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Shamsnia HS, Peyrovinasab A, Amirlou D, Sirouskabiri S, Rostamian F, Basiri N, Shalmani LM, Hashemi M, Hushmandi K, Abdolghaffari AH. BDNF-TrkB Signaling Pathway in Spinal Cord Injury: Insights and Implications. Mol Neurobiol 2024:10.1007/s12035-024-04381-4. [PMID: 39046702 DOI: 10.1007/s12035-024-04381-4] [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: 03/19/2024] [Accepted: 07/18/2024] [Indexed: 07/25/2024]
Abstract
Spinal cord injury (SCI) is a neurodegenerative disorder that has critical impact on patient's life expectance and life span, and this disorder also leads to negative socioeconomic features. SCI is defined as a firm collision to the spinal cord which leads to the fracture and the dislocation of vertebrae. The current available treatment is surgery. However, it cannot fully treat SCI, and many consequences remain after the surgery. Accordingly, finding new therapeutics is critical. BDNF-TrkB signaling is a vital signaling in neuronal differentiation, survival, overgrowth, synaptic plasticity, etc. Hence, many studies evaluate its impact on various neurodegenerative disorders. There are several studies evaluating this signaling in SCI, and they show promising outcomes. It was shown that various exercises, chemical interventions, etc. had significant positive impact on SCI by affecting BDNF-TrkB signaling pathway. This study aims to accumulate and evaluate these data and inspect whether this signaling is effective or not.
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Affiliation(s)
- Hedieh Sadat Shamsnia
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Amirreza Peyrovinasab
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Dorsa Amirlou
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Shirin Sirouskabiri
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Fatemeh Rostamian
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Nasim Basiri
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Leila Mohaghegh Shalmani
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran.
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
| | - Mehrdad Hashemi
- Department of Genetics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
- Farhikhtegan Medical Convergence Sciences Research Center, Farhikhtegan Hospital Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
| | | | - Amir Hossein Abdolghaffari
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, No. 99, Yakhchal, Gholhak, Shariati St, P. O. Box: 19419-33111, Tehran, Iran.
- GI Pharmacology Interest Group (GPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
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2
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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.
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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
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3
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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.
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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.
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4
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Keramidis I, McAllister BB, Bourbonnais J, Wang F, Isabel D, Rezaei E, Sansonetti R, Degagne P, Hamel JP, Nazari M, Inayat S, Dudley JC, Barbeau A, Froux L, Paquet ME, Godin AG, Mohajerani MH, De Koninck Y. Restoring neuronal chloride extrusion reverses cognitive decline linked to Alzheimer's disease mutations. Brain 2023; 146:4903-4915. [PMID: 37551444 PMCID: PMC10690023 DOI: 10.1093/brain/awad250] [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: 05/12/2022] [Revised: 06/23/2023] [Accepted: 07/09/2023] [Indexed: 08/09/2023] Open
Abstract
Disinhibition during early stages of Alzheimer's disease is postulated to cause network dysfunction and hyperexcitability leading to cognitive deficits. However, the underlying molecular mechanism remains unknown. Here we show that, in mouse lines carrying Alzheimer's disease-related mutations, a loss of neuronal membrane potassium-chloride cotransporter KCC2, responsible for maintaining the robustness of GABAA-mediated inhibition, occurs pre-symptomatically in the hippocampus and prefrontal cortex. KCC2 downregulation was inversely correlated with the age-dependent increase in amyloid-β 42 (Aβ42). Acute administration of Aβ42 caused a downregulation of membrane KCC2. Loss of KCC2 resulted in impaired chloride homeostasis. Preventing the decrease in KCC2 using long term treatment with CLP290 protected against deterioration of learning and cortical hyperactivity. In addition, restoring KCC2, using short term CLP290 treatment, following the transporter reduction effectively reversed spatial memory deficits and social dysfunction, linking chloride dysregulation with Alzheimer's disease-related cognitive decline. These results reveal KCC2 hypofunction as a viable target for treatment of Alzheimer's disease-related cognitive decline; they confirm target engagement, where the therapeutic intervention takes place, and its effectiveness.
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Affiliation(s)
- Iason Keramidis
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
- Graduate Program in Neuroscience, Faculty of Medicine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Brendan B McAllister
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Julien Bourbonnais
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
| | - Feng Wang
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
- Faculty of Dentistry, Université Laval, Québec, QC G1V 0A6, Canada
| | - Dominique Isabel
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
| | - Edris Rezaei
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Romain Sansonetti
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
| | - Phil Degagne
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Justin P Hamel
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
| | - Mojtaba Nazari
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Samsoon Inayat
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Jordan C Dudley
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Annie Barbeau
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
| | - Lionel Froux
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
| | - Marie-Eve Paquet
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
- Department of Biochemistry, Microbiology, and Bio-informatics, Université Laval, Québec, QC G1V 0A6, Canada
| | - Antoine G Godin
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
- Graduate Program in Neuroscience, Faculty of Medicine, Université Laval, Québec, QC G1V 0A6, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec, QC G1V 0A6, Canada
| | - Majid H Mohajerani
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Yves De Koninck
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
- Graduate Program in Neuroscience, Faculty of Medicine, Université Laval, Québec, QC G1V 0A6, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec, QC G1V 0A6, Canada
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5
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Tessier M, Garcia MS, Goubert E, Blasco E, Consumi A, Dehapiot B, Tian L, Molinari F, Laurin J, Guillemot F, Hübner CA, Pellegrino C, Rivera C. Bumetanide induces post-traumatic microglia-interneuron contact to promote neurogenesis and recovery. Brain 2023; 146:4247-4261. [PMID: 37082944 PMCID: PMC10545516 DOI: 10.1093/brain/awad132] [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: 03/03/2022] [Revised: 02/20/2023] [Accepted: 03/27/2023] [Indexed: 04/22/2023] Open
Abstract
Although the Na-K-Cl cotransporter (NKCC1) inhibitor bumetanide has prominent positive effects on the pathophysiology of many neurological disorders, the mechanism of action is obscure. Attention paid to elucidating the role of Nkcc1 has mainly been focused on neurons, but recent single cell mRNA sequencing analysis has demonstrated that the major cellular populations expressing NKCC1 in the cortex are non-neuronal. We used a combination of conditional transgenic animals, in vivo electrophysiology, two-photon imaging, cognitive behavioural tests and flow cytometry to investigate the role of Nkcc1 inhibition by bumetanide in a mouse model of controlled cortical impact (CCI). Here, we found that bumetanide rescues parvalbumin-positive interneurons by increasing interneuron-microglia contacts shortly after injury. The longitudinal phenotypic changes in microglia were significantly modified by bumetanide, including an increase in the expression of microglial-derived BDNF. These effects were accompanied by the prevention of CCI-induced decrease in hippocampal neurogenesis. Treatment with bumetanide during the first week post-CCI resulted in significant recovery of working and episodic memory as well as changes in theta band oscillations 1 month later. These results disclose a novel mechanism for the neuroprotective action of bumetanide mediated by an acceleration of microglial activation dynamics that leads to an increase in parvalbumin interneuron survival following CCI, possibly resulting from increased microglial BDNF expression and contact with interneurons. Salvage of interneurons may normalize ambient GABA, resulting in the preservation of adult neurogenesis processes as well as contributing to bumetanide-mediated improvement of cognitive performance.
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Affiliation(s)
- Marine Tessier
- Aix Marseille Univ, INSERM, INMED, 13273 Marseille, France
| | - Marta Saez Garcia
- Neuroscience Center, 00014 University of Helsinki, Helsinki, Finland
| | | | - Edith Blasco
- Aix Marseille Univ, INSERM, INMED, 13273 Marseille, France
| | | | - Benoit Dehapiot
- Aix Marseille Univ, CNRS, IBDM-UMR7288, Turing Center for Living Systems, 13288 Marseille, France
| | - Li Tian
- Institute of Biomedicine and Translational Medicine, University of Tartu, 50411 Tartu, Estonia
| | | | - Jerome Laurin
- Aix Marseille Univ, INSERM, INMED, 13273 Marseille, France
| | | | - Christian A Hübner
- Institut für Humangenetik, Universitätsklinikum Jena, 07747 Jena, Germany
| | | | - Claudio Rivera
- Aix Marseille Univ, INSERM, INMED, 13273 Marseille, France
- Neuroscience Center, 00014 University of Helsinki, Helsinki, Finland
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6
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Furukawa T, Fukuda A. Maternal taurine as a modulator of Cl - homeostasis as well as of glycine/GABA A receptors for neocortical development. Front Cell Neurosci 2023; 17:1221441. [PMID: 37601283 PMCID: PMC10435090 DOI: 10.3389/fncel.2023.1221441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/20/2023] [Indexed: 08/22/2023] Open
Abstract
During brain and spinal cord development, GABA and glycine, the inhibitory neurotransmitters, cause depolarization instead of hyperpolarization in adults. Since glycine and GABAA receptors (GABAARs) are chloride (Cl-) ion channel receptor, the conversion of GABA/glycine actions during development is influenced by changes in the transmembrane Cl- gradient, which is regulated by Cl- transporters, NKCC1 (absorption) and KCC2 (expulsion). In immature neurons, inhibitory neurotransmitters are released in a non-vesicular/non-synaptic manner, transitioning to vesicular/synaptic release as the neuron matures. In other word, in immature neurons, neurotransmitters generally act tonically. Thus, the glycine/GABA system is a developmentally multimodal system that is required for neurogenesis, differentiation, migration, and synaptogenesis. The endogenous agonists for these receptors are not fully understood, we address taurine. In this review, we will discuss about the properties and function of taurine during development of neocortex. Taurine cannot be synthesized by fetuses or neonates, and is transferred from maternal blood through the placenta or maternal milk ingestion. In developing neocortex, taurine level is higher than GABA level, and taurine tonically activates GABAARs to control radial migration as a stop signal. In the marginal zone (MZ) of the developing neocortex, endogenous taurine modulates the spread of excitatory synaptic transmission, activating glycine receptors (GlyRs) as an endogenous agonist. Thus, taurine affects information processing and crucial developmental processes such as axonal growth, cell migration, and lamination in the developing cerebral cortex. Additionally, we also refer to the possible mechanism of taurine-regulating Cl- homeostasis. External taurine is uptake by taurine transporter (TauT) and regulates NKCC1 and KCC2 mediated by intracellular signaling pathway, with-no-lysine kinase 1 (WNK1) and its subsequent kinases STE20/SPS1-related proline-alanine-rich protein kinase (SPAK) and oxidative stress response kinase-1 (OSR1). Through the regulation of NKCC1 and KCC2, mediated by the WNK-SPAK/OSR1 signaling pathway, taurine plays a role in maintaining Cl- homeostasis during normal brain development.
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Affiliation(s)
- Tomonori Furukawa
- Department of Neurophysiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
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7
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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: 10] [Impact Index Per Article: 10.0] [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.
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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
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8
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Simonnet C, Sinha M, Goutierre M, Moutkine I, Daumas S, Poncer JC. Silencing KCC2 in mouse dorsal hippocampus compromises spatial and contextual memory. Neuropsychopharmacology 2023; 48:1067-1077. [PMID: 36302847 PMCID: PMC10209115 DOI: 10.1038/s41386-022-01480-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 10/11/2022] [Accepted: 10/12/2022] [Indexed: 11/09/2022]
Abstract
Delayed upregulation of the neuronal chloride extruder KCC2 underlies the progressive shift in GABA signaling polarity during development. Conversely, KCC2 downregulation is observed in a variety of neurological and psychiatric disorders often associated with cognitive impairment. Reduced KCC2 expression and function in mature networks may disrupt GABA signaling and promote anomalous network activities underlying these disorders. However, the causal link between KCC2 downregulation, altered brain rhythmogenesis, and cognitive function remains elusive. Here, by combining behavioral exploration with in vivo electrophysiology we assessed the impact of chronic KCC2 downregulation in mouse dorsal hippocampus and showed it compromises both spatial and contextual memory. This was associated with altered hippocampal rhythmogenesis and neuronal hyperexcitability, with increased burst firing in CA1 neurons during non-REM sleep. Reducing neuronal excitability with terbinafine, a specific Task-3 leak potassium channel opener, occluded the impairment of contextual memory upon KCC2 knockdown. Our results establish a causal relationship between KCC2 expression and cognitive performance and suggest that non-epileptiform rhythmopathies and neuronal hyperexcitability are central to the deficits caused by KCC2 downregulation in the adult mouse brain.
