of Health and Rehabilitation Sciences, Qingdao, China,*Correspondence: Liangjie Du, ; Jianjun Li,
| |
Collapse
|
22
|
Grau JW, Hudson KE, Tarbet MM, Strain MM. Behavioral studies of spinal conditioning: The spinal cord is smarter than you think it is. JOURNAL OF EXPERIMENTAL PSYCHOLOGY. ANIMAL LEARNING AND COGNITION 2022; 48:435-457. [PMID: 35901417 PMCID: PMC10391333 DOI: 10.1037/xan0000332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In 1988 Robert Rescorla published an article in the Annual Review of Neuroscience that addressed the circumstances under which learning occurs, some key methodological issues, and what constitutes an example of learning. The article has inspired a generation of neuroscientists, opening the door to a wider range of learning phenomena. After reviewing the historical context for his article, its key points are briefly reviewed. The perspective outlined enabled the study of learning in simpler preparations, such as the spinal cord. The period after 1988 revealed that pain (nociceptive) stimuli can induce a lasting sensitization of spinal cord circuits, laying down a kind of memory mediated by signal pathways analogous to those implicated in brain dependent learning and memory. Evidence suggests that the spinal cord is sensitive to instrumental response-outcome (R-O) relations, that learning can induce a peripheral modification (muscle memory) that helps maintain the learned response, and that learning can promote adaptive plasticity (a form of metaplasticity). Conversely, exposure to uncontrollable stimulation disables the capacity to learn. Spinal cord neurons can also abstract that stimuli occur in a regular (predictable) manner, a capacity that appears linked to a neural oscillator (central pattern generator). Disrupting communication with the brain has been shown to transform how GABA affects neuronal function (an example of ionic plasticity), releasing a brake that enables plasticity. We conclude by presenting a framework for understanding these findings and the implications for the broader study of learning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
Collapse
Affiliation(s)
- James W. Grau
- Cellular and Behavioral Neuroscience, Department of Psychology, Texas A&M University, College Station, TX, 77843 USA
| | - Kelsey E. Hudson
- Cellular and Behavioral Neuroscience, Department of Psychology, Texas A&M University, College Station, TX, 77843 USA
| | - Megan M. Tarbet
- McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX
| | - Misty M. Strain
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX 78229
| |
Collapse
|
23
|
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.
Collapse
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
| |
Collapse
|
24
|
Prael III FJ, Kim K, Du Y, Spitznagel BD, Sulikowski GA, Delpire E, Weaver CD. Discovery of Small Molecule KCC2 Potentiators Which Attenuate In Vitro Seizure-Like Activity in Cultured Neurons. Front Cell Dev Biol 2022; 10:912812. [PMID: 35813195 PMCID: PMC9263442 DOI: 10.3389/fcell.2022.912812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 06/02/2022] [Indexed: 01/14/2023] Open
Abstract
KCC2 is a K+-Cl- cotransporter that is expressed in neurons throughout the central nervous system. Deficits in KCC2 activity have been implicated in a variety of neurological disorders, including epilepsy, chronic pain, autism spectrum disorders, and Rett syndrome. Therefore, it has been hypothesized that pharmacological potentiation of KCC2 activity could provide a treatment for these disorders. To evaluate the therapeutic potential of pharmacological KCC2 potentiation, drug-like, selective KCC2 potentiators are required. Unfortunately, the lack of such tools has greatly hampered the investigation of the KCC2 potentiation hypothesis. Herein, we describe the discovery and characterization of a new class of small-molecule KCC2 potentiator. This newly discovered class exhibits KCC2-dependent activity and a unique mechanistic profile relative to previously reported small molecules. Furthermore, we demonstrate that KCC2 potentiation by this new class of KCC2 potentiator attenuates seizure-like activity in neuronal-glial co-cultures. Together, our results provide evidence that pharmacological KCC2 potentiation, by itself, is sufficient to attenuate neuronal excitability in an in vitro model that is sensitive to anti-epileptic drugs. Our findings and chemical tools are important for evaluating the promise of KCC2 as a therapeutic target and could lay a foundation for the development of KCC2-directed therapeutics for multiple neurological disorders.
Collapse
Affiliation(s)
- Francis J. Prael III
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States
| | - Kwangho Kim
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States,Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Yu Du
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
| | | | - Gary A. Sulikowski
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States,Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - C. David Weaver
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States,Department of Chemistry, Vanderbilt University, Nashville, TN, United States,*Correspondence: C. David Weaver,
| |
Collapse
|
25
|
Cao T, Chen H, Huang W, Xu S, Liu P, Zou W, Pang M, Xu Y, Bai X, Liu B, Rong L, Cui ZK, Li M. hUC-MSC-mediated recovery of subacute spinal cord injury through enhancing the pivotal subunits β3 and γ2 of the GABA A receptor. Theranostics 2022; 12:3057-3078. [PMID: 35547766 PMCID: PMC9065192 DOI: 10.7150/thno.72015] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 03/12/2022] [Indexed: 12/19/2022] Open
Abstract
Rationale: Spinal cord injury (SCI) remains an incurable neurological disorder leading to permanent and profound neurologic deficits and disabilities. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) are particularly appealing in SCI treatment to curtail damage, restore homeostasis and possible neural relay. However, the detailed mechanisms underlying hUC-MSC-mediated functional recovery of SCI have not been fully elucidated. The purpose of our current study is to identify novel therapeutic targets and depict the molecular mechanisms underlying the hUC-MSC-mediated recovery of subacute SCI. Methods: Adult female rats suffering from subacute incomplete thoracic SCI were treated with intrathecal transplantation of hUC-MSCs. The beneficial effects of hUC-MSCs on SCI repair were evaluated by a series of behavioral analyses, motor evoked potentials (MEPs) recording of hindlimb and immunohistochemistry. We carried out extensive transcriptome comparative analyses of spinal cord tissues at the lesion site from the subacute phase of SCI (sub-SCI) either treated without (+PBS) or with hUC-MSCs (+MSC) at 0 (sub-SCI), 1, 2, and 4 weeks post-transplantation (wpt), as well as normal spinal cord segments of intact/sham rats (Intact). Adeno-associated virus (AAV)-mediated neuron-specific expression system was employed to functionally screen specific γ-aminobutyric acid type A receptor (GABAAR) subunits promoting the functional recovery of SCI in vivo. The mature cortical axon scrape assay and transplantation of genetically modified MSCs with either overexpression or knockdown of brain-derived neurotrophic factor (BDNF) were employed to demonstrate that hUC-MSCs ameliorated the reduction of GABAAR subunits in the injured spinal cord via BDNF secretion in vitro and in vivo, respectively. Results: Comparative transcriptome analysis revealed the GABAergic synapse pathway is significantly enriched as a main target of hUC-MSC-activated genes in the injured spinal cord. Functional screening of the primary GABAAR subunits uncovered that Gabrb3 and Garbg2 harbored the motor and electrophysiological recovery-promoting competence. Moreover, targeting either of the two pivotal subunits β3 or γ2 in combination with/without the K+/Cl- cotransporter 2 (KCC2) reinforced the therapeutic effects. Mechanistically, BDNF secreted by hUC-MSCs contributed to the upregulation of GABAAR subunits (β3 & γ2) and KCC2 in the injured neurons. Conclusions: Our study identifies a novel mode for hUC-MSC-mediated locomotor recovery of SCI through synergistic upregulation of GABAAR β3 and γ2 along with KCC2 by BDNF secretion, indicating the significance of restoring the excitation/inhibition balance in the injured neurons for the reestablishment of neuronal circuits. This study also provides a potential combinatorial approach by targeting the pivotal subunit β3 or γ2 and KCC2, opening up possibilities for efficacious drug design.
