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Pelz L, Dossou L, Kompier N, Jüttner R, Siemonsmeier G, Meyer N, Lowenstein ED, Lahmann I, Kettenmann H, Birchmeier C, Rathjen FG. The IgCAM BT-IgSF (IgSF11) is essential for connexin43-mediated astrocyte-astrocyte coupling in mice. eNeuro 2024; 11:ENEURO.0283-23.2024. [PMID: 38388443 PMCID: PMC10957231 DOI: 10.1523/eneuro.0283-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 02/24/2024] Open
Abstract
The type I transmembrane protein BT-IgSF is predominantly localized in the brain and testes. It belongs to the CAR subgroup of Ig cell adhesion proteins, that are hypothesized to regulate connexin expression or localization. Here, we studied the putative link between BT-IgSF and connexins in astrocytes, ependymal cells and neurons of the mouse. Global knockout of BT-IgSF caused an increase in the clustering of connexin43 (Gja1), but not of connexin30 (Gjb6), on astrocytes and ependymal cells. Additionally, knockout animals displayed reduced expression levels of connexin43 protein in the cortex and hippocampus. Importantly, analysis of biocytin spread in hippocampal or cortical slices from mature mice of either sex revealed a decrease in astrocytic cell-cell coupling in the absence of BT-IgSF. Blocking either protein biosynthesis or proteolysis showed that the lysosomal pathway increased connexin43 degradation in astrocytes. Localization of connexin43 in subcellular compartments was not impaired in astrocytes of BT-IgSF mutants. In contrast to connexin43 the localization and expression of connexin36 (Gjd2) on neurons was not affected by the absence of BT-IgSF. Overall, our data indicate that the IgCAM BT-IgSF is essential for correct gap junction-mediated astrocyte-to-astrocyte cell communication.Significance Statement Astrocytes regulate a variety of physiological processes in the developing and adult brain that are essential for proper brain function. Astrocytes form extensive networks in the brain and communicate via gap junctions. Disruptions of gap junction coupling are found in several diseases such as neurodegeneration or epilepsy. Here, we demonstrate that the cell adhesion protein BT-IgSF is essential for gap junction mediated coupling between astrocytes in the cortex and hippocampus.
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Affiliation(s)
- Laura Pelz
- Max-Delbrück-Center for Molecular Medicine, Berlin DE-13092, Germany
| | - Laura Dossou
- Max-Delbrück-Center for Molecular Medicine, Berlin DE-13092, Germany
| | - Nine Kompier
- Max-Delbrück-Center for Molecular Medicine, Berlin DE-13092, Germany
| | - René Jüttner
- Max-Delbrück-Center for Molecular Medicine, Berlin DE-13092, Germany
| | | | - Niklas Meyer
- Max-Delbrück-Center for Molecular Medicine, Berlin DE-13092, Germany
| | | | - Ines Lahmann
- Max-Delbrück-Center for Molecular Medicine, Berlin DE-13092, Germany
| | - Helmut Kettenmann
- Max-Delbrück-Center for Molecular Medicine, Berlin DE-13092, Germany
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Carmen Birchmeier
- Max-Delbrück-Center for Molecular Medicine, Berlin DE-13092, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin 10117, Germany
| | - Fritz G. Rathjen
- Max-Delbrück-Center for Molecular Medicine, Berlin DE-13092, Germany
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Paciello F, Pisani A, Rolesi R, Montuoro R, Mohamed-Hizam V, Boni G, Ripoli C, Galli J, Sisto R, Fetoni AR, Grassi C. Oxidative stress and inflammation cause auditory system damage via glial cell activation and dysregulated expression of gap junction proteins in an experimental model of styrene-induced oto/neurotoxicity. J Neuroinflammation 2024; 21:4. [PMID: 38178142 PMCID: PMC10765700 DOI: 10.1186/s12974-023-02996-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 12/13/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND Redox imbalance and inflammation have been proposed as the principal mechanisms of damage in the auditory system, resulting in functional alterations and hearing loss. Microglia and astrocytes play a crucial role in mediating oxidative/inflammatory injury in the central nervous system; however, the role of glial cells in the auditory damage is still elusive. OBJECTIVES Here we investigated glial-mediated responses to toxic injury in peripheral and central structures of the auditory pathway, i.e., the cochlea and the auditory cortex (ACx), in rats exposed to styrene, a volatile compound with well-known oto/neurotoxic properties. METHODS Male adult Wistar rats were treated with styrene (400 mg/kg daily for 3 weeks, 5/days a week). Electrophysiological, morphological, immunofluorescence and molecular analyses were performed in both the cochlea and the ACx to evaluate the mechanisms underlying styrene-induced oto/neurotoxicity in the auditory system. RESULTS We showed that the oto/neurotoxic insult induced by styrene increases oxidative stress in both cochlea and ACx. This was associated with macrophages and glial cell activation, increased expression of inflammatory markers (i.e., pro-inflammatory cytokines and chemokine receptors) and alterations in connexin (Cxs) and pannexin (Panx) expression, likely responsible for dysregulation of the microglia/astrocyte network. Specifically, we found downregulation of Cx26 and Cx30 in the cochlea, and high level of Cx43 and Panx1 in the ACx. CONCLUSIONS Collectively, our results provide novel evidence on the role of immune and glial cell activation in the oxidative/inflammatory damage induced by styrene in the auditory system at both peripheral and central levels, also involving alterations of gap junction networks. Our data suggest that targeting glial cells and connexin/pannexin expression might be useful to attenuate oxidative/inflammatory damage in the auditory system.
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Affiliation(s)
- Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
| | - Anna Pisani
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Rolando Rolesi
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Raffaele Montuoro
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | | | - Giammarco Boni
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
| | - Cristian Ripoli
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
| | - Jacopo Galli
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Renata Sisto
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Italian Workers' Compensation Authority (INAIL), Monte Porzio Catone, Rome, Italy
| | - Anna Rita Fetoni
- Department of Neuroscience, Unit of Audiology, Università Degli Studi di Napoli Federico II, Naples, Italy.
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
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Hastings N, Yu Y, Huang B, Middya S, Inaoka M, Erkamp NA, Mason RJ, Carnicer‐Lombarte A, Rahman S, Knowles TPJ, Bance M, Malliaras GG, Kotter MRN. Electrophysiological In Vitro Study of Long-Range Signal Transmission by Astrocytic Networks. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301756. [PMID: 37485646 PMCID: PMC10582426 DOI: 10.1002/advs.202301756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/09/2023] [Indexed: 07/25/2023]
Abstract
Astrocytes are diverse brain cells that form large networks communicating via gap junctions and chemical transmitters. Despite recent advances, the functions of astrocytic networks in information processing in the brain are not fully understood. In culture, brain slices, and in vivo, astrocytes, and neurons grow in tight association, making it challenging to establish whether signals that spread within astrocytic networks communicate with neuronal groups at distant sites, or whether astrocytes solely respond to their local environments. A multi-electrode array (MEA)-based device called AstroMEA is designed to separate neuronal and astrocytic networks, thus allowing to study the transfer of chemical and/or electrical signals transmitted via astrocytic networks capable of changing neuronal electrical behavior. AstroMEA demonstrates that cortical astrocytic networks can induce a significant upregulation in the firing frequency of neurons in response to a theta-burst charge-balanced biphasic current stimulation (5 pulses of 100 Hz × 10 with 200 ms intervals, 2 s total duration) of a separate neuronal-astrocytic group in the absence of direct neuronal contact. This result corroborates the view of astrocytic networks as a parallel mechanism of signal transmission in the brain that is separate from the neuronal connectome. Translationally, it highlights the importance of astrocytic network protection as a treatment target.
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Affiliation(s)
- Nataly Hastings
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Yi‐Lin Yu
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Department of Neurological SurgeryTri‐Service General HospitalNational Defence Medical CentreTaipei, Neihu District11490Taiwan
| | - Botian Huang
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
| | - Sagnik Middya
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Misaki Inaoka
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Nadia A. Erkamp
- Yusuf Hamied Department of ChemistryCentre for Misfolding DiseasesUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Roger J. Mason
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
| | | | - Saifur Rahman
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
| | - Tuomas P. J. Knowles
- Yusuf Hamied Department of ChemistryCentre for Misfolding DiseasesUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
- Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJ J Thomson AveCambridgeCB3 0HEUK
| | - Manohar Bance
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
| | - George G. Malliaras
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Mark R. N. Kotter
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
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Clarkson-Paredes C, Karl MT, Popratiloff A, Miller RH. A unique cell population expressing the Epithelial-Mesenchymal Transition-transcription factor Snail moderates microglial and astrocyte injury responses. PNAS NEXUS 2023; 2:pgad334. [PMID: 37901440 PMCID: PMC10612478 DOI: 10.1093/pnasnexus/pgad334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 09/26/2023] [Indexed: 10/31/2023]
Abstract
Insults to the central nervous system (CNS) elicit common glial responses including microglial activation evidenced by functional, morphological, and phenotypic changes, as well as astrocyte reactions including hypertrophy, altered process orientation, and changes in gene expression and function. However, the cellular and molecular mechanisms that initiate and modulate such glial response are less well-defined. Here we show that an adult cortical lesion generates a population of ultrastructurally unique microglial-like cells that express Epithelial-Mesenchymal Transcription factors including Snail. Knockdown of Snail with antisense oligonucleotides results in a postinjury increase in activated microglial cells, elevation in astrocyte reactivity with increased expression of C3 and phagocytosis, disruption of astrocyte junctions and neurovascular structure, increases in neuronal cell death, and reduction in cortical synapses. These changes were associated with alterations in pro-inflammatory cytokine expression. By contrast, overexpression of Snail through microglia-targeted an adeno-associated virus (AAV) improved many of the injury characteristics. Together, our results suggest that the coordination of glial responses to CNS injury is partly mediated by epithelial-mesenchymal transition-factors (EMT-Fsl).
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Affiliation(s)
- Cheryl Clarkson-Paredes
- Department of Anatomy and Cell Biology, School of Medicine and Health Sciences, George Washington University, 2300 Eye Street NW, Ross 735, Washington, DC 20052, USA
- Nanofabrication and Imaging Center, The George Washington University, 800 22nd Street NW, Washington, DC 20052, USA
| | - Molly T Karl
- Department of Anatomy and Cell Biology, School of Medicine and Health Sciences, George Washington University, 2300 Eye Street NW, Ross 735, Washington, DC 20052, USA
| | - Anastas Popratiloff
- Department of Anatomy and Cell Biology, School of Medicine and Health Sciences, George Washington University, 2300 Eye Street NW, Ross 735, Washington, DC 20052, USA
- Nanofabrication and Imaging Center, The George Washington University, 800 22nd Street NW, Washington, DC 20052, USA
| | - Robert H Miller
- Department of Anatomy and Cell Biology, School of Medicine and Health Sciences, George Washington University, 2300 Eye Street NW, Ross 735, Washington, DC 20052, USA
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5
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Huang H, Li S, Zhang Y, He C, Hua Z. Microglial Priming in Bilirubin-Induced Neurotoxicity. Neurotox Res 2023; 41:338-348. [PMID: 37058197 DOI: 10.1007/s12640-023-00643-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 03/05/2023] [Accepted: 04/02/2023] [Indexed: 04/15/2023]
Abstract
Neuroinflammation is a major contributor to bilirubin-induced neurotoxicity, which results in severe neurological deficits. Microglia are the primary immune cells in the brain, with M1 microglia promoting inflammatory injury and M2 microglia inhibiting neuroinflammation. Controlling microglial inflammation could be a promising therapeutic strategy for reducing bilirubin-induced neurotoxicity. Primary microglial cultures were prepared from 1-3-day-old rats. In the early stages of bilirubin treatment, pro-/anti-inflammatory (M1/M2) microglia mixed polarization was observed. In the late stages, bilirubin persistence induced dominant proinflammatory microglia, forming an inflammatory microenvironment and inducing iNOS expression as well as the release of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β. Simultaneously, nuclear factor-kappa B (NF-κB) was activated and translocated into the nucleus, upregulating inflammatory target genes. As well known, neuroinflammation can have an effect on N-methyl-D-aspartate receptor (NMDAR) expression or function, which is linked to cognition. Treatment with bilirubin-treated microglia-conditioned medium did affect the expression of IL-1β, NMDA receptor subunit 2A (NR2A), and NMDA receptor subunit 2B (NR2B) in neurons. However, VX-765 effectively reduces the levels of proinflammatory cytokines TNF-α, IL-6, and IL-1β, as well as the expressions of CD86, and increases the expressions of anti-inflammatory related Arg-1. A timely reduction in proinflammatory microglia could protect against bilirubin-induced neurotoxicity.
