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Qiu Q, Yang M, Gong D, Liang H, Chen T. Potassium and calcium channels in different nerve cells act as therapeutic targets in neurological disorders. Neural Regen Res 2025; 20:1258-1276. [PMID: 38845230 DOI: 10.4103/nrr.nrr-d-23-01766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 04/07/2024] [Indexed: 07/31/2024] Open
Abstract
The central nervous system, information integration center of the body, is mainly composed of neurons and glial cells. The neuron is one of the most basic and important structural and functional units of the central nervous system, with sensory stimulation and excitation conduction functions. Astrocytes and microglia belong to the glial cell family, which is the main source of cytokines and represents the main defense system of the central nervous system. Nerve cells undergo neurotransmission or gliotransmission, which regulates neuronal activity via the ion channels, receptors, or transporters expressed on nerve cell membranes. Ion channels, composed of large transmembrane proteins, play crucial roles in maintaining nerve cell homeostasis. These channels are also important for control of the membrane potential and in the secretion of neurotransmitters. A variety of cellular functions and life activities, including functional regulation of the central nervous system, the generation and conduction of nerve excitation, the occurrence of receptor potential, heart pulsation, smooth muscle peristalsis, skeletal muscle contraction, and hormone secretion, are closely related to ion channels associated with passive transmembrane transport. Two types of ion channels in the central nervous system, potassium channels and calcium channels, are closely related to various neurological disorders, including Alzheimer's disease, Parkinson's disease, and epilepsy. Accordingly, various drugs that can affect these ion channels have been explored deeply to provide new directions for the treatment of these neurological disorders. In this review, we focus on the functions of potassium and calcium ion channels in different nerve cells and their involvement in neurological disorders such as Parkinson's disease, Alzheimer's disease, depression, epilepsy, autism, and rare disorders. We also describe several clinical drugs that target potassium or calcium channels in nerve cells and could be used to treat these disorders. We concluded that there are few clinical drugs that can improve the pathology these diseases by acting on potassium or calcium ions. Although a few novel ion-channel-specific modulators have been discovered, meaningful therapies have largely not yet been realized. The lack of target-specific drugs, their requirement to cross the blood-brain barrier, and their exact underlying mechanisms all need further attention. This review aims to explain the urgent problems that need research progress and provide comprehensive information aiming to arouse the research community's interest in the development of ion channel-targeting drugs and the identification of new therapeutic targets for that can increase the cure rate of nervous system diseases and reduce the occurrence of adverse reactions in other systems.
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Affiliation(s)
- Qing Qiu
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, Jiangsu Province, China
- Jiangsu Province Key Laboratory of Inflammation and Molecular Drug Target, Nantong, Jiangsu Province, China
| | - Mengting Yang
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, Jiangsu Province, China
- Jiangsu Province Key Laboratory of Inflammation and Molecular Drug Target, Nantong, Jiangsu Province, China
| | - Danfeng Gong
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, Jiangsu Province, China
- Jiangsu Province Key Laboratory of Inflammation and Molecular Drug Target, Nantong, Jiangsu Province, China
| | - Haiying Liang
- Department of Pharmacy, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, Fujian Province, China
| | - Tingting Chen
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, Jiangsu Province, China
- Jiangsu Province Key Laboratory of Inflammation and Molecular Drug Target, Nantong, Jiangsu Province, China
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2
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Fabbri R, Scidà A, Saracino E, Conte G, Kovtun A, Candini A, Kirdajova D, Spennato D, Marchetti V, Lazzarini C, Konstantoulaki A, Dambruoso P, Caprini M, Muccini M, Ursino M, Anderova M, Treossi E, Zamboni R, Palermo V, Benfenati V. Graphene oxide electrodes enable electrical stimulation of distinct calcium signalling in brain astrocytes. NATURE NANOTECHNOLOGY 2024:10.1038/s41565-024-01711-4. [PMID: 38987650 DOI: 10.1038/s41565-024-01711-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 05/31/2024] [Indexed: 07/12/2024]
Abstract
Astrocytes are responsible for maintaining homoeostasis and cognitive functions through calcium signalling, a process that is altered in brain diseases. Current bioelectronic tools are designed to study neurons and are not suitable for controlling calcium signals in astrocytes. Here, we show that electrical stimulation of astrocytes using electrodes coated with graphene oxide and reduced graphene oxide induces respectively a slow response to calcium, mediated by external calcium influx, and a sharp one, exclusively due to calcium release from intracellular stores. Our results suggest that the different conductivities of the substrate influence the electric field at the cell-electrolyte or cell-material interfaces, favouring different signalling events in vitro and ex vivo. Patch-clamp, voltage-sensitive dye and calcium imaging data support the proposed model. In summary, we provide evidence of a simple tool to selectively control distinct calcium signals in brain astrocytes for straightforward investigations in neuroscience and bioelectronic medicine.
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Affiliation(s)
- Roberta Fabbri
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy
| | - Alessandra Scidà
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy
| | - Emanuela Saracino
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy
| | - Giorgia Conte
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy
| | - Alessandro Kovtun
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy
| | - Andrea Candini
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy
| | - Denisa Kirdajova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, CAS, Prague, Czech Republic
| | - Diletta Spennato
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy
| | - Valeria Marchetti
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, CAS, Prague, Czech Republic
- Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Chiara Lazzarini
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy
| | - Aikaterini Konstantoulaki
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy
| | - Paolo Dambruoso
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy
| | - Marco Caprini
- Department of Pharmacy and Biotechnology (FaBit), University of Bologna, Bologna, Italy
| | - Michele Muccini
- Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati, Bologna, Italy
| | - Mauro Ursino
- Dipartimento di Ingegneria dell'Energia Elettrica e dell'Informazione 'Guglielmo Marconi', University of Bologna, Cesena, Italy
| | - Miroslava Anderova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, CAS, Prague, Czech Republic
| | - Emanuele Treossi
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy.
| | - Roberto Zamboni
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy
| | - Vincenzo Palermo
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy.
| | - Valentina Benfenati
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività, Bologna, Italy.
