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Su Y, Verkhratsky A, Yi C. Targeting connexins: possible game changer in managing neuropathic pain? Trends Mol Med 2024; 30:642-659. [PMID: 38594094 DOI: 10.1016/j.molmed.2024.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/08/2024] [Accepted: 03/18/2024] [Indexed: 04/11/2024]
Abstract
Neuropathic pain is a chronic debilitating condition caused by nerve injury or a variety of diseases. At the core of neuropathic pain lies the aberrant neuronal excitability in the peripheral and/or central nervous system (PNS and CNS). Enhanced connexin expression and abnormal activation of connexin-assembled gap junctional channels are prominent in neuropathic pain along with reactive gliosis, contributing to neuronal hypersensitivity and hyperexcitability. In this review, we delve into the current understanding of how connexin expression and function contribute to the pathogenesis and pathophysiology of neuropathic pain and argue for connexins as potential therapeutic targets for neuropathic pain management.
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Affiliation(s)
- Yixun Su
- Research Centre, Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK; Achucarro Center for Neuroscience, IKERBASQUE, Bilbao, Spain; Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania; Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China.
| | - Chenju Yi
- Research Centre, Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China; Guangdong Provincial Key Laboratory of Brain Function and Disease, Guangzhou, China; Shenzhen Key Laboratory of Chinese Medicine Active substance screening and Translational Research, Shenzhen, China.
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2
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Yang Y, Liu T, Li J, Yan D, Hu Y, Wu P, Fang F, McQuillan PM, Hang W, Leng J, Hu Z. General anesthetic agents induce neurotoxicity through astrocytes. Neural Regen Res 2024; 19:1299-1307. [PMID: 37905879 DOI: 10.4103/1673-5374.385857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 09/09/2023] [Indexed: 11/02/2023] Open
Abstract
ABSTRACT Neuroscientists have recognized the importance of astrocytes in regulating neurological function and their influence on the release of glial transmitters. Few studies, however, have focused on the effects of general anesthetic agents on neuroglia or astrocytes. Astrocytes can also be an important target of general anesthetic agents as they exert not only sedative, analgesic, and amnesic effects but also mediate general anesthetic-induced neurotoxicity and postoperative cognitive dysfunction. Here, we analyzed recent advances in understanding the mechanism of general anesthetic agents on astrocytes, and found that exposure to general anesthetic agents will destroy the morphology and proliferation of astrocytes, in addition to acting on the receptors on their surface, which not only affect Ca2+ signaling, inhibit the release of brain-derived neurotrophic factor and lactate from astrocytes, but are even involved in the regulation of the pro- and anti-inflammatory processes of astrocytes. These would obviously affect the communication between astrocytes as well as between astrocytes and neighboring neurons, other neuroglia, and vascular cells. In this review, we summarize how general anesthetic agents act on neurons via astrocytes, and explore potential mechanisms of action of general anesthetic agents on the nervous system. We hope that this review will provide a new direction for mitigating the neurotoxicity of general anesthetic agents.
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Affiliation(s)
- Yanchang Yang
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Tiantian Liu
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Department of Anesthesiology, Ningbo Women and Children's Hospital, Ningbo, Zhejiang Province, China
| | - Jun Li
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Department of Anesthesiology, Shulan (Hangzhou) Hospital Affiliated to Zhejiang Shuren University Shulan International Medical College, Hangzhou, Zhejiang Province, China
| | - Dandan Yan
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Yuhan Hu
- Cell Biology Department, Yale University, New Haven, CT, USA
| | - Pin Wu
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Fuquan Fang
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Patrick M McQuillan
- Department of Anesthesiology, Penn State Hershey Medical Centre, Penn State College of Medicine, Hershey, PA, USA
| | - Wenxin Hang
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Jianhang Leng
- Department of Central Laboratory, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Zhiyong Hu
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
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Lei L, Wang YT, Hu D, Gai C, Zhang Y. Astroglial Connexin 43-Mediated Gap Junctions and Hemichannels: Potential Antidepressant Mechanisms and the Link to Neuroinflammation. Cell Mol Neurobiol 2023; 43:4023-4040. [PMID: 37875763 DOI: 10.1007/s10571-023-01426-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 10/14/2023] [Indexed: 10/26/2023]
Abstract
Major depression disorder (MDD) is a neuropsychiatric disorder associated with a high suicide rate and a higher disability rate than any other disease. Evidence suggests that the pathological mechanism of MDD is related to astrocyte dysfunction. Depression is mainly associated with the expression of connexin 43 (Cx43) and the function of Cx43-mediated gap junctions and hemichannels in astrocytes. Moreover, neuroinflammation has been a hotspot in research on the pathology of depression, and Cx43-mediated functions are thought to be involved in neuroinflammation-related depression. However, the specific mechanism of Cx43-mediated functions in neuroinflammation-related depression pathology remains unclear. Therefore, this review summarizes and discusses Cx43 expression, the role of gap junction intercellular communication, and its relationship with neuroinflammation in depression. This review also focuses on the effects of antidepressant drugs (e.g., monoamine antidepressants, psychotropic drugs, and N-methyl-D-aspartate receptor antagonists) on Cx43-mediated function and provides evidence for Cx43 as a novel target for the treatment of MDD. The pathogenesis of MDD is related to astrocyte dysfunction, with reduced Cx43 expression, GJ dysfunction, decreased GJIC and reduced BDNF expression in the depressed brain. The effect of Cx43 on neuroinflammation-related depression involving inflammatory cytokines, glutamate excitotoxicity, and HPA axis dysregulation. Antidepressant drugs targeting Cx43 can effectively relieve depressive symptoms.
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Affiliation(s)
- Lan Lei
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Sunshine Southern Avenue, Fang-Shan District, Beijing, 102488, China
| | - Ya-Ting Wang
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Sunshine Southern Avenue, Fang-Shan District, Beijing, 102488, China
| | - Die Hu
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Sunshine Southern Avenue, Fang-Shan District, Beijing, 102488, China
| | - Cong Gai
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Sunshine Southern Avenue, Fang-Shan District, Beijing, 102488, China
| | - Yi Zhang
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Sunshine Southern Avenue, Fang-Shan District, Beijing, 102488, China.
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Jiwaji Z, Márkus NM, McQueen J, Emelianova K, He X, Dando O, Chandran S, Hardingham GE. General anesthesia alters CNS and astrocyte expression of activity-dependent and activity-independent genes. FRONTIERS IN NETWORK PHYSIOLOGY 2023; 3:1216366. [PMID: 37670849 PMCID: PMC10476527 DOI: 10.3389/fnetp.2023.1216366] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 07/21/2023] [Indexed: 09/07/2023]
Abstract
General anesthesia represents a common clinical intervention and yet can result in long-term adverse CNS effects particularly in the elderly or dementia patients. Suppression of cortical activity is a key feature of the anesthetic-induced unconscious state, with activity being a well-described regulator of pathways important for brain health. However, the extent to which the effects of anesthesia go beyond simple suppression of neuronal activity is incompletely understood. We found that general anesthesia lowered cortical expression of genes induced by physiological activity in vivo, and recapitulated additional patterns of gene regulation induced by total blockade of firing activity in vitro, including repression of neuroprotective genes and induction of pro-apoptotic genes. However, the influence of anesthesia extended beyond that which could be accounted for by activity modulation, including the induction of non activity-regulated genes associated with inflammation and cell death. We next focused on astrocytes, important integrators of both neuronal activity and inflammatory signaling. General anesthesia triggered gene expression changes consistent with astrocytes being in a low-activity environment, but additionally caused induction of a reactive profile, with transcriptional changes enriched in those triggered by stroke, neuroinflammation, and Aß/tau pathology. Thus, while the effects of general anesthesia on cortical gene expression are consistent with the strong repression of brain activity, further deleterious effects are apparent including a reactive astrocyte profile.
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Affiliation(s)
- Zoeb Jiwaji
- UK Dementia Research Institute, Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Department of Anaesthesia, Critical Care and Pain Medicine, Usher Institute, Edinburgh Royal Infirmary, Edinburgh, United Kingdom
| | - Nóra M. Márkus
- UK Dementia Research Institute, Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jamie McQueen
- UK Dementia Research Institute, Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Katie Emelianova
- UK Dementia Research Institute, Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Xin He
- UK Dementia Research Institute, Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Owen Dando
- UK Dementia Research Institute, Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Siddharthan Chandran
- UK Dementia Research Institute, Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Giles E. Hardingham
- UK Dementia Research Institute, Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
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Li H, Guo A, Salgado M, Sáez JC, Lau CG. The connexin hemichannel inhibitor D4 produces rapid antidepressant-like effects in mice. J Neuroinflammation 2023; 20:191. [PMID: 37599352 PMCID: PMC10440914 DOI: 10.1186/s12974-023-02873-z] [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: 04/14/2023] [Accepted: 08/14/2023] [Indexed: 08/22/2023] Open
Abstract
Depression is a common mood disorder characterized by a range of clinical symptoms, including prolonged low mood and diminished interest. Although many clinical and animal studies have provided significant insights into the pathophysiology of depression, current treatment strategies are not sufficient to manage this disorder. It has been suggested that connexin (Cx)-based hemichannels are candidates for depression intervention by modifying the state of neuroinflammation. In this study, we investigated the antidepressant-like effect of a recently discovered selective Cx hemichannel inhibitor, a small organic molecule called D4. We first showed that D4 reduced hemichannel activity following systemic inflammation after LPS injections. Next, we found that D4 treatment prevented LPS-induced inflammatory response and depressive-like behaviors. These behavioral effects were accompanied by reduced astrocytic activation and hemichannel activity in depressive-like mice induced by repeated low-dose LPS challenges. D4 treatment also reverses depressive-like symptoms in mice subjected to chronic restraint stress (CRS). To test whether D4 broadly affected neural activity, we measured c-Fos expression in depression-related brain regions and found a reduction in c-Fos+ cells in different brain regions. D4 significantly normalized CRS-induced hypoactivation in several brain regions, including the hippocampus, entorhinal cortex, and lateral septum. Together, these results indicate that blocking Cx hemichannels using D4 can normalize neuronal activity and reduce depressive-like symptoms in mice by reducing neuroinflammation. Our work provides evidence of the antidepressant-like effect of D4 and supports glial Cx hemichannels as potential therapeutic targets for depression.
