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Chen L, Yang W, Yang F, Xu T, Yu Y, Wu Q, Han Y. Astrocyte mitochondria: Potential therapeutic targets for epilepsy. Heliyon 2024; 10:e29950. [PMID: 38756598 PMCID: PMC11096718 DOI: 10.1016/j.heliyon.2024.e29950] [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: 09/12/2023] [Revised: 04/08/2024] [Accepted: 04/17/2024] [Indexed: 05/18/2024] Open
Abstract
Epilepsy is a chronic, relapsing neurological disorder, and current treatments focus primarily on neurons, yet one-third of patients still develop drug-resistant epilepsy. Therefore, there is an urgent need to explore new therapeutic targets. Interestingly, astrocytes can transfer their healthy mitochondria into neighboring neurons, thus preventing neuronal damage. Astrocyte mitochondria have been shown to have a therapeutic role in stroke and neurodegenerative diseases. However, their therapeutic effect in epilepsy and its related mechanisms have been less studied. In this review, we mainly summarize the regulatory role of astrocyte mitochondria in glutamate, calcium ion, and adenosine triphosphate (ATP) homeostasis and outline the protective role of astrocyte mitochondria in nervous system diseases, revealing a new target for epilepsy treatment.
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Affiliation(s)
| | | | - Fei Yang
- First Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Tingwan Xu
- First Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Yanying Yu
- First Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Qian Wu
- First Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Yanbing Han
- First Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
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2
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Puebla M, Muñoz MF, Lillo MA, Contreras JE, Figueroa XF. Control of astrocytic Ca 2+ signaling by nitric oxide-dependent S-nitrosylation of Ca 2+ homeostasis modulator 1 channels. Biol Res 2024; 57:19. [PMID: 38689353 PMCID: PMC11059852 DOI: 10.1186/s40659-024-00503-3] [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: 08/31/2023] [Accepted: 04/18/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND Astrocytes Ca2+ signaling play a central role in the modulation of neuronal function. Activation of metabotropic glutamate receptors (mGluR) by glutamate released during an increase in synaptic activity triggers coordinated Ca2+ signals in astrocytes. Importantly, astrocytes express the Ca2+-dependent nitric oxide (NO)-synthetizing enzymes eNOS and nNOS, which might contribute to the Ca2+ signals by triggering Ca2+ influx or ATP release through the activation of connexin 43 (Cx43) hemichannels, pannexin-1 (Panx-1) channels or Ca2+ homeostasis modulator 1 (CALHM1) channels. Hence, we aim to evaluate the participation of NO in the astrocytic Ca2+ signaling initiated by stimulation of mGluR in primary cultures of astrocytes from rat brain cortex. RESULTS Astrocytes were stimulated with glutamate or t-ACPD and NO-dependent changes in [Ca2+]i and ATP release were evaluated. In addition, the activity of Cx43 hemichannels, Panx-1 channels and CALHM1 channels was also analyzed. The expression of Cx43, Panx-1 and CALHM1 in astrocytes was confirmed by immunofluorescence analysis and both glutamate and t-ACPD induced NO-mediated activation of CALHM1 channels via direct S-nitrosylation, which was further confirmed by assessing CALHM1-mediated current using the two-electrode voltage clamp technique in Xenopus oocytes. Pharmacological blockade or siRNA-mediated inhibition of CALHM1 expression revealed that the opening of these channels provides a pathway for ATP release and the subsequent purinergic receptor-dependent activation of Cx43 hemichannels and Panx-1 channels, which further contributes to the astrocytic Ca2+ signaling. CONCLUSIONS Our findings demonstrate that activation of CALHM1 channels through NO-mediated S-nitrosylation in astrocytes in vitro is critical for the generation of glutamate-initiated astrocytic Ca2+ signaling.
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Affiliation(s)
- Mariela Puebla
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 8330025, Santiago, Chile
| | - Manuel F Muñoz
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 8330025, Santiago, Chile
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Mauricio A Lillo
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Jorge E Contreras
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Xavier F Figueroa
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 8330025, Santiago, Chile.