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Verkhratsky A, Butt A, Li B, Illes P, Zorec R, Semyanov A, Tang Y, Sofroniew MV. Astrocytes in human central nervous system diseases: a frontier for new therapies. Signal Transduct Target Ther 2023; 8:396. [PMID: 37828019 PMCID: PMC10570367 DOI: 10.1038/s41392-023-01628-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 08/15/2023] [Accepted: 08/22/2023] [Indexed: 10/14/2023] Open
Abstract
Astroglia are a broad class of neural parenchymal cells primarily dedicated to homoeostasis and defence of the central nervous system (CNS). Astroglia contribute to the pathophysiology of all neurological and neuropsychiatric disorders in ways that can be either beneficial or detrimental to disorder outcome. Pathophysiological changes in astroglia can be primary or secondary and can result in gain or loss of functions. Astroglia respond to external, non-cell autonomous signals associated with any form of CNS pathology by undergoing complex and variable changes in their structure, molecular expression, and function. In addition, internally driven, cell autonomous changes of astroglial innate properties can lead to CNS pathologies. Astroglial pathophysiology is complex, with different pathophysiological cell states and cell phenotypes that are context-specific and vary with disorder, disorder-stage, comorbidities, age, and sex. Here, we classify astroglial pathophysiology into (i) reactive astrogliosis, (ii) astroglial atrophy with loss of function, (iii) astroglial degeneration and death, and (iv) astrocytopathies characterised by aberrant forms that drive disease. We review astroglial pathophysiology across the spectrum of human CNS diseases and disorders, including neurotrauma, stroke, neuroinfection, autoimmune attack and epilepsy, as well as neurodevelopmental, neurodegenerative, metabolic and neuropsychiatric disorders. Characterising cellular and molecular mechanisms of astroglial pathophysiology represents a new frontier to identify novel therapeutic strategies.
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Affiliation(s)
- Alexei Verkhratsky
- International Joint Research Centre on Purinergic Signalling/School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China.
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
- Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102, Vilnius, Lithuania.
| | - Arthur Butt
- Institute of Biomedical and Biomolecular Sciences, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
| | - Baoman Li
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
| | - Peter Illes
- International Joint Research Centre on Purinergic Signalling/School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04109, Leipzig, Germany
| | - Robert Zorec
- Celica Biomedical, Lab Cell Engineering, Technology Park, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Alexey Semyanov
- Department of Physiology, Jiaxing University College of Medicine, 314033, Jiaxing, China
| | - Yong Tang
- International Joint Research Centre on Purinergic Signalling/School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
- Key Laboratory of Acupuncture for Senile Disease (Chengdu University of TCM), Ministry of Education/Acupuncture and Chronobiology Key Laboratory of Sichuan Province, Chengdu, China.
| | - Michael V Sofroniew
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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Signal transduction associated with lead-induced neurological disorders: A review. Food Chem Toxicol 2021; 150:112063. [PMID: 33596455 DOI: 10.1016/j.fct.2021.112063] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 02/05/2021] [Accepted: 02/09/2021] [Indexed: 12/28/2022]
Abstract
Lead is a heavy metal pollutant that is widely present in the environment. It affects every organ system, yet the nervous system appears to be the most sensitive and primary target. Although many countries have made significant strides in controlling Pb pollution, Pb poisoning continuous to be a major public health concern. Exposure to Pb causes neurotoxicity that ranges from neurodevelopmental disorders to severe neurodegenerative lesions, leading to impairments in learning, memory, and cognitive function. Studies on the mechanisms of Pb-induced nervous system injury have convincingly shown that this metal can affect a plethora of cellular pathways affecting on cell survival, altering calcium dyshomeostasis, and inducing apoptosis, inflammation, energy metabolism disorders, oxidative stress, autophagy and glial stress. This review summarizes recent knowledge on multiple signaling pathways associated with Pb-induced neurological disorders in vivo and in vitro.
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Hopp SC. Targeting microglia L-type voltage-dependent calcium channels for the treatment of central nervous system disorders. J Neurosci Res 2021; 99:141-162. [PMID: 31997405 PMCID: PMC9394523 DOI: 10.1002/jnr.24585] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 01/03/2020] [Accepted: 01/08/2020] [Indexed: 12/14/2022]
Abstract
Calcium (Ca2+ ) is a ubiquitous mediator of a multitude of cellular functions in the central nervous system (CNS). Intracellular Ca2+ is tightly regulated by cells, including entry via plasma membrane Ca2+ permeable channels. Of specific interest for this review are L-type voltage-dependent Ca2+ channels (L-VDCCs), due to their pleiotropic role in several CNS disorders. Currently, there are numerous approved drugs that target L-VDCCs, including dihydropyridines. These drugs are safe and effective for the treatment of humans with cardiovascular disease and may also confer neuroprotection. Here, we review the potential of L-VDCCs as a target for the treatment of CNS disorders with a focus on microglia L-VDCCs. Microglia, the resident immune cells of the brain, have attracted recent attention for their emerging inflammatory role in several CNS diseases. Intracellular Ca2+ regulates microglia transition from a resting quiescent state to an "activated" immune-effector state and is thus a valuable target for manipulation of microglia phenotype. We will review the literature on L-VDCC expression and function in the CNS and on microglia in vitro and in vivo and explore the therapeutic landscape of L-VDCC-targeting agents at present and future challenges in the context of Alzheimer's disease, Parkinson's disease, Huntington's disease, neuropsychiatric diseases, and other CNS disorders.