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Affiliation(s)
- Hongmei Huang
- Department of Neonatology Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China
- Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China
| | - Siyu Li
- Department of Neonatology Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China
- Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China
| | - Yan Zhang
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China
- Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China
| | - Chunmei He
- Department of Neonatology Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China
- Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China
| | - Ziyu Hua
- Department of Neonatology Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China.
- Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China.
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6
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Calafatti M, Cocozza G, Limatola C, Garofalo S. Microglial crosstalk with astrocytes and immune cells in amyotrophic lateral sclerosis. Front Immunol 2023; 14:1223096. [PMID: 37564648 PMCID: PMC10410456 DOI: 10.3389/fimmu.2023.1223096] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 07/03/2023] [Indexed: 08/12/2023] Open
Abstract
In recent years, biomedical research efforts aimed to unravel the mechanisms involved in motor neuron death that occurs in amyotrophic lateral sclerosis (ALS). While the main causes of disease progression were first sought in the motor neurons, more recent studies highlight the gliocentric theory demonstrating the pivotal role of microglia and astrocyte, but also of infiltrating immune cells, in the pathological processes that take place in the central nervous system microenvironment. From this point of view, microglia-astrocytes-lymphocytes crosstalk is fundamental to shape the microenvironment toward a pro-inflammatory one, enhancing neuronal damage. In this review, we dissect the current state-of-the-art knowledge of the microglial dialogue with other cell populations as one of the principal hallmarks of ALS progression. Particularly, we deeply investigate the microglia crosstalk with astrocytes and immune cells reporting in vitro and in vivo studies related to ALS mouse models and human patients. At last, we highlight the current experimental therapeutic approaches that aim to modulate microglial phenotype to revert the microenvironment, thus counteracting ALS progression.
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Affiliation(s)
- Matteo Calafatti
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
| | - Germana Cocozza
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
| | - Cristina Limatola
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
- Department of Physiology and Pharmacology, Sapienza University, Laboratory Affiliated to Istituto Pasteur, Rome, Italy
| | - Stefano Garofalo
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
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7
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Zhao Q, Li H, Li H, Xie F, Zhang J. Research progress of neuroinflammation-related cells in traumatic brain injury: A review. Medicine (Baltimore) 2023; 102:e34009. [PMID: 37352020 PMCID: PMC10289497 DOI: 10.1097/md.0000000000034009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 06/25/2023] Open
Abstract
Neuroinflammation after traumatic brain injury (TBI) is related to chronic neurodegenerative diseases and is one of the causes of acute secondary injury after TBI. Therefore, it is particularly important to clarify the role of cellular mechanisms in the neuroinflammatory response after TBI. The objective of this article is to understand the involvement of cells during the TBI inflammatory response (for instance, astrocytes, microglia, and oligodendrocytes) and shed light on the recent progress in the stimulation and interaction of granulocytes and lymphocytes, to provide a novel approach for clinical research. We searched articles in PubMed published between 1950 and 2023, using the following keywords: TBI, neuroinflammation, inflammatory cells, neuroprotection, clinical. Articles for inclusion in this paper were finalized based on their novelty, representativeness, and relevance to the main arguments of this review. We found that the neuroinflammatory response after TBI includes the activation of glial cells, the release of inflammatory mediators in the brain, and the recruitment of peripheral immune cells. These inflammatory responses not only induce secondary brain damage, but also have a role in repairing the nervous system to some extent. However, not all of the mechanisms of cell-to-cell interactions have been well studied. After TBI, clinical treatment cannot simply suppress the inflammatory response, and the inflammatory phenotype of patients' needs to be defined according to their specific conditions after injury. Clinical trials of personalized inflammation regulation therapy for specific patients should be carried out in order to improve the prognosis of patients.
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Affiliation(s)
- Qinghui Zhao
- Institute of Physical Culture, Huanghuai University, Zhumadian, China
| | - Huige Li
- Institute of Physical Culture, Huanghuai University, Zhumadian, China
| | - Hongru Li
- Zhumadian Central Hospital, Zhumadian, China
| | - Fei Xie
- Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Jianhua Zhang
- Institute of Physical Culture, Huanghuai University, Zhumadian, China
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8
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Bedner P, Steinhäuser C. Role of Impaired Astrocyte Gap Junction Coupling in Epileptogenesis. Cells 2023; 12:1669. [PMID: 37371139 DOI: 10.3390/cells12121669] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 05/25/2023] [Accepted: 06/19/2023] [Indexed: 06/29/2023] Open
Abstract
The gap-junction-coupled astroglial network plays a central role in the regulation of neuronal activity and synchronisation, but its involvement in the pathogenesis of neuronal diseases is not yet understood. Here, we present the current state of knowledge about the impact of impaired glial coupling in the development and progression of epilepsy and discuss whether astrocytes represent alternative therapeutic targets. We focus mainly on temporal lobe epilepsy (TLE), which is the most common form of epilepsy in adults and is characterised by high therapy resistance. Functional data from TLE patients and corresponding experimental models point to a complete loss of astrocytic coupling, but preservation of the gap junction forming proteins connexin43 and connexin30 in hippocampal sclerosis. Several studies further indicate that astrocyte uncoupling is a causal event in the initiation of TLE, as it occurs very early in epileptogenesis, clearly preceding dysfunctional changes in neurons. However, more research is needed to fully understand the role of gap junction channels in epilepsy and to develop safe and effective therapeutic strategies targeting astrocytes.
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Affiliation(s)
- Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
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Gullotta GS, Costantino G, Sortino MA, Spampinato SF. Microglia and the Blood-Brain Barrier: An External Player in Acute and Chronic Neuroinflammatory Conditions. Int J Mol Sci 2023; 24:ijms24119144. [PMID: 37298096 DOI: 10.3390/ijms24119144] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 05/18/2023] [Accepted: 05/20/2023] [Indexed: 06/12/2023] Open
Abstract
Microglia are the resident immune cells of the central nervous system that guarantee immune surveillance and exert also a modulating role on neuronal synaptic development and function. Upon injury, microglia get activated and modify their morphology acquiring an ameboid phenotype and pro- or anti-inflammatory features. The active role of microglia in blood-brain barrier (BBB) function and their interaction with different cellular components of the BBB-endothelial cells, astrocytes and pericytes-are described. Here, we report the specific crosstalk of microglia with all the BBB cell types focusing in particular on the involvement of microglia in the modulation of BBB function in neuroinflammatory conditions that occur in conjunction with an acute event, such as a stroke, or in a slow neurodegenerative disease, such as Alzheimer's disease. The potential of microglia to exert a dual role, either protective or detrimental, depending on disease stages and environmental conditioning factors is also discussed.
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Affiliation(s)
- Giorgia Serena Gullotta
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Giuseppe Costantino
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
- Ph.D. Program in Neuroscience and Education, DISTUM, University of Foggia, 71121 Foggia, Italy
| | - Maria Angela Sortino
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
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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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11
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Sompol P, Gollihue JL, Weiss BE, Lin RL, Case SL, Kraner SD, Weekman EM, Gant JC, Rogers CB, Niedowicz DM, Sudduth TL, Powell DK, Lin AL, Nelson PT, Thibault O, Wilcock DM, Norris CM. Targeting Astrocyte Signaling Alleviates Cerebrovascular and Synaptic Function Deficits in a Diet-Based Mouse Model of Small Cerebral Vessel Disease. J Neurosci 2023; 43:1797-1813. [PMID: 36746627 PMCID: PMC10010459 DOI: 10.1523/jneurosci.1333-22.2023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 01/25/2023] [Accepted: 01/31/2023] [Indexed: 02/08/2023] Open
Abstract
Despite the indispensable role that astrocytes play in the neurovascular unit, few studies have investigated the functional impact of astrocyte signaling in cognitive decline and dementia related to vascular pathology. Diet-mediated induction of hyperhomocysteinemia (HHcy) recapitulates numerous features of vascular contributions to cognitive impairment and dementia (VCID). Here, we used astrocyte targeting approaches to evaluate astrocyte Ca2+ dysregulation and the impact of aberrant astrocyte signaling on cerebrovascular dysfunction and synapse impairment in male and female HHcy diet mice. Two-photon imaging conducted in fully awake mice revealed activity-dependent Ca2+ dysregulation in barrel cortex astrocytes under HHcy. Stimulation of contralateral whiskers elicited larger Ca2+ transients in individual astrocytes of HHcy diet mice compared with control diet mice. However, evoked Ca2+ signaling across astrocyte networks was impaired in HHcy mice. HHcy also was associated with increased activation of the Ca2+/calcineurin-dependent transcription factor NFAT4, which has been linked previously to the reactive astrocyte phenotype and synapse dysfunction in amyloid and brain injury models. Targeting the NFAT inhibitor VIVIT to astrocytes, using adeno-associated virus vectors, led to reduced GFAP promoter activity in HHcy diet mice and improved functional hyperemia in arterioles and capillaries. VIVIT expression in astrocytes also preserved CA1 synaptic function and improved spontaneous alternation performance on the Y maze. Together, the results demonstrate that aberrant astrocyte signaling can impair the major functional properties of the neurovascular unit (i.e., cerebral vessel regulation and synaptic regulation) and may therefore represent a promising drug target for treating VCID and possibly Alzheimer's disease and other related dementias.SIGNIFICANCE STATEMENT The impact of reactive astrocytes in Alzheimer's disease and related dementias is poorly understood. Here, we evaluated Ca2+ responses and signaling in barrel cortex astrocytes of mice fed with a B-vitamin deficient diet that induces hyperhomocysteinemia (HHcy), cerebral vessel disease, and cognitive decline. Multiphoton imaging in awake mice with HHcy revealed augmented Ca2+ responses in individual astrocytes, but impaired signaling across astrocyte networks. Stimulation-evoked arteriole dilation and elevated red blood cell velocity in capillaries were also impaired in cortex of awake HHcy mice. Astrocyte-specific inhibition of the Ca2+-dependent transcription factor, NFAT, normalized cerebrovascular function in HHcy mice, improved synaptic properties in brain slices, and stabilized cognition. Results suggest that astrocytes are a mechanism and possible therapeutic target for vascular-related dementia.