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3
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Uribe-Arias A, Rozenblat R, Vinepinsky E, Marachlian E, Kulkarni A, Zada D, Privat M, Topsakalian D, Charpy S, Candat V, Nourin S, Appelbaum L, Sumbre G. Radial astrocyte synchronization modulates the visual system during behavioral-state transitions. Neuron 2023; 111:4040-4057.e6. [PMID: 37863038 PMCID: PMC10783638 DOI: 10.1016/j.neuron.2023.09.022] [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: 01/23/2023] [Revised: 08/01/2023] [Accepted: 09/15/2023] [Indexed: 10/22/2023]
Abstract
Glial cells support the function of neurons. Recent evidence shows that astrocytes are also involved in brain computations. To explore whether and how their excitable nature affects brain computations and motor behaviors, we used two-photon Ca2+ imaging of zebrafish larvae expressing GCaMP in both neurons and radial astrocytes (RAs). We found that in the optic tectum, RAs synchronize their Ca2+ transients immediately after the end of an escape behavior. Using optogenetics, ablations, and a genetically encoded norepinephrine sensor, we observed that RA synchronous Ca2+ events are mediated by the locus coeruleus (LC)-norepinephrine circuit. RA synchronization did not induce direct excitation or inhibition of tectal neurons. Nevertheless, it modulated the direction selectivity and the long-distance functional correlations among neurons. This mechanism supports freezing behavior following a switch to an alerted state. These results show that LC-mediated neuro-glial interactions modulate the visual system during transitions between behavioral states.
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Affiliation(s)
- Alejandro Uribe-Arias
- Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Rotem Rozenblat
- The Faculty of Life Sciences and The Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Ehud Vinepinsky
- Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Emiliano Marachlian
- Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Anirudh Kulkarni
- Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - David Zada
- The Faculty of Life Sciences and The Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Martin Privat
- Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Diego Topsakalian
- Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Sarah Charpy
- Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Virginie Candat
- Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Sarah Nourin
- Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Lior Appelbaum
- The Faculty of Life Sciences and The Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Germán Sumbre
- Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France.
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4
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Johnson GA, Krishnamoorthy RR, Stankowska DL. Modulating mitochondrial calcium channels (TRPM2/MCU/NCX) as a therapeutic strategy for neurodegenerative disorders. Front Neurosci 2023; 17:1202167. [PMID: 37928737 PMCID: PMC10622973 DOI: 10.3389/fnins.2023.1202167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 10/03/2023] [Indexed: 11/07/2023] Open
Abstract
Efficient cellular communication is essential for the brain to regulate diverse functions like muscle contractions, memory formation and recall, decision-making, and task execution. This communication is facilitated by rapid signaling through electrical and chemical messengers, including voltage-gated ion channels and neurotransmitters. These messengers elicit broad responses by propagating action potentials and mediating synaptic transmission. Calcium influx and efflux are essential for releasing neurotransmitters and regulating synaptic transmission. Mitochondria, which are involved in oxidative phosphorylation, and the energy generation process, also interact with the endoplasmic reticulum to store and regulate cytoplasmic calcium levels. The number, morphology, and distribution of mitochondria in different cell types vary based on energy demands. Mitochondrial damage can cause excess reactive oxygen species (ROS) generation. Mitophagy is a selective process that targets and degrades damaged mitochondria via autophagosome-lysosome fusion. Defects in mitophagy can lead to a buildup of ROS and cell death. Numerous studies have attempted to characterize the relationship between mitochondrial dysfunction and calcium dysregulation in neurodegenerative diseases such as Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, Amyotrophic lateral sclerosis, spinocerebellar ataxia, and aging. Interventional strategies to reduce mitochondrial damage and accumulation could serve as a therapeutic target, but further research is needed to unravel this potential. This review offers an overview of calcium signaling related to mitochondria in various neuronal cells. It critically examines recent findings, exploring the potential roles that mitochondrial dysfunction might play in multiple neurodegenerative diseases and aging. Furthermore, the review identifies existing gaps in knowledge to guide the direction of future research.