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Affiliation(s)
- Clémence Simonnet
- Inserm UMR-S 1270, 75005, Paris, France
- Sorbonne Université, 75005, Paris, France
- Institut du Fer à Moulin, 75005, Paris, France
- Basic Neuroscience Department, Centre Medical Universitaire, 1211, Geneva, Switzerland
| | - Manisha Sinha
- 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
| | - Imane Moutkine
- Inserm UMR-S 1270, 75005, Paris, France
- Sorbonne Université, 75005, Paris, France
- Institut du Fer à Moulin, 75005, Paris, France
| | - Stéphanie Daumas
- Sorbonne Université, 75005, Paris, France
- Neuroscience Paris Seine-Institut de Biologie Paris Seine (NPS-IBPS), 75005, Paris, France
| | - Jean Christophe Poncer
- Inserm UMR-S 1270, 75005, Paris, France.
- Sorbonne Université, 75005, Paris, France.
- Institut du Fer à Moulin, 75005, Paris, France.
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9
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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.
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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
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10
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Pajer K, Bellák T, Grósz T, Nógrádi B, Patai R, Sinkó J, Vinay L, Liabeuf S, Erdélyi M, Nógrádi A. Riluzole treatment modulates KCC2 and EAAT-2 receptor expression and Ca 2+ accumulation following ventral root avulsion injury. Eur J Cell Biol 2023; 102:151317. [PMID: 37099936 DOI: 10.1016/j.ejcb.2023.151317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 04/18/2023] [Accepted: 04/19/2023] [Indexed: 04/28/2023] Open
Abstract
Avulsion injury results in motoneuron death due to the increased excitotoxicity developing in the affected spinal segments. This study focused on possible short and long term molecular and receptor expression alterations which are thought to be linked to the excitotoxic events in the ventral horn with or without the anti-excitotoxic riluzole treatment. In our experimental model the left lumbar 4 and 5 (L4, 5) ventral roots of the spinal cord were avulsed. Treated animals received riluzole for 2 weeks. Riluzole is a compound that acts to block voltage-activated Na+ and Ca2+ channels. In control animals the L4, 5 ventral roots were avulsed without riluzole treatment. Expression of astrocytic EAAT-2 and that of KCC2 in motoneurons on the affected side of the L4 spinal segment were detected after the injury by confocal and dSTORM imaging, intracellular Ca2+ levels in motoneurons were quantified by electron microscopy. The KCC2 labeling in the lateral and ventrolateral parts of the L4 ventral horn was weaker compared with the medial part of L4 ventral horn in both groups. Riluzole treatment dramatically enhanced motoneuron survival but was not able to prevent the down-regulation of KCC2 expression in injured motoneurons. In contrast, riluzole successfully obviated the increase of intracellular calcium level and the decrease of EAAT-2 expression in astrocytes compared with untreated injured animals. We conclude that KCC2 may not be an essential component for survival of injured motoneurons and riluzole is able to modulate the intracellular level of calcium and expression of EAAT-2.
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Affiliation(s)
- Krisztián Pajer
- Department of Anatomy, Histology and Embryology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Tamás Bellák
- Department of Anatomy, Histology and Embryology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Tímea Grósz
- Department of Optics and Quantum Electronics, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Bernát Nógrádi
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary; Department of Neurology, Albert Szent-Györgyi Health Center, University of Szeged, Szeged, Hungary
| | - Roland Patai
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - József Sinkó
- Department of Optics and Quantum Electronics, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Laurent Vinay
- Institut de Neurosciences de la Timone, UMR 7289, CNRS and Aix Marseille Université, Campus Santé Timone, 13385 Marseille, France
| | - Sylvie Liabeuf
- Institut de Neurosciences de la Timone, UMR 7289, CNRS and Aix Marseille Université, Campus Santé Timone, 13385 Marseille, France
| | - Miklós Erdélyi
- Department of Optics and Quantum Electronics, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Antal Nógrádi
- Department of Anatomy, Histology and Embryology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary.
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11
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Hu JJ, Liu Y, Yao H, Cao B, Liao H, Yang R, Chen P, Song XJ. Emergence of consciousness from anesthesia through ubiquitin degradation of KCC2 in the ventral posteromedial nucleus of the thalamus. Nat Neurosci 2023; 26:751-764. [PMID: 36973513 DOI: 10.1038/s41593-023-01290-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 02/23/2023] [Indexed: 03/29/2023]
Abstract
The emergence of consciousness from anesthesia, once assumed to be a passive process, is now considered as an active and controllable process. In the present study, we show in mice that, when the brain is forced into a minimum responsive state by diverse anesthetics, a rapid downregulation of K+/Cl- cotransporter 2 (KCC2) in the ventral posteromedial nucleus (VPM) serves as a common mechanism by which the brain regains consciousness. Ubiquitin-proteasomal degradation is responsible for KCC2 downregulation, which is driven by ubiquitin ligase Fbxl4. Phosphorylation of KCC2 at Thr1007 promotes interaction between KCC2 and Fbxl4. KCC2 downregulation leads to γ-aminobutyric acid type A receptor-mediated disinhibition, enabling accelerated recovery of VPM neuron excitability and emergence of consciousness from anesthetic inhibition. This pathway to recovery is an active process and occurs independent of anesthetic choice. The present study demonstrates that ubiquitin degradation of KCC2 in the VPM is an important intermediate step en route to emergence of consciousness from anesthesia.
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12
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Wan Y, Morikawa M, Morikawa M, Iwata S, Naseer MI, Ahmed Chaudhary AG, Tanaka Y, Hirokawa N. KIF4 regulates neuronal morphology and seizure susceptibility via the PARP1 signaling pathway. J Cell Biol 2023; 222:e202208108. [PMID: 36482480 PMCID: PMC9735414 DOI: 10.1083/jcb.202208108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 10/19/2022] [Accepted: 11/10/2022] [Indexed: 12/13/2022] Open
Abstract
Epilepsy is a common neurological disease worldwide, and one of its causes is genetic abnormalities. Here, we identified a point mutation in KIF4A, a member of kinesin superfamily molecular motors, in patients with neurological disorders such as epilepsy, developmental delay, and intellectual disability. KIF4 is involved in the poly (ADP-ribose) polymerase (PARP) signaling pathway, and the mutation (R728Q) strengthened its affinity with PARP1 through elongation of the KIF4 coiled-coil domain. Behavioral tests showed that KIF4-mutant mice exhibited mild developmental delay with lower seizure threshold. Further experiments revealed that the KIF4 mutation caused aberrant morphology in dendrites and spines of hippocampal pyramidal neurons through PARP1-TrkB-KCC2 pathway. Furthermore, supplementing NAD, which activates PARP1, could modulate the TrkB-KCC2 pathway and rescue the seizure susceptibility phenotype of the mutant mice. Therefore, these findings indicate that KIF4 is engaged in a fundamental mechanism regulating seizure susceptibility and could be a potential target for epilepsy treatment.
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Affiliation(s)
- Yuansong Wan
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Momo Morikawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Department of Anatomy and Neuroscience, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Manatsu Morikawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Suguru Iwata
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Department of Anatomy and Neuroscience, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Muhammad Imran Naseer
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Yosuke Tanaka
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Nobutaka Hirokawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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13
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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.
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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.
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14
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Chloride ion dysregulation in epileptogenic neuronal networks. Neurobiol Dis 2023; 177:106000. [PMID: 36638891 DOI: 10.1016/j.nbd.2023.106000] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/25/2022] [Accepted: 01/09/2023] [Indexed: 01/13/2023] Open
Abstract
GABA is the major inhibitory neurotransmitter in the mature CNS. When GABAA receptors are activated the membrane potential is driven towards hyperpolarization due to chloride entry into the neuron. However, chloride ion dysregulation that alters the ionic gradient can result in depolarizing GABAergic post-synaptic potentials instead. In this review, we highlight that GABAergic inhibition prevents and restrains focal seizures but then reexamine this notion in the context of evidence that a static and/or a dynamic chloride ion dysregulation, that increases intracellular chloride ion concentrations, promotes epileptiform activity and seizures. To reconcile these findings, we hypothesize that epileptogenic pathologically interconnected neuron (PIN) microcircuits, representing a small minority of neurons, exhibit static chloride dysregulation and should exhibit depolarizing inhibitory post-synaptic potentials (IPSPs). We speculate that chloride ion dysregulation and PIN cluster activation may generate fast ripples and epileptiform spikes as well as initiate the hypersynchronous seizure onset pattern and microseizures. Also, we discuss the genetic, molecular, and cellular players important in chloride dysregulation which regulate epileptogenesis and initiate the low-voltage fast seizure onset pattern. We conclude that chloride dysregulation in neuronal networks appears to be critical for epileptogenesis and seizure genesis, but feed-back and feed-forward inhibitory GABAergic neurotransmission plays an important role in preventing and restraining seizures as well.
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15
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Rong J, Yang Y, Liang M, Zhong H, Li Y, Zhu Y, Sha S, Chen L, Zhou R. Neonatal inflammation increases hippocampal KCC2 expression through methylation-mediated TGF-β1 downregulation leading to impaired hippocampal cognitive function and synaptic plasticity in adult mice. J Neuroinflammation 2023; 20:15. [PMID: 36691035 PMCID: PMC9872321 DOI: 10.1186/s12974-023-02697-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 01/12/2023] [Indexed: 01/25/2023] Open
Abstract
The mechanisms by which neonatal inflammation leads to cognitive deficits in adulthood remain poorly understood. Inhibitory GABAergic synaptic transmission plays a vital role in controlling learning, memory and synaptic plasticity. Since early-life inflammation has been reported to adversely affect the GABAergic synaptic transmission, the aim of this study was to investigate whether and how neonatal inflammation affects GABAergic synaptic transmission resulting in cognitive impairment. Neonatal mice received a daily subcutaneous injection of lipopolysaccharide (LPS, 50 μg/kg) or saline on postnatal days 3-5. It was found that blocking GABAergic synaptic transmission reversed the deficit in hippocampus-dependent memory or the induction failure of long-term potentiation in the dorsal CA1 in adult LPS mice. An increase of mIPSCs amplitude was further detected in adult LPS mice indicative of postsynaptic potentiation of GABAergic transmission. Additionally, neonatal LPS resulted in the increased expression and function of K+-Cl--cotransporter 2 (KCC2) and the decreased expression of transforming growth factor-beta 1 (TGF-β1) in the dorsal CA1 during adulthood. The local TGF-β1 overexpression improved KCC2 expression and function, synaptic plasticity and memory of adult LPS mice. Adult LPS mice show hypermethylation of TGFb1 promoter and negatively correlate with reduced TGF-β1 transcripts. 5-Aza-deoxycytidine restored the changes in TGFb1 promoter methylation and TGF-β1 expression. Altogether, the results suggest that hypermethylation-induced reduction of TGF-β1 leads to enhanced GABAergic synaptic inhibition through increased KCC2 expression, which is a underlying mechanism of neonatal inflammation-induced hippocampus-dependent memory impairment in adult mice.