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Affiliation(s)
- Sarah C. Hopp
- Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
- Department of Pharmacology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
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Harrison PJ, Hall N, Mould A, Al-Juffali N, Tunbridge EM. Cellular calcium in bipolar disorder: systematic review and meta-analysis. Mol Psychiatry 2021; 26:4106-4116. [PMID: 31801967 PMCID: PMC8550977 DOI: 10.1038/s41380-019-0622-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/20/2019] [Accepted: 11/22/2019] [Indexed: 12/31/2022]
Abstract
Calcium signalling has long been implicated in bipolar disorder, especially by reports of altered intracellular calcium ion concentrations ([Ca2+]). However, the evidence has not been appraised critically. We carried out a systematic review and meta-analysis of studies of cellular calcium indices in bipolar disorder. 2281 records were identified and 117 screened, of which 32 were eligible and 21 were suitable for meta-analyses. The latter each involved up to 642 patients and 404 control subjects. We found that basal free intracellular [Ca2+] is increased in bipolar disorder, both in platelets and in lymphocytes. The effect size is 0.55, with an estimated elevation of 29%. It is observed in medication-free patients. It is present in mania and bipolar depression, but data are equivocal for euthymia. Cells from bipolar disorder individuals also show an enhanced [Ca2+] response to stimulation with 5-HT or thrombin, by an estimated 25%, with an effect size of 0.63. In studies which included other diagnoses, intracellular basal [Ca2+] was higher in bipolar disorder than in unipolar depression, but not significantly different from schizophrenia. Functional parameters of cellular Ca2+ (e.g. calcium transients), and neuronal [Ca2+], have been much less investigated, and no firm conclusions can be drawn. In summary, there is a robust, medium effect size elevation of basal and stimulated free intracellular [Ca2+] in bipolar disorder. The results suggest altered calcium functioning in the disorder, and encourage further investigations into the underlying mechanisms, and the implications for pathophysiology and therapeutics.
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Affiliation(s)
- Paul J. Harrison
- grid.4991.50000 0004 1936 8948Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX UK ,grid.451190.80000 0004 0573 576XOxford Health NHS Foundation Trust, Oxford, UK
| | - Nicola Hall
- grid.4991.50000 0004 1936 8948Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX UK
| | - Arne Mould
- grid.4991.50000 0004 1936 8948Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX UK ,grid.451190.80000 0004 0573 576XOxford Health NHS Foundation Trust, Oxford, UK
| | - Noura Al-Juffali
- grid.4991.50000 0004 1936 8948Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX UK ,grid.451190.80000 0004 0573 576XOxford Health NHS Foundation Trust, Oxford, UK
| | - Elizabeth M. Tunbridge
- grid.4991.50000 0004 1936 8948Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX UK ,grid.451190.80000 0004 0573 576XOxford Health NHS Foundation Trust, Oxford, UK
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Neuron-derived factors negatively modulate ryanodine receptor-mediated calcium release in cultured mouse astrocytes. Cell Calcium 2020; 92:102304. [PMID: 33065384 DOI: 10.1016/j.ceca.2020.102304] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/01/2020] [Accepted: 10/01/2020] [Indexed: 12/22/2022]
Abstract
Changes in intracellular Ca2+ concentration ([Ca2+]i) produced by ryanodine receptor (RyR) agonist, caffeine (caf), and ionotropic agonists: N-methyl-d-aspartate (NMDA) receptor (NMDAR) agonist, NMDA and P2X7 receptor (P2X7R) agonist, 3'-O-(4-benzoyl)benzoyl adenosine 5'-triphosphate (BzATP) were measured in cultured mouse cortical astrocytes loaded with the fluorescent calcium indicator Fluo3-AM in a confocal laser scanning microscope. In mouse astrocytes cultured in standard medium (SM), treatment with caf increased [Ca2+]i, with a peak response occurring about 10 min after stimulus application. Peak responses to NMDA or BzATP were observed about <1 min and 4.5 min post stimulus, respectively. Co-treatment with NMDA or BzATP did not alter the peak response to caf in astrocytes cultured in SM, the absence of the effects being most likely due to asynchrony between the response to caf, NMDA and BzATP. Incubation of astrocytes with neuron-condition medium (NCM) for 24 h totally abolished the caf-evoked [Ca2+]i increase. In NCM-treated astrocytes, peak of [Ca2+]i rise evoked by NMDA was delayed to about 3.5 min, and that induced by BzATP occurred about three minutes earlier than in SM. The results show that neurons secrete factors that negatively modulate RyR-mediated Ca2+-induced Ca2+ release (CICR) in astrocytes and alter the time course of Ca2+ responses to ionotropic stimuli.
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L-type Voltage-Gated Calcium Channel Modulators Inhibit Glutamate-Induced Morphology Changes in U118-MG Astrocytoma Cells. Cell Mol Neurobiol 2020; 40:1429-1437. [PMID: 32172458 DOI: 10.1007/s10571-020-00828-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 03/06/2020] [Indexed: 10/24/2022]
Abstract
The excitatory neurotransmitter glutamate evokes physiological responses within the astrocytic network that lead to fine morphological changes. However, the mechanism by which astrocytes couple glutamate sensing with cellular calcium rise remains unclear. We tested a possible connection between L-type voltage-gated calcium channels (Cav) and glutamate-induced response in U118-MG astrocytoma cells. While astrocytoma cells differ from primary astrocytes, they demonstrate the same response to glutamate. In this study, the extension of U118-MG processes upon glutamate exposure was shown to depend on extracellular calcium entry via L-type Cav's. Drugs known to bind to the pore-forming subunit of Cav's decreased the astrocytic filopodia extension caused by glutamate, and ligands of the α2δ auxiliary subunit inhibited all process growth (e.g., gabapentinoids). The observed phenotypic responses suggest that α2δ is a main contributor to the role of Cavs in glutamate-dependent filopodiagenesis, thereby opening new avenues of research on the role of α2δ in astrocytic neurochemical signaling.
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Activation of Protein Kinase Cδ Contributes to the Induction of Src/EGF Receptor/ERK Signaling in Ammonia-treated Astrocytes. J Mol Neurosci 2020; 70:1110-1119. [PMID: 32125625 DOI: 10.1007/s12031-020-01517-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 02/19/2020] [Indexed: 02/06/2023]
Abstract
Previously, we showed that Src-mediated EGF receptor transactivation/ERK activation mediates ammonia-induced astrocyte swelling, which represents a major component of brain edema in hyperammonemic disorders. Here, we tested the role of PKC in the induction of this signaling pathway and its involvement in ammonia-mediated cell swelling. We found that incubating astrocytes with bisindolylmaleimide (BIM, an inhibitor of classical and novel PKC isoforms) or rottlerin, a PKCδ-specific inhibitor, attenuated the ammonia-induced phosphorylation of EGFR, while GF109203X had no effect on this pathway. We further found that BIM or rottlerin pretreatment inhibited the ammonia-induced phosphorylation of Src and that ammonia significantly increased the level of PKCδ pulled down by a Src antibody. AG1478, a specific EGFR kinase activity inhibitor, effectively inhibited phosphorylation at Tyr1068 but had no discernable effect on phosphorylation at Tyr845. Moreover, BIM or rottlerin abrogated ammonia-induced ERK phosphorylation. BIM-, rottlerin-, or GF109203X-treated astrocytes showed a significant reduction in cell swelling compared to that observed after treatment with ammonia alone. Finally, it was found that AG1478 attenuated ammonia-induced PKCα translocation to the particulate fraction. Taken together, our results indicate that PKCδ mediates ammonia-induced astrocyte swelling by activating Src and downstream EGF receptor/ERK signaling, which may contribute to the pathogenesis of neuropsychiatric disorders associated with hyperammonemia.