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Affiliation(s)
- Pradoldej Sompol
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | | | - Blaine E Weiss
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | - Ruei-Lung Lin
- Departments of Pharmacology and Nutritional Sciences
| | - Sami L Case
- Departments of Pharmacology and Nutritional Sciences
| | | | | | - John C Gant
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | | | | | | | | | - Ai-Ling Lin
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | - Peter T Nelson
- Sanders-Brown Center on Aging
- Pathology, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Olivier Thibault
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | | | - Christopher M Norris
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
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12
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Jiang H, Zhang Y, Wang ZZ, Chen NH. Connexin 43: An Interface Connecting Neuroinflammation to Depression. Molecules 2023; 28:molecules28041820. [PMID: 36838809 PMCID: PMC9961786 DOI: 10.3390/molecules28041820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023] Open
Abstract
Major depressive disorder (MDD) is a leading chronic mental illness worldwide, characterized by anhedonia, pessimism and even suicidal thoughts. Connexin 43 (Cx43), mainly distributed in astrocytes of the brain, is by far the most widely and ubiquitously expressed connexin in almost all vital organs. Cx43 forms gap junction channels in the brain, which mediate energy exchange and effectively maintain physiological homeostasis. Increasing evidence suggests the crucial role of Cx43 in the pathogenesis of MDD. Neuroinflammation is one of the most common pathological features of the central nervous system dysfunctions. Inflammatory factors are abnormally elevated in patients with depression and are closely related to nearly all links of depression. After activating the inflammatory pathway in the brain, the release and uptake of glutamate and adenosine triphosphate, through Cx43 in the synaptic cleft, would be affected. In this review, we have summarized the association between Cx43 and neuroinflammation, the cornerstones linking inflammation and depression, and Cx43 abnormalities in depression. We also discuss the significant association of Cx43 in inflammation and depression, which will help to explore new antidepressant drug targets.
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Affiliation(s)
- Hong Jiang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical, Science 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, Science and Peking Union Medical College, Beijing 100050, China
- Correspondence: (Z.-Z.W.); (N.-H.C.); Tel.: +86-10-6316-5182 (Z.-Z.W.); +86-10-63165177 (N.-H.C.)
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical, Science and Peking Union Medical College, Beijing 100050, China
- Correspondence: (Z.-Z.W.); (N.-H.C.); Tel.: +86-10-6316-5182 (Z.-Z.W.); +86-10-63165177 (N.-H.C.)
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13
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Di Mauro G, Amoriello R, Lozano N, Carnasciali A, Guasti D, Becucci M, Cellot G, Kostarelos K, Ballerini C, Ballerini L. Graphene Oxide Nanosheets Reduce Astrocyte Reactivity to Inflammation and Ameliorate Experimental Autoimmune Encephalomyelitis. ACS NANO 2023; 17:1965-1978. [PMID: 36692902 PMCID: PMC9933621 DOI: 10.1021/acsnano.2c06609] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
In neuroinflammation, astrocytes play multifaceted roles that regulate the neuronal environment. Astrocytes sense and respond to pro-inflammatory cytokines (CKs) and, by a repertoire of intracellular Ca2+ signaling, contribute to disease progression. Therapeutic approaches wish to reduce the overactivation in Ca2+ signaling in inflammatory-reactive astrocytes to restore dysregulated cellular changes. Cell-targeting therapeutics might take advantage by the use of nanomaterial-multifunctional platforms such as graphene oxide (GO). GO biomedical applications in the nervous system involve therapeutic delivery and sensing, and GO flakes were shown to enable interfacing of neuronal and glial membrane dynamics. We exploit organotypic spinal cord cultures and optical imaging to explore Ca2+ changes in astrocytes, and we report, when spinal tissue is exposed to CKs, neuroinflammatory-associated modulation of resident glia. We show the efficacy of GO to revert these dynamic changes in astrocytic reactivity to CKs, and we translate this potential in an animal model of immune-mediated neuroinflammatory disease.
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Affiliation(s)
- Giuseppe Di Mauro
- International
School for Advanced Studies (SISSA/ISAS), 34136Trieste, Italy
| | - Roberta Amoriello
- International
School for Advanced Studies (SISSA/ISAS), 34136Trieste, Italy
- Dipartimento
di Medicina Sperimentale e Clinica, University
of Florence, 50139Florence, Italy
| | - Neus Lozano
- Catalan
Institute of Nanoscience and Nanotechnology (ICN2), 08193Barcelona, Spain
| | - Alberto Carnasciali
- Dipartimento
di Medicina Sperimentale e Clinica, University
of Florence, 50139Florence, Italy
| | - Daniele Guasti
- Dipartimento
di Medicina Sperimentale e Clinica, University
of Florence, 50139Florence, Italy
| | - Maurizio Becucci
- Dipartimento
di Chimica “Ugo Schiff”, DICUS, University of Florence, 50139Florence, Italy
| | - Giada Cellot
- International
School for Advanced Studies (SISSA/ISAS), 34136Trieste, Italy
| | - Kostas Kostarelos
- Catalan
Institute of Nanoscience and Nanotechnology (ICN2), 08193Barcelona, Spain
- Nanomedicine
Lab, and Faculty of Biology, Medicine & Health, The National Graphene
Institute, University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Clara Ballerini
- Dipartimento
di Medicina Sperimentale e Clinica, University
of Florence, 50139Florence, Italy
| | - Laura Ballerini
- International
School for Advanced Studies (SISSA/ISAS), 34136Trieste, Italy
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14
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Henning L, Antony H, Breuer A, Müller J, Seifert G, Audinat E, Singh P, Brosseron F, Heneka MT, Steinhäuser C, Bedner P. Reactive microglia are the major source of tumor necrosis factor alpha and contribute to astrocyte dysfunction and acute seizures in experimental temporal lobe epilepsy. Glia 2023; 71:168-186. [PMID: 36373840 DOI: 10.1002/glia.24265] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/12/2022] [Accepted: 08/17/2022] [Indexed: 11/09/2022]
Abstract
Extensive microglia reactivity has been well described in human and experimental temporal lobe epilepsy (TLE). To date, however, it is not clear whether and based on which molecular mechanisms microglia contribute to the development and progression of focal epilepsy. Astroglial gap junction coupled networks play an important role in regulating neuronal activity and loss of interastrocytic coupling causally contributes to TLE. Here, we show in the unilateral intracortical kainate (KA) mouse model of TLE that reactive microglia are primary producers of tumor necrosis factor (TNF)α and contribute to astrocyte dysfunction and severity of status epilepticus (SE). Immunohistochemical analyses revealed pronounced and persistent microglia reactivity, which already started 4 h after KA-induced SE. Partial depletion of microglia using a colony stimulating factor 1 receptor inhibitor prevented early astrocyte uncoupling and attenuated the severity of SE, but increased the mortality of epileptic mice following surgery. Using microglia-specific inducible TNFα knockout mice we identified microglia as the major source of TNFα during early epileptogenesis. Importantly, microglia-specific TNFα knockout prevented SE-induced gap junction uncoupling in astrocytes. Continuous telemetric EEG recordings revealed that during the first 4 weeks after SE induction, microglial TNFα did not significantly contribute to spontaneous generalized seizure activity. Moreover, the absence of microglial TNFα did not affect the development of hippocampal sclerosis but attenuated gliosis. Taken together, these data implicate reactive microglia in astrocyte dysfunction and network hyperexcitability after an epileptogenic insult.
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Affiliation(s)
- Lukas Henning
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Henrike Antony
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Annika Breuer
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Julia Müller
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Gerald Seifert
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Etienne Audinat
- Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, Montpellier, France
| | | | | | | | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
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15
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Murray CJ, Vecchiarelli HA, Tremblay MÈ. Enhancing axonal myelination in seniors: A review exploring the potential impact cannabis has on myelination in the aged brain. Front Aging Neurosci 2023; 15:1119552. [PMID: 37032821 PMCID: PMC10073480 DOI: 10.3389/fnagi.2023.1119552] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 02/22/2023] [Indexed: 04/11/2023] Open
Abstract
Consumption of cannabis is on the rise as public opinion trends toward acceptance and its consequent legalization. Specifically, the senior population is one of the demographics increasing their use of cannabis the fastest, but research aimed at understanding cannabis' impact on the aged brain is still scarce. Aging is characterized by many brain changes that slowly alter cognitive ability. One process that is greatly impacted during aging is axonal myelination. The slow degradation and loss of myelin (i.e., demyelination) in the brain with age has been shown to associate with cognitive decline and, furthermore, is a common characteristic of numerous neurological diseases experienced in aging. It is currently not known what causes this age-dependent degradation, but it is likely due to numerous confounding factors (i.e., heightened inflammation, reduced blood flow, cellular senescence) that impact the many cells responsible for maintaining overall homeostasis and myelin integrity. Importantly, animal studies using non-human primates and rodents have also revealed demyelination with age, providing a reliable model for researchers to try and understand the cellular mechanisms at play. In rodents, cannabis was recently shown to modulate the myelination process. Furthermore, studies looking at the direct modulatory impact cannabis has on microglia, astrocytes and oligodendrocyte lineage cells hint at potential mechanisms to prevent some of the more damaging activities performed by these cells that contribute to demyelination in aging. However, research focusing on how cannabis impacts myelination in the aged brain is lacking. Therefore, this review will explore the evidence thus far accumulated to show how cannabis impacts myelination and will extrapolate what this knowledge may mean for the aged brain.
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Affiliation(s)
- Colin J. Murray
- Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- *Correspondence: Colin J. Murray,
| | | | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Départment de Médicine Moléculaire, Université Laval, Québec City, QC, Canada
- Axe Neurosciences, Center de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
- Neurology and Neurosurgery Department, McGill University, Montréal, QC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada
- Institute for Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada
- Marie-Ève Tremblay,
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16
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Liang Z, Lou Y, Hao Y, Li H, Feng J, Liu S. The Relationship of Astrocytes and Microglia with Different Stages of Ischemic Stroke. Curr Neuropharmacol 2023; 21:2465-2480. [PMID: 37464832 PMCID: PMC10616922 DOI: 10.2174/1570159x21666230718104634] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 01/31/2023] [Accepted: 02/04/2023] [Indexed: 07/20/2023] Open
Abstract
Ischemic stroke is the predominant cause of severe morbidity and mortality worldwide. Post-stroke neuroinflammation has recently received increasing attention with the aim of providing a new effective treatment strategy for ischemic stroke. Microglia and astrocytes are major components of the innate immune system of the central nervous system. They can be involved in all phases of ischemic stroke, from the early stage, contributing to the first wave of neuronal cell death, to the late stage involving phagocytosis and repair. In the early stage of ischemic stroke, a vicious cycle exists between the activation of microglia and astrocytes (through astrocytic connexin 43 hemichannels), aggravating neuroinflammatory injury post-stroke. However, in the late stage of ischemic stroke, repeatedly activated microglia can induce the formation of glial scars by triggering reactive astrogliosis in the peri-infarct regions, which may limit the movement of activated microglia in reverse and restrict the diffusion of inflammation to healthy brain tissues, alleviating the neuroinflammatory injury poststroke. In this review, we elucidated the various roles of astrocytes and microglia and summarized their relationship with neuroinflammation. We also examined how astrocytes and microglia influence each other at different stages of ischemic stroke. Several potential therapeutic approaches targeting astrocytes and microglia in ischemic stroke have been reviewed. Understanding the details of astrocytemicroglia interaction processes will contribute to a better understanding of the mechanisms underlying ischemic stroke, contributing to the identification of new therapeutic interventions.