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Affiliation(s)
- Jing Rong
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Yang Yang
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Min Liang
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Haiquan Zhong
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Yingchun Li
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Yichao Zhu
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Sha Sha
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Lei Chen
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Rong Zhou
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
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16
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Hu Z, Yu X, Chen P, Jin K, Zhou J, Wang G, Yu J, Wu T, Wang Y, Lin F, Zhang T, Wang Y, Zhao X. BDNF-TrkB signaling pathway-mediated microglial activation induces neuronal KCC2 downregulation contributing to dynamic allodynia following spared nerve injury. Mol Pain 2023; 19:17448069231185439. [PMID: 37321969 PMCID: PMC10402286 DOI: 10.1177/17448069231185439] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 05/02/2023] [Accepted: 05/16/2023] [Indexed: 06/17/2023] Open
Abstract
Mechanical allodynia can be evoked by punctate pressure contact with the skin (punctate mechanical allodynia) and dynamic contact stimulation induced by gentle touching of the skin (dynamic mechanical allodynia). Dynamic allodynia is insensitive to morphine treatment and is transmitted through the spinal dorsal horn by a specific neuronal pathway, which is different from that for punctate allodynia, leading to difficulties in clinical treatment. K+-Cl- cotransporter-2 (KCC2) is one of the major determinants of inhibitory efficiency, and the inhibitory system in the spinal cord is important in the regulation of neuropathic pain. The aim of the current study was to determine whether neuronal KCC2 is involved in the induction of dynamic allodynia and to identify underlying spinal mechanisms involved in this process. Dynamic and punctate allodynia were assessed using either von Frey filaments or a paint brush in a spared nerve injury (SNI) mouse model. Our study discovered that the downregulated neuronal membrane KCC2 (mKCC2) in the spinal dorsal horn of SNI mice is closely associated with SNI-induced dynamic allodynia, as the prevention of KCC2 downregulation significantly suppressed the induction of dynamic allodynia. The over activation of microglia in the spinal dorsal horn after SNI was at least one of the triggers in SNI-induced mKCC2 reduction and dynamic allodynia, as these effects were blocked by the inhibition of microglial activation. Finally, the BDNF-TrkB pathway mediated by activated microglial affected SNI-induced dynamic allodynia through neuronal KCC2 downregulation. Overall, our findings revealed that activation of microglia through the BDNF-TrkB pathway affected neuronal KCC2 downregulation, contributing to dynamic allodynia induction in an SNI mouse model.
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Affiliation(s)
- Zihan Hu
- Department of Anesthesiology, School of Medicine, Tongji University, Shanghai tenth People’s Hospital, Shanghai, China
| | - Xinren Yu
- Department of Anesthesiology, School of Medicine, Tongji University, Shanghai tenth People’s Hospital, Shanghai, China
| | - Pei Chen
- Department of Anesthesiology, School of Medicine, Tongji University, Shanghai tenth People’s Hospital, Shanghai, China
| | - Keyu Jin
- Department of Anesthesiology, School of Medicine, Tongji University, Shanghai tenth People’s Hospital, Shanghai, China
| | - Jing Zhou
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
- Rehabilitation Center, First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen Second People’s Hospital, Shenzhen, China
| | - Guoxiang Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jiangning Yu
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Tong Wu
- Department of Anesthesiology, School of Medicine, Tongji University, Shanghai tenth People’s Hospital, Shanghai, China
| | - Yulong Wang
- Rehabilitation Center, First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen Second People’s Hospital, Shenzhen, China
| | - Fuqing Lin
- Department of Anesthesiology, School of Medicine, Tongji University, Shanghai tenth People’s Hospital, Shanghai, China
| | - Tingting Zhang
- Department of Anesthesiology, School of Medicine, Tongji University, Shanghai tenth People’s Hospital, Shanghai, China
| | - Yun Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xuan Zhao
- Department of Anesthesiology, School of Medicine, Tongji University, Shanghai tenth People’s Hospital, Shanghai, China
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17
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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.
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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,
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18
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Impaired synaptic plasticity in an animal model of autism exhibiting early hippocampal GABAergic-BDNF/TrkB signaling alterations. iScience 2022; 26:105728. [PMID: 36582822 PMCID: PMC9793278 DOI: 10.1016/j.isci.2022.105728] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/25/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
In Neurodevelopmental Disorders, alterations of synaptic plasticity may trigger structural changes in neuronal circuits involved in cognitive functions. This hypothesis was tested in mice carrying the human R451C mutation of Nlgn3 gene (NLG3R451C KI), found in some families with autistic children. To this aim, the spike time dependent plasticity (STDP) protocol was applied to immature GABAergic Mossy Fibers (MF)-CA3 connections in hippocampal slices from NLG3R451C KI mice. These animals failed to exhibit STD-LTP, an effect that persisted in adulthood when these synapses became glutamatergic. Similar results were obtained in mice lacking the Nlgn3 gene (NLG3 KO mice), suggesting a loss of function. The loss of STD-LTP was associated with a premature shift of GABA from the depolarizing to the hyperpolarizing direction, a reduced BDNF availability and TrkB phosphorylation at potentiated synapses. These effects may constitute a general mechanism underlying cognitive deficits in those forms of Autism caused by synaptic dysfunctions.
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19
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Rigkou A, Magyar A, Speer JM, Roussa E. TGF-β2 Regulates Transcription of the K +/Cl - Cotransporter 2 (KCC2) in Immature Neurons and Its Phosphorylation at T1007 in Differentiated Neurons. Cells 2022; 11:cells11233861. [PMID: 36497119 PMCID: PMC9739967 DOI: 10.3390/cells11233861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/28/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022] Open
Abstract
KCC2 mediates extrusion of K+ and Cl- and assuresthe developmental "switch" in GABA function during neuronal maturation. However, the molecular mechanisms underlying KCC2 regulation are not fully elucidated. We investigated the impact of transforming growth factor beta 2 (TGF-β2) on KCC2 during neuronal maturation using quantitative RT-PCR, immunoblotting, immunofluorescence and chromatin immunoprecipitation in primary mouse hippocampal neurons and brain tissue from Tgf-β2-deficient mice. Inhibition of TGF-β/activin signaling downregulates Kcc2 transcript in immature neurons. In the forebrain of Tgf-β2-/- mice, expression of Kcc2, transcription factor Ap2β and KCC2 protein is downregulated. AP2β binds to Kcc2 promoter, a binding absent in Tgf-β2-/-. In hindbrain/brainstem tissue of Tgf-β2-/- mice, KCC2 phosphorylation at T1007 is increased and approximately half of pre-Bötzinger-complex neurons lack membrane KCC2 phenotypes rescued through exogenous TGF-β2. These results demonstrate that TGF-β2 regulates KCC2 transcription in immature neurons, possibly acting upstream of AP2β, and contributes to the developmental dephosphorylation of KCC2 at T1007. The present work suggests multiple and divergent roles for TGF-β2 on KCC2 during neuronal maturation and provides novel mechanistic insights for TGF-β2-mediated regulation of KCC2 gene expression, posttranslational modification and surface expression. We propose TGF-β2 as a major regulator of KCC2 with putative implications for pathophysiological conditions.
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20
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Long-term effects of prenatal stress on the development of prefrontal cortex in the adolescent offspring. J Chem Neuroanat 2022; 125:102169. [DOI: 10.1016/j.jchemneu.2022.102169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 09/25/2022] [Accepted: 10/06/2022] [Indexed: 11/23/2022]
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21
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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).
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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
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22
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Arjun McKinney A, Petrova R, Panagiotakos G. Calcium and activity-dependent signaling in the developing cerebral cortex. Development 2022; 149:dev198853. [PMID: 36102617 PMCID: PMC9578689 DOI: 10.1242/dev.198853] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Calcium influx can be stimulated by various intra- and extracellular signals to set coordinated gene expression programs into motion. As such, the precise regulation of intracellular calcium represents a nexus between environmental cues and intrinsic genetic programs. Mounting genetic evidence points to a role for the deregulation of intracellular calcium signaling in neuropsychiatric disorders of developmental origin. These findings have prompted renewed enthusiasm for understanding the roles of calcium during normal and dysfunctional prenatal development. In this Review, we describe the fundamental mechanisms through which calcium is spatiotemporally regulated and directs early neurodevelopmental events. We also discuss unanswered questions about intracellular calcium regulation during the emergence of neurodevelopmental disease, and provide evidence that disruption of cell-specific calcium homeostasis and/or redeployment of developmental calcium signaling mechanisms may contribute to adult neurological disorders. We propose that understanding the normal developmental events that build the nervous system will rely on gaining insights into cell type-specific calcium signaling mechanisms. Such an understanding will enable therapeutic strategies targeting calcium-dependent mechanisms to mitigate disease.
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Affiliation(s)
- Arpana Arjun McKinney
- Graduate Program in Developmental and Stem Cell Biology, University of California, San Francisco, CA 94143, USA
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA 94143, USA
| | - Ralitsa Petrova
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA 94143, USA
| | - Georgia Panagiotakos
- Graduate Program in Developmental and Stem Cell Biology, University of California, San Francisco, CA 94143, USA
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA 94143, USA
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Microglial Dynamics Modulate Vestibular Compensation in a Rodent Model of Vestibulopathy and Condition the Expression of Plasticity Mechanisms in the Deafferented Vestibular Nuclei. Cells 2022; 11:cells11172693. [PMID: 36078101 PMCID: PMC9454928 DOI: 10.3390/cells11172693] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/17/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022] Open
Abstract
Unilateral vestibular loss (UVL) induces a vestibular syndrome composed of posturo-locomotor, oculomotor, vegetative, and perceptivo-cognitive symptoms. With time, these functional deficits progressively disappear due to a phenomenon called vestibular compensation, known to be supported by the expression in the deafferented vestibular nuclei (VNs) of various adaptative plasticity mechanisms. UVL is known to induce a neuroinflammatory response within the VNs, thought to be caused by the structural alteration of primary vestibular afferents. The acute inflammatory response, expressed in the deafferented VNs was recently proven to be crucial for the expression of the endogenous plasticity supporting functional recovery. Neuroinflammation is supported by reactive microglial cells, known to have various phenotypes with adverse effects on brain tissue. Here, we used markers of pro-inflammatory and anti-inflammatory phenotypes of reactive microglia to study microglial dynamics following a unilateral vestibular neurectomy (UVN) in the adult rat. In addition, to highlight the role of acute inflammation in vestibular compensation and its underlying mechanisms, we enhanced the inflammatory state of the deafferented VNs using systemic injections of lipopolysaccharide (LPS) during the acute phase after a UVN. We observed that the UVN induced the expression of both M1 proinflammatory and M2 anti-inflammatory microglial phenotypes in the deafferented VNs. The acute LPS treatment exacerbated the inflammatory reaction and increased the M1 phenotype while decreasing M2 expression. These effects were associated with impaired postlesional plasticity in the deafferented VNs and exacerbated functional deficits. These results highlight the importance of a homeostatic inflammatory level in the expression of the adaptative plasticity mechanisms underlying vestibular compensation. Understanding the rules that govern neuroinflammation would provide therapeutic leads in neuropathologies associated with these processes.