Collapse
Affiliation(s)
- Tingting Cao
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Huan Chen
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Weiping Huang
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Sisi Xu
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Peilin Liu
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Weiwei Zou
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Mao Pang
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510515, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, 510630, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, 510630, China
| | - Ying Xu
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510515, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, 510630, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, 510630, China
| | - Xiaochun Bai
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Bin Liu
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510515, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, 510630, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, 510630, China
| | - Limin Rong
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510515, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, 510630, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, 510630, China
| | - Zhong-Kai Cui
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Mangmang Li
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| |
Collapse
|
26
|
Liedtke W. Long March Toward Safe and Effective Analgesia by Enhancing Gene Expression of Kcc2: First Steps Taken. Front Mol Neurosci 2022; 15:865600. [PMID: 35645734 PMCID: PMC9137411 DOI: 10.3389/fnmol.2022.865600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/08/2022] [Indexed: 11/15/2022] Open
Abstract
Low intraneuronal chloride in spinal cord dorsal horn pain relay neurons is critical for physiologic transmission of primary pain afferents because low intraneuronal chloride dictates whether GABA-ergic and glycin-ergic neurotransmission is inhibitory. If the neuronal chloride elevates to pathologic levels, then spinal cord primary pain relay becomes leaky and exhibits the behavioral hallmarks of pathologic pain, namely hypersensitivity and allodynia. Low chloride in spinal cord dorsal horn neurons is maintained by proper gene expression of Kcc2 and sustained physiologic function of the KCC2 chloride extruding electroneutral transporter. Peripheral nerve injury and other forms of neural injury evoke greatly diminished Kcc2 gene expression and subsequent corruption of inhibitory neurotransmission in the spinal cord dorsal horn, thus causing derailment of the gate function for pain. Here I review key discoveries that have helped us understand these fundamentals, and focus on recent insights relating to the discovery of Kcc2 gene expression enhancing compounds via compound screens in neurons. One such study characterized the kinase inhibitor, kenpaullone, more in-depth, revealing its function as a robust and long-lasting analgesic in preclinical models of nerve injury and cancer bone pain, also elucidating its mechanism of action via GSK3β inhibition, diminishing delta-catenin phosphorylation, and facilitating its nuclear transfer and subsequent enhancement of Kcc2 gene expression by de-repressing Kaiso epigenetic transcriptional regulator. Future directions re Kcc2 gene expression enhancement are discussed, namely combination with other analgesics and analgesic methods, such as spinal cord stimulation and electroacupuncture, gene therapy, and leveraging Kcc2 gene expression-enhancing nanomaterials.
Collapse
|
27
|
Bie B, Wu J, Lin F, Naguib M, Xu J. Suppression of hippocampal GABAergic transmission impairs memory in rodent models of Alzheimer's disease. Eur J Pharmacol 2022; 917:174771. [PMID: 35041847 DOI: 10.1016/j.ejphar.2022.174771] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 11/27/2022]
Abstract
Emerging evidence demonstrates the potential involvement of hippocampal GABAergic transmission in the process of memory acquisition and consolidation, while no consistent report is available to address the adaptation of hippocampal GABAergic transmission and its contribution to memory deficiency in the setting of Alzheimer's disease (AD). Brain-derived neurotrophic factor (BDNF) is a key molecule that regulates GABAergic transmission. In the brain, mature BDNF is generated from the proteolytic cleavage of proBDNF, while BDNF and proBDNF have differential effects on central GABAergic transmission. First, the present study reports a remarkable increase of proBDNF/BNDF ratio in the hippocampal CA1 area in rodent models of AD, indicating a potential impaired process of BDNF maturation from proBDNF cleavage. We report a suppressed hippocampal GABAergic strength, potentially resulting from the reduced expression of anion chloride co-transporter KCC2 and subsequent positive shift of GABAergic Cl-equilibrium potential (ECl-), which is attenuated by microinjection of BDNF with proBDNF inhibitor TAT-Pep5. We also show that normalization of proBDNF/BDNF signaling or GABAergic ECl-by intracerebroventricular (i.c.v.) administration of bumetanide remarkably improves the cognitive performance in Morris water maze test and fear conditioning test in rodent models of AD. These results demonstrate a critical role of hippocampal proBDNF/BDNF in regulating GABAergic transmission and contributing to memory dysfunction in rodent models of AD.
Collapse
Affiliation(s)
- Bihua Bie
- Department of Pain Management, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Jiang Wu
- Department of Pain Management, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Feng Lin
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Mohamed Naguib
- Department of General Anesthesiology, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Jijun Xu
- Department of Pain Management, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, 44195, USA; Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA.
| |
Collapse
|
28
|
Lodovichi C, Ratto GM, Trevelyan AJ, Arosio D. Genetically encoded sensors for Chloride concentration. J Neurosci Methods 2022; 368:109455. [PMID: 34952088 DOI: 10.1016/j.jneumeth.2021.109455] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 12/11/2021] [Accepted: 12/18/2021] [Indexed: 12/12/2022]
Abstract
Insights into chloride regulation in neurons have come slowly, but they are likely to be critical for our understanding of how the brain works. The reason is that the intracellular Cl- level ([Cl-]i) is the key determinant of synaptic inhibitory function, and this in turn dictates all manner of neuronal network function. The true impact on the network will only be apparent, however, if Cl- is measured at many locations at once (multiple neurons, and also across the subcellular compartments of single neurons), which realistically, can only be achieved using imaging. The development of genetically-encoded anion biosensors (GABs) brings the additional benefit that Cl- imaging may be done in identified cell-classes and hopefully in subcellular compartments. Here, we describe the historical background and motivation behind the development of these sensors and how they have been used so far. There are, however, still major limitations for their use, the most important being the fact that all GABs are sensitive to both pH and Cl-. Disambiguating the two signals has proved a major challenge, but there are potential solutions; notable among these is ClopHensor, which has now been developed for in vivo measurements of both ion species. We also speculate on how these biosensors may yet be improved, and how this could advance our understanding of Cl- regulation and its impact on brain function.
Collapse
Affiliation(s)
- Claudia Lodovichi
- Neuroscience Institute-CNR, Depart. Biomedical Sciences, Unipd, Padova, Veneto Institute of Molecular Medicine, Padova Neuroscience Center, Padova, Italy.
| | - Gian Michele Ratto
- National Enterprise for nanoScience and nanoTechnology (NEST), Istituto Nanoscienze, Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore Pisa, 56127 Pisa, Italy
| | - Andrew J Trevelyan
- Newcastle University Biosciences Institute, Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Daniele Arosio
- Consiglio Nazionale delle Ricerche (CNR), Istituto di Biofisica, 38123 Trento, Italy.
| |
Collapse
|
29
|
Fauss GNK, Hudson KE, Grau JW. Role of Descending Serotonergic Fibers in the Development of Pathophysiology after Spinal Cord Injury (SCI): Contribution to Chronic Pain, Spasticity, and Autonomic Dysreflexia. BIOLOGY 2022; 11:234. [PMID: 35205100 PMCID: PMC8869318 DOI: 10.3390/biology11020234] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/27/2022] [Accepted: 01/29/2022] [Indexed: 12/12/2022]
Abstract
As the nervous system develops, nerve fibers from the brain form descending tracts that regulate the execution of motor behavior within the spinal cord, incoming sensory signals, and capacity to change (plasticity). How these fibers affect function depends upon the transmitter released, the receptor system engaged, and the pattern of neural innervation. The current review focuses upon the neurotransmitter serotonin (5-HT) and its capacity to dampen (inhibit) neural excitation. A brief review of key anatomical details, receptor types, and pharmacology is provided. The paper then considers how damage to descending serotonergic fibers contributes to pathophysiology after spinal cord injury (SCI). The loss of serotonergic fibers removes an inhibitory brake that enables plasticity and neural excitation. In this state, noxious stimulation can induce a form of over-excitation that sensitizes pain (nociceptive) circuits, a modification that can contribute to the development of chronic pain. Over time, the loss of serotonergic fibers allows prolonged motor drive (spasticity) to develop and removes a regulatory brake on autonomic function, which enables bouts of unregulated sympathetic activity (autonomic dysreflexia). Recent research has shown that the loss of descending serotonergic activity is accompanied by a shift in how the neurotransmitter GABA affects neural activity, reducing its inhibitory effect. Treatments that target the loss of inhibition could have therapeutic benefit.