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Affiliation(s)
- Huanhuan Li
- Department of Neuroscience, City University of Hong Kong, Hong Kong SAR, China
- Shenzhen Research Institute, City University of Hong Kong, Shenzhen, China
| | - Anni Guo
- Department of Neuroscience, City University of Hong Kong, Hong Kong SAR, China
- Shenzhen Research Institute, City University of Hong Kong, Shenzhen, China
| | - Magdiel Salgado
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, 2381850, Valparaíso, Chile
| | - Juan C Sáez
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, 2381850, Valparaíso, Chile
| | - Chunyue Geoffrey Lau
- Department of Neuroscience, City University of Hong Kong, Hong Kong SAR, China.
- Shenzhen Research Institute, City University of Hong Kong, Shenzhen, China.
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Caruso G, Di Pietro L, Caraci F. Gap Junctions and Connexins in Microglia-Related Oxidative Stress and Neuroinflammation: Perspectives for Drug Discovery. Biomolecules 2023; 13:biom13030505. [PMID: 36979440 PMCID: PMC10046203 DOI: 10.3390/biom13030505] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/28/2023] [Accepted: 03/07/2023] [Indexed: 03/12/2023] Open
Abstract
Microglia represent the immune system of the brain. Their role is central in two phenomena, neuroinflammation and oxidative stress, which are at the roots of different pathologies related to the central nervous system (CNS). In order to maintain the homeostasis of the brain and re-establish the equilibrium after a threatening imbalance, microglia communicate with each other and other cells within the CNS by receiving specific signals through membrane-bound receptors and then releasing neurotrophic factors into either the extracellular milieu or directly into the cytoplasm of nearby cells, such as astrocytes and neurons. These last two mechanisms rely on the activity of protein structures that enable the formation of channels in the membrane, namely, connexins and pannexins, that group and form gap junctions, hemichannels, and pannexons. These channels allow the release of gliotransmitters, such as adenosine triphosphate (ATP) and glutamate, together with calcium ion (Ca2+), that seem to play a pivotal role in inter-cellular communication. The aim of the present review is focused on the physiology of channel protein complexes and their contribution to neuroinflammatory and oxidative stress-related phenomena, which play a central role in neurodegenerative disorders. We will then discuss how pharmacological modulation of these channels can impact neuroinflammatory phenomena and hypothesize that currently available nutraceuticals, such as carnosine and N-acetylcysteine, can modulate the activity of connexins and pannexins in microglial cells and reduce oxidative stress in neurodegenerative disorders.
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Affiliation(s)
- Giuseppe Caruso
- Department of Drug and Health Sciences, University of Catania, 95123 Catania, Italy
- Unit of Neuropharmacology and Translational Neurosciences, Oasi Research Institute-IRCCS, 94018 Troina, Italy
- Correspondence: ; Tel.: +39-0957385036
| | - Lucia Di Pietro
- Department of Drug and Health Sciences, University of Catania, 95123 Catania, Italy
- Scuola Superiore di Catania, University of Catania, 95123 Catania, Italy
| | - Filippo Caraci
- Department of Drug and Health Sciences, University of Catania, 95123 Catania, Italy
- Unit of Neuropharmacology and Translational Neurosciences, Oasi Research Institute-IRCCS, 94018 Troina, Italy
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Zhang NN, Zhang Y, Wang ZZ, Chen NH. Connexin 43: insights into candidate pathological mechanisms of depression and its implications in antidepressant therapy. Acta Pharmacol Sin 2022; 43:2448-2461. [PMID: 35145238 PMCID: PMC9525669 DOI: 10.1038/s41401-022-00861-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 01/06/2022] [Indexed: 11/09/2022] Open
Abstract
Major depressive disorder (MDD), a chronic and recurrent disease characterized by anhedonia, pessimism or even suicidal thought, remains a major chronic mental concern worldwide. Connexin 43 (Cx43) is the most abundant connexin expressed in astrocytes and forms the gap junction channels (GJCs) between astrocytes, the most abundant and functional glial cells in the brain. Astrocytes regulate neurons' synaptic strength and function by expressing receptors and regulating various neurotransmitters. Astrocyte dysfunction causes synaptic abnormalities, which are related to various mood disorders, e.g., depression. Increasing evidence suggests a crucial role of Cx43 in the pathogenesis of depression. Depression down-regulates Cx43 expression in humans and rats, and dysfunction of Cx43 also induces depressive behaviors in rats and mice. Recently Cx43 has received considerable critical attention and is highly implicated in the onset of depression. However, the pathological mechanisms of depression-like behavior associated with Cx43 still remain ambiguous. In this review we summarize the recent progress regarding the underlying mechanisms of Cx43 in the etiology of depression-like behaviors including gliotransmission, metabolic disorders, and neuroinflammation. We also discuss the effects of antidepressants (monoamine antidepressants and ketamine) on Cx43. The clarity of the candidate pathological mechanisms of depression-like behaviors associated with Cx43 and its potential pharmacological roles for antidepressants will benefit the exploration of a novel antidepressant target.
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Affiliation(s)
- Ning-Ning Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Yi Zhang
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, 102488, China
| | - Zhen-Zhen Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
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Altered neural cell junctions and ion-channels leading to disrupted neuron communication in Parkinson's disease. NPJ Parkinsons Dis 2022; 8:66. [PMID: 35650269 PMCID: PMC9160246 DOI: 10.1038/s41531-022-00324-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 05/05/2022] [Indexed: 12/16/2022] Open
Abstract
Parkinson’s disease (PD) is a neurological disorder that affects the movement of the human body. It is primarily characterized by reduced dopamine levels in the brain. The causative agent of PD is still unclear but it is generally accepted that α-synuclein has a central role to play. It is also known that gap-junctions and associated connexins are complicated structures that play critical roles in nervous system signaling and associated misfunctioning. Thus, our current article emphasizes how, alongside α-synuclein, ion-channels, gap-junctions, and related connexins, all play vital roles in influencing multiple metabolic activities of the brain during PD. It also highlights that ion-channel and gap-junction disruptions, which are primarily mediated by their structural-functional changes and alterations, have a role in PD. Furthermore, we discussed available drugs and advanced therapeutic interventions that target Parkinson’s pathogenesis. In conclusion, it warrants creating better treatments for PD patients. Although, dopaminergic replenishment therapy is useful in treating neurological problems, such therapies are, however, unable to control the degeneration that underpins the disease, thereby declining their overall efficacy. This creates an additional challenge and an untapped scope for neurologists to adopt treatments for PD by targeting the ion-channels and gap-junctions, which is well-reviewed in the present article.
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Mulkey DK, Olsen ML, Ou M, Cleary CM, Du G. Putative Roles of Astrocytes in General Anesthesia. Curr Neuropharmacol 2022; 20:5-15. [PMID: 33588730 PMCID: PMC9199541 DOI: 10.2174/1570159x19666210215120755] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/29/2021] [Accepted: 02/06/2021] [Indexed: 02/08/2023] Open
Abstract
General anesthetics are a mainstay of modern medicine, and although much progress has been made towards identifying molecular targets of anesthetics and neural networks contributing to endpoints of general anesthesia, our understanding of how anesthetics work remains unclear. Reducing this knowledge gap is of fundamental importance to prevent unwanted and life-threatening side-effects associated with general anesthesia. General anesthetics are chemically diverse, yet they all have similar behavioral endpoints, and so for decades, research has sought to identify a single underlying mechanism to explain how anesthetics work. However, this effort has given way to the 'multiple target hypothesis' as it has become clear that anesthetics target many cellular proteins, including GABAA receptors, glutamate receptors, voltage-independent K+ channels, and voltagedependent K+, Ca2+ and Na+ channels, to name a few. Yet, despite evidence that astrocytes are capable of modulating multiple aspects of neural function and express many anesthetic target proteins, they have been largely ignored as potential targets of anesthesia. The purpose of this brief review is to highlight the effects of anesthetic on astrocyte processes and identify potential roles of astrocytes in behavioral endpoints of anesthesia (hypnosis, amnesia, analgesia, and immobilization).
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Affiliation(s)
- Daniel K. Mulkey
- Department of Physiology and Neurobiology, University of Connecticut, StorrsCT, USA;,Address correspondence to this author at the Department of Physiology and Neurobiology, University of Connecticut, Storrs CT, USA; E-mail:
| | | | | | - Colin M. Cleary
- Department of Physiology and Neurobiology, University of Connecticut, StorrsCT, USA
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Effects of an Atypical Antipsychotic, Zotepine, on Astroglial L-Glutamate Release through Hemichannels: Exploring the Mechanism of Mood-Stabilising Antipsychotic Actions and Antipsychotic-Induced Convulsion. Pharmaceuticals (Basel) 2021; 14:ph14111116. [PMID: 34832898 PMCID: PMC8625878 DOI: 10.3390/ph14111116] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 10/28/2021] [Accepted: 10/28/2021] [Indexed: 02/06/2023] Open
Abstract
Accumulating neuropsychopharmacological evidence has suggested that functional abnormalities of astroglial transmission and protein kinase B (Akt) contribute to the pathophysiology and/or pathomechanisms of several neuropsychiatric disorders, such as epilepsy, schizophrenia, affective disorders and antipsychotic-induced convulsions. Therefore, to explore the pathophysiology of mood-stabilising antipsychotics and the proconvulsive actions of atypical antipsychotics, the present study determined the effects of a mood-stabilising, atypical, antipsychotic agent, zotepine (ZTP), on astroglial L-glutamate release and the expression of connexin43 (Cx43) protein in cortical, primary, cultured astrocytes using ultra-high-pressure liquid chromatography and capillary immunoblotting systems. Both acute and subchronic administrations of therapeutically relevant concentrations of ZTP did not affect astroglial L-glutamate release or Cx43 expression in plasma membranes; however, chronic administration of a therapeutically relevant concentration of ZTP increased astroglial L-glutamate release and Cx43 expression in the plasma membrane. Subchronic administrations of a supratherapeutic concentration of ZTP enhanced astroglial L-glutamate release and Cx43 expression in the plasma membrane, whereas acute administration of a supratherapeutic concentration of ZTP enhanced astroglial L-glutamate release without affecting Cx43 expression. These stimulatory effects of ZTP on astroglial L-glutamate release through activated hemichannels and Cx43 trafficking to the astroglial plasma membrane were suppressed by the Akt inhibitor. These results suggest that ZTP enhances astroglial L-glutamate release in a concentration-dependent and time-dependent manner due to the enhanced function of astroglial hemichannels, probably via activation of Akt signalling. Therefore, the enhanced astroglial L-glutamatergic transmission induced by ZTP is, at least partially, involved in the mood-stabilising antipsychotic and proconvulsive actions of ZTP.