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Affiliation(s)
- Zhen Liang
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun, China
| | - Yingyue Lou
- Department of Rehabilitation, The Second Hospital of Jilin University, Changchun, China
| | - Yulei Hao
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Hui Li
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Jiachun Feng
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Songyan Liu
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun, China
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17
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Huang W, Xia Q, Zheng F, Zhao X, Ge F, Xiao J, Liu Z, Shen Y, Ye K, Wang D, Li Y. Microglia-Mediated Neurovascular Unit Dysfunction in Alzheimer's Disease. J Alzheimers Dis 2023; 94:S335-S354. [PMID: 36683511 PMCID: PMC10473143 DOI: 10.3233/jad-221064] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/2022] [Indexed: 01/21/2023]
Abstract
The neurovascular unit (NVU) is involved in the pathological changes in Alzheimer's disease (AD). The NVU is a structural and functional complex that maintains microenvironmental homeostasis and metabolic balance in the central nervous system. As one of the most important components of the NVU, microglia not only induce blood-brain barrier breakdown by promoting neuroinflammation, the infiltration of peripheral white blood cells and oxidative stress but also mediate neurovascular uncoupling by inducing mitochondrial dysfunction in neurons, abnormal contraction of cerebral vessels, and pericyte loss in AD. In addition, microglia-mediated dysfunction of cellular components in the NVU, such as astrocytes and pericytes, can destroy the integrity of the NVU and lead to NVU impairment. Therefore, we review the mechanisms of microglia-mediated NVU dysfunction in AD. Furthermore, existing therapeutic advancements aimed at restoring the function of microglia and the NVU in AD are discussed. Finally, we predict the role of pericytes in microglia-mediated NVU dysfunction in AD is the hotspot in the future.
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Affiliation(s)
- Wenhao Huang
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Qing Xia
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Feifei Zheng
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Xue Zhao
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Fangliang Ge
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Jiaying Xiao
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Zijie Liu
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Yingying Shen
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Ke Ye
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Dayong Wang
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
- Basic Medical Institute, Heilongjiang Medical Science Academy, Harbin, Heilongjiang Province, China
- Translational Medicine Center of Northern China, Harbin, Heilongjiang Province, China
- Key Laboratory of Heilongjiang Province for Genetically Modified Animals, Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Yanze Li
- Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, Heilongjiang Province, China
- Basic Medical Institute, Heilongjiang Medical Science Academy, Harbin, Heilongjiang Province, China
- Translational Medicine Center of Northern China, Harbin, Heilongjiang Province, China
- Key Laboratory of Heilongjiang Province for Genetically Modified Animals, Harbin Medical University, Harbin, Heilongjiang Province, China
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18
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Andrioli A, Fabene PF, Mudò G, Barresi V, Di Liberto V, Frinchi M, Bentivoglio M, Condorelli DF. Downregulation of the Astroglial Connexin Expression and Neurodegeneration after Pilocarpine-Induced Status Epilepticus. Int J Mol Sci 2022; 24:ijms24010023. [PMID: 36613467 PMCID: PMC9819917 DOI: 10.3390/ijms24010023] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/12/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
Astrocytic networks and gap junctional communication mediated by connexins (Cxs) have been repeatedly implicated in seizures, epileptogenesis, and epilepsy. However, the effect of seizures on Cx expression is controversial. The present study focused on the response of Cxs to status epilepticus (SE), which is in turn an epileptogenic insult. The expression of neuronal Cx36 and astrocytic Cx30 and Cx43 mRNAs was investigated in the brain of rats in the first day after pilocarpine-induced SE. In situ hybridization revealed a progressive decrease in Cx43 and Cx30 mRNA levels, significantly marked 24 h after SE onset in neocortical areas and the hippocampus, and in most thalamic domains, whereas Cx36 mRNA did not exhibit obvious changes. Regional evaluation with quantitative real-time-RT-PCR confirmed Cx43 and Cx30 mRNA downregulation 24 h after SE, when ongoing neuronal cell death was found in the same brain regions. Immunolabeling showed at the same time point marked a decrease in Cx43, microglia activation, and interleukin-1β induction in some microglial cells. The data showed a transient downregulation of astroglial Cxs in the cortical and thalamic areas in which SE triggers neurodegenerative events in concomitance with microglia activation and cytokine expression. This could potentially represent a protective response of neuroglial networks to SE-induced acute damage.
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Affiliation(s)
- Anna Andrioli
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy
| | - Paolo Francesco Fabene
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy
- Verona Unit, National Institute of Neuroscience (INN), 37129 Verona, Italy
| | - Giuseppa Mudò
- Department of Biomedicine, Neuroscience and Advanced Diagnostic (BiND), University of Palermo, 90133 Palermo, Italy
| | - Vincenza Barresi
- Unit of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Valentina Di Liberto
- Department of Biomedicine, Neuroscience and Advanced Diagnostic (BiND), University of Palermo, 90133 Palermo, Italy
| | - Monica Frinchi
- Department of Biomedicine, Neuroscience and Advanced Diagnostic (BiND), University of Palermo, 90133 Palermo, Italy
| | - Marina Bentivoglio
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy
- Verona Unit, National Institute of Neuroscience (INN), 37129 Verona, Italy
| | - Daniele Filippo Condorelli
- Unit of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
- Correspondence:
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19
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TNF-α Plus IL-1β Induces Opposite Regulation of Cx43 Hemichannels and Gap Junctions in Mesangial Cells through a RhoA/ROCK-Dependent Pathway. Int J Mol Sci 2022; 23:ijms231710097. [PMID: 36077498 PMCID: PMC9456118 DOI: 10.3390/ijms231710097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 11/17/2022] Open
Abstract
Connexin 43 (Cx43) is expressed in kidney tissue where it forms hemichannels and gap junction channels. However, the possible functional relationship between these membrane channels and their role in damaged renal cells remains unknown. Here, analysis of ethidium uptake and thiobarbituric acid reactive species revealed that treatment with TNF-α plus IL-1β increases Cx43 hemichannel activity and oxidative stress in MES-13 cells (a cell line derived from mesangial cells), and in primary mesangial cells. The latter was also accompanied by a reduction in gap junctional communication, whereas Western blotting assays showed a progressive increase in phosphorylated MYPT (a target of RhoA/ROCK) and Cx43 upon TNF-α/IL-1β treatment. Additionally, inhibition of RhoA/ROCK strongly antagonized the TNF-α/IL-1β-induced activation of Cx43 hemichannels and reduction in gap junctional coupling. We propose that activation of Cx43 hemichannels and inhibition of cell-cell coupling during pro-inflammatory conditions could contribute to oxidative stress and damage of mesangial cells via the RhoA/ROCK pathway.
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20
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Zhang FF, Wang H, Zhou YM, Yu HY, Zhang M, Du X, Wang D, Zhang F, Xu Y, Zhang JG, Zhang HT. Inhibition of phosphodiesterase-4 in the spinal dorsal horn ameliorates neuropathic pain via cAMP-cytokine-Cx43 signaling in mice. CNS Neurosci Ther 2022; 28:749-760. [PMID: 35156776 PMCID: PMC8981432 DOI: 10.1111/cns.13807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 12/13/2021] [Accepted: 12/28/2021] [Indexed: 01/21/2023] Open
Abstract
Background The spinal phosphodiesterase‐4 (PDE4) plays an important role in chronic pain. Inhibition of PDE4, an enzyme catalyzing the hydrolysis of cyclic adenosine monophosphate AMP (cAMP), produces potent antinociceptive activity. However, the antinociceptive mechanism remains largely unknown. Connexin43 (Cx43), a gap junction protein, has been shown to be involved in controlling pain transduction at the spinal level; restoration of Cx43 expression in spinal astrocytes to the normal levels reduces nerve injury‐induced pain. Here, we evaluate the novel mechanisms involving spinal cAMP‐Cx43 signaling by which PDE4 inhibitors produce antinociceptive activity. Methods First, we determined the effect of PDE4 inhibitors rolipram and roflumilast on partial sciatic nerve ligation (PSNL)‐induced mechanical hypersensitivity. Next, we observed the role of cAMP‐Cx43 signaling in the effect of PDE4 inhibitors on PSNL‐induced mechanical hypersensitivity. Results Single or repeated, intraperitoneal or intrathecal administration of rolipram or roflumilast significantly reduced mechanical hypersensitivity in mice following PSNL. In addition, repeated intrathecal treatment with either of PDE4 inhibitors reduced PSNL‐induced downregulation of cAMP and Cx43, and upregulation of proinflammatory cytokines tumor necrosis factor‐α (TNF‐α) and interleukin‐1β. Furthermore, the antinociceptive effects of PDE4 inhibitors were attenuated by the protein kinase A (PKA) inhibitor H89, TNF‐α, or Cx43 antagonist carbenoxolone. Finally, PSNL‐induced upregulation of PDE4B and PDE4D, especially the PDE4B subtype, was reduced by treatment with either of the PDE4 inhibitors. Conclusions The results suggest that the antinociceptive effect of PDE4 inhibitors is contributed by increasing Cx43 expression via cAMP‐PKA‐cytokine signaling in the spinal dorsal horn.
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Affiliation(s)
- Fang-Fang Zhang
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Hao Wang
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Yan-Meng Zhou
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Hai-Yang Yu
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Melanie Zhang
- Department of Neurobiology, Northwestern University Feinberg School of Medicine, Evanston, Illinois, USA
| | - Xian Du
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Dong Wang
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Feng Zhang
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Ying Xu
- Department of Pharmaceutical Sciences, School of Pharmacy & Pharmaceutical Sciences, University at Buffalo, the State University of New York, Buffalo, New York, USA
| | - Ji-Guo Zhang
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Han-Ting Zhang
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China.,Department of Pharmacology, School of Pharmacy, Qingdao University, Qingdao, China
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21
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Zhao Y, Qi Y, Li Q, Quan H, Liu D, Zhou H. Connexin43 inhibition attenuated dopaminergic neuronal loss in the lipopolysaccharide-induced mice model of Parkinson's disease. Neurosci Lett 2022; 771:136471. [PMID: 35065246 DOI: 10.1016/j.neulet.2022.136471] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 11/29/2021] [Accepted: 01/17/2022] [Indexed: 10/19/2022]
Abstract
Studies using in vitro Parkinson's disease (PD) models have found that lipopolysaccharide (LPS) induced reduction of connexin 43 (Cx43) gap junction communication and elevation of hemichannel function, which could cause neurotoxicity directly and indirectly via excessive ATP and glutamate release. However, in vivo study about Cx43 expression and function, as well as the efficacy of Cx43 inhibition for neuronal survival in PD is lacking. This study aimed to unravel the role of Cx43 in PD and understand the underlying mechanisms using an in vivo PD model. Male C57BL/6 mice received intranigral injection of LPS (5 μg) and 43Gap27 (4 μg), a Cx43 inhibitor, simultaneously. Results showed that following LPS treatment, total Cx43 expression decreased by about 60%, but the relative level of phosphorylated Cx43 increased to about double that controls (all p < 0.05). The administration of 43Gap27 significantly attenuated the loss of dopaminergic neurons and restored dopamine and its metabolites levels. Moreover, 43Gap27 treatment inhibited intense microgliosis and astrogliosis in nigrostriatal system induced by LPS and also ameliorated elevated levels of inflammatory mediators. Interestingly, Cx43 inhibition also increased nerve growth factors. In conclusion, Cx43 inhibition was able to prevent LPS-mediated dopaminergic neuronal death, possibly via neuroinflammation reaction reduction and neurotrophic factors elevation. Therefore, Cx43 may be a promising therapeutic target for degenerative neurological disorders such as PD.