Collapse
Affiliation(s)
| | | | - James W. Grau
- Department of Psychological and Brain Sciences, Texas A&M University, College Station, TX 77843, USA; (G.N.K.F.); (K.E.H.)
| |
Collapse
|
30
|
Cao TT, Chen H, Pang M, Xu SS, Wen HQ, Liu B, Rong LM, Li MM. Dose optimization of intrathecal administration of human umbilical cord mesenchymal stem cells for the treatment of subacute incomplete spinal cord injury. Neural Regen Res 2022; 17:1785-1794. [PMID: 35017439 PMCID: PMC8820722 DOI: 10.4103/1673-5374.332151] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Human umbilical cord mesenchymal stem cells (hUC-MSCs) are a promising candidate for spinal cord injury (SCI) repair owing to their advantages of low immunogenicity and easy accessibility over other MSC sources. However, modest clinical efficacy hampered the progression of these cells to clinical translation. This discrepancy may be due to many variables, such as cell source, timing of implantation, route of administration, and relevant efficacious cell dose, which are critical factors that affect the efficacy of treatment of patients with SCI. Previously, we have evaluated the safety and efficacy of 4 × 106 hUC-MSCs/kg in the treatment of subacute SCI by intrathecal implantation in rat models. To search for a more accurate dose range for clinical translation, we compared the effects of three different doses of hUC-MSCs – low (0.25 × 106 cells/kg), medium (1 × 106 cells/kg) and high (4 × 106 cells/kg) – on subacute SCI repair through an elaborate combination of behavioral analyses, anatomical analyses, magnetic resonance imaging-diffusion tensor imaging (MRI-DTI), biotinylated dextran amine (BDA) tracing, electrophysiology, and quantification of mRNA levels of ion channels and neurotransmitter receptors. Our study demonstrated that the medium dose, but not the low dose, is as efficient as the high dose in producing the desired therapeutic outcomes. Furthermore, partial restoration of the γ-aminobutyric acid type A (GABAA) receptor expression by the effective doses indicates that GABAA receptors are possible candidates for therapeutic targeting of dormant relay pathways in injured spinal cord. Overall, this study revealed that intrathecal implantation of 1 × 106 hUC-MSCs/kg is an alternative approach for treating subacute SCI.
Collapse
Affiliation(s)
- Ting-Ting Cao
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Huan Chen
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Mao Pang
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat-sen University; Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery; Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, Guangzhou, Guangdong Province, China
| | - Si-Si Xu
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Hui-Quan Wen
- Department of Radiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Bin Liu
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat-sen University; Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery; Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, Guangzhou, Guangdong Province, China
| | - Li-Min Rong
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat-sen University; Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery; Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, Guangzhou, Guangdong Province, China
| | - Mang-Mang Li
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| |
Collapse
|
31
|
Al Awabdh S, Donneger F, Goutierre M, Séveno M, Vigy O, Weinzettl P, Russeau M, Moutkine I, Lévi S, Marin P, Poncer JC. Gephyrin Interacts with the K-Cl Cotransporter KCC2 to Regulate Its Surface Expression and Function in Cortical Neurons. J Neurosci 2022; 42:166-182. [PMID: 34810232 PMCID: PMC8802937 DOI: 10.1523/jneurosci.2926-20.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 08/31/2021] [Accepted: 10/17/2021] [Indexed: 11/21/2022] Open
Abstract
The K+-Cl- cotransporter KCC2, encoded by the Slc12a5 gene, is a neuron-specific chloride extruder that tunes the strength and polarity of GABAA receptor-mediated transmission. In addition to its canonical ion transport function, KCC2 also regulates spinogenesis and excitatory synaptic function through interaction with a variety of molecular partners. KCC2 is enriched in the vicinity of both glutamatergic and GABAergic synapses, the activity of which in turn regulates its membrane stability and function. KCC2 interaction with the submembrane actin cytoskeleton via 4.1N is known to control its anchoring near glutamatergic synapses on dendritic spines. However, the molecular determinants of KCC2 clustering near GABAergic synapses remain unknown. Here, we used proteomics to identify novel KCC2 interacting proteins in the adult rat neocortex. We identified both known and novel candidate KCC2 partners, including some involved in neuronal development and synaptic transmission. These include gephyrin, the main scaffolding molecule at GABAergic synapses. Gephyrin interaction with endogenous KCC2 was confirmed by immunoprecipitation from rat neocortical extracts. We showed that gephyrin stabilizes plasmalemmal KCC2 and promotes its clustering in hippocampal neurons, mostly but not exclusively near GABAergic synapses, thereby controlling KCC2-mediated chloride extrusion. This study identifies gephyrin as a novel KCC2 anchoring molecule that regulates its membrane expression and function in cortical neurons.SIGNIFICANCE STATEMENT Fast synaptic inhibition in the brain is mediated by chloride-permeable GABAA receptors (GABAARs) and therefore relies on transmembrane chloride gradients. In neurons, these gradients are primarily maintained by the K/Cl cotransporter KCC2. Therefore, understanding the mechanisms controlling KCC2 expression and function is crucial to understand its physiological regulation and rescue its function in the pathology. KCC2 function depends on its membrane expression and clustering, but the underlying mechanisms remain unknown. We describe the interaction between KCC2 and gephyrin, the main scaffolding protein at inhibitory synapses. We show that gephyrin controls plasmalemmal KCC2 clustering and that loss of gephyrin compromises KCC2 function. Our data suggest functional units comprising GABAARs, gephyrin, and KCC2 act to regulate synaptic GABA signaling.
Collapse
Affiliation(s)
- Sana Al Awabdh
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Florian Donneger
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Marie Goutierre
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Martial Séveno
- BCM, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Oana Vigy
- IGF, Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France
| | - Pauline Weinzettl
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
- Institute of Biotechnology, University of Applied Sciences, Krems, Austria
| | - Marion Russeau
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Imane Moutkine
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Sabine Lévi
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Philippe Marin
- IGF, Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France
| | - Jean Christophe Poncer
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| |
Collapse
|
32
|
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.
Collapse
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
| |
Collapse
|
33
|
Asraf H, Bogdanovic M, Gottesman N, Sekler I, Aizenman E, Hershfinkel M. SNAP23 regulates KCC2 membrane insertion and activity following mZnR/GPR39 activation in hippocampal neurons. iScience 2022; 25:103751. [PMID: 35118363 PMCID: PMC8800107 DOI: 10.1016/j.isci.2022.103751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/25/2021] [Accepted: 01/06/2022] [Indexed: 11/23/2022] Open
Abstract
Modulation of the neuronal K+/Cl− cotransporter 2 (KCC2) activity, which mediates Cl− export, is critical to neuronal function. Here, we demonstrate that KCC2 interacts with the SNARE protein synaptosome-associated protein 23, SNAP23, an essential component of membrane insertion machinery. Using KCC2 truncated mutants, we show that KCC2 C-terminal domain is essential for membrane targeting and SNAP23-dependent upregulation of KCC2 activity triggered by activation of the Zn2+-sensitive receptor mZnR/GPR39 in HEK293 cells. Expression of SNAP23 phosphorylation-insensitive mutants or inhibition of its upstream activator IκB kinase (IKK) prevents mZnR/GPR39 upregulation of KCC2 activity in mouse hippocampal neurons. We further find that SNAP23 interacts with Syntaxin 1A and KCC2, and that all three proteins exhibit increased membrane insertion following mZnR/GPR39 activation in neurons. Our results elucidate a G-protein-coupled receptor-dependent pathway for regulation of KCC activity, mediated via interaction with SNARE proteins. Neuronal K+/Cl− cotransporter 2 (KCC2) is regulated via interaction with SNAP23 Zn2+ enhances interaction and membrane insertion of SNAP23, Syntaxin 1A, and KCC2 Zn2+-dependent mZnR/GPR39 regulation of KCC2 requires SNAP23 phosphorylation Epithelial KCC3 regulation by ZnR/GPR39 also requires SNAP23
Collapse
|
34
|
Hamze M, Medina I, Delmotte Q, Porcher C. Contribution of Smoothened Receptor Signaling in GABAergic Neurotransmission and Chloride Homeostasis in the Developing Rodent Brain. Front Physiol 2021; 12:798066. [PMID: 34955901 PMCID: PMC8703190 DOI: 10.3389/fphys.2021.798066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/17/2021] [Indexed: 11/13/2022] Open
Abstract
In the early stages of the central nervous system growth and development, γ-aminobutyric acid (GABA) plays an instructive trophic role for key events including neurogenesis, migration, synaptogenesis, and network formation. These actions are associated with increased concentration of chloride ions in immature neurons [(Cl−)i] that determines the depolarizing strength of ion currents mediated by GABAA receptors, a ligand-gated Cl− permeable ion channel. During neuron maturation the (Cl−)i progressively decreases leading to weakening of GABA induced depolarization and enforcing GABA function as principal inhibitory neurotransmitter. A neuron restricted potassium-chloride co-transporter KCC2 is a key molecule governing Cl− extrusion and determining the resting level of (Cl−)i in developing and mature mammalian neurons. Among factors controlling the functioning of KCC2 and the maturation of inhibitory circuits, is Smoothened (Smo), the transducer in the receptor complex of the developmental protein Sonic Hedgehog (Shh). Too much or too little Shh-Smo action will have mirror effects on KCC2 stability at the neuron membrane, the GABA inhibitory strength, and ultimately on the newborn susceptibility to neurodevelopmental disorders. Both canonical and non-canonical Shh-Smo signal transduction pathways contribute to the regulation of KCC2 and GABAergic synaptic activity. In this review, we discuss the recent findings of the action of Shh-Smo signaling pathways on chloride ions homeostasis through the control of KCC2 membrane trafficking, and consequently on inhibitory neurotransmission and network activity during postnatal development.