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Chen J, Wang H, He Z, Li T. Analysis of Risk Factors for Postoperative Delirium After Liver Transplantation. Neuropsychiatr Dis Treat 2020; 16:1645-1652. [PMID: 32753870 PMCID: PMC7343290 DOI: 10.2147/ndt.s254920] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 06/17/2020] [Indexed: 01/29/2023] Open
Abstract
PURPOSE The study aimed to analyze the incidence of postoperative delirium (POD) and associated risk factors after liver transplantation (LT). PATIENTS AND METHODS We identified and enrolled patients undergoing LT at the Second Xiangya Hospital, Central South University between August 2018 and May 2019. We abstracted their relevant clinical information and assigned the patients into a POD group and non-POD group to compare differences in clinical information. Risk factors of POD were analyzed using logistic regression. RESULTS A total of 159 LT patients were enrolled. Forty-two patients exhibited delirium (26.4%). Of the 42 with delirium, 33 (78.6%) had delirium within 3 days postoperatively and a median duration of 5 days (quartile 3-7 days). The results of binary logistic regression are as follows: preoperative ammonia (≥46 vs <46 μmol/L; OR 3.51, 95% CI [1.31-9.46], P<0.05), Model for End-Stage Liver Disease (MELD) score (≥15 vs.<15; OR 3.33, 95% CI [1.27-8.79], P<0.05), presence of hepatic encephalopathy (OR 3.30, 95% CI [1.20-9.07], P<0.05), aspartate aminotransferase (AST) on day 1 postoperatively (OR 1.33, 95% CI [1.06 -1.68], P<0.05), anhepatic period (OR 1.04, 95% CI [1.02 -1.06], P<0.01). The POD group had a longer intubation time (2925.0 vs 1410.0 min, P<0.01), ICU length of stay (6 vs 4 d, P<0.01) and increased medical costs (43.96 vs 33.74 ten thousand yuan, P<0.01). CONCLUSION The incidence of POD in LT patients is a significant clinical feature. Ammonia ≥46 μmol/l, MELD score ≥15, hepatic encephalopathy, anhepatic period, and AST at 1 day postoperatively were independent risk factors for POD.
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Affiliation(s)
- Junguo Chen
- Department of Organ Transplantation, The Second Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Hao Wang
- Department of Organ Transplantation, The Second Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Zhijun He
- Department of Organ Transplantation, The Second Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Ting Li
- Department of Organ Transplantation, The Second Xiangya Hospital, Central South University, Changsha, People's Republic of China
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Calcium Signaling in Neurons and Glial Cells: Role of Cav1 channels. Neuroscience 2019; 421:95-111. [DOI: 10.1016/j.neuroscience.2019.09.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/27/2019] [Accepted: 09/30/2019] [Indexed: 11/18/2022]
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12
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Verkhratsky A, Parpura V, Vardjan N, Zorec R. Physiology of Astroglia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1175:45-91. [PMID: 31583584 DOI: 10.1007/978-981-13-9913-8_3] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Astrocytes are principal cells responsible for maintaining the brain homeostasis. Additionally, these glial cells are also involved in homocellular (astrocyte-astrocyte) and heterocellular (astrocyte-other cell types) signalling and metabolism. These astroglial functions require an expression of the assortment of molecules, be that transporters or pumps, to maintain ion concentration gradients across the plasmalemma and the membrane of the endoplasmic reticulum. Astrocytes sense and balance their neurochemical environment via variety of transmitter receptors and transporters. As they are electrically non-excitable, astrocytes display intracellular calcium and sodium fluctuations, which are not only used for operative signalling but can also affect metabolism. In this chapter we discuss the molecules that achieve ionic gradients and underlie astrocyte signalling.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK. .,Faculty of Health and Medical Sciences, Center for Basic and Translational Neuroscience, University of Copenhagen, 2200, Copenhagen, Denmark. .,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
| | - Vladimir Parpura
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Nina Vardjan
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia.,Celica Biomedical, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia.,Celica Biomedical, Ljubljana, Slovenia
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Ammonium induced dysfunction of 5-HT 2B receptor in astrocytes. Neurochem Int 2019; 129:104479. [PMID: 31145970 DOI: 10.1016/j.neuint.2019.104479] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 05/24/2019] [Accepted: 05/26/2019] [Indexed: 11/24/2022]
Abstract
Previously we reported that gene expression of astrocytic 5-HT2B receptors was decreased in brains of depressed animals exposed to chronic mild stress (CMS) (Li et al., 2012) and of Parkinson's disease (Song et al., 2018). Depression is also one of the psychiatric symptoms in hyperammonemia, and astrocyte is a primary target of ammonium in brain in vivo. In the present study, we have used preparations of the brains of urease-treated mice and ammonium-treated astrocytes in culture to study gene expression and function of 5-HT2B receptors. The urease-treated mice showed depressive behaviour. Both mRNA and protein of 5-HT2B receptors were increased in the brains of urease-treated mice and in ammonium-treated cultured astrocytes. Further study revealed that mRNA and protein expression of adenosine deaminase acting on RNA 2 (ADAR2), an enzyme catalyze RNA deamination of adenosine to inosine was increased in the brains of urease-treated mice and in ammonium-treated cultured astrocytes. This increase in ADAR2 induced RNA editing of 5-HT2B receptors. Cultured astrocytes treated with ammonium lost 5-HT induced Ca2+ signalling and ERK1/2 phosphorylation, indicating dysfunction of 5-HT2B receptors. This is in agreement with our previous observation that edited 5-HT2B receptors no longer respond to 5-HT (Hertz et al., 2014). Ammonium effects are inhibited by ADAR2 siRNA in cultured astrocytes, suggesting that increased gene expression and editing and loss of function of 5-HT2B receptors are results of increased activity of ADAR2. In summary, we have demonstrated that functional malfunction of astrocytic 5-HT2B receptors occurs in animal models of major depression, Parkinson depression and hepatic encephalopathy albeit via different mechanisms. Understanding the role of astrocytic 5-HT2B receptors in different pathological contexts may instigate development of novel therapeutic strategies for treating disease-specific depressive behaviour.