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Affiliation(s)
- Yujia Zhao
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China; The Institute for Risk Assessment Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Yuze Qi
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
| | - Qingru Li
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
| | - Huihui Quan
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
| | - Dan Liu
- Population Health Sciences, German Centre for Neurodegenerative Disease, Bonn, Germany
| | - Hui Zhou
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
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22
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Bedner P, Wu Z, Steinhäuser C. Response: Astrocytes as alternative targets for more efficient antiepileptogenic drugs. Epilepsia 2021; 62:2299-2300. [PMID: 34169524 DOI: 10.1111/epi.16965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/16/2021] [Accepted: 06/02/2021] [Indexed: 11/27/2022]
Affiliation(s)
- Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Zhou Wu
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
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23
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Decreased connexin43 expression in the hippocampus is related to the antidepressant effect of amitriptyline in neuropathic pain mice. Biochem Biophys Res Commun 2021; 566:141-147. [PMID: 34126344 DOI: 10.1016/j.bbrc.2021.06.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 06/04/2021] [Indexed: 12/17/2022]
Abstract
Downregulation of astrocytic connexin43 (Cx43) has been observed in several brain regions in rodents and patients with depression. However, its specific role in this effect remains unknown. Moreover, chronic pain can induce depressive disorders. Therefore, the current study examined the relationship between Cx43 expression and depressive-like behavior in a neuropathic pain model. Neuropathic pain was induced by spared nerve injury (SNI) in mice. Depressive-like behavior was evaluated using the forced swim test. Expression of Cx43 in the hippocampus was evaluated using Western blotting and real-time PCR. SNI downregulated Cx43 protein in the contralateral hippocampus of mice, whereas expression of hippocampal Cx43 mRNA was not altered following SNI. Although SNI mice showed longer immobility time compared with sham mice during the forced swim test, duration of depressive-like behavior was not correlated with the expression of Cx43 in the hippocampus of SNI mice. Repeated intraperitoneal administration of amitriptyline ameliorated SNI-induced depressive-like behavior. Furthermore, the antidepressant effect of amitriptyline was correlated with decreased hippocampal Cx43 expression in SNI mice. The current findings suggest that the alteration of Cx43 expression in the hippocampus may not be involved in the induction of depressive disorder but may influence the efficacy of antidepressants. Therefore, the level of Cx43 expression in the hippocampus could be a key parameter to evaluate individual differences in antidepressant effects in patients with depressive disorder.
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24
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Prasad JD, Gunn KC, Davidson JO, Galinsky R, Graham SE, Berry MJ, Bennet L, Gunn AJ, Dean JM. Anti-Inflammatory Therapies for Treatment of Inflammation-Related Preterm Brain Injury. Int J Mol Sci 2021; 22:4008. [PMID: 33924540 PMCID: PMC8069827 DOI: 10.3390/ijms22084008] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/09/2021] [Accepted: 04/10/2021] [Indexed: 12/13/2022] Open
Abstract
Despite the prevalence of preterm brain injury, there are no established neuroprotective strategies to prevent or alleviate mild-to-moderate inflammation-related brain injury. Perinatal infection and inflammation have been shown to trigger acute neuroinflammation, including proinflammatory cytokine release and gliosis, which are associated with acute and chronic disturbances in brain cell survival and maturation. These findings suggest the hypothesis that the inhibition of peripheral immune responses following infection or nonspecific inflammation may be a therapeutic strategy to reduce the associated brain injury and neurobehavioral deficits. This review provides an overview of the neonatal immunity, neuroinflammation, and mechanisms of inflammation-related brain injury in preterm infants and explores the safety and efficacy of anti-inflammatory agents as potentially neurotherapeutics.
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Affiliation(s)
- Jaya D. Prasad
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1010, New Zealand; (J.D.P.); (K.C.G.); (J.O.D.); (L.B.); (A.J.G.)
| | - Katherine C. Gunn
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1010, New Zealand; (J.D.P.); (K.C.G.); (J.O.D.); (L.B.); (A.J.G.)
| | - Joanne O. Davidson
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1010, New Zealand; (J.D.P.); (K.C.G.); (J.O.D.); (L.B.); (A.J.G.)
| | - Robert Galinsky
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC 3168, Australia;
| | - Scott E. Graham
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1010, New Zealand;
| | - Mary J. Berry
- Department of Pediatrics and Health Care, University of Otago, Dunedin 9016, New Zealand;
| | - Laura Bennet
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1010, New Zealand; (J.D.P.); (K.C.G.); (J.O.D.); (L.B.); (A.J.G.)
| | - Alistair J. Gunn
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1010, New Zealand; (J.D.P.); (K.C.G.); (J.O.D.); (L.B.); (A.J.G.)
| | - Justin M. Dean
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1010, New Zealand; (J.D.P.); (K.C.G.); (J.O.D.); (L.B.); (A.J.G.)
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25
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Synaptic Reshaping and Neuronal Outcomes in the Temporal Lobe Epilepsy. Int J Mol Sci 2021; 22:ijms22083860. [PMID: 33917911 PMCID: PMC8068229 DOI: 10.3390/ijms22083860] [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: 02/12/2021] [Revised: 04/02/2021] [Accepted: 04/04/2021] [Indexed: 12/11/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is one of the most common types of focal epilepsy, characterized by recurrent spontaneous seizures originating in the temporal lobe(s), with mesial TLE (mTLE) as the worst form of TLE, often associated with hippocampal sclerosis. Abnormal epileptiform discharges are the result, among others, of altered cell-to-cell communication in both chemical and electrical transmissions. Current knowledge about the neurobiology of TLE in human patients emerges from pathological studies of biopsy specimens isolated from the epileptogenic zone or, in a few more recent investigations, from living subjects using positron emission tomography (PET). To overcome limitations related to the use of human tissue, animal models are of great help as they allow the selection of homogeneous samples still presenting a more various scenario of the epileptic syndrome, the presence of a comparable control group, and the availability of a greater amount of tissue for in vitro/ex vivo investigations. This review provides an overview of the structural and functional alterations of synaptic connections in the brain of TLE/mTLE patients and animal models.
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26
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Binder DK, Steinhäuser C. Astrocytes and Epilepsy. Neurochem Res 2021; 46:2687-2695. [PMID: 33661442 DOI: 10.1007/s11064-021-03236-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 12/12/2022]
Abstract
Changes in astrocyte channels, transporters, and metabolism play a critical role in seizure generation and epilepsy. In particular, alterations in astrocyte potassium, glutamate, water and adenosine homeostasis and gap junctional coupling have all been associated with hyperexcitability and epileptogenesis (largely in temporal lobe epilepsy). Distinct astrocytic changes have also been identified in other types of epilepsy, such as tuberous sclerosis, tumor-associated epilepsy and post-traumatic epilepsy. Together, the emerging literature on astrocytes and epilepsy provides powerful rationale for distinct new therapeutic targets that are astrocyte-specific.
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Affiliation(s)
- Devin K Binder
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA.
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
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27
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Hypothalamic Microglial Heterogeneity and Signature under High Fat Diet-Induced Inflammation. Int J Mol Sci 2021; 22:ijms22052256. [PMID: 33668314 PMCID: PMC7956484 DOI: 10.3390/ijms22052256] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 12/17/2022] Open
Abstract
Under high-fat feeding, the hypothalamus atypically undergoes pro-inflammatory signaling activation. Recent data from transcriptomic analysis of microglia from rodents and humans has allowed the identification of several microglial subpopulations throughout the brain. Numerous studies have clarified the roles of these cells in hypothalamic inflammation, but how each microglial subset plays its functions upon inflammatory stimuli remains unexplored. Fortunately, these data unveiling microglial heterogeneity have triggered the development of novel experimental models for studying the roles and characteristics of each microglial subtype. In this review, we explore microglial heterogeneity in the hypothalamus and their crosstalk with astrocytes under high fat diet-induced inflammation. We present novel currently available ex vivo and in vivo experimental models that can be useful when designing a new research project in this field of study. Last, we examine the transcriptomic data already published to identify how the hypothalamic microglial signature changes upon short-term and prolonged high-fat feeding.
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28
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Zhang C, Wang H, Liang W, Yang Y, Cong C, Wang Y, Wang S, Wang X, Wang D, Huo D, Feng H. Diphenyl diselenide protects motor neurons through inhibition of microglia-mediated inflammatory injury in amyotrophic lateral sclerosis. Pharmacol Res 2021; 165:105457. [PMID: 33515706 DOI: 10.1016/j.phrs.2021.105457] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 12/15/2022]
Abstract
Microglia-mediated neuroinflammatory response and neuron damage are considered as a self-propelling progressive cycle, being strongly implicated in the progression of neurodegeneration in amyotrophic lateral sclerosis (ALS). Diphenyl diselenide (DPDS), a simple organoselenium compound, has been known to possess multiple pharmacological properties. The purpose of this study was to explore the neuroprotective effects of DPDS against microglia-mediated neuroinflammatory injury in ALS models. We found that DPDS pretreatment inhibited LPS-induced activation of IκB/NF-κB pathway and subsequent release of proinflammatory factors from activated primary hSOD1G93A microglia. Moreover, DPDS suppressed NLRP3 inflammasome activation by decreasing protein nitration via reduction in NO and ROS levels, whose low levels are related to NF-κB inhibition responsible for iNOS and NOX2 down-regulations, respectively. Notably, DPDS-mediated ROS attenuation was not linked to Nrf2 activation in this cellular model. Furthermore, in the absence of activated microglia, DPDS has no significant effect on the individual hSOD1G93A-NSC34 cells; however, in in vitro neuron-microglia conditional culture and co-culture experiments, DPDS protected motor neurons from neurotoxic damage caused by LPS or BzATP-stimulated microglia activation. Above observations suggest that DPDS-afforded neuroprotection is linked to inhibition of microglia-mediated neuroinflammation in ALS, which was further verified in vivo as shown by improvements of motor deficits, prolonged survival, and reduction of motor neuron loss and reactive microgliosis in hSOD1G93A transgenic mouse. Altogether, our results show that DPDS elicited neuroprotection in ALS models through inactivation of microglia by inhibiting IκB/NF-κB pathway and NLRP3 inflammasome activation, suggesting that DPDS may be a promising candidate for potential therapy for ALS.
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Affiliation(s)
- Chunting Zhang
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei City, Anhui Province, PR China; Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China
| | - Hongyong Wang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China
| | - Weiwei Liang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China; Department of Neurology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China
| | - Yueqing Yang
- Department of Neurology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China
| | - Chaohua Cong
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China
| | - Ying Wang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China
| | - Shuyu Wang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China
| | - Xudong Wang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China
| | - Di Wang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China
| | - Di Huo
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China
| | - Honglin Feng
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China.
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29
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Liang Z, Wang X, Hao Y, Qiu L, Lou Y, Zhang Y, Ma D, Feng J. The Multifaceted Role of Astrocyte Connexin 43 in Ischemic Stroke Through Forming Hemichannels and Gap Junctions. Front Neurol 2020; 11:703. [PMID: 32849190 PMCID: PMC7411525 DOI: 10.3389/fneur.2020.00703] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/09/2020] [Indexed: 12/13/2022] Open
Abstract
Ischemic stroke is a multi-factorial cerebrovascular disease with high worldwide morbidity and mortality. In the past few years, multiple studies have revealed the underlying mechanism of ischemia/reperfusion injury, including calcium overload, amino acid toxicity, oxidative stress, and inflammation. Connexin 43 (Cx43), the predominant connexin protein in astrocytes, has been recently proven to display non-substitutable roles in the pathology of ischemic stroke development and progression through forming gap junctions and hemichannels. Under normal conditions, astrocytic Cx43 could be found in hemichannels or in the coupling with other hemichannels on astrocytes, neurons, or oligodendrocytes to form the neuro-glial syncytium, which is involved in metabolites exchange between communicated cells, thus maintaining the homeostasis of the CNS environment. In ischemic stroke, the phosphorylation of Cx43 might cause the degradation of gap junctions and the opening of hemichannels, contributing to the release of inflammatory mediators. However, the remaining gap junctions could facilitate the exchange of protective and harmful metabolites between healthy and injured cells, protecting the injured cells to some extent or damaging the healthy cells depending on the balance of the exchange of protective and harmful metabolites. In this study, we review the changes in astrocytic Cx43 expression and distribution as well as the influence of these changes on the function of astrocytes and other cells in the CNS, providing new insight into the pathology of ischemic stroke injury; we also discuss the potential of astrocytic Cx43 as a target for the treatment of ischemic stroke.