Collapse
Affiliation(s)
- Mira Hamze
- Aix-Marseille University, INSERM, INMED, Parc Scientifique de Luminy, Marseille, France.,INSERM (Institut National de la Santé et de la Recherche Médicale) Unité, Parc Scientifique de Luminy, Marseille, France.,INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Igor Medina
- Aix-Marseille University, INSERM, INMED, Parc Scientifique de Luminy, Marseille, France.,INSERM (Institut National de la Santé et de la Recherche Médicale) Unité, Parc Scientifique de Luminy, Marseille, France.,INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Quentin Delmotte
- Aix-Marseille University, INSERM, INMED, Parc Scientifique de Luminy, Marseille, France.,INSERM (Institut National de la Santé et de la Recherche Médicale) Unité, Parc Scientifique de Luminy, Marseille, France.,INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Christophe Porcher
- Aix-Marseille University, INSERM, INMED, Parc Scientifique de Luminy, Marseille, France.,INSERM (Institut National de la Santé et de la Recherche Médicale) Unité, Parc Scientifique de Luminy, Marseille, France.,INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, Marseille, France
| |
Collapse
|
35
|
Ponomareva D, Petukhova E, Bregestovski P. Simultaneous Monitoring of pH and Chloride (Cl -) in Brain Slices of Transgenic Mice. Int J Mol Sci 2021; 22:13601. [PMID: 34948398 PMCID: PMC8708776 DOI: 10.3390/ijms222413601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 11/16/2022] Open
Abstract
Optosensorics is the direction of research possessing the possibility of non-invasive monitoring of the concentration of intracellular ions or activity of intracellular components using specific biosensors. In recent years, genetically encoded proteins have been used as effective optosensory means. These probes possess fluorophore groups capable of changing fluorescence when interacting with certain ions or molecules. For monitoring of intracellular concentrations of chloride ([Cl-]i) and hydrogen ([H+] i) the construct, called ClopHensor, which consists of a H+- and Cl--sensitive variant of the enhanced green fluorescent protein (E2GFP) fused with a monomeric red fluorescent protein (mDsRed) has been proposed. We recently developed a line of transgenic mice expressing ClopHensor in neurons and obtained the map of its expression in different areas of the brain. The purpose of this study was to examine the effectiveness of transgenic mice expressing ClopHensor for estimation of [H+]i and [Cl-]i concentrations in neurons of brain slices. We performed simultaneous monitoring of [H+]i and [Cl-]i under different experimental conditions including changing of external concentrations of ions (Ca2+, Cl-, K+, Na+) and synaptic stimulation of Shaffer's collaterals of hippocampal slices. The results obtained illuminate different pathways of regulation of Cl- and pH equilibrium in neurons and demonstrate that transgenic mice expressing ClopHensor represent a reliable tool for non-invasive simultaneous monitoring of intracellular Cl- and pH.
Collapse
Affiliation(s)
- Daria Ponomareva
- Institut de Neurosciences des Systèmes, Aix-Marseille University, INSERM, INS, 13005 Marseille, France;
- Institute of Neurosciences, Kazan State Medical University, 420111 Kazan, Russia;
- Department of Normal Physiology, Kazan State Medical University, 420111 Kazan, Russia
| | - Elena Petukhova
- Institute of Neurosciences, Kazan State Medical University, 420111 Kazan, Russia;
- Department of Normal Physiology, Kazan State Medical University, 420111 Kazan, Russia
| | - Piotr Bregestovski
- Institut de Neurosciences des Systèmes, Aix-Marseille University, INSERM, INS, 13005 Marseille, France;
- Institute of Neurosciences, Kazan State Medical University, 420111 Kazan, Russia;
- Department of Normal Physiology, Kazan State Medical University, 420111 Kazan, Russia
| |
Collapse
|
36
|
Orihuel J, Capellán R, Roura-Martínez D, Ucha M, Ambrosio E, Higuera-Matas A. Δ 9-Tetrahydrocannabinol During Adolescence Reprograms the Nucleus Accumbens Transcriptome, Affecting Reward Processing, Impulsivity, and Specific Aspects of Cocaine Addiction-Like Behavior in a Sex-Dependent Manner. Int J Neuropsychopharmacol 2021; 24:920-933. [PMID: 34436576 PMCID: PMC8598305 DOI: 10.1093/ijnp/pyab058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 08/13/2021] [Accepted: 08/24/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Cannabis exposure during adolescence is associated with emotional and motivational alterations that may entail an enhanced risk of developing psychiatric disorders. In rodent models, exposure to cannabinoids during adolescence leads to increased self-administration of opiates and cocaine, however, the psychological and neural mechanisms and the sex-specificity of this phenomenon are largely unknown. METHODS We exposed male and female adolescent rats to Δ9-tetrahydrocannabinol (THC) and studied at adulthood the effects of such treatment on psychological processes related to reward, such as Pavlovian conditioned approach, Pavlovian to instrumental transfer, habit formation and waiting impulsivity. In the light of these data and given the involvement of the nucleus accumbens in the processes examined, we performed an RNASeq transcriptomic study and assessed cocaine addiction-like behavior. RESULTS THC exposure increased goal-tracking (in males and females) and enhanced Pavlovian to instrumental transfer (especially in males) but did not affect habit formation. THC-exposed rats exhibited subtle, state-dependent changes in premature responding in the 2-CSRTT task. RNASeq data showed gene expression alterations in a marked sex-specific manner. While no effects were found on the acquisition of cocaine self-administration or punished drug-seeking, rats exposed to THC self-administered more cocaine under a progressive ratio schedule (males), had a higher rebound upon returning to continuous access to the drug (females) and showed reduced drug-seeking after 30 days of withdrawal (females). CONCLUSIONS Adolescent THC affects specific aspects of reward- (and cocaine-) guided behavior and the function of a key brain region mediating these effects, in a remarkable sex-specific manner.