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15
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Lima LCD, Miranda AS, Ferreira RN, Rachid MA, Simões E Silva AC. Hepatic encephalopathy: Lessons from preclinical studies. World J Hepatol 2019; 11:173-185. [PMID: 30820267 PMCID: PMC6393717 DOI: 10.4254/wjh.v11.i2.173] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/19/2018] [Accepted: 01/28/2019] [Indexed: 02/06/2023] Open
Abstract
Hepatic encephalopathy (HE) is a major complication that is closely related to the progression of end-stage liver disease. Metabolic changes in advanced liver failure can promote cognition impairment, attention deficits and motor dysfunction that may result in coma and death. HE can be subdivided according to the type of hepatic injury, namely, type A, which results from acute liver failure, type B, which is associated with a portosystemic shunting without intrinsic liver disease, and type C, which is due to chronic liver disease. Several studies have investigated the pathogenesis of the disease, and most of the mechanisms have been explored using animal models. This article aimed to review the use of preclinical models to investigate HE. The most used animal species are rats and mice. Experimental models of type A HE include surgical procedures and the administration of hepatotoxic medications, whereas models of types B and C HE are generally surgically induced lesions in liver tissue, which evolve to hepatic cirrhosis. Preclinical models have allowed the comprehension of the pathways related to HE.
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Affiliation(s)
- Luiza Cioglia Dias Lima
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais 31270-901, Brasil
| | - Aline Silva Miranda
- Departamento de Morfologia, Instituto de Ciências Biológicas, UFMG, Belo Horizonte, Minas Gerais 30130-100, Brasil
| | - Rodrigo Novaes Ferreira
- Departamento de Morfologia, Instituto de Ciências Biológicas, UFMG, Belo Horizonte, Minas Gerais 30130-100, Brasil
| | - Milene Alvarenga Rachid
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais 31270-901, Brasil
| | - Ana Cristina Simões E Silva
- Laboratório Interdisciplinar de Investigação Médica, Faculdade de Medicina, UFMG, Belo Horizonte, Minas Gerais 30130-100, Brasil.
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Verkhratsky A, Ho MS, Vardjan N, Zorec R, Parpura V. General Pathophysiology of Astroglia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1175:149-179. [PMID: 31583588 PMCID: PMC7188602 DOI: 10.1007/978-981-13-9913-8_7] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Astroglial cells are involved in most if not in all pathologies of the brain. These cells can change the morpho-functional properties in response to pathology or innate changes of these cells can lead to pathologies. Overall pathological changes in astroglia are complex and diverse and often vary with different disease stages. We classify astrogliopathologies into reactive astrogliosis, astrodegeneration with astroglial atrophy and loss of function, and pathological remodelling of astrocytes. Such changes can occur in neurological, neurodevelopmental, metabolic and psychiatric disorders as well as in infection and toxic insults. Mutation in astrocyte-specific genes leads to specific pathologies, such as Alexander disease, which is a leukodystrophy. We discuss changes in astroglia in the pathological context and identify some molecular entities underlying pathology. These entities within astroglia may repent targets for novel therapeutic intervention in the management of brain pathologies.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
- Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark.
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
| | - Margaret S Ho
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Nina Vardjan
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
- Celica BIOMEDICAL, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
- Celica BIOMEDICAL, Ljubljana, Slovenia
| | - Vladimir Parpura
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
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Wang P, Wang X, Li L, Kan Q, Yu Z, Feng R, Chen Z, Shi Y, Gao J. Role of sodium-hydrogen exchanger isoform 1 in regulating hepatocyte apoptosis induced by hyperammonaemia. GASTROENTEROLOGIA Y HEPATOLOGIA 2018; 41:490-497. [PMID: 30033048 DOI: 10.1016/j.gastrohep.2018.05.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 05/23/2018] [Accepted: 05/24/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND The "secondary injury" theory of liver failure indicated that hyperammonaemia due to liver failure causes further deterioration of hepatocytes. Our previous studies have demonstrated that high blood ammonia levels may lead to hepatocyte apoptosis, as NH4Cl loading caused metabolic acidosis and an increase in sodium-hydrogen exchanger isoform 1 (NHE1). In this study, we established a hyperammonia hepatocyte model to determine the role of NHE1 in the regulation of hepatocyte apoptosis induced by NH4Cl. MATERIALS AND METHODS In current studies, intracellular pH (pHi) and NHE1 activity were analyzed using the pHi-sensitive dye BCECF-AM. The results showed that intracellular pH dropped and NHE1 activity increased in hepatocytes under NH4Cl treatment. As expected, decreased pHi induced by NH4Cl was associated with increased apoptosis, low cell proliferation and ATP depletion, which was exacerbated by exposure to the NHE1 inhibitor cariporide. We also found that NH4Cl treatment stimulated PI3K and Akt phosphorylation and this effect was considerably reduced by NHE1 inhibition. CONCLUSION This study highlighted the significant role of NHE1 in the regulation of cell apoptosis induced by hyperammonaemia.