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Affiliation(s)
- Gretchen A. Johnson
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, United States
- Department of Microbiology, Immunology and Genetics, School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Raghu R. Krishnamoorthy
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, United States
- Department of Pharmacology and Neuroscience, School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Dorota L. Stankowska
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, United States
- Department of Microbiology, Immunology and Genetics, School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX, United States
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5
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Keto L, Manninen T. CellRemorph: A Toolkit for Transforming, Selecting, and Slicing 3D Cell Structures on the Road to Morphologically Detailed Astrocyte Simulations. Neuroinformatics 2023; 21:483-500. [PMID: 37133688 PMCID: PMC10406679 DOI: 10.1007/s12021-023-09627-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/06/2023] [Indexed: 05/04/2023]
Abstract
Understanding functions of astrocytes can be greatly enhanced by building and simulating computational models that capture their morphological details. Novel computational tools enable utilization of existing morphological data of astrocytes and building models that have appropriate level of details for specific simulation purposes. In addition to analyzing existing computational tools for constructing, transforming, and assessing astrocyte morphologies, we present here the CellRemorph toolkit implemented as an add-on for Blender, a 3D modeling platform increasingly recognized for its utility for manipulating 3D biological data. To our knowledge, CellRemorph is the first toolkit for transforming astrocyte morphologies from polygonal surface meshes into adjustable surface point clouds and vice versa, precisely selecting nanoprocesses, and slicing morphologies into segments with equal surface areas or volumes. CellRemorph is an open-source toolkit under the GNU General Public License and easily accessible via an intuitive graphical user interface. CellRemorph will be a valuable addition to other Blender add-ons, providing novel functionality that facilitates the creation of realistic astrocyte morphologies for different types of morphologically detailed simulations elucidating the role of astrocytes both in health and disease.
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Affiliation(s)
- Laura Keto
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.
| | - Tiina Manninen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.
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6
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Qian K, Jiang X, Liu ZQ, Zhang J, Fu P, Su Y, Brazhe NA, Liu D, Zhu LQ. Revisiting the critical roles of reactive astrocytes in neurodegeneration. Mol Psychiatry 2023; 28:2697-2706. [PMID: 37037874 DOI: 10.1038/s41380-023-02061-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 03/27/2023] [Accepted: 03/28/2023] [Indexed: 04/12/2023]
Abstract
Astrocytes, an integral component of the central nervous system (CNS), contribute to the maintenance of physiological homeostasis through their roles in synaptic function, K+ buffering, blood-brain barrier (BBB) maintenance, and neuronal metabolism. Reactive astrocytes refer to astrocytes undergoing morphological, molecular and functional remodelling in response to pathological stimuli. The activation and differentiation of astrocytes are implicated in the pathogenesis of multiple neurodegenerative diseases. However, there are still controversies regarding their subset identification, function and nomenclature in neurodegeneration. In this review, we revisit the multidimensional roles of reactive astrocytes in Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). Furthermore, we propose a precise linkage between astrocyte subsets and their functions based on single-cell sequencing analyses.
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Affiliation(s)
- Kang Qian
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Department of Neurosurgery, Union Hospital, Huazhong University of Science and Technology, Jiefang Avenue No. 1277, 430022, Wuhan, China
| | - Xiaobing Jiang
- Department of Neurosurgery, Union Hospital, Huazhong University of Science and Technology, Jiefang Avenue No. 1277, 430022, Wuhan, China
| | - Zhi-Qiang Liu
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Juan Zhang
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Peng Fu
- Department of Neurosurgery, Union Hospital, Huazhong University of Science and Technology, Jiefang Avenue No. 1277, 430022, Wuhan, China
| | - Ying Su
- Department of Neurology, Union Hospital, Huazhong University of Science and Technology, Jiefang Avenue No. 1277, 430022, Wuhan, China
| | - Nadezda A Brazhe
- Biophysics Department, Biological Faculty, Moscow State University, Moscow, Russia
| | - Dan Liu
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Ling-Qiang Zhu