Collapse
Affiliation(s)
- Javier Orihuel
- Department of Psychobiology, School of Psychology, National University for Distance Learning (UNED), Madrid, Spain
| | - Roberto Capellán
- Department of Psychobiology, School of Psychology, National University for Distance Learning (UNED), Madrid, Spain
| | - David Roura-Martínez
- Department of Psychobiology, School of Psychology, National University for Distance Learning (UNED), Madrid, Spain
- Institut de Neurosciences de la Timone, Marseille, France
| | - Marcos Ucha
- Department of Psychobiology, School of Psychology, National University for Distance Learning (UNED), Madrid, Spain
| | - Emilio Ambrosio
- Department of Psychobiology, School of Psychology, National University for Distance Learning (UNED), Madrid, Spain
| | - Alejandro Higuera-Matas
- Department of Psychobiology, School of Psychology, National University for Distance Learning (UNED), Madrid, Spain
| |
Collapse
|
37
|
Biney RP, Djankpa FT, Osei SA, Egbenya DL, Aboagye B, Karikari AA, Ussif A, Wiafe GA, Nuertey D. Effects of in utero exposure to monosodium glutamate on locomotion, anxiety, depression, memory and KCC2 expression in offspring. Int J Dev Neurosci 2021; 82:50-62. [PMID: 34755371 DOI: 10.1002/jdn.10158] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 09/16/2021] [Accepted: 11/02/2021] [Indexed: 11/11/2022] Open
Abstract
In pregnancy, there is a significant risk for developing embryos to be adversely affected by everyday chemicals such as food additives and environmental toxins. In recent times, several studies have documented the detrimental effect of exposure to such chemicals on the behaviour and neurodevelopment of the offspring. This study evaluated the influence of the food additive, monosodium glutamate (MSG), on behaviour and development in mice. Pregnant dams were exposed to MSG 2 or 4 g/kg or distilled water from gestation day 10-20. On delivery, postnatal day 1 (PN 1), 3 pups were sacrificed and whole brain samples assayed for KCC2 expression by western blot. The remaining pups were housed until PN 43 before commencing behavioural assessment. Their weights were measured at birth and at 3 days intervals until PN 42. The impact of prenatal exposure to MSG on baseline exploratory, anxiety and depression behaviours as well as spatial and working memory was assessed. In utero exposure to 4 g/kg MSG significantly reduced exploratory drive and increased depression-like behaviours but did not exert any significant impact on anxiety-like behaviours (p < 0.01). Additionally, there was a two-fold increase in KCC2 expression in both 2 and 4 g/kg MSG-exposed offspring. CONCLUSION: This study indicates that, in utero exposure to MSG increases the expression of KCC2 and causes significant effect on locomotion and depression-like behaviours but only marginally affects memory function.
Collapse
Affiliation(s)
| | - Francis Tanam Djankpa
- Department of Physiology, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Silas Acheampong Osei
- School of Pharmacy and Pharmaceutical Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Daniel Lawer Egbenya
- Department of Anatomy and Cell Biology, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Benjamin Aboagye
- Department of Forensic Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Akua Afriyie Karikari
- School of Pharmacy and Pharmaceutical Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Abdala Ussif
- Department of Forensic Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Gideon Akuamoah Wiafe
- Department of Physiology, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana
| | - David Nuertey
- Department of Physiology, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana
| |
Collapse
|
38
|
Toritsuka M, Yoshino H, Makinodan M, Ikawa D, Kimoto S, Yamamuro K, Okamura K, Akamatsu W, Okada Y, Matsumoto T, Hashimoto K, Ogawa Y, Saito Y, Watanabe K, Aoki C, Takada R, Fukami SI, Hamano-Iwasa K, Okano H, Kishimoto T. Developmental dysregulation of excitatory-to-inhibitory GABA-polarity switch may underlie schizophrenia pathology: A monozygotic-twin discordant case analysis in human iPS cell-derived neurons. Neurochem Int 2021; 150:105179. [PMID: 34500023 DOI: 10.1016/j.neuint.2021.105179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 08/26/2021] [Accepted: 09/05/2021] [Indexed: 01/04/2023]
Abstract
Schizophrenia is a major psychiatric disorder, but the molecular mechanisms leading to its initiation or progression remain unclear. To elucidate the pathophysiology of schizophrenia, we used an in vitro neuronal cell culture model involving human induced pluripotent stem cells (hiPSCs) derived from a monozygotic-twin discordant schizophrenia pair. The cultured neurons differentiated from hiPSCs were composed of a mixture of glutamatergic excitatory neurons and gamma aminobutyric acid (GABA)ergic inhibitory neurons. In the electrophysiological analysis, a different pattern of spontaneous neuronal activity was observed under the condition without any stimulants. The frequency of spontaneous excitatory post-synaptic currents (sEPSCs) was significantly higher in the hiPSC-derived neurons of the patient with schizophrenia than in the control sibling at day-in-vitro 30. However, the synaptic formation was not different between the patient with schizophrenia and the control sibling during the same culture period. To explain underlying mechanisms of higher excitability of presynaptic cells, we focused on the potassium-chloride co-transporter KCC2, which contributes to excitatory-to-inhibitory GABA polarity switch in developing neurons. We also revealed the altered expression pattern of KCC2 in hiPSC-derived neurons from the patient with schizophrenia, which could contribute to understanding the pathology of schizophrenia in the developing nervous system.
Collapse
Affiliation(s)
- Michihiro Toritsuka
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan.
| | - Hiroki Yoshino
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan
| | - Manabu Makinodan
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan
| | - Daisuke Ikawa
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan; Sakai Municipal Mental Health Center, 4-3-1 Asahigaoka-naka-machi, Sakai-ku, Sakai-shi, Osaka, 590-0808, Japan
| | - Sohei Kimoto
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan
| | - Kazuhiko Yamamuro
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan
| | - Kazuya Okamura
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan
| | - Wado Akamatsu
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan; Center for Genomic and Regenerative Medicine, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8431, Japan
| | - Yohei Okada
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan; Department of Neurology, Aichi Medical University School of Medicine, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan
| | - Takuya Matsumoto
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Kazumichi Hashimoto
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan; Department of Psychiatry, Tenri Hospital Shirakawa Branch, 604 Iwaya-cho, Tenri, Nara, 632-0003, Japan
| | - Yoichi Ogawa
- Department of Neurophysiology, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan
| | - Yasuhiko Saito
- Department of Neurophysiology, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan
| | - Kyosuke Watanabe
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan
| | - Chieko Aoki
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan
| | - Ryohei Takada
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan
| | - Shin-Ichi Fukami
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan
| | - Kaori Hamano-Iwasa
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Toshifumi Kishimoto
- Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan
| |
Collapse
|
39
|
Kipnis PA, Kadam SD. Novel Concepts for the Role of Chloride Cotransporters in Refractory Seizures. Aging Dis 2021; 12:1056-1069. [PMID: 34221549 PMCID: PMC8219493 DOI: 10.14336/ad.2021.0129] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 01/29/2021] [Indexed: 12/12/2022] Open
Abstract
Epilepsy is associated with a multitude of acquired or genetic neurological disorders characterized by a predisposition to spontaneous recurrent seizures. An estimated 15 million patients worldwide have ongoing seizures despite optimal management and are classified as having refractory epilepsy. Early-life seizures like those caused by perinatal hypoxic ischemic encephalopathy (HIE) remain a clinical challenge because although transient, they are difficult to treat and associated with poor neurological outcomes. Pediatric epilepsy syndromes are consistently associated with intellectual disability and neurocognitive comorbidities. HIE and arterial ischemic stroke are the most common causes of seizures in term neonates and account for 7.5-20% of neonatal seizures. Standard first-line treatments such as phenobarbital (PB) and phenytoin fail to curb seizures in ~50% of neonates. In the long-term, HIE can result in hippocampal sclerosis and temporal lobe epilepsy (TLE), which is the most common adult epilepsy, ~30% of which is associated with refractory seizures. For patients with refractory TLE seizures, a viable option is the surgical resection of the epileptic foci. Novel insights gained from investigating the developmental role of Cl- cotransporter function have helped to elucidate some of the mechanisms underlying the emergence of refractory seizures in both HIE and TLE. KCC2 as the chief Cl- extruder in neurons is critical for enabling strong hyperpolarizing synaptic inhibition in the brain and has been implicated in the pathophysiology underlying both conditions. More recently, KCC2 function has become a novel therapeutic target to combat refractory seizures.
Collapse
Affiliation(s)
- Pavel A Kipnis
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
| | - Shilpa D Kadam
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
40
|
Ahnaou A, Drinkenburg WHIM. Sleep, neuronal hyperexcitability, inflammation and neurodegeneration: Does early chronic short sleep trigger and is it the key to overcoming Alzheimer's disease? Neurosci Biobehav Rev 2021; 129:157-179. [PMID: 34214513 DOI: 10.1016/j.neubiorev.2021.06.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 05/13/2021] [Accepted: 06/25/2021] [Indexed: 01/13/2023]
Abstract
Evidence links neuroinflammation to Alzheimer's disease (AD); however, its exact contribution to the onset and progression of the disease is poorly understood. Symptoms of AD can be seen as the tip of an iceberg, consisting of a neuropathological build-up in the brain of extracellular amyloid-β (Aβ) plaques and intraneuronal hyperphosphorylated aggregates of Tau (pTau), which are thought to stem from an imbalance between its production and clearance resulting in loss of synaptic health and dysfunctional cortical connectivity. The glymphatic drainage system, which is particularly active during sleep, plays a key role in the clearance of proteinopathies. Poor sleep can cause hyperexcitability and promote Aβ and tau pathology leading to systemic inflammation. The early neuronal hyperexcitability of γ-aminobutyric acid (GABA)-ergic inhibitory interneurons and impaired inhibitory control of cortical pyramidal neurons lie at the crossroads of excitatory/inhibitory imbalance and inflammation. We outline, with a prospective framework, a possible vicious spiral linking early chronic short sleep, neuronal hyperexcitability, inflammation and neurodegeneration. Understanding the early predictors of AD, through an integrative approach, may hold promise for reducing attrition in the late stages of neuroprotective drug development.