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11
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Mazaud D, Capano A, Rouach N. The many ways astroglial connexins regulate neurotransmission and behavior. Glia 2021; 69:2527-2545. [PMID: 34101261 DOI: 10.1002/glia.24040] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 05/17/2021] [Accepted: 05/21/2021] [Indexed: 12/18/2022]
Abstract
Astrocytes have emerged as major players in the brain, contributing to many functions such as energy supply, neurotransmission, and behavior. They accomplish these functions in part via their capacity to form widespread intercellular networks and to release neuroactive factors, which can modulate neurotransmission at different levels, from individual synapses to neuronal networks. The extensive network communication of astrocytes is primarily mediated by gap junction channels composed of two connexins, Cx30 and Cx43, which present distinct temporal and spatial expression patterns. Yet, astroglial connexins are also involved in direct exchange with the extracellular space via hemichannels, as well as in adhesion and signaling processes via unconventional nonchannel functions. Accumulating evidence indicate that astrocytes modulate neurotransmission and behavior through these diverse connexin functions. We here review the many ways astroglial connexins regulate neuronal activity from the molecular level to behavior.
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Affiliation(s)
- David Mazaud
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France
| | - Anna Capano
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France.,Doctoral School N°158, Sorbonne University, Paris, France
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France
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12
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Li Y, Wang Y, Chang H, Cheng B, Miao J, Li S, Hu H, Huang L, Wang Q. Inhibitory Effects of Dexmedetomidine and Propofol on Gastrointestinal Tract Motility Involving Impaired Enteric Glia Ca 2+ Response in Mice. Neurochem Res 2021; 46:1410-1422. [PMID: 33656693 DOI: 10.1007/s11064-021-03280-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 02/20/2021] [Accepted: 02/20/2021] [Indexed: 12/31/2022]
Abstract
Propofol and dexmedetomidine are popular used for sedation in ICU, however, inadequate attention has been paid to their effect on gastrointestinal tract (GIT) motility. Present study aimed to compare the effect of propofol and dexmedetomidine on GIT motility at parallel level of sedation and explore the possible mechanism. Male C57BL/6 mice (8-10 weeks) were randomly divided into control, propofol and dexmedetomidine group. After intraperitoneal injection of propofol or dexmedetomidine, comparable sedative level was confirmed by sedative score, physiological parameters and electroencephalogram (EEG). Different segments of GIT motility in vivo (gastric emptying, small intestine transit, distal colon bead expulsion, stool weight and number of fecal pellets, gastrointestinal transit and whole gut transit time) and colonic migrating motor complexes (CMMCs) pattern in vitro were evaluated. The Ca2+ response of primary enteric glia was examined under the treatment of propofol or dexmedetomidine. There is little difference in physiological parameters and composite permutation entropy index (CPEI) between administration of 50 mg/kg propofol and 40 μg/kg dexmedetomidine, indicated that parallel level of sedation was reached. Data showed that propofol and dexmedetomidine had significantly inhibitory effect on GIT motility while dexmedetomidine was stronger. Also, the amplitude (ΔF/F0) of Ca2+ response in primary enteric glia was attenuated after treated with the sedatives while the effect of dexmedetomidine was greater than propofol. These findings demonstrated that dexmedetomidine caused stronger inhibitory effects on GIT motility in sedative mice, which may involve impaired Ca2+ response in enteric glia. Hence, dexmedetomidine should be carefully applied especially for potential GIT dysmotility patient.
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Affiliation(s)
- Yansong Li
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Yubo Wang
- School of Life Science and Technology, Xidian University, Xi'an, 710061, Shaanxi, China
| | - Haiqing Chang
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Bo Cheng
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Jiwen Miao
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Shuang Li
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Hao Hu
- Department of Pharmacology, School of Basic Medical Sciences, Health Science Center, Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Liyu Huang
- School of Life Science and Technology, Xidian University, Xi'an, 710061, Shaanxi, China
| | - Qiang Wang
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China.
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13
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Effects of Atypical Antipsychotics, Clozapine, Quetiapine and Brexpiprazole on Astroglial Transmission Associated with Connexin43. Int J Mol Sci 2021; 22:ijms22115623. [PMID: 34070699 PMCID: PMC8198373 DOI: 10.3390/ijms22115623] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/21/2021] [Accepted: 05/24/2021] [Indexed: 02/07/2023] Open
Abstract
Recently, accumulating preclinical findings suggest the possibility that functional abnormalities of tripartite synaptic transmission play important roles in the pathophysiology of schizophrenia and affective disorder. Therefore, to explore the novel mechanisms of mood-stabilizing effects associated with tripartite synaptic transmission, the present study determined the effects of mood-stabilizing antipsychotics, clozapine (CLZ), quetiapine (QTP) and brexpiprazole (BPZ), on the astroglial l-glutamate release and expression of connexin43 (Cx43) in the astroglial plasma membrane using cortical primary cultured astrocytes. Neither acute (for 120 min) nor subchronic (for 7 days) administrations of CLZ, QTP and BPZ affected basal astroglial l-glutamate release, whereas both acute and subchronic administration of CLZ, QTP and BPZ concentration-dependently enhanced astroglial l-glutamate release through activated hemichannels. Subchronic administration of therapeutic-relevant concentration of valproate (VPA), a histone deacetylase inhibiting mood-stabilizing antiepileptic drug, enhanced the stimulatory effects of therapeutic-relevant concentration of CLZ, QTP and BPZ on astroglial l-glutamate release through activated hemichannel. Subchronic administration of therapeutic-relevant concentration of CLZ, QTP and BPZ did not affect Cx43 protein expression in the plasma membrane during resting stage. After subchronic administration of VPA, acute and subchronic administration of therapeutic-relevant concentrations of CLZ increased Cx43 protein expression in the plasma membrane. Both acute administrations of therapeutic-relevant concentrations of QTP and BPZ did not affect, but subchronic administrations enhanced Cx43 protein expression in the astroglial plasma membrane. Furthermore, protein kinase B (Akt) inhibitor suppressed the stimulatory effects of CLZ and QTP, but did not affect Cx43 protein expression in the astroglial plasma membrane. These results suggest that three mood-stabilizing atypical antipsychotics, CLZ, QTP and BPZ enhance tripartite synaptic glutamatergic transmission due to enhancement of astroglial Cx43 containing hemichannel activities; however, the Cx43 activating mechanisms of these three mood-stabilizing antipsychotics were not identical. The enhanced astroglial glutamatergic transmission induced by CLZ, QTP and BPZ is, at least partially, involved in the actions of these three mood-stabilizing antipsychotics.
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14
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Korai SA, Sepe G, Luongo L, Cragnolini AB, Cirillo G. Editorial: Glial Cells, Maladaptive Plasticity, and Neurodegeneration: Mechanisms, Targeted Therapies, and Future Directions. Front Cell Neurosci 2021; 15:682524. [PMID: 33994952 PMCID: PMC8119640 DOI: 10.3389/fncel.2021.682524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 03/29/2021] [Indexed: 11/15/2022] Open
Affiliation(s)
- Sohaib Ali Korai
- Division of Human Anatomy - Laboratory of Neuronal Networks, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Giovanna Sepe
- Division of Human Anatomy - Laboratory of Neuronal Networks, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Livio Luongo
- Division of Pharmacology, University of Campania "Luigi Vanvitelli", Naples, Italy.,IRCSS Neuromed, Pozzilli, Italy
| | - Andrea Beatriz Cragnolini
- Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba, Argentina.,Instituto de Investigaciones Biológicas y Tecnológicas (IIByT), CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Giovanni Cirillo
- Division of Human Anatomy - Laboratory of Neuronal Networks, University of Campania "Luigi Vanvitelli", Naples, Italy
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15
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Relationship between Artificial Intelligence-Based General Anesthetics and Postoperative Cognitive Dysfunction. JOURNAL OF HEALTHCARE ENGINEERING 2021; 2021:5553029. [PMID: 33868620 PMCID: PMC8032528 DOI: 10.1155/2021/5553029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/08/2021] [Accepted: 03/20/2021] [Indexed: 11/23/2022]
Abstract
Postoperative cognitive dysfunction (POCD) refers to the complications of the central nervous system before and after surgery in patients without mental disorders. Many studies have shown that surgical anesthesia may cause POCD, especially in elderly patients. This article aims to study the relationship between artificial intelligence-based general anesthetics and postoperative cognitive dysfunction. This article first describes and classifies artificial intelligence, introduces its realization method, machine learning algorithms, and briefly introduces the basic principles of regression and classification methods in machine learning; then, the principles and techniques of general anesthetics are proposed. The pathogenesis of postoperative cognitive dysfunction (POCD) is explained in detail. Finally, the effect of anesthetics on postoperative cognitive dysfunction is obtained from both inhaled anesthetics and intravenous anesthetics. The impact on postoperative cognitive function is explained. The experimental results in this article show that there is no statistically significant difference in the two groups of patients' age, gender ratio, body mass index, education level, preoperative comorbidities, and other general indicators. Through the use of EEG bispectral index monitors to monitor the depth of anesthesia and postoperative cognitive dysfunction, first, there was no obvious relationship between the occurrence of postoperative cognitive dysfunction at 1, 5, 10, and 50 days and discharge time. The comprehensive monitoring group can reduce the clinical dose of preventive medication and cis-atracurium and shorten the patient's recovery time, extubation time, and recovery time. In addition, it can also reduce the increase of serum protein S100β in elderly patients and reduce the incidence of early postoperative cognitive dysfunction.