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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7
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Fedotova A, Brazhe A, Doronin M, Toptunov D, Pryazhnikov E, Khiroug L, Verkhratsky A, Semyanov A. Dissociation Between Neuronal and Astrocytic Calcium Activity in Response to Locomotion in Mice. FUNCTION 2023; 4:zqad019. [PMID: 37342415 PMCID: PMC10278990 DOI: 10.1093/function/zqad019] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 06/22/2023] Open
Abstract
Locomotion triggers a coordinated response of both neurons and astrocytes in the brain. Here we performed calcium (Ca2+) imaging of these two cell types in the somatosensory cortex in head-fixed mice moving on the airlifted platform. Ca2+ activity in astrocytes significantly increased during locomotion from a low quiescence level. Ca2+ signals first appeared in the distal processes and then propagated to astrocytic somata, where it became significantly larger and exhibited oscillatory behaviour. Thus, astrocytic soma operates as both integrator and amplifier of Ca2+ signal. In neurons, Ca2+ activity was pronounced in quiescent periods and further increased during locomotion. Neuronal Ca2+ concentration ([Ca2+]i) rose almost immediately following the onset of locomotion, whereas astrocytic Ca2+ signals lagged by several seconds. Such a long lag suggests that astrocytic [Ca2+]i elevations are unlikely to be triggered by the activity of synapses among local neurons. Ca2+ responses to pairs of consecutive episodes of locomotion did not significantly differ in neurons, while were significantly diminished in response to the second locomotion in astrocytes. Such astrocytic refractoriness may arise from distinct mechanisms underlying Ca2+ signal generation. In neurons, the bulk of Ca2+ enters through the Ca2+ channels in the plasma membrane allowing for steady-level Ca2+ elevations in repetitive runs. Astrocytic Ca2+ responses originate from the intracellular stores, the depletion of which affects subsequent Ca2+ signals. Functionally, neuronal Ca2+ response reflects sensory input processed by neurons. Astrocytic Ca2+ dynamics is likely to provide metabolic and homeostatic support within the brain active milieu.
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Affiliation(s)
- Anna Fedotova
- Faculty of Biology, Moscow State University, Moscow 119991, Russia
- Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow 117997, Russia
| | - Alexey Brazhe
- Faculty of Biology, Moscow State University, Moscow 119991, Russia
- Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow 117997, Russia
| | - Maxim Doronin
- Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow 117997, Russia
- College of Medicine, Jiaxing University, Jiaxing, Zhejiang Province, 314001, China
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8
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Lim D, Tapella L, Dematteis G, Talmon M, Genazzani AA. Calcineurin Signalling in Astrocytes: From Pathology to Physiology and Control of Neuronal Functions. Neurochem Res 2023; 48:1077-1090. [PMID: 36083398 PMCID: PMC10030417 DOI: 10.1007/s11064-022-03744-4] [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: 07/31/2022] [Revised: 07/31/2022] [Accepted: 08/29/2022] [Indexed: 10/14/2022]
Abstract
Calcineurin (CaN), a Ca2+/calmodulin-activated serine/threonine phosphatase, acts as a Ca2+-sensitive switch regulating cellular functions through protein dephosphorylation and activation of gene transcription. In astrocytes, the principal homeostatic cells in the CNS, over-activation of CaN is known to drive pathological transcriptional remodelling, associated with neuroinflammation in diseases such as Alzheimer's disease, epilepsy and brain trauma. Recent reports suggest that, in physiological conditions, the activity of CaN in astrocytes is transcription-independent and is required for maintenance of basal protein synthesis rate and activation of astrocytic Na+/K+ pump thereby contributing to neuronal functions such as neuronal excitability and memory formation. In this contribution we overview the role of Ca2+ and CaN signalling in astroglial pathophysiology focusing on the emerging physiological role of CaN in astrocytes. We propose a model for the context-dependent switch of CaN activity from the post-transcriptional regulation of cell proteostasis in healthy astrocytes to the CaN-dependent transcriptional activation in neuroinflammation-associated diseases.
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Affiliation(s)
- Dmitry Lim
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Via Bovio 6, 28100, Novara, Italy.
| | - Laura Tapella
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Via Bovio 6, 28100, Novara, Italy
| | - Giulia Dematteis
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Via Bovio 6, 28100, Novara, Italy
| | - Maria Talmon
- Department of Health Sciences, School of Medicine, Università del Piemonte Orientale "Amedeo Avogadro", Via Solaroli 17, 28100, Novara, Italy
| | - Armando A Genazzani
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Via Bovio 6, 28100, Novara, Italy.