Collapse
Affiliation(s)
- A Ahnaou
- Dept. of Neuroscience Discovery, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, Beerse, B-2340, Belgium.
| | - W H I M Drinkenburg
- Dept. of Neuroscience Discovery, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, Beerse, B-2340, Belgium
| |
Collapse
|
41
|
Schieweck R, Riedemann T, Forné I, Harner M, Bauer KE, Rieger D, Ang FY, Hutten S, Demleitner AF, Popper B, Derdak S, Sutor B, Bilban M, Imhof A, Kiebler MA. Pumilio2 and Staufen2 selectively balance the synaptic proteome. Cell Rep 2021; 35:109279. [PMID: 34161769 DOI: 10.1016/j.celrep.2021.109279] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/05/2021] [Accepted: 05/28/2021] [Indexed: 12/11/2022] Open
Abstract
Neurons have the capacity to adapt to environmental stimuli, a phenomenon termed cellular plasticity. The underlying processes are controlled by a network of RNA-binding proteins (RBPs). Their precise impact, however, is largely unknown. To address this important question, we chose Pumilio2 (Pum2) and Staufen2 (Stau2), which both regulate synaptic transmission. Surprisingly, even though both RBPs dynamically interact with each other in neurons, their respective impact on the transcriptome and proteome is highly selective. Although Pum2 deficiency leads to reduced translation and protein expression, Stau2 depletion preferentially impacts RNA levels and increases protein abundance. Furthermore, we show that Pum2 activates expression of key GABAergic synaptic components, e.g., the GABAA receptor scaffold protein Gephyrin. Consequently, Pum2 depletion selectively reduced the amplitude of miniature inhibitory postsynaptic currents. Together, our data argue for an important role of RBPs to maintain proteostasis in order to control distinct aspects of synaptic transmission.
Collapse
Affiliation(s)
- Rico Schieweck
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Therese Riedemann
- Biomedical Center (BMC), Department of Physiological Genomics, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Ignasi Forné
- Biomedical Center (BMC), Department for Molecular Biology (Protein Analysis Unit), Medical Faculty, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Max Harner
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Karl E Bauer
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Daniela Rieger
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Foong Yee Ang
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Saskia Hutten
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Antonia F Demleitner
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Bastian Popper
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany; Biomedical Center (BMC), Core Facility Animal Models, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Sophia Derdak
- Medical University of Vienna, Core Facilities, Lazarettgasse 14, 1090 Vienna, Austria
| | - Bernd Sutor
- Biomedical Center (BMC), Department of Physiological Genomics, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Martin Bilban
- Department of Laboratory Medicine and Core Facility Genomics, Medical University of Vienna, 1090 Vienna, Austria
| | - Axel Imhof
- Biomedical Center (BMC), Department for Molecular Biology (Protein Analysis Unit), Medical Faculty, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Michael A Kiebler
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany.
| |
Collapse
|
42
|
Bilchak JN, Yeakle K, Caron G, Malloy D, Côté MP. Enhancing KCC2 activity decreases hyperreflexia and spasticity after chronic spinal cord injury. Exp Neurol 2021; 338:113605. [PMID: 33453210 PMCID: PMC7904648 DOI: 10.1016/j.expneurol.2021.113605] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/21/2020] [Accepted: 01/09/2021] [Indexed: 02/03/2023]
Abstract
After spinal cord injury (SCI), the majority of individuals develop spasticity, a debilitating condition involving involuntary movements, co-contraction of antagonistic muscles, and hyperreflexia. By acting on GABAergic and Ca2+-dependent signaling, current anti-spastic medications lead to serious side effects, including a drastic decrease in motoneuronal excitability which impairs motor function and rehabilitation efforts. Exercise, in contrast, decreases spastic symptoms without decreasing motoneuron excitability. These functional improvements coincide with an increase in expression of the chloride co-transporter KCC2 in lumbar motoneurons. Thus, we hypothesized that spastic symptoms can be alleviated directly through restoration of chloride homeostasis and endogenous inhibition by increasing KCC2 activity. Here, we used the recently developed KCC2 enhancer, CLP257, to evaluate the effects of acutely increasing KCC2 extrusion capability on spastic symptoms after chronic SCI. Sprague Dawley rats received a spinal cord transection at T12 and were either bike-trained or remained sedentary for 5 weeks. Increasing KCC2 activity in the lumbar enlargement improved the rate-dependent depression of the H-reflex and reduced both phasic and tonic EMG responses to muscle stretch in sedentary animals after chronic SCI. Furthermore, the improvements due to this pharmacological treatment mirror those of exercise. Together, our results suggest that pharmacologically increasing KCC2 activity is a promising approach to decrease spastic symptoms in individuals with SCI. By acting to directly restore endogenous inhibition, this strategy has potential to avoid severe side effects and improve the quality of life of affected individuals.
Collapse
Affiliation(s)
- Jadwiga N Bilchak
- Marion Murray Spinal Cord Injury Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States of America
| | - Kyle Yeakle
- Marion Murray Spinal Cord Injury Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States of America
| | - Guillaume Caron
- Marion Murray Spinal Cord Injury Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States of America
| | - Dillon Malloy
- Marion Murray Spinal Cord Injury Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States of America
| | - Marie-Pascale Côté
- Marion Murray Spinal Cord Injury Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States of America.
| |
Collapse
|
43
|
Doi A, Miyazaki T, Mihara T, Ikeda M, Niikura R, Andoh T, Goto T. CLP290 promotes the sedative effects of midazolam in neonatal rats in a KCC2-dependent manner: A laboratory study in rats. PLoS One 2021; 16:e0248113. [PMID: 33711029 PMCID: PMC7954344 DOI: 10.1371/journal.pone.0248113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 02/22/2021] [Indexed: 11/25/2022] Open
Abstract
Immature neurons dominantly express the Na+-K+-2Cl- cotransporter isoform 1 (NKCC1) rather than the K+-Cl- cotransporter isoform 2 (KCC2). The intracellular chloride ion concentration ([Cl-]i) is higher in immature neurons than in mature neurons; therefore, γ-aminobutyric acid type A (GABAA) receptor activation in immature neurons does not cause chloride ion influx and subsequent hyperpolarization. In our previous work, we found that midazolam, benzodiazepine receptor agonist, causes less sedation in neonatal rats compared to adult rats and that NKCC1 blockade by bumetanide enhances the midazolam-induced sedation in neonatal, but not in adult, rats. These results suggest that GABA receptor activation requires the predominance of KCC2 over NKCC1 to exert sedative effects. In this study, we focused on CLP290, a novel KCC2-selective activator, and found that midazolam administration at 20 mg/kg after oral CLP290 intake significantly prolonged the righting reflex latency even in neonatal rats at postnatal day 7. By contrast, CLP290 alone did not exert sedative effects. Immunohistochemistry showed that midazolam combined with CLP290 decreased the number of phosphorylated cAMP response element-binding protein-positive cells in the cerebral cortex, suggesting that CLP290 reverted the inhibitory effect of midazolam. Moreover, the sedative effect of combined CLP290 and midazolam treatment was inhibited by the administration of the KCC2-selective inhibitor VU0463271, suggesting indirectly that the sedation-promoting effect of CLP290 was mediated by KCC2 activation. To our knowledge, this study is the first report showing the sedation-promoting effect of CLP290 in neonates and providing behavioral and histological evidence that CLP290 reverted the sedative effect of GABAergic drugs through the activation of KCC2. Our data suggest that the clinical application of CLP290 may provide a breakthrough in terms of midazolam-resistant sedation.