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Affiliation(s)
- Peng Wang
- Department of Basic Medicine, Nursing College, Zhengzhou University, Zhengzhou, Henan, PR China
| | - Xin Wang
- Department of Basic Medicine, Nursing College, Zhengzhou University, Zhengzhou, Henan, PR China.
| | - Ling Li
- Department of Palliative and Hospice Care, The Ninth People's Hospital of Zhengzhou, Henan, PR China
| | - Quancheng Kan
- Department of Infectious Disease, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China
| | - Zujiang Yu
- Department of Infectious Disease, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China
| | - Rongfang Feng
- Department of Basic Medicine, Nursing College, Zhengzhou University, Zhengzhou, Henan, PR China
| | - ZiXiao Chen
- Department of Basic Medicine, Nursing College, Zhengzhou University, Zhengzhou, Henan, PR China
| | - Yan Shi
- Department of Basic Medicine, Nursing College, Zhengzhou University, Zhengzhou, Henan, PR China
| | - Jinling Gao
- Department of Basic Medicine, Nursing College, Zhengzhou University, Zhengzhou, Henan, PR China
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Sompol P, Norris CM. Ca 2+, Astrocyte Activation and Calcineurin/NFAT Signaling in Age-Related Neurodegenerative Diseases. Front Aging Neurosci 2018; 10:199. [PMID: 30038565 PMCID: PMC6046440 DOI: 10.3389/fnagi.2018.00199] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/12/2018] [Indexed: 12/12/2022] Open
Abstract
Mounting evidence supports a fundamental role for Ca2+ dysregulation in astrocyte activation. Though the activated astrocyte phenotype is complex, cell-type targeting approaches have revealed a number of detrimental roles of activated astrocytes involving neuroinflammation, release of synaptotoxic factors and loss of glutamate regulation. Work from our lab and others has suggested that the Ca2+/calmodulin dependent protein phosphatase, calcineurin (CN), provides a critical link between Ca2+ dysregulation and the activated astrocyte phenotype. A proteolyzed, hyperactivated form of CN appears at high levels in activated astrocytes in both human tissue and rodent tissue around regions of amyloid and vascular pathology. Similar upregulation of the CN-dependent transcription factor nuclear factor of activated T cells (NFAT4) also appears in activated astrocytes in mouse models of Alzheimer's disease (ADs) and traumatic brain injury (TBI). Major consequences of hyperactivated CN/NFAT4 signaling in astrocytes are neuroinflammation, synapse dysfunction and glutamate dysregulation/excitotoxicity, which will be covered in this review article.
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Affiliation(s)
- Pradoldej Sompol
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Christopher M Norris
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, United States.,Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, United States
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Abstract
Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
| | - Maiken Nedergaard
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
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Verkhratsky A, Nedergaard M. Physiology of Astroglia. Physiol Rev 2018; 98:239-389. [PMID: 29351512 PMCID: PMC6050349 DOI: 10.1152/physrev.00042.2016] [Citation(s) in RCA: 942] [Impact Index Per Article: 157.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/22/2017] [Accepted: 04/27/2017] [Indexed: 02/07/2023] Open
Abstract
Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
| | - Maiken Nedergaard
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
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Abstract
Hepatic encephalopathy describes the array of neurological alterations that occur during acute liver failure or chronic liver injury. While key players in the pathogenesis of hepatic encephalopathy, such as increases in brain ammonia, alterations in neurosteroid levels, and neuroinflammation, have been identified, there is still a paucity in our knowledge of the precise pathogenic mechanism. This review gives a brief overview of our understanding of the pathogenesis of hepatic encephalopathy and then summarizes the significant recent advances made in clinical and basic research contributing to our understanding, diagnosis, and possible treatment of hepatic encephalopathy. A literature search using the PubMed database was conducted in May 2017 using "hepatic encephalopathy" as a keyword, and selected manuscripts were limited to those research articles published since May 2014. While the authors acknowledge that many significant advances have been made in the understanding of hepatic encephalopathy prior to May 2014, we have limited the scope of this review to the previous three years only.
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Affiliation(s)
- Victoria Liere
- Department of Medical Physiology, College of Medicine, Texas A&M Health Science Center, Temple, TX, USA
| | | | - Sharon DeMorrow
- Department of Medical Physiology, College of Medicine, Texas A&M Health Science Center, Temple, TX, USA
- Central Texas Veterans Healthcare System, Temple, TX, USA
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22
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Chaban YHG, Chen Y, Hertz E, Hertz L. Severe Convulsions and Dysmyelination in Both Jimpy and Cx32/47 -/- Mice may Associate Astrocytic L-Channel Function with Myelination and Oligodendrocytic Connexins with Internodal K v Channels. Neurochem Res 2017; 42:1747-1766. [PMID: 28214987 DOI: 10.1007/s11064-017-2194-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 12/12/2022]
Abstract
The Jimpy mouse illustrates the importance of interactions between astrocytes and oligodendrocytes. It has a mutation in Plp coding for proteolipid protein and DM20. Its behavior is normal at birth but from the age of ~2 weeks it shows severe convulsions associated with oligodendrocyte/myelination deficits and early death. A normally occurring increase in oxygen consumption by highly elevated K+ concentrations is absent in Jimpy brain slices and cultured astrocytes, reflecting that Plp at early embryonic stages affects common precursors as also shown by the ability of conditioned medium from normal astrocytes to counteract histological abnormalities. This metabolic response is now known to reflect opening of L-channels for Ca2+. The resulting deficiency in Ca2+ entry has many consequences, including lack of K+-stimulated glycogenolysis and release of gliotransmitter ATP. Lack of purinergic stimulation compromises oligodendrocyte survival and myelination and affects connexins and K+ channels. Mice lacking the oligodendrocytic connexins Cx32 and 47 show similar neurological dysfunction as Jimpy. This possibly reflects that K+ released by intermodal axonal Kv channels is transported underneath a loosened myelin sheath instead of reaching the extracellular space via connexin-mediated transport to oligodendrocytes, followed by release and astrocytic Na+,K+-ATPase-driven uptake with subsequent Kir4.1-facilitated release and neuronal uptake.
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Affiliation(s)
| | - Ye Chen
- Henry M. Jackson Foundation, Bethesda, MD, 20817, USA
| | - Elna Hertz
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, People's Republic of China
| | - Leif Hertz
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, People's Republic of China.