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9
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Liu L, Gao H, Li J, Chen S. Probing microdomain Ca 2+ activity and synaptic transmission with a node-based tripartite synapse model. FRONTIERS IN NETWORK PHYSIOLOGY 2023; 3:1111306. [PMID: 36926546 PMCID: PMC10013067 DOI: 10.3389/fnetp.2023.1111306] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 01/27/2023] [Indexed: 06/08/2023]
Abstract
Astrocytic fine processes are the most minor structures of astrocytes but host much of the Ca2+ activity. These localized Ca2+ signals spatially restricted to microdomains are crucial for information processing and synaptic transmission. However, the mechanistic link between astrocytic nanoscale processes and microdomain Ca2+ activity remains hazily understood because of the technical difficulties in accessing this structurally unresolved region. In this study, we used computational models to disentangle the intricate relations of morphology and local Ca2+ dynamics involved in astrocytic fine processes. We aimed to answer: 1) how nano-morphology affects local Ca2+ activity and synaptic transmission, 2) and how fine processes affect Ca2+ activity of large process they connect. To address these issues, we undertook the following two computational modeling: 1) we integrated the in vivo astrocyte morphological data from a recent study performed with super-resolution microscopy that discriminates sub-compartments of various shapes, referred to as nodes and shafts to a classic IP3R-mediated Ca2+ signaling framework describing the intracellular Ca2+ dynamics, 2) we proposed a node-based tripartite synapse model linking with astrocytic morphology to predict the effect of structural deficits of astrocytes on synaptic transmission. Extensive simulations provided us with several biological insights: 1) the width of nodes and shafts could strongly influence the spatiotemporal variability of Ca2+ signals properties but what indeed determined the Ca2+ activity was the width ratio between nodes and shafts, 2) the connectivity of nodes to larger processes markedly shaped the Ca2+ signal of the parent process rather than nodes morphology itself, 3) the morphological changes of astrocytic part might potentially induce the abnormality of synaptic transmission by affecting the level of glutamate at tripartite synapses. Taken together, this comprehensive model which integrated theoretical computation and in vivo morphological data highlights the role of the nanomorphology of astrocytes in signal transmission and its possible mechanisms related to pathological conditions.
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Affiliation(s)
- Langzhou Liu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Huayi Gao
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Jinyu Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Shangbin Chen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
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10
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Nanotopography and Microconfinement Impact on Primary Hippocampal Astrocyte Morphology, Cytoskeleton and Spontaneous Calcium Wave Signalling. Cells 2023; 12:cells12020293. [PMID: 36672231 PMCID: PMC9856934 DOI: 10.3390/cells12020293] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/19/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Astrocytes' organisation affects the functioning and the fine morphology of the brain, both in physiological and pathological contexts. Although many aspects of their role have been characterised, their complex functions remain, to a certain extent, unclear with respect to their contribution to brain cell communication. Here, we studied the effects of nanotopography and microconfinement on primary hippocampal rat astrocytes. For this purpose, we fabricated nanostructured zirconia surfaces as homogenous substrates and as micrometric patterns, the latter produced by a combination of an additive nanofabrication and micropatterning technique. These engineered substrates reproduce both nanotopographical features and microscale geometries that astrocytes encounter in their natural environment, such as basement membrane topography, as well as blood vessels and axonal fibre topology. The impact of restrictive adhesion manifests in the modulation of several cellular properties of single cells (morphological and actin cytoskeletal changes) and the network organisation and functioning. Calcium wave signalling was observed only in astrocytes grown in confined geometries, with an activity enhancement in cells forming elongated agglomerates with dimensions typical of blood vessels or axon fibres. Our results suggest that calcium oscillation and wave propagation are closely related to astrocytic morphology and actin cytoskeleton organisation.