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Hui KK, Chater TE, Goda Y, Tanaka M. How Staying Negative Is Good for the (Adult) Brain: Maintaining Chloride Homeostasis and the GABA-Shift in Neurological Disorders. Front Mol Neurosci 2022; 15:893111. [PMID: 35875665 PMCID: PMC9305173 DOI: 10.3389/fnmol.2022.893111] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 06/10/2022] [Indexed: 01/27/2023] Open
Abstract
Excitatory-inhibitory (E-I) imbalance has been shown to contribute to the pathogenesis of a wide range of neurodevelopmental disorders including autism spectrum disorders, epilepsy, and schizophrenia. GABA neurotransmission, the principal inhibitory signal in the mature brain, is critically coupled to proper regulation of chloride homeostasis. During brain maturation, changes in the transport of chloride ions across neuronal cell membranes act to gradually change the majority of GABA signaling from excitatory to inhibitory for neuronal activation, and dysregulation of this GABA-shift likely contributes to multiple neurodevelopmental abnormalities that are associated with circuit dysfunction. Whilst traditionally viewed as a phenomenon which occurs during brain development, recent evidence suggests that this GABA-shift may also be involved in neuropsychiatric disorders due to the "dematuration" of affected neurons. In this review, we will discuss the cell signaling and regulatory mechanisms underlying the GABA-shift phenomenon in the context of the latest findings in the field, in particular the role of chloride cotransporters NKCC1 and KCC2, and furthermore how these regulatory processes are altered in neurodevelopmental and neuropsychiatric disorders. We will also explore the interactions between GABAergic interneurons and other cell types in the developing brain that may influence the GABA-shift. Finally, with a greater understanding of how the GABA-shift is altered in pathological conditions, we will briefly outline recent progress on targeting NKCC1 and KCC2 as a therapeutic strategy against neurodevelopmental and neuropsychiatric disorders associated with improper chloride homeostasis and GABA-shift abnormalities.
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Affiliation(s)
- Kelvin K. Hui
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, United States
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Thomas E. Chater
- Laboratory for Synaptic Plasticity and Connectivity, RIKEN Center for Brain Science, Wako, Japan
| | - Yukiko Goda
- Laboratory for Synaptic Plasticity and Connectivity, RIKEN Center for Brain Science, Wako, Japan
- Synapse Biology Unit, Okinawa Institute for Science and Technology Graduate University, Onna, Japan
| | - Motomasa Tanaka
- Laboratory for Protein Conformation Diseases, RIKEN Center for Brain Science, Wako, Japan
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25
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Patel DC, Thompson EG, Sontheimer H. Brain-Derived Neurotrophic Factor Inhibits the Function of Cation-Chloride Cotransporter in a Mouse Model of Viral Infection-Induced Epilepsy. Front Cell Dev Biol 2022; 10:961292. [PMID: 35874836 PMCID: PMC9304572 DOI: 10.3389/fcell.2022.961292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 06/20/2022] [Indexed: 11/15/2022] Open
Abstract
Well over 100 different viruses can infect the brain and cause brain inflammation. In the developing world, brain inflammation is a leading cause for epilepsy and often refractory to established anti-seizure drugs. Epilepsy generally results from an imbalance in excitatory glutamatergic and inhibitory GABAergic neurotransmission. GABAergic inhibition is determined by the intracellular Cl− concentration which is established through the opposing action of two cation chloride cotransporters namely NKCC1 and KCC2. Brain-derived neurotrophic factor (BDNF) signaling is known to regulate expression of KCC2. Hence we hypothesized that viral induced epilepsy may result from aberrant BDNF signaling. We tested this hypothesis using a mouse model of Theiler’s murine encephalomyelitis virus (TMEV) infection-induced epilepsy. We found that BDNF levels in the hippocampus from TMEV-infected mice with seizures was increased at the onset of acute seizures and continued to increase during the peak of acute seizure as well as in latent and chronic phases of epilepsy. During the acute phase of epilepsy, we found significant reduction in the expression of KCC2 in hippocampus, whereas the level of NKCC1 was unaltered. Importantly, inhibiting BDNF using scavenging bodies of BDNF in live brain slices from TMEV-infected mice with seizures normalized the level of KCC2 in hippocampus. Our results suggest that BDNF can directly decrease the relative expression of NKCC1 and KCC2 such as to favor accumulation of chloride intracellularly which in turn causes hyperexcitability by reversing GABA-mediated inhibition. Although our attempt to inhibit the BDNF signaling mediated through tyrosine kinase B–phospholipase Cγ1 (TrkB-PLCγ1) using a small peptide did not change the course of seizure development following TMEV infection, alternative strategies for controlling the BDNF signaling could be useful in preventing seizure generation and development of epilepsy in this model.
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Affiliation(s)
- Dipan C. Patel
- Glial Biology in Health, Disease, and Cancer Center, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA, United States
| | - Emily G. Thompson
- Glial Biology in Health, Disease, and Cancer Center, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA, United States
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Harald Sontheimer
- Glial Biology in Health, Disease, and Cancer Center, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA, United States
- School of Neuroscience, Virginia Tech, Blacksburg, VA, United States
- *Correspondence: Harald Sontheimer,
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26
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Neuroprotective effect of oxytocin on cognitive dysfunction, DNA damage, and intracellular chloride disturbance in young mice after cranial irradiation. Biochem Biophys Res Commun 2022; 612:1-7. [DOI: 10.1016/j.bbrc.2022.04.099] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 04/21/2022] [Indexed: 11/22/2022]
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27
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Llorca A, Deogracias R. Origin, Development, and Synaptogenesis of Cortical Interneurons. Front Neurosci 2022; 16:929469. [PMID: 35833090 PMCID: PMC9272671 DOI: 10.3389/fnins.2022.929469] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 06/01/2022] [Indexed: 11/13/2022] Open
Abstract
The mammalian cerebral cortex represents one of the most recent and astonishing inventions of nature, responsible of a large diversity of functions that range from sensory processing to high-order cognitive abilities, such as logical reasoning or language. Decades of dedicated study have contributed to our current understanding of this structure, both at structural and functional levels. A key feature of the neocortex is its outstanding richness in cell diversity, composed by multiple types of long-range projecting neurons and locally connecting interneurons. In this review, we will describe the great diversity of interneurons that constitute local neocortical circuits and summarize the mechanisms underlying their development and their assembly into functional networks.
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Affiliation(s)
- Alfredo Llorca
- Visual Neuroscience Laboratory, Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, Edinburg, United Kingdom
- *Correspondence: Alfredo Llorca
| | - Ruben Deogracias
- Neuronal Circuits Formation and Brain Disorders Laboratory, Institute of Neurosciences of Castilla y León (INCyL), University of Salamanca, Salamanca, Spain
- Institute of Biomedical Research of Salamanca, Salamanca, Spain
- Department of Cell Biology and Pathology, School of Medicine, University of Salamanca, Salamanca, Spain
- Ruben Deogracias
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28
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Chen L, Yu J, Wan L, Wu Z, Wang G, Hu Z, Ren L, Zhou J, Qian B, Zhao X, Zhang J, Liu X, Wang Y. Furosemide prevents membrane KCC2 downregulation during convulsant stimulation in the hippocampus. IBRO Neurosci Rep 2022; 12:355-365. [PMID: 35746976 PMCID: PMC9210493 DOI: 10.1016/j.ibneur.2022.04.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/15/2022] [Accepted: 04/25/2022] [Indexed: 02/08/2023] Open
Abstract
In adults, γ-aminobutyric acid (GABA) type A receptor (GABAAR)-mediated inhibition depends on the maintenance of low intracellular chloride anion concentration through neuron-specific potassium-chloride cotransporter-2 (KCC2). KCC2 has been widely reported to have a plasticity change during the course of epilepsy development, with an early downregulation and late recovery in neuronal cell membranes after epileptic stimulation, which facilitates epileptiform burst activity. Furosemide is a clinical loop diuretic that inhibits KCC2. Here, we first confirmed that furosemide pretreatment could effectively prevented convulsant stimulation-induced neuronal membrane KCC2 downregulation in the hippocampus in both in vivo and in vitro cyclothiazide-induced seizure model. Second, we verified that furosemide pretreatment rescued KCC2 function deficits, as indicated by E GABA depolarizing shift and GABAAR inhibitory function impairment induced via cyclothiazide treatment. Further, we demonstrated that furosemide also suppressed cyclothiazide-induced epileptiform burst activity in cultured hippocampal neurons and lowered the mortality rate during acute seizure induction. Overall, furosemide prevents membrane KCC2 downregulation during acute seizure induction, restores KCC2-mediated GABA inhibition, and interrupts the progression from acute seizure to epileptogenesis.
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Affiliation(s)
- Lulan Chen
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Jiangning Yu
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Li Wan
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
- Rehabilitation Center, Shenzhen Second People's Hospital/ the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518035, China Institute of
| | - Zheng Wu
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Guoxiang Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Zihan Hu
- Department of Anesthesiology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
| | - Liang Ren
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Jing Zhou
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
- Rehabilitation Center, Shenzhen Second People's Hospital/ the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518035, China Institute of
| | - Binbin Qian
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Xuan Zhao
- Department of Anesthesiology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
- Correspondence to: Department of Anesthesiology, Shanghai Tenth People’s Hospital, China.
| | - Jinwei Zhang
- Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, Hatherly Laboratories, Exeter EX4 4PS, UK
| | - Xu Liu
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
- Correspondence to: Department of Neurology, Zhongshan Hospital, Fudan University, China.
| | - Yun Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
- Correspondence to: Institutes of Brain Science, Fudan University, Shanghai 200032, China.
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29
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Boychuk JA, Butler CR, Smith KC, Halmos MB, Smith BN. Zolpidem Profoundly Augments Spared Tonic GABAAR Signaling in Dentate Granule Cells Ipsilateral to Controlled Cortical Impact Brain Injury in Mice. Front Syst Neurosci 2022; 16:867323. [PMID: 35694044 PMCID: PMC9178240 DOI: 10.3389/fnsys.2022.867323] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/05/2022] [Indexed: 11/18/2022] Open
Abstract
Type A GABA receptors (GABAARs) are pentameric combinations of protein subunits that give rise to tonic (ITonicGABA) and phasic (i.e., synaptic; ISynapticGABA) forms of inhibitory GABAAR signaling in the central nervous system. Remodeling and regulation of GABAAR protein subunits are implicated in a wide variety of healthy and injury-dependent states, including epilepsy. The present study undertook a detailed analysis of GABAAR signaling using whole-cell patch clamp recordings from mouse dentate granule cells (DGCs) in coronal slices containing dorsal hippocampus at 1–2 or 8–13 weeks after a focal, controlled cortical impact (CCI) or sham brain injury. Zolpidem, a benzodiazepine-like positive modulator of GABAARs, was used to test for changes in GABAAR signaling of DGCs due to its selectivity for α1 subunit-containing GABAARs. Electric charge transfer and statistical percent change were analyzed in order to directly compare tonic and phasic GABAAR signaling and to account for zolpidem’s ability to modify multiple parameters of GABAAR kinetics. We observed that baseline ITonicGABA is preserved at both time-points tested in DGCs ipsilateral to injury (Ipsi-DGCs) compared to DGCs contralateral to injury (Contra-DGCs) or after sham injury (Sham-DGCs). Interestingly, application of zolpidem resulted in modulation of ITonicGABA across groups, with Ipsi-DGCs exhibiting the greatest responsiveness to zolpidem. We also report that the combination of CCI and acute application of zolpidem profoundly augments the proportion of GABAAR charge transfer mediated by tonic vs. synaptic currents at both time-points tested, whereas gene expression of GABAAR α1, α2, α3, and γ2 subunits is unchanged at 8–13 weeks post-injury. Overall, this work highlights the shift toward elevated influence of tonic inhibition in Ipsi-DGCs, the impact of zolpidem on all components of inhibitory control of DGCs, and the sustained nature of these changes in inhibitory tone after CCI injury.