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Affiliation(s)
- Zhen Liang
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Xu Wang
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Yulei Hao
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Lin Qiu
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Yingyue Lou
- Department of Plastic and Reconstructive Surgery, The First Hospital of Jilin University, Changchun, China
| | - Yaoting Zhang
- Department of Cardiology, The First Hospital of Jilin University, Changchun, China
| | - Di Ma
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Jiachun Feng
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
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30
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Tabernero A, Koulakoff A, Roux L, Venance L, Leybaert L, Sáez JC, Naus CC. Christian Giaume (November 1951–July 2019). Glia 2020. [DOI: 10.1002/glia.23836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Arantxa Tabernero
- Department of Biochemistry and Molecular Biology. Institute of Neurosciences Castilla y León (INCYL), University of Salamanc Salamanca Spain
| | - Annette Koulakoff
- Center for Interdisciplinary Research in Biology, Collége de France, CNRSUMR7241/INSERM U1050, MemoLife Labex, 75005 Paris France
| | - Lisa Roux
- Interdisciplinary Institute for Neuroscience, UMR5297, Centre National de la Recherche Scientifique, University of Bordeaux Bordeaux France
| | - Laurent Venance
- Center for Interdisciplinary Research in Biology, Collége de France, CNRSUMR7241/INSERM U1050, MemoLife Labex, 75005 Paris France
| | - Luc Leybaert
- Department of Basic and Applied Medical Sciences, Physiology GroupUniversity of Ghent Ghent Belgium
| | - Juan C. Sáez
- Departamento de Ciencias FisiológicasPontificia Universidad Católica de Chile, Instituto de Neurociencias, Universidad de Valparaíso Chile
| | - Christian C. Naus
- Department of Cellular and Physiological SciencesLife Sciences Institute, The University of British Columbia Vancouver British Columbia Canada
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31
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Sáez JC, Vargas AA, Hernández DE, Ortiz FC, Giaume C, Orellana JA. Permeation of Molecules through Astroglial Connexin 43 Hemichannels Is Modulated by Cytokines with Parameters Depending on the Permeant Species. Int J Mol Sci 2020; 21:ijms21113970. [PMID: 32492823 PMCID: PMC7312936 DOI: 10.3390/ijms21113970] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/25/2020] [Accepted: 05/29/2020] [Indexed: 12/11/2022] Open
Abstract
Recent studies indicate that connexin hemichannels do not act as freely permeable non-selective pores, but they select permeants in an isoform-specific manner with cooperative, competitive and saturable kinetics. The aim of this study was to investigate whether the treatment with a mixture of IL-1β plus TNF-α, a well-known pro-inflammatory condition that activates astroglial connexin 43 (Cx43) hemichannels, could alter their permeability to molecules. We found that IL-1β plus TNF-α left-shifted the dye uptake rate vs. dye concentration relationship for Etd and 2-NBDG, but the opposite took place for DAPI or YO-PRO-1, whereas no alterations were observed for Prd. The latter modifications were accompanied of changes in Kd (Etd, DAPI, YO-PRO-1 or 2-NBDG) and Hill coefficients (Etd and YO-PRO-1), but not in alterations of Vmax. We speculate that IL-1β plus TNF-α may distinctively affect the binding sites to permeants in astroglial Cx43 hemichannels rather than their number in the cell surface. Alternatively, IL-1β plus TNF-α could induce the production of endogenous permeants that may favor or compete for in the pore-lining residues of Cx43 hemichannels. Future studies shall elucidate whether the differential ionic/molecule permeation of Cx43 hemichannels in astrocytes could impact their communication with neurons in the normal and inflamed nervous system.
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Affiliation(s)
- Juan C. Sáez
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; (J.C.S.); (D.E.H.)
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso 2381850, Chile
| | - Aníbal A. Vargas
- Instituto de Ciencias de la Salud, Universidad de O′Higgins, Rancagua 2820000, Chile;
| | - Diego E. Hernández
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; (J.C.S.); (D.E.H.)
| | - Fernando C. Ortiz
- Mechanisms on Myelin Formation and Repair Laboratory, Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago 8910060, Chile;
| | - Christian Giaume
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, PSL Research University, 75005 Paris, France;
| | - Juan A. Orellana
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
- Correspondence: ; Tel.: +56-2-968399128
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32
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Muñoz P, Ardiles ÁO, Pérez-Espinosa B, Núñez-Espinosa C, Paula-Lima A, González-Billault C, Espinosa-Parrilla Y. Redox modifications in synaptic components as biomarkers of cognitive status, in brain aging and disease. Mech Ageing Dev 2020; 189:111250. [PMID: 32433996 DOI: 10.1016/j.mad.2020.111250] [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: 12/09/2019] [Revised: 03/05/2020] [Accepted: 04/10/2020] [Indexed: 02/06/2023]
Abstract
Aging is a natural process that includes several changes that gradually make organisms degenerate and die. Harman's theory proposes that aging is a consequence of the progressive accumulation of oxidative modifications mediated by reactive oxygen/nitrogen species, which plays an essential role in the development and progression of many neurodegenerative diseases. This review will focus on how abnormal redox modifications induced by age impair the functionality of neuronal redox-sensitive proteins involved in axonal elongation and guidance, synaptic plasticity, and intercellular communication. We will discuss post-transcriptional regulation of gene expression by microRNAs as a mechanism that controls the neuronal redox state. Finally, we will discuss how some brain-permeant antioxidants from the diet have a beneficial effect on cognition. Taken together, the evidence revised here indicates that oxidative-driven modifications of specific proteins and changes in microRNA expression may be useful biomarkers for aging and neurodegenerative diseases. Also, some specific antioxidant therapies have undoubtedly beneficial neuroprotective effects when administered in the correct doses, in the ideal formulation combination, and during the appropriate therapeutic window. The use of some antioxidants is, therefore, still poorly explored for the treatment of neurodegenerative diseases such as Alzheimer's disease.
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Affiliation(s)
- Pablo Muñoz
- Department of Pathology and Physiology, Medical School, Faculty of Medicine, Universidad de Valparaíso, Valparaíso, Chile; Translational Neurology Center, Faculty of Medicine, Universidad de Valparaíso, Valparaíso, Chile; Biomedical Research Center, Universidad de Valparaíso, Valparaíso, Chile; Thematic Task Force on Healthy Aging, CUECH Research Network.
| | - Álvaro O Ardiles
- Department of Pathology and Physiology, Medical School, Faculty of Medicine, Universidad de Valparaíso, Valparaíso, Chile; Translational Neurology Center, Faculty of Medicine, Universidad de Valparaíso, Valparaíso, Chile; Thematic Task Force on Healthy Aging, CUECH Research Network; Interdisciplinary Center of Neuroscience of Valparaíso, Universidad de Valparaíso, Valparaíso, Chile; Interdisciplinary Center for Health Studies, Universidad de Valparaíso, Valparaíso, Chile
| | - Boris Pérez-Espinosa
- Thematic Task Force on Healthy Aging, CUECH Research Network; Laboratorio biología de la Reproduccion, Departamento Biomédico, Facultad Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
| | - Cristian Núñez-Espinosa
- Thematic Task Force on Healthy Aging, CUECH Research Network; School of Medicine, Universidad de Magallanes, Punta Arenas, Chile
| | - Andrea Paula-Lima
- Thematic Task Force on Healthy Aging, CUECH Research Network; Institute for Research in Dental Sciences, Faculty of Dentistry; Universidad de Chile, Santiago, Chile; Biomedical Neuroscience Institute (BNI) and Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Christian González-Billault
- Thematic Task Force on Healthy Aging, CUECH Research Network; Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile; FONDAP Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Buck Institute for Research on Aging, Novato, CA, USA.
| | - Yolanda Espinosa-Parrilla
- Thematic Task Force on Healthy Aging, CUECH Research Network; School of Medicine, Universidad de Magallanes, Punta Arenas, Chile; Laboratory of Molecular Medicine - LMM, Center for Education, Healthcare and Investigation - CADI, University of Magallanes, Punta Arenas, Chile.
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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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34
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Immune cell regulation of glia during CNS injury and disease. Nat Rev Neurosci 2020; 21:139-152. [DOI: 10.1038/s41583-020-0263-9] [Citation(s) in RCA: 146] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2020] [Indexed: 12/13/2022]
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35
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Nikolic L, Nobili P, Shen W, Audinat E. Role of astrocyte purinergic signaling in epilepsy. Glia 2019; 68:1677-1691. [DOI: 10.1002/glia.23747] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 10/08/2019] [Accepted: 10/25/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Ljiljana Nikolic
- Institute for Biological Research Siniša Stanković, University of Belgrade Serbia
| | | | - Weida Shen
- Zhejiang University City College Zhejiang Hangzhou China
| | - Etienne Audinat
- Institute for Functional Genomics (IGF), University of Montpellier, CNRS, INSERM Montpellier France
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36
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Trosko JE. What Can Chemical Carcinogenesis Shed Light on the LNT Hypothesis in Radiation Carcinogenesis? Dose Response 2019; 17:1559325819876799. [PMID: 31565039 PMCID: PMC6755642 DOI: 10.1177/1559325819876799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 08/27/2019] [Indexed: 12/14/2022] Open
Abstract
To protect the public’s health from exposure to physical, chemical, and microbiological
agents, it is important that any policy be based on rigorous scientifically based
research. The concept of “linear no-threshold” (LNT) has been implemented to provide
guideline exposures to these agents. The practical limitation to testing this hypothesis
is to provide sufficient samples for experimental or epidemiological studies. While there
is no universally accepted understanding of most human diseases, there seems to be better
understanding of cancer that might help resolve the “LNT” model. The public’s concern,
after being exposed to radiation, is the potential of producing cancer. The most rigorous
hypothesis of human carcinogenesis is the “multistage, multimechanism” chemical
carcinogenesis model. The radiation carcinogenesis LNT model, rarely, if ever, built it
into their support. It will be argued that this multistage, multimechanism model of
carcinogenesis, involving the “initiation” of a single cell by a mutagen event, followed
by chronic exposure to threshold levels of epigenetic agents or conditions that stimulate
the clonal expansion of the “initiated” cell, can convert these benign cells to become
invasive and metastatic. This “promotion” process can be interrupted, thereby preventing
these initiated cells from transitioning to the “progression” process of invasion and
metastasis.
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Affiliation(s)
- James E Trosko
- Department Pediatrics and Human Development, College of Human Medicine, Michigan State University, East Lansing, MI, USA
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OTX2 Signals from the Choroid Plexus to Regulate Adult Neurogenesis. eNeuro 2019; 6:ENEURO.0262-18.2019. [PMID: 31064838 PMCID: PMC6506823 DOI: 10.1523/eneuro.0262-18.2019] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 02/12/2019] [Accepted: 02/16/2019] [Indexed: 01/09/2023] Open
Abstract
Proliferation and migration during adult neurogenesis are regulated by a microenvironment of signaling molecules originating from local vasculature, from CSF produced by the choroid plexus, and from local supporting cells including astrocytes. Here, we focus on the function of OTX2 homeoprotein transcription factor in the mouse adult ventricular-subventricular zone (V-SVZ), which generates olfactory bulb neurons. We find that OTX2 secreted by choroid plexus is transferred to the supporting cells of the V-SVZ and rostral migratory stream. Deletion of Otx2 in choroid plexus affects neuroblast migration and reduces the number of olfactory bulb newborn neurons. Adult neurogenesis was also decreased by expressing secreted single-chain antibodies to sequester OTX2 in the CSF, demonstrating the importance of non-cell-autonomous OTX2. We show that OTX2 activity modifies extracellular matrix components and signaling molecules produced by supporting astrocytes. Thus, we reveal a multilevel and non-cell-autonomous role of a homeoprotein and reinforce the choroid plexus and astrocytes as key niche compartments affecting adult neurogenesis.