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11
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Eraso‐Pichot A, Pouvreau S, Olivera‐Pinto A, Gomez‐Sotres P, Skupio U, Marsicano G. Endocannabinoid signaling in astrocytes. Glia 2023; 71:44-59. [PMID: 35822691 PMCID: PMC9796923 DOI: 10.1002/glia.24246] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 06/28/2022] [Accepted: 07/04/2022] [Indexed: 01/07/2023]
Abstract
The study of the astrocytic contribution to brain functions has been growing in popularity in the neuroscience field. In the last years, and especially since the demonstration of the involvement of astrocytes in synaptic functions, the astrocyte field has revealed multiple functions of these cells that seemed inconceivable not long ago. In parallel, cannabinoid investigation has also identified different ways by which cannabinoids are able to interact with these cells, modify their functions, alter their communication with neurons and impact behavior. In this review, we will describe the expression of different endocannabinoid system members in astrocytes. Moreover, we will relate the latest findings regarding cannabinoid modulation of some of the most relevant astroglial functions, namely calcium (Ca2+ ) dynamics, gliotransmission, metabolism, and inflammation.
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Affiliation(s)
- Abel Eraso‐Pichot
- U1215 Neurocentre MagendieInstitut national de la santé et de la recherche médicale (INSERM)BordeauxFrance,University of BordeauxBordeauxFrance
| | - Sandrine Pouvreau
- U1215 Neurocentre MagendieInstitut national de la santé et de la recherche médicale (INSERM)BordeauxFrance,University of BordeauxBordeauxFrance
| | - Alexandre Olivera‐Pinto
- U1215 Neurocentre MagendieInstitut national de la santé et de la recherche médicale (INSERM)BordeauxFrance,University of BordeauxBordeauxFrance
| | - Paula Gomez‐Sotres
- U1215 Neurocentre MagendieInstitut national de la santé et de la recherche médicale (INSERM)BordeauxFrance,University of BordeauxBordeauxFrance
| | - Urszula Skupio
- U1215 Neurocentre MagendieInstitut national de la santé et de la recherche médicale (INSERM)BordeauxFrance,University of BordeauxBordeauxFrance
| | - Giovanni Marsicano
- U1215 Neurocentre MagendieInstitut national de la santé et de la recherche médicale (INSERM)BordeauxFrance,University of BordeauxBordeauxFrance
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12
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Goenaga J, Araque A, Kofuji P, Herrera Moro Chao D. Calcium signaling in astrocytes and gliotransmitter release. Front Synaptic Neurosci 2023; 15:1138577. [PMID: 36937570 PMCID: PMC10017551 DOI: 10.3389/fnsyn.2023.1138577] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/16/2023] [Indexed: 03/06/2023] Open
Abstract
Glia are as numerous in the brain as neurons and widely known to serve supportive roles such as structural scaffolding, extracellular ionic and neurotransmitter homeostasis, and metabolic support. However, over the past two decades, several lines of evidence indicate that astrocytes, which are a type of glia, play active roles in neural information processing. Astrocytes, although not electrically active, can exhibit a form of excitability by dynamic changes in intracellular calcium levels. They sense synaptic activity and release neuroactive substances, named gliotransmitters, that modulate neuronal activity and synaptic transmission in several brain areas, thus impacting animal behavior. This "dialogue" between astrocytes and neurons is embodied in the concept of the tripartite synapse that includes astrocytes as integral elements of synaptic function. Here, we review the recent work and discuss how astrocytes via calcium-mediated excitability modulate synaptic information processing at various spatial and time scales.