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Affiliation(s)
- Jeffery A Boychuk
- Department of Physiology, University of Kentucky, Lexington, KY, United States
- Department of Cellular and Integrative Physiology, UT Health San Antonio, San Antonio, TX, United States
| | - Corwin R Butler
- Department of Physiology, University of Kentucky, Lexington, KY, United States
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Katalin Cs Smith
- Department of Physiology, University of Kentucky, Lexington, KY, United States
- Department of Neuroscience, University of Kentucky, Lexington, KY, United States
| | - Miklos B Halmos
- Department of Psychology, Georgia State University, Atlanta, GA, United States
| | - Bret N Smith
- Department of Physiology, University of Kentucky, Lexington, KY, United States
- Department of Neuroscience, University of Kentucky, Lexington, KY, United States
- Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, KY, United States
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, United States
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30
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Why won't it stop? The dynamics of benzodiazepine resistance in status epilepticus. Nat Rev Neurol 2022; 18:428-441. [PMID: 35538233 DOI: 10.1038/s41582-022-00664-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/19/2022] [Indexed: 11/08/2022]
Abstract
Status epilepticus is a life-threatening neurological emergency that affects both adults and children. Approximately 36% of episodes of status epilepticus do not respond to the current preferred first-line treatment, benzodiazepines. The proportion of episodes that are refractory to benzodiazepines is higher in low-income and middle-income countries (LMICs) than in high-income countries (HICs). Evidence suggests that longer episodes of status epilepticus alter brain physiology, thereby contributing to the emergence of benzodiazepine resistance. Such changes include alterations in GABAA receptor function and in the transmembrane gradient for chloride, both of which erode the ability of benzodiazepines to enhance inhibitory synaptic signalling. Often, current management guidelines for status epilepticus do not account for these duration-related changes in pathophysiology, which might differentially impact individuals in LMICs, where the average time taken to reach medical attention is longer than in HICs. In this Perspective article, we aim to combine clinical insights and the latest evidence from basic science to inspire a new, context-specific approach to efficiently managing status epilepticus.
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31
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NKCC1 Deficiency in Forming Hippocampal Circuits Triggers Neurodevelopmental Disorder: Role of BDNF-TrkB Signalling. Brain Sci 2022; 12:brainsci12040502. [PMID: 35448033 PMCID: PMC9030861 DOI: 10.3390/brainsci12040502] [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: 03/06/2022] [Revised: 04/06/2022] [Accepted: 04/12/2022] [Indexed: 12/10/2022] Open
Abstract
The time-sensitive GABA shift from excitatory to inhibitory is critical in early neural circuits development and depends upon developmentally regulated expression of cation-chloride cotransporters NKCC1 and KCC2. NKCC1, encoded by the SLC12A2 gene, regulates neuronal Cl− homeostasis by chloride import working opposite KCC2. The high NKCC1/KCC2 expression ratio decreases in early neural development contributing to GABA shift. Human SLC12A2 loss-of-function mutations were recently associated with a multisystem disorder affecting neural development. However, the multisystem phenotype of rodent Nkcc1 knockout models makes neurodevelopment challenging to study. Brain-Derived Neurotrophic Factor (BDNF)-NTRK2/TrkB signalling controls KCC2 expression during neural development, but its impact on NKCC1 is still controversial. Here, we discuss recent evidence supporting BDNF-TrkB signalling controlling Nkcc1 expression and the GABA shift during hippocampal circuit formation. Namely, specific deletion of Ntrk2/Trkb from immature mouse hippocampal dentate granule cells (DGCs) affects their integration and maturation in the hippocampal circuitry and reduces Nkcc1 expression in their target region, the CA3 principal cells, leading to premature GABA shift, ultimately influencing the establishment of functional hippocampal circuitry and animal behaviour in adulthood. Thus, immature DGCs emerge as a potential therapeutic target as GABAergic transmission is vital for specific neural progenitors generating dentate neurogenesis in early development and the mature brain.
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Lam P, Vinnakota C, Guzmán BCF, Newland J, Peppercorn K, Tate WP, Waldvogel HJ, Faull RLM, Kwakowsky A. Beta-Amyloid (Aβ 1-42) Increases the Expression of NKCC1 in the Mouse Hippocampus. Molecules 2022; 27:2440. [PMID: 35458638 PMCID: PMC9027496 DOI: 10.3390/molecules27082440] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/22/2022] [Accepted: 04/06/2022] [Indexed: 11/16/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder with an increasing need for developing disease-modifying treatments as current therapies only provide marginal symptomatic relief. Recent evidence suggests the γ-aminobutyric acid (GABA) neurotransmitter system undergoes remodeling in AD, disrupting the excitatory/inhibitory (E/I) balance in the brain. Altered expression levels of K-Cl-2 (KCC2) and N-K-Cl-1 (NKCC1), which are cation-chloride cotransporters (CCCs), have been implicated in disrupting GABAergic activity by regulating GABAA receptor signaling polarity in several neurological disorders, but these have not yet been explored in AD. NKCC1 and KCC2 regulate intracellular chloride [Cl-]i by accumulating and extruding Cl-, respectively. Increased NKCC1 expression in mature neurons has been reported in these disease conditions, and bumetanide, an NKCC1 inhibitor, is suggested to show potential therapeutic benefits. This study used primary mouse hippocampal neurons to explore if KCC2 and NKCC1 expression levels are altered following beta-amyloid (Aβ1-42) treatment and the potential neuroprotective effects of bumetanide. KCC2 and NKCC1 expression levels were also examined in 18-months-old male C57BL/6 mice following bilateral hippocampal Aβ1-42 stereotaxic injection. No change in KCC2 and NKCC1 expression levels were observed in mouse hippocampal neurons treated with 1 nM Aβ1-42, but NKCC1 expression increased 30-days post-Aβ1-42-injection in the CA1 region of the mouse hippocampus. Primary mouse hippocampal cultures were treated with 1 nM Aβ1-42 alone or with various concentrations of bumetanide (1 µM, 10 µM, 100 µM, 1 mM) to investigate the effect of the drug on cell viability. Aβ1-42 produced 53.1 ± 1.4% cell death after 5 days, and the addition of bumetanide did not reduce this. However, the drug at all concentrations significantly reduced cell viability, suggesting bumetanide is highly neurotoxic. In summary, these results suggest that chronic exposure to Aβ1-42 alters the balance of KCC2 and NKCC1 expression in a region-and layer-specific manner in mouse hippocampal tissue; therefore, this process most likely contributes to altered hippocampal E/I balance in this model. Furthermore, bumetanide induces hippocampal neurotoxicity, thus questioning its suitability for AD therapy. Further investigations are required to examine the effects of Aβ1-42 on KCC2 and NKCC1 expression and whether targeting CCCs might offer a therapeutic approach for AD.
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Affiliation(s)
- Patricia Lam
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (P.L.); (C.V.); (B.C.-F.G.); (J.N.); (H.J.W.); (R.L.M.F.)
| | - Chitra Vinnakota
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (P.L.); (C.V.); (B.C.-F.G.); (J.N.); (H.J.W.); (R.L.M.F.)
| | - Beatriz Calvo-Flores Guzmán
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (P.L.); (C.V.); (B.C.-F.G.); (J.N.); (H.J.W.); (R.L.M.F.)
| | - Julia Newland
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (P.L.); (C.V.); (B.C.-F.G.); (J.N.); (H.J.W.); (R.L.M.F.)
| | - Katie Peppercorn
- Department of Biochemistry, University of Otago, Dunedin 9054, New Zealand; (K.P.); (W.P.T.)
| | - Warren P. Tate
- Department of Biochemistry, University of Otago, Dunedin 9054, New Zealand; (K.P.); (W.P.T.)
| | - Henry J. Waldvogel
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (P.L.); (C.V.); (B.C.-F.G.); (J.N.); (H.J.W.); (R.L.M.F.)
| | - Richard L. M. Faull
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (P.L.); (C.V.); (B.C.-F.G.); (J.N.); (H.J.W.); (R.L.M.F.)
| | - Andrea Kwakowsky
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (P.L.); (C.V.); (B.C.-F.G.); (J.N.); (H.J.W.); (R.L.M.F.)
- Pharmacology and Therapeutics, Galway Neuroscience Centre, School of Medicine, National University of Ireland Galway, H91 W5P7 Galway, Ireland
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Okumo T, Takayama Y, Maruyama K, Kato M, Sunagawa M. Senso-Immunologic Prospects for Complex Regional Pain Syndrome Treatment. Front Immunol 2022; 12:786511. [PMID: 35069559 PMCID: PMC8767061 DOI: 10.3389/fimmu.2021.786511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/13/2021] [Indexed: 12/14/2022] Open
Abstract
Complex regional pain syndrome (CRPS) is a chronic pain syndrome that occurs in tissue injuries as the result of surgery, trauma, or ischemia. The clinical features of this severely painful condition include redness and swelling of the affected skin. Intriguingly, it was recently suggested that transient receptor potential ankyrin 1 (TRPA1) is involved in chronic post-ischemia pain, a CRPS model. TRPA1 is a non-selective cation channel expressed in calcitonin gene-related peptide (CGRP)-positive primary nociceptors that becomes highly activated in ischemic conditions, leading to the generation of pain. In this review, we summarize the history of TRPA1 and its involvement in pain sensation, inflammation, and CRPS. Furthermore, bone atrophy is also thought to be a characteristic clinical sign of CRPS. The altered bone microstructure of CRPS patients is thought to be caused by aggravated bone resorption via enhanced osteoclast differentiation and activation. Although TRPA1 could be a target for pain treatment in CRPS patients, we also discuss the paradoxical situation in this review. Nociceptor activation decreases the risk of bone destruction via CGRP secretion from free nerve endings. Thus, TRPA1 inhibition could cause severe bone atrophy. However, the suitable therapeutic strategy is controversial because the pathologic mechanisms of bone atrophy in CRPS are unclear. Therefore, we propose focusing on the remission of abnormal bone turnover observed in CRPS using a recently developed concept: senso-immunology.
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Affiliation(s)
- Takayuki Okumo
- Department of Physiology, Showa University School of Medicine, Shinagawa, Japan
| | - Yasunori Takayama
- Department of Physiology, Showa University School of Medicine, Shinagawa, Japan
| | - Kenta Maruyama
- Department of Physiology, Showa University School of Medicine, Shinagawa, Japan.,Division of Cell Signaling, National Institute for Physiological Sciences, Natural Institutes for Natural Sciences, Okazaki, Japan
| | - Mami Kato
- Department of Physiology, Showa University School of Medicine, Shinagawa, Japan.,Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Masataka Sunagawa
- Department of Physiology, Showa University School of Medicine, Shinagawa, Japan
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Caravagna C, Casciato A, Coq JO, Liabeuf S, Brocard C, Peyronnet J, Bodineau L, Cayetanot F. Prenatal Hypoxia Induces Cl– Cotransporters KCC2 and NKCC1 Developmental Abnormality and Disturbs the Influence of GABAA and Glycine Receptors on Fictive Breathing in a Newborn Rat. Front Physiol 2022; 13:786714. [PMID: 35250609 PMCID: PMC8890663 DOI: 10.3389/fphys.2022.786714] [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: 09/30/2021] [Accepted: 01/17/2022] [Indexed: 11/13/2022] Open
Abstract
Prenatal hypoxia is a recognised risk factor for neurodevelopmental disorders associated with both membrane proteins involved in neuron homeostasis, e.g., chloride (Cl–) cotransporters, and alterations in brain neurotransmitter systems, e.g., catecholamines, dopamine, and GABA. Our study aimed to determine whether prenatal hypoxia alters central respiratory drive by disrupting the development of Cl– cotransporters KCC2 and NKCC1. Cl– homeostasis seems critical for the strength and efficiency of inhibition mediated by GABAA and glycine receptors within the respiratory network, and we searched for alterations of GABAergic and glycinergic respiratory influences after prenatal hypoxia. We measured fictive breathing from brainstem in ex vivo preparations during pharmacological blockade of KCC2 and NKCC1 Cl– cotransporters, GABAA, and glycine receptors. We also evaluated the membrane expression of Cl– cotransporters in the brainstem by Western blot and the expression of Cl– cotransporter regulators brain-derived neurotrophic factor (BDNF) and calpain. First, pharmacological experiments showed that prenatal hypoxia altered the regulation of fictive breathing by NKCC1 and KCC2 Cl– cotransporters, GABA/GABAA, and glycin. NKCC1 inhibition decreased fictive breathing at birth in control mice while it decreased at 4 days after birth in pups exposed to prenatal hypoxia. On the other hand, inhibition of KCC2 decreased fictive breathing 4 days after birth in control mice without any change in prenatal hypoxia pups. The GABAergic system appeared to be more effective in prenatal hypoxic pups whereas the glycinergic system increased its effectiveness later. Second, we observed a decrease in the expression of the Cl– cotransporter KCC2, and a decrease with age in NKCC1, as well as an increase in the expression of BDNF and calpain after prenatal hypoxia exposure. Altogether, our data support the idea that prenatal hypoxia alters the functioning of GABAA and glycinergic systems in the respiratory network by disrupting maturation of Cl– homeostasis, thereby contributing to long-term effects by disrupting ventilation.