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16
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Okada M. Can rodent models elucidate the pathomechanisms of genetic epilepsy? Br J Pharmacol 2021; 179:1620-1639. [PMID: 33689168 PMCID: PMC9291625 DOI: 10.1111/bph.15443] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 02/03/2021] [Accepted: 03/04/2021] [Indexed: 12/31/2022] Open
Abstract
Autosomal dominant sleep-related hypermotor epilepsy (ADSHE; previously autosomal dominant nocturnal frontal lobe epilepsy, ADNFLE), originally reported in 1994, was the first distinct genetic epilepsy shown to be caused by CHNRA4 mutation. In the past two decades, we have identified several functional abnormalities of mutant ion channels and their associated transmissions using several experiments involving single-cell and genetic animal (rodent) models. Currently, epileptologists understand that functional abnormalities underlying epileptogenesis/ictogenesis in humans and rodents are more complicated than previously believed and that the function of mutant molecules alone cannot contribute to the development of epileptogenesis/ictogenesis but play important roles in the development of epileptogenesis/ictogenesis through formation of abnormalities in various other transmission systems before epilepsy onset. Based on our recent findings using genetic rat ADSHE models, harbouring Chrna4 mutant, corresponding to human S284L-mutant CRHNA4, this review proposes a hypothesis associated with tripartite synaptic transmission in ADSHE pathomechanisms induced by mutant ACh receptors.
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Affiliation(s)
- Motohiro Okada
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu, Japan
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17
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Charvériat M, Mouthon F, Rein W, Verkhratsky A. Connexins as therapeutic targets in neurological and neuropsychiatric disorders. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166098. [PMID: 33545299 DOI: 10.1016/j.bbadis.2021.166098] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 01/06/2021] [Accepted: 01/19/2021] [Indexed: 12/16/2022]
Abstract
Astrocytes represent the reticular part of the central nervous system; gap junctions formed by connexins Cx43, Cx30- and Cx26 provide for homocellular astrocyte-astrocyte coupling, whereas connexins Cx30, Cx32, Cx43, and Cx47 connect astrocytes and oligodendrocytes. Astroglial networks are anatomically and functionally segregated being homologous to neuronal ensembles. Connexons, gap junctions and hemichannels (unpaired connexons) are affected in various neuropathologies from neuropsychiatric to neurodegenerative diseases. Manipulation of astrocytic connexins modulates the size and outreach of astroglial syncytia thus affecting astroglial homeostatic support. Modulation of astrocytic connexin significantly modifies pharmacological profile of many CNS drugs, which represents an innovative therapeutic approach for CNS disorders; this approach is now actively tested in pre-clinical and clinical studies. Wide combination of connexin modulators with CNS drugs open new promising perspectives for fundamental studies and therapeutic strategies.
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Affiliation(s)
| | | | | | - A Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK; Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
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18
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Astroglial Connexin43 as a Potential Target for a Mood Stabiliser. Int J Mol Sci 2020; 22:ijms22010339. [PMID: 33396966 PMCID: PMC7795839 DOI: 10.3390/ijms22010339] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/24/2020] [Accepted: 12/27/2020] [Indexed: 02/06/2023] Open
Abstract
Mood disorders remain a major public health concern worldwide. Monoaminergic hypotheses of pathophysiology of bipolar and major depressive disorders have led to the development of monoamine transporter-inhibiting antidepressants for the treatment of major depression and have contributed to the expanded indications of atypical antipsychotics for the treatment of bipolar disorders. In spite of psychopharmacological progress, current pharmacotherapy according to the monoaminergic hypothesis alone is insufficient to improve or prevent mood disorders. Recent approval of esketamine for treatment of treatment-resistant depression has attracted attention in psychopharmacology as a glutamatergic hypothesis of the pathophysiology of mood disorders. On the other hand, in the last decade, accumulated findings regarding the pathomechanisms of mood disorders emphasised that functional abnormalities of tripartite synaptic transmission play important roles in the pathophysiology of mood disorders. At first glance, the enhancement of astroglial connexin seems to contribute to antidepressant and mood-stabilising effects, but in reality, antidepressive and mood-stabilising actions are mediated by more complicated interactions associated with the astroglial gap junction and hemichannel. Indeed, several depressive mood-inducing stress stimulations suppress connexin43 expression and astroglial gap junction function, but enhance astroglial hemichannel activity. On the other hand, monoamine transporter-inhibiting antidepressants suppress astroglial hemichannel activity and enhance astroglial gap junction function, whereas several non-antidepressant mood stabilisers activate astroglial hemichannel activity. Based on preclinical findings, in this review, we summarise the effects of antidepressants, mood-stabilising antipsychotics, and anticonvulsants on astroglial connexin, and then, to establish a novel strategy for treatment of mood disorders, we reveal the current progress in psychopharmacology, changing the question from "what has been revealed?" to "what should be clarified?".
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19
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Luo KJ, Chen CX, Yang JP, Huang YC, Cardenas ER, Jiang JX. Connexins in Lung Cancer and Brain Metastasis. Front Oncol 2020; 10:599383. [PMID: 33425756 PMCID: PMC7786366 DOI: 10.3389/fonc.2020.599383] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/11/2020] [Indexed: 01/20/2023] Open
Abstract
Connexins (Cxs) are involved in the brain metastasis of lung cancer cells. Thus, it is necessary to determine whether gap junction-forming Cxs are involved in the communication between lung cancer cells and the host cells, such as endothelial cells, forming the brain-blood-barrier, and cells in the central nervous system. Data from multiple studies support that Cxs function as tumor suppressors during lung cancer occurrence. However, recent evidence suggests that during metastasis to the brain, cancer cells establish communication with the host. This review discusses junctional or non-junctional hemichannel studies in lung cancer development and brain metastasis, highlighting important unanswered questions and controversies.
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Affiliation(s)
- Kai-Jun Luo
- School of Life Sciences, Yunnan University, Kunming, China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, China
| | - Chang-Xu Chen
- School of Life Sciences, Yunnan University, Kunming, China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, China
| | - Jia-Peng Yang
- Department of Thoracic Surgery I, The Third Affiliated Hospital of Kunming Medical University/Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China
- Joint International Research Laboratory of Regional Tumor in High Altitude Area, Kunming, China
| | - Yun-Chao Huang
- Department of Thoracic Surgery I, The Third Affiliated Hospital of Kunming Medical University/Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China
- Joint International Research Laboratory of Regional Tumor in High Altitude Area, Kunming, China
| | - Eduardo R. Cardenas
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, United States
| | - Jean X. Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, United States
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20
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Perioperative Dexmedetomidine attenuates brain ischemia reperfusion injury possibly via up-regulation of astrocyte Connexin 43. BMC Anesthesiol 2020; 20:299. [PMID: 33287729 PMCID: PMC7722427 DOI: 10.1186/s12871-020-01211-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 11/25/2020] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Astrocyte Connexin 43 (Cx43) is essential for the trophic and protective support of neurons during brain ischemia reperfusion (I/R) injury. It is believed that dexmedetomidine participates in Cx43-mediated effects. However, its mechanisms remained unclear. This study aims to address the relationship and regulation among them. METHODS Adult male Sprague-Dawley rats were allocated to the 90-min right middle cerebral arterial occlusion with or without dexmedetomidine pretreatment (5 μg/kg). Neurological functions were evaluated and brain lesions, as well as inflammatory factors (IL-1β, IL-6, TNF-α), were assessed. Ischemic penumbral cortex was harvested to determine the expression of astrocyte Cx43. Primary astrocytes were cultured to evaluate the effect of dexmedetomidine on Cx43 after oxygen-glucose deprivation. RESULTS Dexmedetomidine pretreatment attenuated neurological injury, brain lesions and expression of inflammatory factors (IL-1β, IL-6, TNF-α) after brain ischemia (P < 0.05). Astrocyte Cx43 was down-regulated by brain I/R injury, both in vivo and in vitro, which were reversed by dexmedetomidine (P < 0.05). This effect was mediated by the phosphorylation of Akt and GSK-3β. Further studies with LY294002 (PI3K inhibitor) or SB216763 (GSK-3β inhibitor) confirmed the effect of dexmedetomidine on astrocyte Cx43. CONCLUSIONS Perioperative dexmedetomidine administration attenuates neurological injury after brain I/R injury, possibly through up-regulation of astrocyte Cx43. Activation of PI3K-Akt-GSK-3β pathway might contribute to this protective effect.
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21
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Neocortical in vivo focal and spreading potassium responses and the influence of astrocytic gap junctional coupling. Neurobiol Dis 2020; 147:105160. [PMID: 33152505 DOI: 10.1016/j.nbd.2020.105160] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/29/2020] [Accepted: 10/31/2020] [Indexed: 11/21/2022] Open
Abstract
Raised extracellular potassium ion (K+) concentration is associated with several disorders including migraine, stroke, neurotrauma and epilepsy. K+ spatial buffering is a well-known mechanism for extracellular K+ regulation/distribution. Astrocytic gap junction-mediated buffering is a controversial candidate for K+ spatial buffering. To further investigate the existence of a K+ spatial buffering and to assess the involvement of astrocytic gap junctional coupling in K+ redistribution, we hypothesized that neocortical K+ and concomitant spreading depolarization (SD)-like responses are controlled by powerful local K+ buffering mechanisms and that K+ buffering/redistribution occurs partially through gap junctional coupling. Herein, we show, in vivo, that a threshold amount of focally applied KCl is required to trigger local and/or distal K+ responses, accompanied by a SD-like response. This observation indicates the presence of powerful local K+ buffering which mediates a rapid return of extracellular K+ to the baseline. Application of gap junctional blockers, carbenoxolone and Gap27, partially modulated the amplitude and shape of the K+ response and noticeably decreased the velocity of the spreading K+ and SD-like responses. Opening of gap junctions by trimethylamine, slightly decreased the amplitude of the K+ response and markedly increased the velocity of redistribution of K+ and SD-like events. We conclude that spreading K+ responses reflect powerful local K+ buffering mechanisms which are partially modulated by gap junctional communication. Gap junctional coupling mainly affected the velocity of the K+ and SD-like responses.