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13
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Ding F, Liang S, Li R, Yang Z, He Y, Yang S, Duan Q, Zhang J, Lyu J, Zhou Z, Huang M, Wang H, Li J, Yang C, Wang Y, Gong M, Chen S, Jia H, Chen X, Liao X, Fu L, Zhang K. Astrocytes exhibit diverse Ca2+ changes at subcellular domains during brain aging. Front Aging Neurosci 2022; 14:1029533. [PMID: 36389078 PMCID: PMC9650392 DOI: 10.3389/fnagi.2022.1029533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 10/11/2022] [Indexed: 11/23/2022] Open
Abstract
Astrocytic Ca2+ transients are essential for astrocyte integration into neural circuits. These Ca2+ transients are primarily sequestered in subcellular domains, including primary branches, branchlets and leaflets, and endfeet. In previous studies, it suggests that aging causes functional defects in astrocytes. Until now, it was unclear whether and how aging affects astrocytic Ca2+ transients at subcellular domains. In this study, we combined a genetically encoded Ca2+ sensor (GCaMP6f) and in vivo two-photon Ca2+ imaging to determine changes in Ca2+ transients within astrocytic subcellular domains during brain aging. We showed that aging increased Ca2+ transients in astrocytic primary branches, higher-order branchlets, and terminal leaflets. However, Ca2+ transients decreased within astrocytic endfeet during brain aging, which could be caused by the decreased expressions of Aquaporin-4 (AQP4). In addition, aging-induced changes of Ca2+ transient types were heterogeneous within astrocytic subcellular domains. These results demonstrate that the astrocytic Ca2+ transients within subcellular domains are affected by aging differently. This finding contributes to a better understanding of the physiological role of astrocytes in aging-induced neural circuit degeneration.
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Affiliation(s)
- Fusheng Ding
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Shanshan Liang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Ruijie Li
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
- Advanced Institute for Brain and Intelligence and School of Physical Science and Technology, Guangxi University, Nanning, China
| | - Zhiqi Yang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Yong He
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Shaofan Yang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Qingtian Duan
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Jianxiong Zhang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Jing Lyu
- Brain Research Instrument Innovation Center, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
| | - Zhenqiao Zhou
- Brain Research Instrument Innovation Center, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
| | - Mingzhu Huang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Haoyu Wang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Jin Li
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Chuanyan Yang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Yuxia Wang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Mingyue Gong
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Shangbin Chen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Hongbo Jia
- Advanced Institute for Brain and Intelligence and School of Physical Science and Technology, Guangxi University, Nanning, China
- Brain Research Instrument Innovation Center, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
- Combinatorial NeuroImaging Core Facility, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Xiaowei Chen
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
- Guangyang Bay Laboratory, Chongqing Institute for Brain and Intelligence, Chongqing, China
| | - Xiang Liao
- Center for Neurointelligence, School of Medicine, Chongqing University, Chongqing, China
- *Correspondence: Xiang Liao,
| | - Ling Fu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
- Ling Fu,
| | - Kuan Zhang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
- Kuan Zhang,
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14
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Brignone MS, Lanciotti A, Michelucci A, Mallozzi C, Camerini S, Catacuzzeno L, Sforna L, Caramia M, D’Adamo MC, Ceccarini M, Molinari P, Macioce P, Macchia G, Petrucci TC, Pessia M, Visentin S, Ambrosini E. The CaMKII/MLC1 Axis Confers Ca2+-Dependence to Volume-Regulated Anion Channels (VRAC) in Astrocytes. Cells 2022; 11:cells11172656. [PMID: 36078064 PMCID: PMC9454758 DOI: 10.3390/cells11172656] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/18/2022] [Accepted: 08/24/2022] [Indexed: 11/30/2022] Open
Abstract
Astrocytes, the main glial cells of the central nervous system, play a key role in brain volume control due to their intimate contacts with cerebral blood vessels and the expression of a distinctive equipment of proteins involved in solute/water transport. Among these is MLC1, a protein highly expressed in perivascular astrocytes and whose mutations cause megalencephalic leukoencephalopathy with subcortical cysts (MLC), an incurable leukodystrophy characterized by macrocephaly, chronic brain edema, cysts, myelin vacuolation, and astrocyte swelling. Although, in astrocytes, MLC1 mutations are known to affect the swelling-activated chloride currents (ICl,swell) mediated by the volume-regulated anion channel (VRAC), and the regulatory volume decrease, MLC1′s proper function is still unknown. By combining molecular, biochemical, proteomic, electrophysiological, and imaging techniques, we here show that MLC1 is a Ca2+/Calmodulin-dependent protein kinase II (CaMKII) target protein, whose phosphorylation, occurring in response to intracellular Ca2+ release, potentiates VRAC-mediated ICl,swell. Overall, these findings reveal that MLC1 is a Ca2+-regulated protein, linking volume regulation to Ca2+ signaling in astrocytes. This knowledge provides new insight into the MLC1 protein function and into the mechanisms controlling ion/water exchanges in the brain, which may help identify possible molecular targets for the treatment of MLC and other pathological conditions caused by astrocyte swelling and brain edema.