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Affiliation(s)
- Céline Caravagna
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, and Harvard Medical School, Boston, MA, United States
| | - Alexis Casciato
- Sorbonne Université, Inserm UMR_S1158, Neurophysiologie Respiratoire Expérimentale et Clinique, Faculté de Médecine Site Pitié-Salpétrière, Paris, France
| | - Jacques-Olivier Coq
- Institut de Neurosciences de la Timone, UMR 7289, CNRS, Aix-Marseille Université, Marseille, France
| | - Sylvie Liabeuf
- Institut de Neurosciences de la Timone, UMR 7289, CNRS, Aix-Marseille Université, Marseille, France
| | - Cécile Brocard
- Institut de Neurosciences de la Timone, UMR 7289, CNRS, Aix-Marseille Université, Marseille, France
| | - Julie Peyronnet
- Institut de Neurosciences de la Timone, UMR 7289, CNRS, Aix-Marseille Université, Marseille, France
| | - Laurence Bodineau
- Sorbonne Université, Inserm UMR_S1158, Neurophysiologie Respiratoire Expérimentale et Clinique, Faculté de Médecine Site Pitié-Salpétrière, Paris, France
| | - Florence Cayetanot
- Sorbonne Université, Inserm UMR_S1158, Neurophysiologie Respiratoire Expérimentale et Clinique, Faculté de Médecine Site Pitié-Salpétrière, Paris, France
- *Correspondence: Florence Cayetanot,
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L-Thyroxine Improves Vestibular Compensation in a Rat Model of Acute Peripheral Vestibulopathy: Cellular and Behavioral Aspects. Cells 2022; 11:cells11040684. [PMID: 35203333 PMCID: PMC8869897 DOI: 10.3390/cells11040684] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 02/07/2023] Open
Abstract
Unilateral vestibular lesions induce a vestibular syndrome, which recovers over time due to vestibular compensation. The therapeutic effect of L-Thyroxine (L-T4) on vestibular compensation was investigated by behavioral testing and immunohistochemical analysis in a rat model of unilateral vestibular neurectomy (UVN). We demonstrated that a short-term L-T4 treatment reduced the vestibular syndrome and significantly promoted vestibular compensation. Thyroid hormone receptors (TRα and TRβ) and type II iodothyronine deiodinase (DIO2) were present in the vestibular nuclei (VN), supporting a local action of L-T4. We confirmed the T4-induced metabolic effects by demonstrating an increase in the number of cytochrome oxidase-labeled neurons in the VN three days after the lesion. L-T4 treatment modulated glial reaction by decreasing both microglia and oligodendrocytes in the deafferented VN three days after UVN and increased cell proliferation. Survival of newly generated cells in the deafferented vestibular nuclei was not affected, but microglial rather than neuronal differentiation was favored by L-T4 treatment.
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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.
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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.)
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Serranilla M, Woodin MA. Striatal Chloride Dysregulation and Impaired GABAergic Signaling Due to Cation-Chloride Cotransporter Dysfunction in Huntington’s Disease. Front Cell Neurosci 2022; 15:817013. [PMID: 35095429 PMCID: PMC8795088 DOI: 10.3389/fncel.2021.817013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 12/24/2021] [Indexed: 11/13/2022] Open
Abstract
Intracellular chloride (Cl–) levels in mature neurons must be tightly regulated for the maintenance of fast synaptic inhibition. In the mature central nervous system (CNS), synaptic inhibition is primarily mediated by gamma-amino butyric acid (GABA), which binds to Cl– permeable GABAA receptors (GABAARs). The intracellular Cl– concentration is primarily maintained by the antagonistic actions of two cation-chloride cotransporters (CCCs): Cl–-importing Na+-K+-Cl– co-transporter-1 (NKCC1) and Cl– -exporting K+-Cl– co-transporter-2 (KCC2). In mature neurons in the healthy brain, KCC2 expression is higher than NKCC1, leading to lower levels of intracellular Cl–, and Cl– influx upon GABAAR activation. However, in neurons of the immature brain or in neurological disorders such as epilepsy and traumatic brain injury, impaired KCC2 function and/or enhanced NKCC1 expression lead to intracellular Cl– accumulation and GABA-mediated excitation. In Huntington’s disease (HD), KCC2- and NKCC1-mediated Cl–-regulation are also altered, which leads to GABA-mediated excitation and contributes to the development of cognitive and motor impairments. This review summarizes the role of Cl– (dys)regulation in the healthy and HD brain, with a focus on the basal ganglia (BG) circuitry and CCCs as potential therapeutic targets in the treatment of HD.
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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: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 08/31/2021] [Accepted: 10/17/2021] [Indexed: 11/21/2022] Open
Abstract
The K+-Cl- cotransporter KCC2, encoded by the Slc12a5 gene, is a neuron-specific chloride extruder that tunes the strength and polarity of GABAA receptor-mediated transmission. In addition to its canonical ion transport function, KCC2 also regulates spinogenesis and excitatory synaptic function through interaction with a variety of molecular partners. KCC2 is enriched in the vicinity of both glutamatergic and GABAergic synapses, the activity of which in turn regulates its membrane stability and function. KCC2 interaction with the submembrane actin cytoskeleton via 4.1N is known to control its anchoring near glutamatergic synapses on dendritic spines. However, the molecular determinants of KCC2 clustering near GABAergic synapses remain unknown. Here, we used proteomics to identify novel KCC2 interacting proteins in the adult rat neocortex. We identified both known and novel candidate KCC2 partners, including some involved in neuronal development and synaptic transmission. These include gephyrin, the main scaffolding molecule at GABAergic synapses. Gephyrin interaction with endogenous KCC2 was confirmed by immunoprecipitation from rat neocortical extracts. We showed that gephyrin stabilizes plasmalemmal KCC2 and promotes its clustering in hippocampal neurons, mostly but not exclusively near GABAergic synapses, thereby controlling KCC2-mediated chloride extrusion. This study identifies gephyrin as a novel KCC2 anchoring molecule that regulates its membrane expression and function in cortical neurons.SIGNIFICANCE STATEMENT Fast synaptic inhibition in the brain is mediated by chloride-permeable GABAA receptors (GABAARs) and therefore relies on transmembrane chloride gradients. In neurons, these gradients are primarily maintained by the K/Cl cotransporter KCC2. Therefore, understanding the mechanisms controlling KCC2 expression and function is crucial to understand its physiological regulation and rescue its function in the pathology. KCC2 function depends on its membrane expression and clustering, but the underlying mechanisms remain unknown. We describe the interaction between KCC2 and gephyrin, the main scaffolding protein at inhibitory synapses. We show that gephyrin controls plasmalemmal KCC2 clustering and that loss of gephyrin compromises KCC2 function. Our data suggest functional units comprising GABAARs, gephyrin, and KCC2 act to regulate synaptic GABA signaling.
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Affiliation(s)
- Sana Al Awabdh
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Florian Donneger
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Marie Goutierre
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Martial Séveno
- BCM, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Oana Vigy
- IGF, Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France
| | - Pauline Weinzettl
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
- Institute of Biotechnology, University of Applied Sciences, Krems, Austria
| | - Marion Russeau
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Imane Moutkine
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Sabine Lévi
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Philippe Marin
- IGF, Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France
| | - Jean Christophe Poncer
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
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Branchereau P, Cattaert D. Chloride Homeostasis in Developing Motoneurons. ADVANCES IN NEUROBIOLOGY 2022; 28:45-61. [PMID: 36066820 DOI: 10.1007/978-3-031-07167-6_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Maturation of GABA/Glycine chloride-mediated synaptic inhibitions is crucial for the establishment of a balance between excitation and inhibition. GABA and glycine are excitatory neurotransmitters on immature neurons that exhibit elevated [Cl-]i. Later in development [Cl-]i drops leading to the occurrence of inhibitory synaptic activity. This ontogenic change is closely correlated to a differential expression of two cation-chloride cotransporters that are the Cl- channel K+/Cl- co-transporter type 2 (KCC2) that extrudes Cl- ions and the Na+-K+-2Cl- cotransporter NKCC1 that accumulates Cl- ions. The classical scheme built from studies performed on cortical and hippocampal networks proposes that immature neurons display high [Cl-]i because NKCC1 is overexpressed compared to KCC2 and that the co-transporters ratio reverses in mature neurons, lowering [Cl-]i. In this chapter, we will see that this classical scheme is not true in motoneurons (MNs) and that an early alteration of the chloride homeostasis may be involved in pathological conditions.
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Affiliation(s)
- Pascal Branchereau
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), Univ. Bordeaux, UMR 5287, CNRS, Bordeaux, France.
| | - Daniel Cattaert
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), Univ. Bordeaux, UMR 5287, CNRS, Bordeaux, France
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Hamze M, Medina I, Delmotte Q, Porcher C. Contribution of Smoothened Receptor Signaling in GABAergic Neurotransmission and Chloride Homeostasis in the Developing Rodent Brain. Front Physiol 2021; 12:798066. [PMID: 34955901 PMCID: PMC8703190 DOI: 10.3389/fphys.2021.798066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/17/2021] [Indexed: 11/13/2022] Open
Abstract
In the early stages of the central nervous system growth and development, γ-aminobutyric acid (GABA) plays an instructive trophic role for key events including neurogenesis, migration, synaptogenesis, and network formation. These actions are associated with increased concentration of chloride ions in immature neurons [(Cl−)i] that determines the depolarizing strength of ion currents mediated by GABAA receptors, a ligand-gated Cl− permeable ion channel. During neuron maturation the (Cl−)i progressively decreases leading to weakening of GABA induced depolarization and enforcing GABA function as principal inhibitory neurotransmitter. A neuron restricted potassium-chloride co-transporter KCC2 is a key molecule governing Cl− extrusion and determining the resting level of (Cl−)i in developing and mature mammalian neurons. Among factors controlling the functioning of KCC2 and the maturation of inhibitory circuits, is Smoothened (Smo), the transducer in the receptor complex of the developmental protein Sonic Hedgehog (Shh). Too much or too little Shh-Smo action will have mirror effects on KCC2 stability at the neuron membrane, the GABA inhibitory strength, and ultimately on the newborn susceptibility to neurodevelopmental disorders. Both canonical and non-canonical Shh-Smo signal transduction pathways contribute to the regulation of KCC2 and GABAergic synaptic activity. In this review, we discuss the recent findings of the action of Shh-Smo signaling pathways on chloride ions homeostasis through the control of KCC2 membrane trafficking, and consequently on inhibitory neurotransmission and network activity during postnatal development.