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22
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Yu H, Cao X, Li W, Liu P, Zhao Y, Song L, Chen J, Chen B, Yu W, Xu Y. Targeting connexin 43 provides anti-inflammatory effects after intracerebral hemorrhage injury by regulating YAP signaling. J Neuroinflammation 2020; 17:322. [PMID: 33115476 PMCID: PMC7594305 DOI: 10.1186/s12974-020-01978-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/01/2020] [Indexed: 12/17/2022] Open
Abstract
Background In the central nervous system (CNS), connexin 43 (Cx43) is mainly expressed in astrocytes and regulates astrocytic network homeostasis. Similar to Cx43 overexpression, abnormal excessive opening of Cx43 hemichannels (Cx43Hcs) on reactive astrocytes aggravates the inflammatory response and cell death in CNS pathologies. However, the role of excessive Cx43Hc opening in intracerebral hemorrhage (ICH) injury is not clear. Methods Hemin stimulation in primary cells and collagenase IV injection in C57BL/6J (B6) mice were used as ICH models in vitro and in vivo. After ICH injury, the Cx43 mimetic peptide Gap19 was used for treatment. Ethidium bromide (EtBr) uptake assays were used to measure the opening of Cx43Hcs. Western blotting and immunofluorescence were used to measure protein expression. qRT-PCR and ELISA were used to determine the levels of cytokines. Coimmunoprecipitation (Co-IP) and the Duolink in situ proximity ligation assay (PLA) were applied to measure the association between proteins. Results In this study, Cx43 expression upregulation and excessive Cx43Hc opening was observed in mice after ICH injury. Delayed treatment with Gap19 significantly alleviated hematoma volume and neurological deficits after ICH injury. In addition, Gap19 decreased inflammatory cytokine levels in the tissue surrounding the hematoma and decreased reactive astrogliosis after ICH injury in vitro and in vivo. Intriguingly, Cx43 transcriptional activity and expression in astrocytes were significantly increased after hemin stimulation in culture. However, Gap19 treatment downregulated astrocytic Cx43 expression through the ubiquitin-proteasome pathway without affecting Cx43 transcription. Additionally, our data showed that Gap19 increased Yes-associated protein (YAP) nuclear translocation. This subsequently upregulated SOCS1 and SOCS3 expression and then inhibited the TLR4-NFκB and JAK2-STAT3 pathways in hemin-stimulated astrocytes. Finally, the YAP inhibitor, verteporfin (VP), reversed the anti-inflammatory effect of Gap19 in vitro and almost completely blocked its protective effects in vivo after ICH injury. Conclusions This study provides new insight into potential treatment strategies for ICH injury involving astroglial Cx43 and Cx43Hcs. Suppression of abnormal astroglial Cx43 expression and Cx43Hc opening by Gap19 has anti-inflammatory and neuroprotective effects after ICH injury.
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Affiliation(s)
- Hailong Yu
- Affiliated of Drum Tower Hospital, Medical school of Nanjing University, Nanjing, Jiangsu, People's Republic of China.,Clinical Medical College of Yangzhou University, Yangzhou, Jiangsu, People's Republic of China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, Jiangsu, People's Republic of China
| | - Xiang Cao
- Affiliated of Drum Tower Hospital, Medical school of Nanjing University, Nanjing, Jiangsu, People's Republic of China
| | - Wei Li
- Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, Jiangsu, People's Republic of China.,Dalian Medical University, Dalian, Liaoning, People's Republic of China
| | - Pinyi Liu
- Affiliated of Drum Tower Hospital, Medical school of Nanjing University, Nanjing, Jiangsu, People's Republic of China
| | - Yuanyuan Zhao
- Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, Jiangsu, People's Republic of China.,Dalian Medical University, Dalian, Liaoning, People's Republic of China
| | - Lilong Song
- Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, Jiangsu, People's Republic of China.,Dalian Medical University, Dalian, Liaoning, People's Republic of China
| | - Jian Chen
- Affiliated of Drum Tower Hospital, Medical school of Nanjing University, Nanjing, Jiangsu, People's Republic of China
| | - Beilei Chen
- Clinical Medical College of Yangzhou University, Yangzhou, Jiangsu, People's Republic of China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, Jiangsu, People's Republic of China.,Dalian Medical University, Dalian, Liaoning, People's Republic of China
| | - Wenkui Yu
- Affiliated of Drum Tower Hospital, Medical school of Nanjing University, Nanjing, Jiangsu, People's Republic of China.
| | - Yun Xu
- Affiliated of Drum Tower Hospital, Medical school of Nanjing University, Nanjing, Jiangsu, People's Republic of China.
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23
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Lou YX, Wang ZZ, Xia CY, Mou Z, Ren Q, Liu DD, Zhang X, Chen NH. The protective effect of ginsenoside Rg1 on depression may benefit from the gap junction function in hippocampal astrocytes. Eur J Pharmacol 2020; 882:173309. [PMID: 32598952 DOI: 10.1016/j.ejphar.2020.173309] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 06/20/2020] [Accepted: 06/22/2020] [Indexed: 01/12/2023]
Abstract
Studies have shown that the ginsenoside Rg1 can improve depressive symptoms in vitro and in vivo. However, the efficacy of Rg1on the hippocampal astrocyte gap junctions in depression are unclear. We mainly aimed to explore the relationship between Rg1, hippocampal astrocyte gap junctions and depression. Using primary cultured astrocytes, corticosterone (CORT) was used to induce stress. CORT (100 μM) significantly reduced the survival rate in astrocytes, and this effect was prevented by additional Rg1 administration. Interestingly, the gap junction blocker carbenoxolone (CBX) was able to revert this Rg1 effect. In in vivo models, one group was exposed to chronic unpredictable stress (CUS) for 47 days, while another group was bilaterally injected with CBX (100 μM) into the hippocampal CA1 region. Rats treated with Rg1 (20 mg/kg) showed an improvement in the sucrose preference and the forced swimming test in both models, indicating an antidepressive activity of Rg1. The levels of astrocyte gap junction connexin 43 (Cx43) were detected by immunofluorescence (IF) and western blotting. The levels of glial fibrillary acidic protein (GFAP) were detected by IF. The gap junctions in the hippocampal CA1 area were evaluated using dye transfer and electron microscopy. The reduction in Cx43 expression, the decrease in the Cx43 to GFAP ratio, the shorter dye diffusion distance, and the abnormal ultrastructure of gap junctions in rats exposed to CUS were markedly alleviated by concomitant Rg1 treatment. Taken together, the ginsenoside Rg1 could improve depression-like behavior in rats induced by astrocyte gap junction dysfunction in the hippocampus.
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Affiliation(s)
- Yu-Xia Lou
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China; Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Zhen-Zhen Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Cong-Yuan Xia
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Zheng Mou
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Qian Ren
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Dan-Dan Liu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Xin Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China; Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
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24
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Hadjihambi A, Karagiannis A, Theparambil SM, Ackland GL, Gourine AV. The effect of general anaesthetics on brain lactate release. Eur J Pharmacol 2020; 881:173188. [PMID: 32439258 PMCID: PMC7456770 DOI: 10.1016/j.ejphar.2020.173188] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 05/04/2020] [Accepted: 05/10/2020] [Indexed: 12/17/2022]
Abstract
The effects of anaesthetic agents on brain energy metabolism may explain their shared neurophysiological actions but remain poorly understood. The brain lactate shuttle hypothesis proposes that lactate, provided by astrocytes, is an important neuronal energy substrate. Here we tested the hypothesis that anaesthetic agents impair the brain lactate shuttle by interfering with astrocytic glycolysis. Lactate biosensors were used to record changes in lactate release by adult rat brainstem and cortical slices in response to thiopental, propofol and etomidate. Changes in cytosolic nicotinamide adenine dinucleotide reduced (NADH) and oxidized (NAD+) ratio as a measure of glycolytic rate were recorded in cultured astrocytes. It was found that in brainstem slices thiopental, propofol and etomidate reduced lactate release by 7.4 ± 3.6% (P < 0.001), 9.7 ± 6.6% (P < 0.001) and 8.0 ± 7.8% (P = 0.04), respectively. In cortical slices, thiopental reduced lactate release by 8.2 ± 5.6% (P = 0.002) and propofol by 6.0 ± 4.5% (P = 0.009). Lactate release in cortical slices measured during the light phase (period of sleep/low activity) was ~25% lower than that measured during the dark phase (period of wakefulness) (326 ± 83 μM vs 430 ± 118 μM, n = 10; P = 0.04). Thiopental and etomidate induced proportionally similar decreases in cytosolic [NADH]:[NAD+] ratio in astrocytes, indicative of a reduction in glycolytic rate. These data suggest that anaesthetic agents inhibit astrocytic glycolysis and reduce the level of extracellular lactate in the brain. Similar reductions in brain lactate release occur during natural state of sleep, suggesting that general anaesthesia may recapitulate some of the effects of sleep on brain energy metabolism.