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Abbink MR, van Deijk ALF, Heine VM, Verheijen MH, Korosi A. The involvement of astrocytes in early-life adversity induced programming of the brain. Glia 2019; 67:1637-1653. [PMID: 31038797 PMCID: PMC6767561 DOI: 10.1002/glia.23625] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 03/29/2019] [Accepted: 03/29/2019] [Indexed: 12/13/2022]
Abstract
Early‐life adversity (ELA) in the form of stress, inflammation, or malnutrition, can increase the risk of developing psychopathology or cognitive problems in adulthood. The neurobiological substrates underlying this process remain unclear. While neuronal dysfunction and microglial contribution have been studied in this context, only recently the role of astrocytes in early‐life programming of the brain has been appreciated. Astrocytes serve many basic roles for brain functioning (e.g., synaptogenesis, glutamate recycling), and are unique in their capacity of sensing and integrating environmental signals, as they are the first cells to encounter signals from the blood, including hormonal changes (e.g., glucocorticoids), immune signals, and nutritional information. Integration of these signals is especially important during early development, and therefore we propose that astrocytes contribute to ELA induced changes in the brain by sensing and integrating environmental signals and by modulating neuronal development and function. Studies in rodents have already shown that ELA can impact astrocytes on the short and long term, however, a critical review of these results is currently lacking. Here, we will discuss the developmental trajectory of astrocytes, their ability to integrate stress, immune, and nutritional signals from the early environment, and we will review how different types of early adversity impact astrocytes.
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Affiliation(s)
- Maralinde R Abbink
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Anne-Lieke F van Deijk
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit, Amsterdam, The Netherlands
| | - Vivi M Heine
- Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit, Amsterdam, The Netherlands
| | - Mark H Verheijen
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit, Amsterdam, The Netherlands
| | - Aniko Korosi
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
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Astroglia in Sepsis Associated Encephalopathy. Neurochem Res 2019; 45:83-99. [PMID: 30778837 PMCID: PMC7089215 DOI: 10.1007/s11064-019-02743-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/25/2019] [Accepted: 01/28/2019] [Indexed: 01/07/2023]
Abstract
Cellular pathophysiology of sepsis associated encephalopathy (SAE) remains poorly characterised. Brain pathology in SAE, which is manifested by impaired perception, consciousness and cognition, results from multifactorial events, including high levels of systemic cytokines, microbial components and endotoxins, which all damage the brain barriers, instigate neuroinflammation and cause homeostatic failure. Astrocytes, being the principal homeostatic cells of the central nervous system contribute to the brain defence against infection. Forming multifunctional anatomical barriers, astroglial cells maintain brain-systemic interfaces and restrict the damage to the nervous tissue. Astrocytes detect, produce and integrate inflammatory signals between immune cells and cells of brain parenchyma, thus regulating brain immune response. In SAE astrocytes are present in both reactive and astrogliopathic states; balance between these states define evolution of pathology and neurological outcomes. In humans pathophysiology of SAE is complicated by frequent presence of comorbidities, as well as age-related remodelling of the brain tissue with senescence of astroglia; these confounding factors further impact upon SAE progression and neurological deficits.
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Targeting of chondrocyte plasticity via connexin43 modulation attenuates cellular senescence and fosters a pro-regenerative environment in osteoarthritis. Cell Death Dis 2018; 9:1166. [PMID: 30518918 PMCID: PMC6281585 DOI: 10.1038/s41419-018-1225-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 10/26/2018] [Accepted: 11/12/2018] [Indexed: 12/12/2022]
Abstract
Osteoarthritis (OA), a chronic disease characterized by articular cartilage degeneration, is a leading cause of disability and pain worldwide. In OA, chondrocytes in cartilage undergo phenotypic changes and senescence, restricting cartilage regeneration and favouring disease progression. Similar to other wound-healing disorders, chondrocytes from OA patients show a chronic increase in the gap junction channel protein connexin43 (Cx43), which regulates signal transduction through the exchange of elements or recruitment/release of signalling factors. Although immature or stem-like cells are present in cartilage from OA patients, their origin and role in disease progression are unknown. In this study, we found that Cx43 acts as a positive regulator of chondrocyte-mesenchymal transition. Overactive Cx43 largely maintains the immature phenotype by increasing nuclear translocation of Twist-1 and tissue remodelling and proinflammatory agents, such as MMPs and IL-1β, which in turn cause cellular senescence through upregulation of p53, p16INK4a and NF-κB, contributing to the senescence-associated secretory phenotype (SASP). Downregulation of either Cx43 by CRISPR/Cas9 or Cx43-mediated gap junctional intercellular communication (GJIC) by carbenoxolone treatment triggered rediferentiation of osteoarthritic chondrocytes into a more differentiated state, associated with decreased synthesis of MMPs and proinflammatory factors, and reduced senescence. We have identified causal Cx43-sensitive circuit in chondrocytes that regulates dedifferentiation, redifferentiation and senescence. We propose that chondrocytes undergo chondrocyte-mesenchymal transition where increased Cx43-mediated GJIC during OA facilitates Twist-1 nuclear translocation as a novel mechanism involved in OA progression. These findings support the use of Cx43 as an appropriate therapeutic target to halt OA progression and to promote cartilage regeneration.
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Li Q, Li QQ, Jia JN, Liu ZQ, Zhou HH, Mao XY. Targeting gap junction in epilepsy: Perspectives and challenges. Biomed Pharmacother 2018; 109:57-65. [PMID: 30396092 DOI: 10.1016/j.biopha.2018.10.068] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/08/2018] [Accepted: 10/12/2018] [Indexed: 12/21/2022] Open
Abstract
Gap junctions (GJs) are multiple cellular intercellular connections that allow ions to pass directly into the cytoplasm of neighboring cells. Electrical coupling mediated by GJs plays a role in the generation of highly synchronous electrical activity. Accumulative investigations show that GJs in the brain are involved in the generation, synchronization and maintenance of seizure events. At the same time, GJ blockers exert potent curative potential on epilepsy in vivo or in vitro. This review aims to shed light on the role of GJs in epileptogenesis. Targeting GJs is likely to be served as a novel therapeutic approach on epileptic patients.
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Affiliation(s)
- Qin Li
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Qiu-Qi Li
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Ji-Ning Jia
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Zhao-Qian Liu
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Hong-Hao Zhou
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Xiao-Yuan Mao
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China.
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Chen Y, Wang L, Zhang L, Chen B, Yang L, Li X, Li Y, Yu H. Inhibition of Connexin 43 Hemichannels Alleviates Cerebral Ischemia/Reperfusion Injury via the TLR4 Signaling Pathway. Front Cell Neurosci 2018; 12:372. [PMID: 30386214 PMCID: PMC6199357 DOI: 10.3389/fncel.2018.00372] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 09/28/2018] [Indexed: 01/01/2023] Open
Abstract
Connexin 43 (Cx43) widely exists in all components of the neurovascular unit (NVU) and is a constituent of gap junctions and hemichannels. In physiological states, gap junctions are open for regular intercellular communication, and the hemichannels present low open probability in astrocytes. After cerebral ischemia, a large number of hemichannels are unusually opened, leading to cell swelling and even death. Most known hemichannel blockers also inhibit gap junctions and sequentially obstruct normal electrical cell-cell communication. In this study, we tested the hypothesis that Gap19, a selective Cx43-hemichannel inhibitor, exhibited neuroprotective effects on cerebral ischemia/reperfusion (I/R). An obvious improvement in neurological scores and infarct volume reduction were observed in Gap19-treated mice after brain ischemia induced by middle cerebral artery occlusion (MCAO). Gap19 treatment attenuated white matter damage. Moreover, Gap19 treatment suppressed the expression of Cx43 and Toll-like receptor 4 (TLR4) pathway-relevant proteins and prevented the overexpression of tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). To further explore downstream signaling, we established an in vitro model-oxygen glucose deprivation (OGD) to simulate ischemic conditions. Immunofluorescence staining showed that Cx43 co-existed with TLR4 in astrocytes. The hemichannel activity was increased after OGD and Gap19 could inhibit this effect on astrocytes. Gap19 substantially improved relative cell vitality and decreased the expression of Cx43, TLR4 and inflammatory cytokines in vitro. In addition, in the lipopolysaccharide (LPS) stimulation OGD model, Gap19 also exhibited a protective effect via inhibiting TLR4 pathway activation. In summary, our results showed that Gap19 exerted a neuroprotective effect after stroke via inhibition of the TLR4-mediated signaling pathway.
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Affiliation(s)
- Yingzhu Chen
- Clinical Medical College of Yangzhou University, Yangzhou, China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China
| | - Liangzhu Wang
- Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China.,Dalian Medical University, Dalian, China
| | - Lingling Zhang
- Clinical Medical College of Yangzhou University, Yangzhou, China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China
| | - Beilei Chen
- Clinical Medical College of Yangzhou University, Yangzhou, China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China
| | - Liu Yang
- Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China.,Dalian Medical University, Dalian, China
| | - Xiaobo Li
- Clinical Medical College of Yangzhou University, Yangzhou, China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China.,Institute of Neuroscience, Northern Jiangsu People's Hospital, Yangzhou, China
| | - Yuping Li
- Clinical Medical College of Yangzhou University, Yangzhou, China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China
| | - Hailong Yu
- Clinical Medical College of Yangzhou University, Yangzhou, China.,Department of Neurology, Northern Jiangsu People's Hospital, Yangzhou, China.,Institute of Neuroscience, Northern Jiangsu People's Hospital, Yangzhou, China.,Drum Tower Hospital, Medical School of Nanjing University, Nanjing, 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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45
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Yin X, Feng L, Ma D, Yin P, Wang X, Hou S, Hao Y, Zhang J, Xin M, Feng J. Roles of astrocytic connexin-43, hemichannels, and gap junctions in oxygen-glucose deprivation/reperfusion injury induced neuroinflammation and the possible regulatory mechanisms of salvianolic acid B and carbenoxolone. J Neuroinflammation 2018; 15:97. [PMID: 29587860 PMCID: PMC5872583 DOI: 10.1186/s12974-018-1127-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/12/2018] [Indexed: 02/07/2023] Open
Abstract
Background Glia-mediated neuroinflammation is related to brain injury exacerbation after cerebral ischemia/reperfusion (I/R) injury. Astrocytic hemichannels or gap junctions, which were mainly formed by connexin-43, have been implicated in I/R damage. However, the exact roles of astrocytic hemichannels and gap junction in neuroinflammatory responses induced by I/R injury remain unknown. Methods Primary cultured astrocytes were subjected to OGD/R injury, an in vitro model of I/R injury. Salvianolic acid B (SalB) or carbenoxolone (CBX) were applied for those astrocytes. Besides, Cx43 mimetic peptides Gap19 or Gap26 were also applied during OGD/R injury; Cx43 protein levels were determined by western blot and cytoimmunofluorescene staining, hemichannel activities by Ethidium bromide uptake and ATP concentration detection, and gap junction intercellular communication (GJIC) permeability by parachute assay. Further, astrocyte-conditioned medium (ACM) was collected and incubated with microglia. Meanwhile, ATP or apyrase were applied to explore the role of ATP during OGD/R injury. Microglial activation, M1/M2 phenotypes, and M1/M2-related cytokines were detected. Also, microglia-conditioned medium (MEM) was collected and incubated with astrocytes to further investigate its influence on astrocytic hemichannel activity and GJIC permeability. Lastly, effects of ACM and MCM on neuronal viability were detected by flow cytometry. Results We found that OGD/R induced abnormally opened hemichannels with increased ATP release and EtBr uptake but reduced GJIC permeability. WB tests showed decreased astrocytic plasma membrane’s Cx43, while showing an increase in cytoplasma. Treating OGD/R-injured microglia with ATP or OGD/R-ACM induced further microglial activation and secondary pro-inflammatory cytokine release, with the M1 phenotype predominating. Conversely, astrocytes incubated with OGD/R-MCM exhibited increased hemichannel opening but reduced GJIC coupling. Both SalB and CBX inhibited abnormal astrocytic hemichannel opening and ATP release and switched the activated microglial phenotype from M1 to M2, thus providing effective neuroprotection. Application of Gap19 or Gap26 showed similar results with CBX. We also found that OGD/R injury caused both plasma membrane p-Cx43(Ser265) and p-Src(Tyr416) significantly upregulated; application of SalB may be inhibiting Src kinase and attenuating Cx43 internalization. Meanwhile, CBX treatment induced obviously downregulation of p-Cx43(Ser368) and p-PKC(Ser729) protein levels in plasma membrane. Conclusions We propose a vicious cycle exists between astrocytic hemichannel and microglial activation after OGD/R injury, which would aggravate neuroinflammatory responses and neuronal damage. Astrocytic Cx43, hemichannels, and GJIC play critical roles in OGD/R injury-induced neuroinflammatory responses; treatment differentially targeting astrocytic Cx43, hemichannels, and GJIC may provide novel avenues for therapeutics during cerebral I/R injury. Electronic supplementary material The online version of this article (10.1186/s12974-018-1127-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiang Yin
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Liangshu Feng
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Di Ma
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Ping Yin
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Xinyu Wang
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Shuai Hou
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Yulei Hao
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Jingdian Zhang
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Meiying Xin
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China
| | - Jiachun Feng
- Department of Neurology and Neuroscience Center, the First Hospital of Jilin University, Changchun, Jilin Province, 130021, People's Republic of China.