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23
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Hertz L, Chen Y. Importance of astrocytes for potassium ion (K+) homeostasis in brain and glial effects of K+ and its transporters on learning. Neurosci Biobehav Rev 2016; 71:484-505. [DOI: 10.1016/j.neubiorev.2016.09.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 08/12/2016] [Accepted: 09/23/2016] [Indexed: 10/20/2022]
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Verkhratsky A, Steardo L, Parpura V, Montana V. Translational potential of astrocytes in brain disorders. Prog Neurobiol 2016; 144:188-205. [PMID: 26386136 PMCID: PMC4794425 DOI: 10.1016/j.pneurobio.2015.09.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/03/2015] [Accepted: 09/08/2015] [Indexed: 12/11/2022]
Abstract
Fundamentally, all brain disorders can be broadly defined as the homeostatic failure of this organ. As the brain is composed of many different cells types, including but not limited to neurons and glia, it is only logical that all the cell types/constituents could play a role in health and disease. Yet, for a long time the sole conceptualization of brain pathology was focused on the well-being of neurons. Here, we challenge this neuron-centric view and present neuroglia as a key element in neuropathology, a process that has a toll on astrocytes, which undergo complex morpho-functional changes that can in turn affect the course of the disorder. Such changes can be grossly identified as reactivity, atrophy with loss of function and pathological remodeling. We outline the pathogenic potential of astrocytes in variety of disorders, ranging from neurotrauma, infection, toxic damage, stroke, epilepsy, neurodevelopmental, neurodegenerative and psychiatric disorders, Alexander disease to neoplastic changes seen in gliomas. We hope that in near future we would witness glial-based translational medicine with generation of deliverables for the containment and cure of disorders. We point out that such as a task will require a holistic and multi-disciplinary approach that will take in consideration the concerted operation of all the cell types in the brain.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Science, The University of Manchester, Manchester, UK
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Luca Steardo
- Department of Psychiatry, University of Naples, SUN, Largo Madonna delle Grazie, Naples, Italy
| | - Vladimir Parpura
- Department of Neurobiology, Center for Glial Biology in Medicine and Atomic Force Microscopy & Nanotechnology Laboratories, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Vedrana Montana
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
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Regulation and the Mechanism of Estrogen on Cav1.2 Gene in Rat-Cultured Cortical Astrocytes. J Mol Neurosci 2016; 60:205-13. [PMID: 27498200 DOI: 10.1007/s12031-016-0803-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 07/28/2016] [Indexed: 12/11/2022]
Abstract
L-type calcium channel (LTCC) gene Cav1.2 is believed to play an important role in the alteration of Ca(2+) homeostasis in brain astrocytes. Increasing evidence shows that alteration of intracellular Ca(2+) concentration is related to the effect of 17β-estradiol (E2) in a variety of neurophysiological and neuropathological conditions. In this study, we measured immunoreactivity of Cav1.2 protein expression in rat primary cortical astrocytes by using Western blots. We demonstrated that E2 upregulated Cav1.2 expression in a dose- and time-dependent manner and the effect of E2 on Cav1.2 expression were blocked by an estrogen receptor (ER) antagonist, ICI-182,780. The ER subtype-selective ERα agonists propylpyrazole triole (PPT) and ERβ agonist diarylpropionitrile (DPN) both increase the expression of Cav1.2 in a dose-dependent manner. Also, the PPT most closely mimicked the upregulation of Cav1.2 protein expression by E2. Similar experiments of 10 nM E2-treated ERα- or ERβ-knockdown astrocytes have also shown that the E2 regulation of Cav1.2 protein expression is mediated through an ERα-dependent pathway. Furthermore, we established that E2 did not change the level of Cav1.2 mRNA. The induction of E2-mediated Cav1.2 expression was inhibited by cycloheximide (CHX) but not by actinomycin D (Act-D), suggesting that E2 regulation of Cav1.2 expression occurred at a posttranscriptional level. We also found that E2 may increase Cav1.2 levels by decreasing its ubiquitination and degradation rate. These findings provide new information about the effect of E2 on Cav1.2 in astrocytes, particularly necessary for the treatment of neurological disease.
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Wang W, Gu L, Verkhratsky A, Peng L. Ammonium Increases TRPC1 Expression Via Cav-1/PTEN/AKT/GSK3β Pathway. Neurochem Res 2016; 42:762-776. [DOI: 10.1007/s11064-016-2004-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/04/2016] [Accepted: 07/08/2016] [Indexed: 12/22/2022]
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Multifactorial Effects on Different Types of Brain Cells Contribute to Ammonia Toxicity. Neurochem Res 2016; 42:721-736. [PMID: 27286679 DOI: 10.1007/s11064-016-1966-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 05/20/2016] [Accepted: 05/24/2016] [Indexed: 12/12/2022]
Abstract
Effects of ammonia on astrocytes play a major role in hepatic encephalopathy, acute liver failure and other diseases caused by increased arterial ammonia concentrations (e.g., inborn errors of metabolism, drug or mushroom poisoning). There is a direct correlation between arterial ammonia concentration, brain ammonia level and disease severity. However, the pathophysiology of hyperammonemic diseases is disputed. One long recognized factor is that increased brain ammonia triggers its own detoxification by glutamine formation from glutamate. This is an astrocytic process due to the selective expression of the glutamine synthetase in astrocytes. A possible deleterious effect of the resulting increase in glutamine concentration has repeatedly been discussed and is supported by improvement of some pathologic effects by GS inhibition. However, this procedure also inhibits a large part of astrocytic energy metabolism and may prevent astrocytes from responding to pathogenic factors. A decrease of the already low glutamate concentration in astrocytes due to increased synthesis of glutamine inhibits the malate-aspartate shuttle and energy metabolism. A more recently described pathogenic factor is the resemblance between NH4+ and K+ in their effects on the Na+,K+-ATPase and the Na+,K+, 2 Cl- and water transporter NKCC1. Stimulation of the Na+,K+-ATPase driven NKCC1 in both astrocytes and endothelial cells is essential for the development of brain edema. Na+,K+-ATPase stimulation also activates production of endogenous ouabains. This leads to oxidative and nitrosative damage and sensitizes NKCC1. Administration of ouabain antagonists may accordingly have therapeutic potential in hyperammonemic diseases.