Collapse
Affiliation(s)
- Akiko Doi
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomoyuki Miyazaki
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Takahiro Mihara
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Maiko Ikeda
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Ryo Niikura
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomio Andoh
- Department of Anesthesiology, Mizonokuchi Hospital, Teikyo University School of Medicine, Kawasaki, Japan
| | - Takahisa Goto
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| |
Collapse
|
44
|
Khirug S, Soni S, Saez Garcia M, Tessier M, Zhou L, Kulesskaya N, Rauvala H, Lindholm D, Ludwig A, Molinari F, Rivera C. Protective Role of Low Ethanol Administration Following Ischemic Stroke via Recovery of KCC2 and p75 NTR Expression. Mol Neurobiol 2021; 58:1145-1161. [PMID: 33099743 PMCID: PMC7878264 DOI: 10.1007/s12035-020-02176-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 10/14/2020] [Indexed: 01/31/2023]
Abstract
A striking result from epidemiological studies show a correlation between low alcohol intake and lower incidence for ischemic stroke and severity of derived brain injury. Although reduced apoptosis and inflammation has been suggested to be involved, little is known about the mechanism mediating this effect in vivo. Increase in intracellular chloride concentration and derived depolarizing GABAAR-mediated transmission are common consequences following various brain injuries and are caused by the abnormal expression levels of the chloride cotransporters NKCC1 and KCC2. Downstream pro-apoptotic signaling through p75NTR may link GABAA depolarization with post-injury neuronal apoptosis. Here, we show that changes in GABAergic signaling, Cl- homeostasis, and expression of chloride cotransporters in the post-traumatic mouse brain can be significantly reduced by administration of 3% ethanol to the drinking water. Ethanol-induced upregulation of KCC2 has a positive impact on neuronal survival, preserving a large part of the cortical peri-infarct zone, as well as preventing the massive post-ischemic upregulation of the pro-apoptotic protein p75NTR. Importantly, intracortical multisite in vivo recordings showed that ethanol treatment could significantly ameliorate stroke-induced reduction in cortical activity. This surprising finding discloses a pathway triggered by low concentration of ethanol as a novel therapeutically relevant target.
Collapse
Affiliation(s)
- Stanislav Khirug
- Neuroscience Center-HiLIFE, University of Helsinki, 00014, Helsinki, Finland.
| | - Shetal Soni
- Neuroscience Center-HiLIFE, University of Helsinki, 00014, Helsinki, Finland
| | - Marta Saez Garcia
- Neuroscience Center-HiLIFE, University of Helsinki, 00014, Helsinki, Finland
| | - Marine Tessier
- INMED (INSERM U1249), Aix-Marseille Université, Marseille, France
| | - Liang Zhou
- Neuroscience Center-HiLIFE, University of Helsinki, 00014, Helsinki, Finland
| | - Natalia Kulesskaya
- Neuroscience Center-HiLIFE, University of Helsinki, 00014, Helsinki, Finland
| | - Heikki Rauvala
- Neuroscience Center-HiLIFE, University of Helsinki, 00014, Helsinki, Finland
| | - Dan Lindholm
- Medicum, Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Helsinki, Finland
| | - Anastasia Ludwig
- Neuroscience Center-HiLIFE, University of Helsinki, 00014, Helsinki, Finland
| | | | - Claudio Rivera
- Neuroscience Center-HiLIFE, University of Helsinki, 00014, Helsinki, Finland.
- INMED (INSERM U1249), Aix-Marseille Université, Marseille, France.
| |
Collapse
|
45
|
Peerboom C, Wierenga CJ. The postnatal GABA shift: A developmental perspective. Neurosci Biobehav Rev 2021; 124:179-192. [PMID: 33549742 DOI: 10.1016/j.neubiorev.2021.01.024] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 01/13/2021] [Accepted: 01/28/2021] [Indexed: 12/13/2022]
Abstract
GABA is the major inhibitory neurotransmitter that counterbalances excitation in the mature brain. The inhibitory action of GABA relies on the inflow of chloride ions (Cl-), which hyperpolarizes the neuron. In early development, GABA signaling induces outward Cl- currents and is depolarizing. The postnatal shift from depolarizing to hyperpolarizing GABA is a pivotal event in brain development and its timing affects brain function throughout life. Altered timing of the postnatal GABA shift is associated with several neurodevelopmental disorders. Here, we argue that the postnatal shift from depolarizing to hyperpolarizing GABA represents the final shift in a sequence of GABA shifts, regulating proliferation, migration, differentiation, and finally plasticity of developing neurons. Each developmental GABA shift ensures that the instructive role of GABA matches the circumstances of the developing network. Sensory input may be a crucial factor in determining proper timing of the postnatal GABA shift. A developmental perspective is necessary to interpret the full consequences of a mismatch between connectivity, activity and GABA signaling during brain development.
Collapse
Affiliation(s)
- Carlijn Peerboom
- Cell Biology, Neurobiology and Biophysics, Biology Department, Faculty of Science, Utrecht University, 3584 CH, Utrecht, the Netherlands
| | - Corette J Wierenga
- Cell Biology, Neurobiology and Biophysics, Biology Department, Faculty of Science, Utrecht University, 3584 CH, Utrecht, the Netherlands.
| |
Collapse
|
46
|
Dugan EA, Schachner B, Jergova S, Sagen J. Intensive Locomotor Training Provides Sustained Alleviation of Chronic Spinal Cord Injury-Associated Neuropathic Pain: A Two-Year Pre-Clinical Study. J Neurotrauma 2021; 38:789-802. [PMID: 33218293 DOI: 10.1089/neu.2020.7378] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Neuropathic pain often accompanies the functional deficits associated with spinal cord injury (SCI) and further reduces a patient's quality of life. Clinical and pre-clinical research is beginning to highlight the beneficial role that rehabilitative therapies such as locomotor training can have not only on functional recovery but also on chronic pain management. Our group has previously developed an intensive locomotor training (ILT) treadmill protocol on rats that reduced SCI neuropathic pain symptoms for at least 3 months. We have extended these findings in the current study to evaluate the ability of regular ILT regimen over a 2 year period post-SCI to maintain neuropathic pain reduction. To assess this, the rat clip compression SCI model (T7/8) was used and treadmill training was initiated starting 4 weeks after SCI and continuing through the duration of the study. Results showed continued suppression of SCI neuropathic pain responses (reduced mechanical, heat, and cold hypersensitivity throughout the entire time course of the study). In contrast, non-exercised rats showed consistent and sustained neuropathic pain responses during this period. In addition, prolonged survival and improved locomotor outcomes were observed in rats undergoing ILT as the study longevity progressed. Potential contributory mechanisms underlying beneficial effects of ILT include reduced inflammation and restoration of anti-nociceptive inhibitory processes as indicated by neurochemical assays in spinal tissue of remaining rats at 2 years post-SCI. The benefits of chronic ILT suggest that long-term physical exercise therapy can produce powerful and prolonged management of neuropathic pain, partly through sustained reduction of spinal pathological processes.
Collapse
Affiliation(s)
- Elizabeth A Dugan
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida, USA
| | - Benjamin Schachner
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida, USA
| | - Stanislava Jergova
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida, USA
| | - Jacqueline Sagen
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida, USA
| |
Collapse
|
47
|
Belaïdouni Y, Diabira D, Zhang J, Graziano JC, Bader F, Montheil A, Menuet C, Wayman GA, Gaiarsa JL. The Chloride Homeostasis of CA3 Hippocampal Neurons Is Not Altered in Fully Symptomatic Mepc2-null Mice. Front Cell Neurosci 2021; 15:724976. [PMID: 34602980 PMCID: PMC8484709 DOI: 10.3389/fncel.2021.724976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/27/2021] [Indexed: 02/05/2023] Open
Abstract
Rett syndrome (RTT) is an X-linked neurodevelopmental disorder caused mainly by mutations in the MECP2 gene. Mouse models of RTT show reduced expression of the cation-chloride cotransporter KCC2 and altered chloride homeostasis at presymptomatic stages. However, whether these alterations persist to late symptomatic stages has not been studied. Here we assess KCC2 and NKCC1 expressions and chloride homeostasis in the hippocampus of early [postnatal (P) day 30-35] and late (P50-60) symptomatic male Mecp2-null (Mecp2 -/y) mice. We found (i) no difference in the relative amount, but an over-phosphorylation, of KCC2 and NKCC1 between wild-type (WT) and Mecp2 -/y hippocampi and (ii) no difference in the inhibitory strength, nor reversal potential, of GABA A -receptor-mediated responses in Mecp2 -/y CA3 pyramidal neurons compared to WT at any stages studied. Altogether, these data indicate the presence of a functional chloride extrusion mechanism in Mecp2 -/y CA3 pyramidal neurons at symptomatic stages.