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Affiliation(s)
- Mira Hamze
- Aix-Marseille University, INSERM, INMED, Parc Scientifique de Luminy, Marseille, France.,INSERM (Institut National de la Santé et de la Recherche Médicale) Unité, Parc Scientifique de Luminy, Marseille, France.,INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Igor Medina
- Aix-Marseille University, INSERM, INMED, Parc Scientifique de Luminy, Marseille, France.,INSERM (Institut National de la Santé et de la Recherche Médicale) Unité, Parc Scientifique de Luminy, Marseille, France.,INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Quentin Delmotte
- Aix-Marseille University, INSERM, INMED, Parc Scientifique de Luminy, Marseille, France.,INSERM (Institut National de la Santé et de la Recherche Médicale) Unité, Parc Scientifique de Luminy, Marseille, France.,INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Christophe Porcher
- Aix-Marseille University, INSERM, INMED, Parc Scientifique de Luminy, Marseille, France.,INSERM (Institut National de la Santé et de la Recherche Médicale) Unité, Parc Scientifique de Luminy, Marseille, France.,INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, Marseille, France
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Marouane E, El Mahmoudi N, Rastoldo G, Péricat D, Watabe I, Lapôtre A, Tonetto A, Xavier F, Dumas O, Chabbert C, Artzner V, Tighilet B. Sensorimotor Rehabilitation Promotes Vestibular Compensation in a Rodent Model of Acute Peripheral Vestibulopathy by Promoting Microgliogenesis in the Deafferented Vestibular Nuclei. Cells 2021; 10:3377. [PMID: 34943885 PMCID: PMC8699190 DOI: 10.3390/cells10123377] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 11/26/2021] [Accepted: 11/29/2021] [Indexed: 12/16/2022] Open
Abstract
Acute peripheral vestibulopathy leads to a cascade of symptoms involving balance and gait disorders that are particularly disabling for vestibular patients. Vestibular rehabilitation protocols have proven to be effective in improving vestibular compensation in clinical practice. Yet, the underlying neurobiological correlates remain unknown. The aim of this study was to highlight the behavioural and cellular consequences of a vestibular rehabilitation protocol adapted to a rat model of unilateral vestibular neurectomy. We developed a progressive sensory-motor rehabilitation task, and the behavioural consequences were quantified using a weight-distribution device. This analysis method provides a precise and ecological analysis of posturolocomotor vestibular deficits. At the cellular level, we focused on the analysis of plasticity mechanisms expressed in the vestibular nuclei. The results obtained show that vestibular rehabilitation induces a faster recovery of posturolocomotor deficits during vestibular compensation associated with a decrease in neurogenesis and an increase in microgliogenesis in the deafferented medial vestibular nucleus. This study reveals for the first time a part of the underlying adaptative neuroplasticity mechanisms of vestibular rehabilitation. These original data incite further investigation of the impact of rehabilitation on animal models of vestibulopathy. This new line of research should improve the management of vestibular patients.
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Affiliation(s)
- Emna Marouane
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint-Charles Case C, 3 Place Victor Hugo, CEDEX 03, 13331 Marseille, France; (E.M.); (N.E.M.); (G.R.); (I.W.); (A.L.); (F.X.); (C.C.)
- BIOSEB ALLCAT Instruments, Couperigne, 13127 Vitrolles, France;
| | - Nada El Mahmoudi
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint-Charles Case C, 3 Place Victor Hugo, CEDEX 03, 13331 Marseille, France; (E.M.); (N.E.M.); (G.R.); (I.W.); (A.L.); (F.X.); (C.C.)
| | - Guillaume Rastoldo
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint-Charles Case C, 3 Place Victor Hugo, CEDEX 03, 13331 Marseille, France; (E.M.); (N.E.M.); (G.R.); (I.W.); (A.L.); (F.X.); (C.C.)
| | - David Péricat
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, 31400 Toulouse, France;
| | - Isabelle Watabe
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint-Charles Case C, 3 Place Victor Hugo, CEDEX 03, 13331 Marseille, France; (E.M.); (N.E.M.); (G.R.); (I.W.); (A.L.); (F.X.); (C.C.)
| | - Agnès Lapôtre
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint-Charles Case C, 3 Place Victor Hugo, CEDEX 03, 13331 Marseille, France; (E.M.); (N.E.M.); (G.R.); (I.W.); (A.L.); (F.X.); (C.C.)
| | - Alain Tonetto
- Fédération de Recherche Sciences Chimiques Marseille FR 1739, Pôle 18 PRATIM, CEDEX 03, 13331 Marseille, France;
| | - Frédéric Xavier
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint-Charles Case C, 3 Place Victor Hugo, CEDEX 03, 13331 Marseille, France; (E.M.); (N.E.M.); (G.R.); (I.W.); (A.L.); (F.X.); (C.C.)
- GDR Physiopathologie Vestibulaire—Unité GDR2074, CNRS, 13003 Marseille, France;
| | - Olivier Dumas
- GDR Physiopathologie Vestibulaire—Unité GDR2074, CNRS, 13003 Marseille, France;
| | - Christian Chabbert
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint-Charles Case C, 3 Place Victor Hugo, CEDEX 03, 13331 Marseille, France; (E.M.); (N.E.M.); (G.R.); (I.W.); (A.L.); (F.X.); (C.C.)
- GDR Physiopathologie Vestibulaire—Unité GDR2074, CNRS, 13003 Marseille, France;
| | - Vincent Artzner
- BIOSEB ALLCAT Instruments, Couperigne, 13127 Vitrolles, France;
| | - Brahim Tighilet
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint-Charles Case C, 3 Place Victor Hugo, CEDEX 03, 13331 Marseille, France; (E.M.); (N.E.M.); (G.R.); (I.W.); (A.L.); (F.X.); (C.C.)
- GDR Physiopathologie Vestibulaire—Unité GDR2074, CNRS, 13003 Marseille, France;
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Zhou Y, Cheng Y, Li Y, Ma J, Wu Z, Chen Y, Mei J, Chen M. Soluble β-amyloid impaired the GABA inhibition by mediating KCC2 in early APP/PS1 mice. Biosci Trends 2021; 15:330-340. [PMID: 34526443 DOI: 10.5582/bst.2021.01245] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder, which has become the leading cause of dementia cases globally. Synaptic failure is an early pathological feature of AD. However, the cause of synaptic failure in AD, especially the GABAergic synaptic activity remains unclear. Extensive evidence indicates that the presence of soluble amyloid-β is an early pathological feature in AD, which triggers synaptic dysfunction and cognitive decline. Our recent study explored the relation of GABAergic transmission and soluble Aβ in early APP/PS1 mice. Firstly, we found soluble Aβ42 levels were significantly increased in serum, hippocampus and prefrontal cortex in 3-4 months APP/PS1 mice, which was much earlier than Aβ plagues formation. In addition, we found TNF-α and BDNF expression levels were increased, while KCC2 and GABAAR expression were decreased in 3-4 months APP/PS1 hippocampus. When we treated 3-4 months APP/PS1 mice with a potent γ-secretase inhibitor, LY411575, which can reduce the soluble Aβ42 levels, the TNF-α and BDNF protein levels were decreased, while KCC2 and GABAAR levels were increased. In conclusion, our study suggested soluble Aβ may impaired the GABA inhibition by mediating KCC2 levels in early APP/PS1 mice. KCC2 may be served as a potential biomarker for AD.
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Affiliation(s)
- Yuan Zhou
- Department of Pharmacology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui, China
| | - Yujie Cheng
- Department of Pharmacology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui, China
| | - Yong Li
- Department of Pharmacology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui, China
| | - Jiyao Ma
- First Clinical Medical College, Anhui Medical University, Hefei, Anhui, China
| | - Zhihan Wu
- First Clinical Medical College, Anhui Medical University, Hefei, Anhui, China
| | - Yuenan Chen
- Department of Pharmacology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui, China
| | - Jinyu Mei
- Department of Otorhinolaryngology, Head and Neck Surgery, the Second Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Ming Chen
- Department of Pharmacology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui, China
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Sullivan BJ, Kipnis PA, Carter BM, Shao LR, Kadam SD. Targeting ischemia-induced KCC2 hypofunction rescues refractory neonatal seizures and mitigates epileptogenesis in a mouse model. Sci Signal 2021; 14:eabg2648. [PMID: 34752143 DOI: 10.1126/scisignal.abg2648] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Brennan J Sullivan
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA
| | - Pavel A Kipnis
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA
| | - Brandon M Carter
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA
| | - Li-Rong Shao
- Division of Pediatric Neurology, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Shilpa D Kadam
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Thorsdottir D, Einwag Z, Erdos B. BDNF shifts excitatory-inhibitory balance in the paraventricular nucleus of the hypothalamus to elevate blood pressure. J Neurophysiol 2021; 126:1209-1220. [PMID: 34406887 DOI: 10.1152/jn.00247.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Presympathetic neurons in the paraventricular nucleus of the hypothalamus (PVN) play a key role in cardiovascular regulation. We have previously shown that brain-derived neurotrophic factor (BDNF), acting in the PVN, increases sympathetic activity and blood pressure and serves as a key regulator of stress-induced hypertensive responses. BDNF is known to alter glutamatergic and GABA-ergic signaling broadly in the central nervous system, but whether BDNF has similar actions in the PVN remains to be investigated. Here, we tested the hypothesis that increased BDNF expression in the PVN elevates blood pressure by enhancing N-methyl-d-aspartate (NMDA) receptor (NMDAR)- and inhibiting GABAA receptor (GABAAR)-mediated signaling. Sprague-Dawley rats received bilateral PVN injections of AAV2 viral vectors expressing green fluorescent protein (GFP) or BDNF. Three weeks later, cardiovascular responses to PVN injections of NMDAR and GABAAR agonists and antagonists were recorded under α-chloralose-urethane anesthesia. In addition, expressions of excitatory and inhibitory signaling components in the PVN were assessed using immunofluorescence. Our results showed that NMDAR inhibition led to a greater decrease in blood pressure in the BDNF vs. GFP group, while GABAAR inhibition led to greater increases in blood pressure in the GFP group compared to BDNF. Conversely, GABAAR activation decreased blood pressure significantly more in GFP vs. BDNF rats. In addition, immunoreactivity of NMDAR1 was upregulated, while GABAAR-α1 and K+/Cl- cotransporter 2 were downregulated by BDNF overexpression in the PVN. In summary, our findings indicate that hypertensive actions of BDNF within the PVN are mediated, at least in part, by augmented NMDAR and reduced GABAAR signaling.NEW & NOTEWORTHY We have shown that BDNF, acting in the PVN, elevates blood pressure in part by augmenting NMDA receptor-mediated excitatory input and by diminishing GABAA receptor-mediated inhibitory input to PVN neurons. In addition, we demonstrate that elevated BDNF expression in the PVN upregulates NMDA receptor immunoreactivity and downregulates GABAA receptor as well as KCC2 transporter immunoreactivity.
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Affiliation(s)
| | - Zachary Einwag
- Department of Pharmacology, University of Vermont, Burlington, Vermont
| | - Benedek Erdos
- Department of Pharmacology, University of Vermont, Burlington, Vermont
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Upaganlawar AB, Wankhede NL, Kale MB, Umare MD, Sehgal A, Singh S, Bhatia S, Al-Harrasi A, Najda A, Nurzyńska-Wierdak R, Bungau S, Behl T. Interweaving epilepsy and neurodegeneration: Vitamin E as a treatment approach. Biomed Pharmacother 2021; 143:112146. [PMID: 34507113 DOI: 10.1016/j.biopha.2021.112146] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/31/2021] [Accepted: 08/31/2021] [Indexed: 12/29/2022] Open
Abstract
Epilepsy is the most common neurological disorder, affecting nearly 50 million people worldwide. The condition can be manifested either due to genetic predisposition or acquired from acute insult which leads to alteration of cellular and molecular mechanisms. Evaluating the latest and the current knowledge in regard to the mechanisms underlying molecular and cellular alteration, hyperexcitability is a consequence of an imbalanced state wherein enhance excitatory glutamatergic and reduced inhibitory GABAergic signaling is considered to be accountable for seizures associated damage. However, neurodegeneration contributing to epileptogenesis has become increasingly appreciated. The components at the helm of neurodegenerative alterations during epileptogenesis include GABAergic neuronal and receptor changes, neuroinflammation, alteration in axonal transport, oxidative stress, excitotoxicity, and other cellular as well as functional changes. Targeting neurodegeneration with vitamin E as an antioxidant, anti-inflammatory and neuroprotective may prove to be one of the therapeutic approaches useful in managing epilepsy. In this review, we discuss and converse about the seizure-induced episodes as a link for the development of neurodegenerative and pathological consequences of epilepsy. We also put forth a summary of the potential intervention with vitamin E therapy in the management of epilepsy.