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Zhang X, Song D, Gu L, Ren Y, Verkhratsky A, Peng L. Decrease of gene expression of astrocytic 5-HT2B receptors parallels development of depressive phenotype in a mouse model of Parkinson's disease. Front Cell Neurosci 2015; 9:388. [PMID: 26500493 PMCID: PMC4594497 DOI: 10.3389/fncel.2015.00388] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 09/17/2015] [Indexed: 12/12/2022] Open
Abstract
Astrocytes contribute to pathogenesis of neuropsychiatric disorders, including major depression. Stimulation of astroglial 5-HT2B receptors transactivates epidermal growth factor receptors (EGFRs) and regulates gene expression. Previously we reported that expression of 5-HT2B receptors in cortical astrocytes is down-regulated in animals, which developed anhedonia in response to chronic stress; moreover this down-regulation as well as anhedonia, are reversed by chronic treatment with fluoxetine. In this study we have investigated whether astrocytic 5-HT2B receptor is involved in anhedonia in C57BL/6 mice model of Parkinson' disease (PD) induced by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 7 days. The MPTP treatment induced anhendonia in 66.7% of animals. The appearance of depressive behavior was accompanied with motor deficiency and decrease of tyrosine hydroxylase (TH) expression. Expression of mRNA and protein of 5-HT2B receptor in animals that became anhedonic decreased to 77.3 and 79.3% of control groups, respectively; in animals that received MPTP but did not develop anhedonia the expression of 5-HT2B receptor did not change. Experiments with FACS-sorted isolated cells demonstrated that decrease in 5-HT2B receptor expression was confined to astrocytes, and did not occur in neurons. Fluoxetine corrected MPTP-induced decrease of 5-HT2B receptor expression and depressive behavior. Our findings indicate that regulation of gene expression of 5-HT2B receptors in astroglia may be associated with pathophysiological evolution of PD-induced depression.
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Affiliation(s)
- Xique Zhang
- Department of Neurology, The First Affiliated Hospital, China Medical University Shenyang, China
| | - Dan Song
- Laboratory of Brain Metabolic Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University Shenyang, China
| | - Li Gu
- Laboratory of Brain Metabolic Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University Shenyang, China
| | - Yan Ren
- Department of Neurology, The First Affiliated Hospital, China Medical University Shenyang, China
| | - Alexei Verkhratsky
- Faculty of Life Science, The University of Manchester Manchester, UK ; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science Bilbao, Spain ; University of Nizhny Novgorod Nizhny Novgorod, Russia
| | - Liang Peng
- Laboratory of Brain Metabolic Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University Shenyang, China
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29
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Illes P, Verkhratsky A. Purinergic neurone-glia signalling in cognitive-related pathologies. Neuropharmacology 2015; 104:62-75. [PMID: 26256423 DOI: 10.1016/j.neuropharm.2015.08.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/19/2015] [Accepted: 08/03/2015] [Indexed: 12/31/2022]
Abstract
Neuroglia, represented by astrocytes, oligodendrocytes, NG glia and microglia are homeostatic, myelinating and defensive cells of the brain. Neuroglial cells express various combinations of purinoceptors, which contribute to multiple intercellular signalling pathways in the healthy and diseased nervous system. Neurological diseases are invariably associated with profound neuroglial remodelling, which is manifest by reactive gliosis, pathological remodelling and functional atrophy of various types of glial cells. Gliopathology is disease and region specific and produces multiple glial phenotypes that may be neuroprotective or neurotoxic. In this review we summarise recent knowledge on the role of glial purinergic signalling in cognitive-related neurological diseases. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.
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Affiliation(s)
- Peter Illes
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany.
| | - Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PT, UK; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain; Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain; University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia.
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Dynnik VV, Kononov AV, Sergeev AI, Teplov IY, Tankanag AV, Zinchenko VP. To Break or to Brake Neuronal Network Accelerated by Ammonium Ions? PLoS One 2015. [PMID: 26217943 PMCID: PMC4517767 DOI: 10.1371/journal.pone.0134145] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Purpose The aim of present study was to investigate the effects of ammonium ions on in vitro neuronal network activity and to search alternative methods of acute ammonia neurotoxicity prevention. Methods Rat hippocampal neuronal and astrocytes co-cultures in vitro, fluorescent microscopy and perforated patch clamp were used to monitor the changes in intracellular Ca2+- and membrane potential produced by ammonium ions and various modulators in the cells implicated in neural networks. Results Low concentrations of NH4Cl (0.1–4 mM) produce short temporal effects on network activity. Application of 5–8 mM NH4Cl: invariably transforms diverse network firing regimen to identical burst patterns, characterized by substantial neuronal membrane depolarization at plateau phase of potential and high-amplitude Ca2+-oscillations; raises frequency and average for period of oscillations Ca2+-level in all cells implicated in network; results in the appearance of group of «run out» cells with high intracellular Ca2+ and steadily diminished amplitudes of oscillations; increases astrocyte Ca2+-signalling, characterized by the appearance of groups of cells with increased intracellular Ca2+-level and/or chaotic Ca2+-oscillations. Accelerated network activity may be suppressed by the blockade of NMDA or AMPA/kainate-receptors or by overactivation of AMPA/kainite-receptors. Ammonia still activate neuronal firing in the presence of GABA(A) receptors antagonist bicuculline, indicating that «disinhibition phenomenon» is not implicated in the mechanisms of networks acceleration. Network activity may also be slowed down by glycine, agonists of metabotropic inhibitory receptors, betaine, L-carnitine, L-arginine, etc. Conclusions Obtained results demonstrate that ammonium ions accelerate neuronal networks firing, implicating ionotropic glutamate receptors, having preserved the activities of group of inhibitory ionotropic and metabotropic receptors. This may mean, that ammonia neurotoxicity might be prevented by the activation of various inhibitory receptors (i.e. by the reinforcement of negative feedback control), instead of application of various enzyme inhibitors and receptor antagonists (breaking of neural, metabolic and signaling systems).
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Affiliation(s)
- Vladimir V. Dynnik
- Laboratory of intracellular signaling, Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
- Laboratory of bioenergetics, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
- * E-mail:
| | - Alexey V. Kononov
- Laboratory of intracellular signaling, Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Alexander I. Sergeev
- Laboratory of intracellular signaling, Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Iliya Y. Teplov
- Laboratory of intracellular signaling, Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Arina V. Tankanag
- Laboratory of intracellular signaling, Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Valery P. Zinchenko
- Laboratory of intracellular signaling, Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
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