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Affiliation(s)
- Anna Hadjihambi
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, UK; Department of Biomedical Sciences, University of Lausanne, Lausanne, 1005, Switzerland.
| | - Anastassios Karagiannis
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, UK
| | - Shefeeq M Theparambil
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, UK
| | - Gareth L Ackland
- Translational Medicine & Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, UK
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25
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Giaume C, Naus CC, Sáez JC, Leybaert L. Glial Connexins and Pannexins in the Healthy and Diseased Brain. Physiol Rev 2020; 101:93-145. [PMID: 32326824 DOI: 10.1152/physrev.00043.2018] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Over the past several decades a large amount of data have established that glial cells, the main cell population in the brain, dynamically interact with neurons and thus impact their activity and survival. One typical feature of glia is their marked expression of several connexins, the membrane proteins forming intercellular gap junction channels and hemichannels. Pannexins, which have a tetraspan membrane topology as connexins, are also detected in glial cells. Here, we review the evidence that connexin and pannexin channels are actively involved in dynamic and metabolic neuroglial interactions in physiological as well as in pathological situations. These features of neuroglial interactions open the way to identify novel non-neuronal aspects that allow for a better understanding of behavior and information processing performed by neurons. This will also complement the "neurocentric" view by facilitating the development of glia-targeted therapeutic strategies in brain disease.
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Affiliation(s)
- Christian Giaume
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France; University Pierre et Marie Curie, Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France; Department of Cellular & Physiological Sciences, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile; Instituo de Neurociencias, Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile; Physiology Group, Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Christian C Naus
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France; University Pierre et Marie Curie, Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France; Department of Cellular & Physiological Sciences, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile; Instituo de Neurociencias, Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile; Physiology Group, Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Juan C Sáez
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France; University Pierre et Marie Curie, Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France; Department of Cellular & Physiological Sciences, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile; Instituo de Neurociencias, Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile; Physiology Group, Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Luc Leybaert
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Paris, France; University Pierre et Marie Curie, Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Paris, France; Department of Cellular & Physiological Sciences, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile; Instituo de Neurociencias, Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile; Physiology Group, Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
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26
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Zhang Y, Wu S, Xie L, Yu S, Zhang L, Liu C, Zhou W, Yu T. Ketamine Within Clinically Effective Range Inhibits Glutamate Transmission From Astrocytes to Neurons and Disrupts Synchronization of Astrocytic SICs. Front Cell Neurosci 2019; 13:240. [PMID: 31244607 PMCID: PMC6581012 DOI: 10.3389/fncel.2019.00240] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 05/14/2019] [Indexed: 01/07/2023] Open
Abstract
Background Astrocytes are now considered as crucial modulators of neuronal synaptic transmission. General anesthetics have been found to inhibit astrocytic activities, but it is not clear whether general anesthetics within the clinical concentration range affects the astrocyte-mediated synaptic regulation. Methods The effects of propofol, dexmedetomidine, and ketamine within clinically effective ranges on the slow inward currents (SICs) were tested by using the whole-cell recording in acute prefrontal cortex (PFC) slice preparations of rats. Astrocytes culture and HPLC were used to measure the effects of different anesthetics on the glutamate release of astrocytes. Results Propofol and dexmedetomidine showed no significant effect on the amplitude or frequency of SICs. Ketamine was found to inhibit the frequency of SICs in a concentration-dependent manner. The SICs synchronization rate of paired neurons was inhibited by 30 μM ketamine (from 42.5 ± 1.4% to 9.6 ± 0.8%) and was abolished by 300 μM ketamine. The astrocytic glutamate release induced by DHPG, an agonist of astrocytic type I metabotropic glutamate receptors, was not affected by ketamine, and ifenprodil, a selective antagonist of GluN1/GluN2B receptor, blocked all SICs and enhanced the inhibitory effect of 30 μM ketamine on the frequency of SICs. Ketamine at low concentration (3 μM) could inhibit the frequency of SICs, not the miniature excitatory postsynaptic currents (mEPSCs), and the inhibition rate of SICs was significantly higher than mEPSCs with 30 μM ketamine (44.5 ± 3% inhibition vs. 28.3 ± 6% inhibition). Conclusion Our data indicated that ketamine, not propofol and dexmedetomidine, within clinical concentration range inhibits glutamatergic transmission from astrocytes to neurons, which is likely mediated by the extrasynaptic GluN1/GluN2B receptor activation.
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Affiliation(s)
- Yu Zhang
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, Guizhou, China.,The Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Guizhou, China
| | - Sisi Wu
- The Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Guizhou, China
| | - Liwei Xie
- The Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Guizhou, China
| | - Shouyang Yu
- The Key Laboratory of Brain Science, Zunyi Medical University, Guizhou, China
| | - Lin Zhang
- The Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Guizhou, China
| | - Chengxi Liu
- The Key Laboratory of Brain Science, Zunyi Medical University, Guizhou, China
| | - Wenjing Zhou
- The Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Guizhou, China
| | - Tian Yu
- The Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Guizhou, China
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27
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Ahmadian E, Eftekhari A, Samiei M, Maleki Dizaj S, Vinken M. The role and therapeutic potential of connexins, pannexins and their channels in Parkinson's disease. Cell Signal 2019; 58:111-118. [DOI: 10.1016/j.cellsig.2019.03.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/10/2019] [Accepted: 03/10/2019] [Indexed: 02/07/2023]
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28
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Wu JI, Lin YP, Tseng CW, Chen HJ, Wang LH. Crabp2 Promotes Metastasis of Lung Cancer Cells via HuR and Integrin β1/FAK/ERK Signaling. Sci Rep 2019; 9:845. [PMID: 30696915 PMCID: PMC6351595 DOI: 10.1038/s41598-018-37443-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 11/30/2018] [Indexed: 01/31/2023] Open
Abstract
Increased Crabp2 levels have been found in various types of cancer, and are associated with poor patients’ survival. Although Crabp2 is found to be overexpressed in lung cancer, its role in metastasis of lung cancer is unclear. In this study, Crabp2 was overexpressed in high-metastatic C10F4 than low-metastatic lung cancer cells. Analysis of clinical samples revealed that high CRABP2 levels were correlated with lymph node metastases, poor overall survival, and increased recurrence. Knockdown of Crabp2 decreased migration, invasion, anoikis resistance, and in vivo metastasis. Crabp2 was co-immunoprecipitated with HuR, and overexpression of Crabp2 increased HuR levels, which promoted integrin β1/FAK/ERK signaling. Inhibition of HuR or integrin β1/FAK/ERK signaling reversed the promoting effect of Crabp2 in migration, invasion, and anoikis resistance. Knockdown of Crabp2 further inhibited the growth of cancer cells as compared with that by gemcitabine or irinotecan alone. The expression of Crabp2 in human lung tumors was correlated with stress marker CHOP. In conclusion, our findings have identified the promoting role of Crabp2 in anoikis resistance and metastasis. CRABP2 may serve as a prognostic marker and targeting CRABP2 may be exploited as a modality to reduce metastasis.
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Affiliation(s)
- Jun-I Wu
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli County, Taiwan.,Department of Life Sciences, National Central University, Taoyuan, Taiwan
| | - Yi-Pei Lin
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli County, Taiwan.,Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Chien-Wei Tseng
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli County, Taiwan.,Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan
| | - Hui-Jane Chen
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli County, Taiwan
| | - Lu-Hai Wang
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli County, Taiwan. .,Department of Life Sciences, National Central University, Taoyuan, Taiwan. .,Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan. .,Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan. .,Chinese Medical Research Center, China Medical University, Taichung, Taiwan.
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29
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Hansson E, Björklund U, Skiöldebrand E, Rönnbäck L. Anti-inflammatory effects induced by pharmaceutical substances on inflammatory active brain astrocytes-promising treatment of neuroinflammation. J Neuroinflammation 2018; 15:321. [PMID: 30447700 PMCID: PMC6240424 DOI: 10.1186/s12974-018-1361-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 11/07/2018] [Indexed: 02/06/2023] Open
Abstract
Background Pharmaceutical treatment with probable anti-inflammatory substances that attack cells in various ways including receptors, ion channels, or transporter systems may slow down the progression of inflammatory conditions. Astrocytes and microglia are the most prominent target cells for inflammation in the central nervous system. Their responses upon inflammatory stimuli work through the NO/cyclic GMP/protein kinase G systems that can downregulate the ATP-induced Ca2+ signaling, as well as G protein activities which alter Na+ transporters including Na+/K+-ATPase pump activity, Toll-like receptor 4 (TLR4), glutamate-induced Ca2+ signaling, and release of pro-inflammatory cytokines. The rationale for this project was to investigate a combination of pharmaceutical substances influencing the NO and the Gi/Gs activations of inflammatory reactive cells in order to make the cells return into a more physiological state. The ATP-evoked Ca2+ signaling is important maybe due to increased ATP release and subsequent activation of purinergic receptors. A balance between intercellular Ca2+ signaling through gap junctions and extracellular signaling mediated by extracellular ATP may be important for physiological function. Methods Astrocytes in primary cultures were incubated with lipopolysaccharide in a physiological glucose concentration for 24 h to induce inflammatory reactivity. The probable anti-inflammatory substances sildenafil and 1α,25-Dihydroxyvitamin D3 together with endomorphin-1, naloxone, and levetiracetam, were used in the presence of high glucose concentration in the medium to restore the cells. Glutamate-, 5-HT-, and ATP-evoked intracellular Ca2+ release, Na+/K+-ATPase expression, expression of inflammatory receptors, and release of tumor necrosis factor alpha were measured. Results Sildenafil in ultralow concentration together with 1α,25-Dihydroxyvitamin D3 showed most prominent effects on the ATP-evoked intracellular Ca2+ release. The μ-opioid agonist endomorphin-1, the μ-opioid antagonist naloxone in ultralow concentration, and the antiepileptic agent levetiracetam downregulated the glutamate-evoked intracellular Ca2+ release and TLR4. The combination of the pharmaceutical substances in high glucose concentration downregulated the glutamate- and ATP-evoked Ca2+ signaling and the TLR4 expression and upregulated the Na+/K+-ATPase pump. Conclusion Pharmaceutical treatment with the combination of substances that have potential anti-inflammatory effects, which attack different biochemical mechanisms in the cells may exert decisive effects to downregulate neuroinflammation in the nervous system.