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Affiliation(s)
- Aman B Upaganlawar
- SNJB's Shriman Sureshdada Jain College of Pharmacy, Neminagar, Chandwad, Nashik, Maharashtra, India
| | - Nitu L Wankhede
- Smt. Kishoritai Bhoyar College of Pharmacy, Kamptee, Nagpur, Maharashtra, India
| | - Mayur B Kale
- Smt. Kishoritai Bhoyar College of Pharmacy, Kamptee, Nagpur, Maharashtra, India
| | - Mohit D Umare
- Smt. Kishoritai Bhoyar College of Pharmacy, Kamptee, Nagpur, Maharashtra, India
| | - Aayush Sehgal
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Sukhbir Singh
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Saurabh Bhatia
- Natural & Medical Sciences Research Centre, University of Nizwa, Nizwa, Oman
| | - Ahmed Al-Harrasi
- Natural & Medical Sciences Research Centre, University of Nizwa, Nizwa, Oman
| | - Agnieszka Najda
- Department of Vegetable Crops and Medicinal Plants, University of Life Sciences, Lublin, Poland.
| | | | - Simona Bungau
- Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, Romania
| | - Tapan Behl
- Chitkara College of Pharmacy, Chitkara University, Punjab, India.
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El Mahmoudi N, Rastoldo G, Marouane E, Péricat D, Watabe I, Tonetto A, Hautefort C, Chabbert C, Sargolini F, Tighilet B. Breaking a dogma: acute anti-inflammatory treatment alters both post-lesional functional recovery and endogenous adaptive plasticity mechanisms in a rodent model of acute peripheral vestibulopathy. J Neuroinflammation 2021; 18:183. [PMID: 34419105 PMCID: PMC8380392 DOI: 10.1186/s12974-021-02222-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 07/19/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Due to their anti-inflammatory action, corticosteroids are the reference treatment for brain injuries and many inflammatory diseases. However, the benefits of acute corticotherapy are now being questioned, particularly in the case of acute peripheral vestibulopathies (APV), characterized by a vestibular syndrome composed of sustained spinning vertigo, spontaneous ocular nystagmus and oscillopsia, perceptual-cognitive, posturo-locomotor, and vegetative disorders. We assessed the effectiveness of acute corticotherapy, and the functional role of acute inflammation observed after sudden unilateral vestibular loss. METHODS We used the rodent model of unilateral vestibular neurectomy, mimicking the syndrome observed in patients with APV. We treated the animals during the acute phase of the vestibular syndrome, either with placebo or methylprednisolone, an anti-inflammatory corticosteroid. At the cellular level, impacts of methylprednisolone on endogenous plasticity mechanisms were assessed through analysis of cell proliferation and survival, glial reactions, neuron's membrane excitability, and stress marker. At the behavioral level, vestibular and posturo-locomotor functions' recovery were assessed with appropriate qualitative and quantitative evaluations. RESULTS We observed that acute treatment with methylprednisolone significantly decreases glial reactions, cell proliferation and survival. In addition, stress and excitability markers were significantly impacted by the treatment. Besides, vestibular syndrome's intensity was enhanced, and vestibular compensation delayed under acute methylprednisolone treatment. CONCLUSIONS We show here, for the first time, that acute anti-inflammatory treatment alters the expression of the adaptive plasticity mechanisms in the deafferented vestibular nuclei and generates enhanced and prolonged vestibular and postural deficits. These results strongly suggest a beneficial role for acute endogenous neuroinflammation in vestibular compensation. They open the way to a change in dogma for the treatment and therapeutic management of vestibular patients.
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Affiliation(s)
- Nada El Mahmoudi
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
- Centre Saint-Charles, Aix-Marseille Université CNRS, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Guillaume Rastoldo
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
- Centre Saint-Charles, Aix-Marseille Université CNRS, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Emna Marouane
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
- Centre Saint-Charles, Aix-Marseille Université CNRS, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - David Péricat
- Institut de Pharmacologie Et de Biologie Structurale, Université de Toulouse Paul Sabatier-CNRS, Toulouse, France
| | - Isabelle Watabe
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
- Centre Saint-Charles, Aix-Marseille Université CNRS, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Alain Tonetto
- Centrale Marseille, FSCM (FR 1739), PRATIM, Aix Marseille Université-CNRS, 13397, Marseille, France
| | - Charlotte Hautefort
- Department of Head and Neck Surgery, Lariboisière University Hospital, Paris, France
| | - Christian Chabbert
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
- Centre Saint-Charles, Aix-Marseille Université CNRS, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
- GDR Physiopathologie Vestibulaire-Unité GDR2074 CNRS, Marseille, France
| | - Francesca Sargolini
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Brahim Tighilet
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France.
- GDR Physiopathologie Vestibulaire-Unité GDR2074 CNRS, Marseille, France.
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Butler-Ryan R, Wood IC. The functions of repressor element 1-silencing transcription factor in models of epileptogenesis and post-ischemia. Metab Brain Dis 2021; 36:1135-1150. [PMID: 33813634 PMCID: PMC8272694 DOI: 10.1007/s11011-021-00719-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/17/2021] [Indexed: 12/14/2022]
Abstract
Epilepsy is a debilitating neurological disorder characterised by recurrent seizures for which 30% of patients are refractory to current treatments. The genetic and molecular aetiologies behind epilepsy are under investigation with the goal of developing new epilepsy medications. The transcriptional repressor REST (Repressor Element 1-Silencing Transcription factor) is a focus of interest as it is consistently upregulated in epilepsy patients and following brain insult in animal models of epilepsy and ischemia. This review analyses data from different epilepsy models and discusses the contribution of REST to epileptogenesis. We propose that in healthy brains REST acts in a protective manner to homeostatically downregulate increases in excitability, to protect against seizure through downregulation of BDNF (Brain-Derived Neurotrophic Factor) and its receptor, TrkB (Tropomyosin receptor kinase B). However, in epilepsy patients and post-seizure, REST may increase to a larger degree, which allows downregulation of the glutamate receptor subunit GluR2. This leads to AMPA glutamate receptors lacking GluR2 subunits, which have increased permeability to Ca2+, causing excitotoxicity, cell death and seizure. This concept highlights therapeutic potential of REST modulation through gene therapy in epilepsy patients.
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Affiliation(s)
- Ruth Butler-Ryan
- School of Biomedical Sciences, Faculty of Biological Sciences, The University of Leeds, Leeds, LS2 9JT UK
| | - Ian C. Wood
- School of Biomedical Sciences, Faculty of Biological Sciences, The University of Leeds, Leeds, LS2 9JT UK
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Abstract
Extracellular nucleosides and nucleotides have widespread functions in responding to physiological stress. The "purinome" encompasses 4 G-protein-coupled receptors (GPCRs) for adenosine, 8 GPCRs activated by nucleotides, 7 adenosine 5'-triphosphate-gated P2X ion channels, as well as the associated enzymes and transporters that regulate native agonist levels. Purinergic signaling modulators, such as receptor agonists and antagonists, have potential for treating chronic pain. Adenosine and its analogues potently suppress nociception in preclinical models by activating A1 and/or A3 adenosine receptors (ARs), but safely harnessing this pathway to clinically treat pain has not been achieved. Both A2AAR agonists and antagonists are efficacious in pain models. Highly selective A3AR agonists offer a novel approach to treat chronic pain. We have explored the structure activity relationship of nucleoside derivatives at this subtype using a computational structure-based approach. Novel A3AR agonists for pain control containing a bicyclic ring system (bicyclo [3.1.0] hexane) in place of ribose were designed and screened using an in vivo phenotypic model, which reflected both pharmacokinetic and pharmacodynamic parameters. High specificity (>10,000-fold selective for A3AR) was achieved with the aid of receptor homology models based on related GPCR structures. These A3AR agonists are well tolerated in vivo and highly efficacious in models of chronic neuropathic pain. Furthermore, signaling molecules acting at P2X3, P2X4, P2X7, and P2Y12Rs play critical roles in maladaptive pain neuroplasticity, and their antagonists reduce chronic or inflammatory pain, and, therefore, purine receptor modulation is a promising approach for future pain therapeutics. Structurally novel antagonists for these nucleotide receptors were discovered recently.
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Bilchak JN, Caron G, Côté MP. Exercise-Induced Plasticity in Signaling Pathways Involved in Motor Recovery after Spinal Cord Injury. Int J Mol Sci 2021; 22:ijms22094858. [PMID: 34064332 PMCID: PMC8124911 DOI: 10.3390/ijms22094858] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 04/28/2021] [Accepted: 04/29/2021] [Indexed: 02/06/2023] Open
Abstract
Spinal cord injury (SCI) leads to numerous chronic and debilitating functional deficits that greatly affect quality of life. While many pharmacological interventions have been explored, the current unsurpassed therapy for most SCI sequalae is exercise. Exercise has an expansive influence on peripheral health and function, and by activating the relevant neural pathways, exercise also ameliorates numerous disorders of the central nervous system (CNS). While the exact mechanisms by which this occurs are still being delineated, major strides have been made in the past decade to understand the molecular underpinnings of this essential treatment. Exercise rapidly and prominently affects dendritic sprouting, synaptic connections, neurotransmitter production and regulation, and ionic homeostasis, with recent literature implicating an exercise-induced increase in neurotrophins as the cornerstone that binds many of these effects together. The field encompasses vast complexity, and as the data accumulate, disentangling these molecular pathways and how they interact will facilitate the optimization of intervention strategies and improve quality of life for individuals affected by SCI. This review describes the known molecular effects of exercise and how they alter the CNS to pacify the injury environment, increase neuronal survival and regeneration, restore normal neural excitability, create new functional circuits, and ultimately improve motor function following SCI.
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50
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Sullivan BJ, Kadam SD. Brain-Derived Neurotrophic Factor in Neonatal Seizures. Pediatr Neurol 2021; 118:35-39. [PMID: 33773288 PMCID: PMC8076080 DOI: 10.1016/j.pediatrneurol.2021.01.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 01/13/2023]
Abstract
Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, has an extensively studied classical role in neuronal growth, differentiation, survival, and plasticity. Neurotrophic, from the Greek neuro and trophos, roughly translates as "vital nutrition for the brain." During development, BDNF and its associated receptor tyrosine receptor kinase B are tightly regulated as they influence the formation and maturation of neuronal synapses. Preclinical research investigating the role of BDNF in neurological disorders has focused on the effects of decreased BDNF expression on the development and maintenance of neuronal synapses. In contrast, heightened BDNF-tyrosine receptor kinase B activity has received less scrutiny for its role in neurological disorders. Recent studies suggest that excessive BDNF-tyrosine receptor kinase B signaling in the developing brain may promote the hyperexcitability that underlies refractory neonatal seizures. This review will critically examine BDNF-tyrosine receptor kinase B signaling in the immature brain, its role in the emergence of refractory neonatal seizures, and the potential of targeting BDNF-TrkB signaling as a novel antiseizure strategy.
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Affiliation(s)
- Brennan J. Sullivan
- 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
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