Collapse
Affiliation(s)
- Yasmine Belaïdouni
- Aix-Marseille University UMR 1249, Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale Unité 1249, Parc Scientifique de Luminy, Marseille, France
| | - Diabe Diabira
- Aix-Marseille University UMR 1249, Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale Unité 1249, Parc Scientifique de Luminy, Marseille, France
| | - Jinwei Zhang
- Institute of Biomedical and Clinical Sciences, College of Medicine and Health, University of Exeter, Hatherly Laboratories, Exeter, United Kingdom
| | - Jean-Charles Graziano
- Aix-Marseille University 105, Institut Paoli Calmettes, U1068, Institut National de la Santé et de la Recherche Médicale U7258, Centre National de Recherche Scientifique, Centre de Recherche en Cancérologie de Marseille, Marseille, France
| | - Francesca Bader
- Aix-Marseille University UMR 1249, Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale Unité 1249, Parc Scientifique de Luminy, Marseille, France
| | - Aurelie Montheil
- Aix-Marseille University UMR 1249, Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale Unité 1249, Parc Scientifique de Luminy, Marseille, France
| | - Clément Menuet
- Aix-Marseille University UMR 1249, Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale Unité 1249, Parc Scientifique de Luminy, Marseille, France
| | - Gary A. Wayman
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, United States
| | - Jean-Luc Gaiarsa
- Aix-Marseille University UMR 1249, Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale Unité 1249, Parc Scientifique de Luminy, Marseille, France
- *Correspondence: Jean-Luc Gaiarsa,
| |
Collapse
|
48
|
Virtanen MA, Uvarov P, Hübner CA, Kaila K. NKCC1, an Elusive Molecular Target in Brain Development: Making Sense of the Existing Data. Cells 2020; 9:cells9122607. [PMID: 33291778 PMCID: PMC7761970 DOI: 10.3390/cells9122607] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 12/14/2022] Open
Abstract
Ionotropic GABA transmission is mediated by anion (mainly Cl−)-permeable GABAA receptors (GABAARs). In immature neurons, GABA exerts depolarizing and sometimes functionally excitatory actions, based on active uptake of Cl− by the Na-K-2Cl cotransporter NKCC1. While functional evidence firmly shows NKCC1-mediated ion transport in immature and diseased neurons, molecular detection of NKCC1 in the brain has turned out to be extremely difficult. In this review, we describe the highly inconsistent data that are available on the cell type-specific expression patterns of the NKCC1 mRNA and protein in the CNS. We discuss the major technical caveats, including a lack of knock-out-controlled immunohistochemistry in the forebrain, possible effects of alternative splicing on the binding of antibodies and RNA probes, and the wide expression of NKCC1 in different cell types, which make whole-tissue analyses of NKCC1 useless for studying its neuronal expression. We also review novel single-cell RNAseq data showing that most of the NKCC1 in the adult CNS may, in fact, be expressed in non-neuronal cells, especially in glia. As future directions, we suggest single-cell NKCC1 mRNA and protein analyses and the use of genetically tagged endogenous proteins or systematically designed novel antibodies, together with proper knock-out controls, for the visualization of endogenous NKCC1 in distinct brain cell types and their subcellular compartments.
Collapse
Affiliation(s)
- Mari A. Virtanen
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; (M.A.V.); (P.U.)
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Pavel Uvarov
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; (M.A.V.); (P.U.)
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Christian A. Hübner
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller Universität, 07747 Jena, Germany;
| | - Kai Kaila
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; (M.A.V.); (P.U.)
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
- Correspondence: ; Tel.: +358-407256759
| |
Collapse
|
49
|
Andrews K, Josiah SS, Zhang J. The Therapeutic Potential of Neuronal K-Cl Co-Transporter KCC2 in Huntington's Disease and Its Comorbidities. Int J Mol Sci 2020; 21:E9142. [PMID: 33266310 PMCID: PMC7730145 DOI: 10.3390/ijms21239142] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/16/2020] [Accepted: 11/28/2020] [Indexed: 02/05/2023] Open
Abstract
Intracellular chloride levels in the brain are regulated primarily through the opposing effects of two cation-chloride co-transporters (CCCs), namely K+-Cl- co-transporter-2 (KCC2) and Na+-K+-Cl- co-transporter-1 (NKCC1). These CCCs are differentially expressed throughout the course of development, thereby determining the excitatory-to-inhibitory γ-aminobutyric acid (GABA) switch. GABAergic excitation (depolarisation) is important in controlling the healthy development of the nervous system; as the brain matures, GABAergic inhibition (hyperpolarisation) prevails. This developmental switch in excitability is important, as uncontrolled regulation of neuronal excitability can have implications for health. Huntington's disease (HD) is an example of a genetic disorder whereby the expression levels of KCC2 are abnormal due to mutant protein interactions. Although HD is primarily considered a motor disease, many other clinical manifestations exist; these often present in advance of any movement abnormalities. Cognitive change, in addition to sleep disorders, is prevalent in the HD population; the effect of uncontrolled KCC2 function on cognition and sleep has also been explored. Several mechanisms by which KCC2 expression is reduced have been proposed recently, thereby suggesting extensive investigation of KCC2 as a possible therapeutic target for the development of pharmacological compounds that can effectively treat HD co-morbidities. Hence, this review summarizes the role of KCC2 in the healthy and HD brain, and highlights recent advances that attest to KCC2 as a strong research and therapeutic target candidate.
Collapse
Affiliation(s)
| | | | - Jinwei Zhang
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, Hatherly Laboratories, Exeter EX4 4PS, UK; (K.A.); (S.S.J.)
| |
Collapse
|
50
|
Dumon C, Belaidouni Y, Diabira D, Appleyard SM, Wayman GA, Gaiarsa JL. Leptin down-regulates KCC2 activity and controls chloride homeostasis in the neonatal rat hippocampus. Mol Brain 2020; 13:151. [PMID: 33183317 PMCID: PMC7661183 DOI: 10.1186/s13041-020-00689-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 10/28/2020] [Indexed: 11/10/2022] Open
Abstract
The canonical physiological role of leptin is to regulate hunger and satiety acting on specific hypothalamic nuclei. Beyond this key metabolic function; leptin also regulates many aspects of development and functioning of neuronal hippocampal networks throughout life. Here we show that leptin controls chloride homeostasis in the developing rat hippocampus in vitro. The effect of leptin relies on the down-regulation of the potassium/chloride extruder KCC2 activity and is present during a restricted period of postnatal development. This study confirms and extends the role of leptin in the ontogenesis of functional GABAergic inhibition and helps understanding how abnormal levels of leptin may contribute to neurological disorders.
Collapse
Affiliation(s)
- Camille Dumon
- Aix-Marseille Univ UMR 1249, INSERM (Institut National de La Santé et de La Recherche Médicale) Unité 1249, INMED (Institut de Neurobiologie de La Méditerranée), Parc Scientifique de Luminy, Marseille, France
- Neurochlore Parc Scientifique et Technologique de Luminy, Bâtiment Beret Delaage, Zone Luminy Entreprises Biotech, Marseille, France
| | - Yasmine Belaidouni
- Aix-Marseille Univ UMR 1249, INSERM (Institut National de La Santé et de La Recherche Médicale) Unité 1249, INMED (Institut de Neurobiologie de La Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Diabe Diabira
- Aix-Marseille Univ UMR 1249, INSERM (Institut National de La Santé et de La Recherche Médicale) Unité 1249, INMED (Institut de Neurobiologie de La Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Suzanne M Appleyard
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, USA
| | - Gary A Wayman
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, USA
| | - Jean-Luc Gaiarsa
- Aix-Marseille Univ UMR 1249, INSERM (Institut National de La Santé et de La Recherche Médicale) Unité 1249, INMED (Institut de Neurobiologie de La Méditerranée), Parc Scientifique de Luminy, Marseille, France.
| |
Collapse
|