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Affiliation(s)
- Elisabeth Hansson
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Blå Stråket 7, 3rd floor, SE 413 45, Gothenburg, Sweden.
| | - Ulrika Björklund
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Blå Stråket 7, 3rd floor, SE 413 45, Gothenburg, Sweden
| | - Eva Skiöldebrand
- Section of Pathology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska University Hospital, Gothenburg University, Gothenburg, Sweden
| | - Lars Rönnbäck
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Blå Stråket 7, 3rd floor, SE 413 45, Gothenburg, Sweden
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30
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Mosquera N, Rodriguez-Trillo A, Mera-Varela A, Gonzalez A, Conde C. Uncovering Cellular retinoic acid-binding protein 2 as a potential target for rheumatoid arthritis synovial hyperplasia. Sci Rep 2018; 8:8731. [PMID: 29880835 PMCID: PMC5992205 DOI: 10.1038/s41598-018-26027-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 05/02/2018] [Indexed: 12/19/2022] Open
Abstract
Rheumatoid arthritis (RA) is a systemic autoimmune disease including synovitis and synovial hyperplasia that contribute to joint destruction. Pivotal pathogenic mechanisms in this process are the dysregulated proliferation and apoptosis of fibroblast-like synoviocytes (FLS). Unfortunately, the mechanisms of FLS dysregulation are not completely elucidated. Here, we explored a new hypothesis based in the potent anti-proliferative and pro-apoptotic activity of retinoids in some types of cancer. Specifically, we investigated the role of retinoids and of the retinoic acid binding proteins, CRABP2 and FABP5, on the proliferation and apoptosis of FLS from RA by adding all-trans retinoic acid (ATRA) or silencing CRABP2 and FABP5. We showed an unconventional behaviour of RA FLS, which were relatively insensitive to ATRA. In effect, ATRA increased the resistance to apoptosis despite the high CRABP2/FABP5 ratio of RA FLS; and CRABP2 suppression sensitized RA FLS to Fas-induced apoptosis. This latter effect was associated with changes in expression of kinases, ASK1 up-regulation and ERK down-regulation, and increased phosphorylation of JNK. In addition, the potentiation of FLS apoptosis by CRABP2 silencing persisted in the presence of pro-inflammatory mediators, TNF e IL1β. Therefore, the results point to CRABP2 as a potential target to decrease synovial hyperplasia in RA.
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Affiliation(s)
- Nerea Mosquera
- Laboratorio de Reumatología Experimental y Observacional, y Servicio de Reumatología, Instituto de Investigacion Sanitaria de Santiago (IDIS), Hospital Clínico Universitario de Santiago de Compostela (CHUS), SERGAS. Travesía da Choupana s/n, Santiago de Compostela, 15706, Spain
| | - Angela Rodriguez-Trillo
- Laboratorio de Reumatología Experimental y Observacional, y Servicio de Reumatología, Instituto de Investigacion Sanitaria de Santiago (IDIS), Hospital Clínico Universitario de Santiago de Compostela (CHUS), SERGAS. Travesía da Choupana s/n, Santiago de Compostela, 15706, Spain
| | - Antonio Mera-Varela
- Servicio de Reumatología, Instituto de Investigacion Sanitaria de Santiago (IDIS), Hospital Clínico Universitario de Santiago de Compostela (CHUS), SERGAS. Travesía da Choupana s/n, Santiago de Compostela, 15706, Spain
| | - Antonio Gonzalez
- Laboratorio de Reumatología Experimental y Observacional, y Servicio de Reumatología, Instituto de Investigacion Sanitaria de Santiago (IDIS), Hospital Clínico Universitario de Santiago de Compostela (CHUS), SERGAS. Travesía da Choupana s/n, Santiago de Compostela, 15706, Spain
| | - Carmen Conde
- Laboratorio de Reumatología Experimental y Observacional, y Servicio de Reumatología, Instituto de Investigacion Sanitaria de Santiago (IDIS), Hospital Clínico Universitario de Santiago de Compostela (CHUS), SERGAS. Travesía da Choupana s/n, Santiago de Compostela, 15706, Spain.
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31
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Lv Y, Dai W, Ge A, Fan Y, Hu G, Zeng Y. Aquaporin-4 knockout mice exhibit increased hypnotic susceptibility to ketamine. Brain Behav 2018; 8:e00990. [PMID: 29745050 PMCID: PMC5991570 DOI: 10.1002/brb3.990] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 02/07/2018] [Accepted: 03/11/2018] [Indexed: 11/06/2022] Open
Abstract
PURPOSE This study examines anesthetic/hypnotic effects of ketamine in AQP4 knockout (KO) and wild-type (WT) mice with the particular focus on neurotransmission. MATERIALS AND METHODS Ketamine (100 mg/kg) was intraperitoneally injected in 16 WT and 16 KO mice. The hypnotic potencies were evaluated by the loss of the righting reflex (LORR). The amino acids neurotransmitter levels in prefrontal cortex were measured by microdialysis. RESULTS This study demonstrated that AQP4 knockout significantly shortened the latency compared with WT mice (98.0 ± 4.2 vs. 138.1 ± 15.0 s, p < .05) and prolonged duration of LORR (884.7 ± 58.6 vs. 562.0 ± 51.7 s, p < .05) compared with WT mice in LORR induced by ketamine. Microdialysis showed that lack of AQP4 markedly decreased glutamate level within 20 min (p < .05) and increased γ-aminobutyric acid (GABA) level within 30-40 min (p < .05) after use of ketamine. Moreover, the levels of taurine were remarkably higher in KO mice than in WT mice, but no obvious differences in aspartate were observed between two genotypes. CONCLUSION AQP4 deficiency led to more susceptibility of mice to ketamine, which is probably due to the modulation of specific neurotransmitters, hinting an essential maintenance of synaptic activity mediated by AQP4 in the action of ketamine.
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Affiliation(s)
- Yunluo Lv
- Department of Anesthesiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Wangshu Dai
- The Comprehensive Cancer Centre of Drum Tower Hospital, Medical School of Nanjing University, Clinical Cancer Institute of Nanjing University, Nanjing, China
| | - Ai Ge
- Department of Respiratory Medicine, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yi Fan
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Gang Hu
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Yinming Zeng
- Jiangsu Province Institute of Anesthesiology, Xuzhou Medical University, Xuzhou, China
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32
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Zhang S, Liu H, Li H, Wu M, Yu Y, Li F, Cheng X. Differential CRABP-II and FABP5 expression patterns and implications for medulloblastoma retinoic acid sensitivity. RSC Adv 2018; 8:14048-14055. [PMID: 35539303 PMCID: PMC9079906 DOI: 10.1039/c8ra00744f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/09/2018] [Indexed: 11/21/2022] Open
Abstract
Medulloblastoma (MB) cells exhibit different responses to retinoid acid (RA) for reasons that are poorly understood. RA signaling can be transduced by two approaches that are mediated by cellular retinoic acid-binding protein 2 (CRABP-II) as a tumor-suppressive pathway, and by fatty acid-binding protein 5 (FABP5) as a tumor-promoting pathway. The biological effects of RA on cancer cells are largely determined by the patterns of CRABP-II and FABP5 expression. This study aims to profile the statuses of CRABP-II and FABP5 expression in MB and to evaluate their correlation with RA sensitivities using RA-sensitive (Med-3) and RA-insensitive (UW228-2, UW228-3) MB cells. Our results show that CRABP-II is distinctly expressed and the level of FABP5 is extremely low in Med-3 cells, while the patterns of CRABP-II and FABP5 expression are reversed in UW228-2 and UW228-3 cells. RA up-regulates CRABP-II expression in Med-3 cells, whereas it up-regulates FABP5 expression in the other two cell lines. The FABP5-specific inhibitor BMS309403 increases the RA sensitivity of UW228-2 cells (p < 0.01). Tissue microarray-based immunohistochemical staining showed CRABP-II/FABP5 expression patterns in MB that were variable (CRABP-II-/FABP5-, CRABP-II-/FABP5+, CRABP-II+/FABP5- and CRABP-II+/FABP5+) and imbalanced (CRABP-II↑/FABP5↓ and CRABP-II↓/FABP5↑). MB cases exhibited patterns ofCRABP-II-/FABP5- (12.24%, 6/49), CRABP-II-/FABP5+ (30.61%, 15/49) or CRABP-II↓/FABP5↑ (12.24%, 6/49), implicating unresponsiveness or insensitivity to RA. In conclusion, the ratios of CRABP-II/FABP5 levels are closely related to the RA sensitivities of MB cells. The differential CRABP-II and FABP5 expression patterns are prospective parameters, and of potential value in personalized RA therapy for MB.
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Affiliation(s)
- Song Zhang
- Department of Cell Biology and Liaoning Laboratory of Cancer Genetics and Epigenetics, Dalian Medical University Liaoning 116044 China
- Qiqihar Medical University Heilongjiang 161006 China
| | - Huan Liu
- Department of Cell Biology and Liaoning Laboratory of Cancer Genetics and Epigenetics, Dalian Medical University Liaoning 116044 China
| | - Hong Li
- Department of Cell Biology and Liaoning Laboratory of Cancer Genetics and Epigenetics, Dalian Medical University Liaoning 116044 China
| | - MoLi Wu
- Department of Cell Biology and Liaoning Laboratory of Cancer Genetics and Epigenetics, Dalian Medical University Liaoning 116044 China
| | - Yang Yu
- Department of Cell Biology and Liaoning Laboratory of Cancer Genetics and Epigenetics, Dalian Medical University Liaoning 116044 China
| | - FengZhi Li
- Department of Cell Biology and Liaoning Laboratory of Cancer Genetics and Epigenetics, Dalian Medical University Liaoning 116044 China
| | - XiaoXin Cheng
- Department of Cell Biology and Liaoning Laboratory of Cancer Genetics and Epigenetics, Dalian Medical University Liaoning 116044 China
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Abstract
Major depressive disorder (MDD) is a chronic and debilitating illness that affects over 350 million people worldwide; however, current treatments have failed to cure or prevent the progress of depression. Increasing evidence suggests a crucial role for connexins in MDD. In this review, we have summarised recent accomplishments regarding the role of connexins, gap junctions, and hemichannels in the aetiology of MDD, and discussed the limitations of current research. A blockage of gap junctions or hemichannels induces depressive behaviour. Possible underlying mechanisms include the regulation of neurosecretory functions and synaptic activity by gap junctions and hemichannels. Gap junctions are functionally inhibited under stress conditions. Conversely, hemichannel permeability is increased. Antidepressants inhibit hemichannel permeability; however, they have contrasting effects on the function of gap junctions under normal conditions and can protect them against stress. In conclusion, the blockage of hemichannels concurrent with improvements in gap junction functionality might be potential targets for depression treatment.