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Labra VC, Santibáñez CA, Gajardo-Gómez R, Díaz EF, Gómez GI, Orellana JA. The Neuroglial Dialog Between Cannabinoids and Hemichannels. Front Mol Neurosci 2018; 11:79. [PMID: 29662436 PMCID: PMC5890195 DOI: 10.3389/fnmol.2018.00079] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 02/28/2018] [Indexed: 12/11/2022] Open
Abstract
The formation of gap junctions was initially thought to be the central role of connexins, however, recent evidence had brought to light the high relevance of unopposed hemichannels as an independent mechanism for the selective release of biomolecules during physiological and pathological conditions. In the healthy brain, the physiological opening of astrocyte hemichannels modulates basal excitatory synaptic transmission. At the other end, the release of potentially neurotoxic compounds through astroglial hemichannels and pannexons has been insinuated as one of the functional alterations that negatively affect the progression of multiple brain diseases. Recent insights in this matter have suggested encannabinoids (eCBs) as molecules that could regulate the opening of these channels during diverse conditions. In this review, we discuss and hypothesize the possible interplay between the eCB system and the hemichannel/pannexon-mediated signaling in the inflamed brain and during event of synaptic plasticity. Most findings indicate that eCBs seem to counteract the activation of major neuroinflammatory pathways that lead to glia-mediated production of TNF-α and IL-1β, both well-known triggers of astroglial hemichannel opening. In contrast to the latter, in the normal brain, eCBs apparently elicit the Ca2+-activation of astrocyte hemichannels, which could have significant consequences on eCB-dependent synaptic plasticity.
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Affiliation(s)
- Valeria C Labra
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Cristian A Santibáñez
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Rosario Gajardo-Gómez
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Esteban F Díaz
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Gonzalo I Gómez
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| | - Juan A Orellana
- Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
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Role of Connexin and Pannexin containing channels in HIV infection and NeuroAIDS. Neurosci Lett 2017; 695:86-90. [PMID: 28886986 DOI: 10.1016/j.neulet.2017.09.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 07/27/2017] [Accepted: 09/01/2017] [Indexed: 01/31/2023]
Abstract
Neuron-Glia crosstalk is essential for efficient synaptic communication, cell growth and differentiation, neuronal activity, neurotransmitter recycling, and brain immune response. The master regulators of this neuron-glia communication are connexin containing Gap Junctions (GJs) and Hemichannels (HCs) as well as pannexin HCs. However, the role of these channels under pathological conditions, especially in infectious diseases is still in exploratory stages. Human Immunodeficiency Virus-1 (HIV) is one such infectious agent that takes advantage of the host intercellular communication systems, GJs and HCs, to exacerbate viral pathogenesis in the brain in spite of the antiretroviral therapy effectively controlling viral replication in the periphery. Although most infectious agents lead to total "shutdown" of gap junctional communication in parenchymal cells, HIV infection maintains and "hijacks" GJs and HCs to enable few infected cells to spread toxic intracellular agents to neighboring uninfected cells aggravating viral neuropathology even in the absence of viral replication. In this mini-review, we present a comprehensive overview of the role of GJs and HCs in augmenting HIV neuropathogenesis.
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Contribution of Astroglial Cx43 Hemichannels to the Modulation of Glutamatergic Currents by D-Serine in the Mouse Prefrontal Cortex. J Neurosci 2017; 37:9064-9075. [PMID: 28821660 DOI: 10.1523/jneurosci.2204-16.2017] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 05/16/2017] [Accepted: 06/10/2017] [Indexed: 11/21/2022] Open
Abstract
Astrocytes interact dynamically with neurons by modifying synaptic activity and plasticity. This interplay occurs through a process named gliotransmission, meaning that neuroactive molecules are released by astrocytes. Acting as a gliotransmitter, D-serine, a co-agonist of the NMDA receptor at the glycine-binding site, can be released by astrocytes in a calcium [Ca2+]i-dependent manner. A typical feature of astrocytes is their high expression level of connexin43 (Cx43), a protein forming gap junction channels and hemichannels associated with dynamic neuroglial interactions. Pharmacological and genetic inhibition of Cx43 hemichannel activity reduced the amplitude of NMDA EPSCs in mouse layer 5 prefrontal cortex pyramidal neurons without affecting AMPA EPSC currents. This reduction of NMDA EPSCs was rescued by addition of D-serine in the extracellular medium. LTP of NMDA and AMPA EPSCs after high-frequency stimulation was reduced by prior inhibition of Cx43 hemichannel activity. Inactivation of D-serine synthesis within the astroglial network resulted in the reduction of NMDA EPSCs, which was rescued by adding extracellular D-serine. We showed that the activity of Cx43 hemichannels recorded in cultured astrocytes was [Ca2+]I dependent. Accordingly, in acute cortical slices, clamping [Ca2+]i at a low level in astroglial network resulted in an inhibition of NMDA EPSC potentiation that was rescued by adding extracellular D-serine. This work demonstrates that astroglial Cx43 hemichannel activity is associated with D-serine release. This process, occurring by direct permeation of D-serine through hemichannels or indirectly by Ca2+ entry and activation of other [Ca2+]i-dependent mechanisms results in the modulation of synaptic activity and plasticity.SIGNIFICANCE STATEMENT We recorded neuronal glutamatergic (NMDA and AMPA) responses in prefrontal cortex (PFC) neurons and used pharmacological and genetic interventions to block connexin-mediated hemichannel activity specifically in a glial cell population. For the first time in astrocytes, we demonstrated that hemichannel activity depends on the intracellular calcium concentration and is associated with D-serine release. Blocking hemichannel activity reduced the LTP of these excitatory synaptic currents triggered by high-frequency stimulation. These observations may be particularly relevant in the PFC, where D-serine and its converting enzyme are highly expressed.
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Deshpande T, Li T, Herde MK, Becker A, Vatter H, Schwarz MK, Henneberger C, Steinhäuser C, Bedner P. Subcellular reorganization and altered phosphorylation of the astrocytic gap junction protein connexin43 in human and experimental temporal lobe epilepsy. Glia 2017; 65:1809-1820. [DOI: 10.1002/glia.23196] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/04/2017] [Accepted: 07/05/2017] [Indexed: 01/12/2023]
Affiliation(s)
- Tushar Deshpande
- Institute of Cellular Neurosciences, Medical Faculty; University of Bonn Germany
| | - Tingsong Li
- Institute of Cellular Neurosciences, Medical Faculty; University of Bonn Germany
- Department of Neurology; Children's Hospital, Chongqing Medical University; Chongqing China
| | - Michel K. Herde
- Institute of Cellular Neurosciences, Medical Faculty; University of Bonn Germany
| | - Albert Becker
- Department of Neuropathology; Medical Faculty, University of Bonn; Bonn Germany
| | - Hartmut Vatter
- Department of Neurosurgery; Medical Faculty, University of Bonn; Bonn Germany
| | - Martin K. Schwarz
- Department of Epileptology, Medical Faculty; University of Bonn; Bonn Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, Medical Faculty; University of Bonn Germany
- Institute of Neurology, University College London; London UK
- German Center for Degenerative Diseases (DZNE); Bonn Germany
| | | | - Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty; University of Bonn Germany
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Li X, Jiang S, Yang H, Liao Q, Cao S, Yan X, Huang D. Breakthrough Cancer Pain Is Associated with Spinal Gap Junction Activation via Regulation of Connexin 43 in a Mouse Model. Front Cell Neurosci 2017; 11:207. [PMID: 28769766 PMCID: PMC5511832 DOI: 10.3389/fncel.2017.00207] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/30/2017] [Indexed: 12/21/2022] Open
Abstract
Breakthrough cancer pain (BTcP) is a high-intensity, short-duration, unpredictable and uncontrollable pain. Recent studies have shown that activation of gap junction (GJ) in spinal cord plays an important role in the pathogenesis of BTcP. We examined the expressions of Glial fibrillary acidic protein (GFAP), connexin (Cx) 43 protein and phosphorylation of Cx43 (p-Cx43) in the spinal cord of mice. In addition, we investigated the effects of Gap26, a selective GJ blocker, on the expressions of GFAP, Cx43 and p-Cx43 in BTcP mice. We found that the expressions of GFAP and Cx43 proteins were significantly upregulated while p-Cx43 was down-regulated in the spinal cord in a mouse model of BTcP. The overexpression of Cx43 protein in the spinal cord increased GJ formation and enhanced BTcP. The variation of the ratio of p-Cx43/T-Cx43 (total Cx43) affected the function of GJ to induce BTcP. Furthermore, BTcP was alleviated by Gap26 via reducing pain hypersensitivity. The inhibition of Cx43 and p-Cx43 by Gap26 attenuated BTcP but the p/T ratio of Cx43 remained unchanged in BTcP mice. We reveal that the expression and phosphorylation of Cx43 affected BTcP and GJ activation facilitated BTcP via a Cx43-mediated signaling in the spinal cord. The finding may provide a scientific rationale for discovery and development of novel therapeutic targets for the treatment of BTcP clinically.
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Affiliation(s)
- Xin Li
- Department of Pain, The Third Xiangya Hospital and Institute of Pain Medicine, Central South UniversityChangsha, China
| | - Siqing Jiang
- Department of Pain, The Third Xiangya Hospital and Institute of Pain Medicine, Central South UniversityChangsha, China
| | - Hui Yang
- Department of Pain, The Third Xiangya Hospital and Institute of Pain Medicine, Central South UniversityChangsha, China
| | - Qian Liao
- Department of Pain, The Third Xiangya Hospital and Institute of Pain Medicine, Central South UniversityChangsha, China
| | - Shousong Cao
- Department of Pharmacology, School of Pharmacy, Southwest Medical UniversityLuzhou, China
| | - Xuebin Yan
- Department of Pain, The Third Xiangya Hospital and Institute of Pain Medicine, Central South UniversityChangsha, China
| | - Dong Huang
- Department of Pain, The Third Xiangya Hospital and Institute of Pain Medicine, Central South UniversityChangsha, China
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