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Affiliation(s)
- Cong-Yuan Xia
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Zhen-Zhen Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Tohru Yamakuni
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China; College of Pharmacy, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China.
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Nuriya M, Yasui D, Yamada T, Aoki T, Yasui M. Direct posttranslational modification of astrocytic connexin 43 proteins by the general anesthetic propofol in the cerebral cortex. Biochem Biophys Res Commun 2018; 497:734-741. [DOI: 10.1016/j.bbrc.2018.02.142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 02/16/2018] [Indexed: 10/18/2022]
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Charvériat M, Naus CC, Leybaert L, Sáez JC, Giaume C. Connexin-Dependent Neuroglial Networking as a New Therapeutic Target. Front Cell Neurosci 2017; 11:174. [PMID: 28694772 PMCID: PMC5483454 DOI: 10.3389/fncel.2017.00174] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 06/08/2017] [Indexed: 12/12/2022] Open
Abstract
Astrocytes and neurons dynamically interact during physiological processes, and it is now widely accepted that they are both organized in plastic and tightly regulated networks. Astrocytes are connected through connexin-based gap junction channels, with brain region specificities, and those networks modulate neuronal activities, such as those involved in sleep-wake cycle, cognitive, or sensory functions. Additionally, astrocyte domains have been involved in neurogenesis and neuronal differentiation during development; they participate in the “tripartite synapse” with both pre-synaptic and post-synaptic neurons by tuning down or up neuronal activities through the control of neuronal synaptic strength. Connexin-based hemichannels are also involved in those regulations of neuronal activities, however, this feature will not be considered in the present review. Furthermore, neuronal processes, transmitting electrical signals to chemical synapses, stringently control astroglial connexin expression, and channel functions. Long-range energy trafficking toward neurons through connexin-coupled astrocytes and plasticity of those networks are hence largely dependent on neuronal activity. Such reciprocal interactions between neurons and astrocyte networks involve neurotransmitters, cytokines, endogenous lipids, and peptides released by neurons but also other brain cell types, including microglial and endothelial cells. Over the past 10 years, knowledge about neuroglial interactions has widened and now includes effects of CNS-targeting drugs such as antidepressants, antipsychotics, psychostimulants, or sedatives drugs as potential modulators of connexin function and thus astrocyte networking activity. In physiological situations, neuroglial networking is consequently resulting from a two-way interaction between astrocyte gap junction-mediated networks and those made by neurons. As both cell types are modulated by CNS drugs we postulate that neuroglial networking may emerge as new therapeutic targets in neurological and psychiatric disorders.
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Affiliation(s)
| | - Christian C Naus
- Department of Cellular and Physiological Science, Life Science Institute, University of British ColumbiaVancouver, BC, Canada
| | - Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent UniversityGhent, Belgium
| | - Juan C Sáez
- Departamento de Fisiología, Pontificia Universidad Católica de ChileSantiago, Chile.,Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto MilenioValparaíso, Chile
| | - Christian Giaume
- Center of Interdisciplinary Research in Biology, Collège de FranceParis, France
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Abstract
Neuronal survival, electrical signaling and synaptic activity require a well-balanced micro-environment in the central nervous system. This is achieved by the blood-brain barrier (BBB), an endothelial barrier situated in the brain capillaries, that controls near-to-all passage in and out of the brain. The endothelial barrier function is highly dependent on signaling interactions with surrounding glial, neuronal and vascular cells, together forming the neuro-glio-vascular unit. Within this functional unit, connexin (Cx) channels are of utmost importance for intercellular communication between the different cellular compartments. Connexins are best known as the building blocks of gap junction (GJ) channels that enable direct cell-cell transfer of metabolic, biochemical and electric signals. In addition, beyond their role in direct intercellular communication, Cxs also form unapposed, non-junctional hemichannels in the plasma membrane that allow the passage of several paracrine messengers, complementing direct GJ communication. Within the NGVU, Cxs are expressed in vascular endothelial cells, including those that form the BBB, and are eminent in astrocytes, especially at their endfoot processes that wrap around cerebral vessels. However, despite the density of Cx channels at this so-called gliovascular interface, it remains unclear as to how Cx-based signaling between astrocytes and BBB endothelial cells may converge control over BBB permeability in health and disease. In this review we describe available evidence that supports a role for astroglial as well as endothelial Cxs in the regulation of BBB permeability during development as well as in disease states.
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Enger R, Dukefoss DB, Tang W, Pettersen KH, Bjørnstad DM, Helm PJ, Jensen V, Sprengel R, Vervaeke K, Ottersen OP, Nagelhus EA. Deletion of Aquaporin-4 Curtails Extracellular Glutamate Elevation in Cortical Spreading Depression in Awake Mice. Cereb Cortex 2017; 27:24-33. [PMID: 28365776 PMCID: PMC5939213 DOI: 10.1093/cercor/bhw359] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 10/25/2016] [Accepted: 10/29/2016] [Indexed: 12/20/2022] Open
Abstract
Cortical spreading depression (CSD) is a phenomenon that challenges the homeostatic mechanisms on which normal brain function so critically depends. Analyzing the sequence of events in CSD holds the potential of providing new insight in the physiological processes underlying normal brain function as well as the pathophysiology of neurological conditions characterized by ionic dyshomeostasis. Here, we have studied the sequential progression of CSD in awake wild-type mice and in mice lacking aquaporin-4 (AQP4) or inositol 1,4,5-triphosphate type 2 receptor (IP3R2). By the use of a novel combination of genetically encoded sensors that a novel combination - an unprecedented temporal and spatial resolution, we show that CSD leads to brisk Ca2+ signals in astrocytes and that the duration of these Ca2+ signals is shortened in the absence of AQP4 but not in the absence of IP3R2. The decrease of the astrocytic, AQP4-dependent Ca2+ signals, coincides in time and space with a decrease in the duration of extracellular glutamate overflow but not with the initial peak of the glutamate release suggesting that in CSD, extracellular glutamate accumulation is extended through AQP4-dependent glutamate release from astrocytes. The present data point to a salient glial contribution to CSD and identify AQP4 as a new target for therapy.
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Affiliation(s)
- Rune Enger
- Department of Neurology, Oslo University Hospital, N-0027 Oslo, Norway
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway
| | - Didrik B. Dukefoss
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway
| | - Wannan Tang
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway
| | - Klas H. Pettersen
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway
| | - Daniel M. Bjørnstad
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway
| | - P. Johannes Helm
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway
| | - Vidar Jensen
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway
| | - Rolf Sprengel
- Department of Molecular Neurobiology, Max Planck Institute for Medical Research, D-69120 Heidelberg, Germany
- Max Planck Research Group at the Institute for Anatomy and Cell Biology, Heidelberg University, D-69120 Heidelberg, Germany
| | - Koen Vervaeke
- Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway
| | - Ole P. Ottersen
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway
| | - Erlend A. Nagelhus
- Department of Neurology, Oslo University Hospital, N-0027 Oslo, Norway
- GliaLab and Letten Centre, Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway
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Orellana JA, Retamal MA, Moraga-Amaro R, Stehberg J. Role of Astroglial Hemichannels and Pannexons in Memory and Neurodegenerative Diseases. Front Integr Neurosci 2016; 10:26. [PMID: 27489539 PMCID: PMC4951483 DOI: 10.3389/fnint.2016.00026] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 07/06/2016] [Indexed: 11/13/2022] Open
Abstract
Under physiological conditions, astroglial hemichannels and pannexons allow the release of gliotransmitters from astrocytes. These gliotransmitters are critical in modulating synaptic transmission, plasticity and memory. However, recent evidence suggests that under pathological conditions, they may be central in the development of various neurodegenerative diseases. Here we review current literature on the role of astroglial hemichannels and pannexons in memory, stress and the development of neurodegenerative diseases, and propose that they are not only crucial for normal brain function, including memory, but also a potential target for the treatment of neurodegenerative diseases.
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Affiliation(s)
- Juan A Orellana
- Departamento de Neurología, Escuela de Medicina, Pontificia Universidad Católica de Chile Santiago, Chile
| | - Mauricio A Retamal
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo Santiago, Chile
| | - Rodrigo Moraga-Amaro
- Laboratorio de Neurobiología, Centro de Investigaciones Biomédicas, Universidad Andres Bello Santiago, Chile
| | - Jimmy Stehberg
- Laboratorio de Neurobiología, Centro de Investigaciones Biomédicas, Universidad Andres Bello Santiago, Chile
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Esseltine JL, Laird DW. Next-Generation Connexin and Pannexin Cell Biology. Trends Cell Biol 2016; 26:944-955. [PMID: 27339936 DOI: 10.1016/j.tcb.2016.06.003] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 06/02/2016] [Accepted: 06/06/2016] [Indexed: 01/17/2023]
Abstract
Connexins and pannexins are two families of large-pore channel forming proteins that are capable of passing small signaling molecules. While connexins serve the seminal task of direct gap junctional intercellular communication, pannexins are far less understood but function primarily as single membrane channels in autocrine and paracrine signaling. Advancements in connexin and pannexin biology in recent years has revealed that in addition to well-described classical functions at the plasma membrane, exciting new evidence suggests that connexins and pannexins participate in alternative pathways involving multiple intracellular compartments. Here we briefly highlight classical functions of connexins and pannexins but focus our attention mostly on the transformative findings that suggest that these channel-forming proteins may serve roles far beyond our current understandings.
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Affiliation(s)
- Jessica L Esseltine
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada
| | - Dale W Laird
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada.
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