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Affiliation(s)
| | - Angela Lanciotti
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Antonio Michelucci
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Cinzia Mallozzi
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Serena Camerini
- Core Facilities (FAST), Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Luigi Catacuzzeno
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Luigi Sforna
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Martino Caramia
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Maria Cristina D’Adamo
- Department of Medicine and Surgery, LUM Giuseppe Degennaro University, 70010 Bari, Italy
| | - Marina Ceccarini
- National Centre for Rare Diseases, Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Paola Molinari
- National Centre for Drug Research and Evaluation (FARVA), Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Pompeo Macioce
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy
| | | | | | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MSD2080 Msida, Malta
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 17666, United Arab Emirates
| | - Sergio Visentin
- National Centre for Drug Research and Evaluation (FARVA), Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Elena Ambrosini
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy
- Correspondence: ; Tel.: +39-06-4990-2037
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15
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Looking to the stars for answers: Strategies for determining how astrocytes influence neuronal activity. Comput Struct Biotechnol J 2022; 20:4146-4156. [PMID: 36016711 PMCID: PMC9379862 DOI: 10.1016/j.csbj.2022.07.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 07/29/2022] [Accepted: 07/29/2022] [Indexed: 11/24/2022] Open
Abstract
Astrocytes are critical components of neural circuits positioned in close proximity to the synapse, allowing them to rapidly sense and respond to neuronal activity. One repeatedly observed biomarker of astroglial activation is an increase in intracellular Ca2+ levels. These astroglial Ca2+ signals are often observed spreading throughout various cellular compartments from perisynaptic astroglial processes, to major astrocytic branches and on to the soma or cell body. Here we review recent evidence demonstrating that astrocytic Ca2+ events are remarkably heterogeneous in both form and function, propagate through the astroglial syncytia, and are directly linked to the ability of astroglia to influence local neuronal activity. As many of the cellular functions of astroglia can be linked to intracellular Ca2+ signaling, and the diversity and heterogeneity of these events becomes more apparent, there is an increasing need for novel experimental strategies designed to better understand the how these signals evolve in parallel with neuronal activity. Here we review the recent advances that enable the characterization of both subcellular and population-wide astrocytic Ca2+ dynamics. Additionally, we also outline the experimental design required for simultaneous in vivo Ca2+ imaging in the context of neuronal or astroglial manipulation, highlighting new experimental strategies made possible by recent advances in viral vector, imaging, and quantification technologies. Through combined usage of these reagents and methodologies, we provide a conceptual framework to study how astrocytes functionally integrate into neural circuits and to what extent they influence and direct the synaptic activity underlying behavioral responses.
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16
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Dsouza C, Moussa MS, Mikolajewicz N, Komarova SV. Extracellular ATP and its derivatives provide spatiotemporal guidance for bone adaptation to wide spectrum of physical forces. Bone Rep 2022; 17:101608. [PMID: 35992507 PMCID: PMC9385560 DOI: 10.1016/j.bonr.2022.101608] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/27/2022] [Accepted: 07/29/2022] [Indexed: 11/17/2022] Open
Abstract
ATP is a ubiquitous intracellular molecule critical for cellular bioenergetics. ATP is released in response to mechanical stimulation through vesicular release, small tears in cellular plasma membranes, or when cells are destroyed by traumatic forces. Extracellular ATP is degraded by ecto-ATPases to form ADP and eventually adenosine. ATP, ADP, and adenosine signal through purinergic receptors, including seven P2X ATP-gated cation channels, seven G-protein coupled P2Y receptors responsive to ATP and ADP, and four P1 receptors stimulated by adenosine. The goal of this review is to build a conceptual model of the role of different components of this complex system in coordinating cellular responses that are appropriate to the degree of mechanical stimulation, cell proximity to the location of mechanical injury, and time from the event. We propose that route and amount of ATP release depend on the scale of mechanical forces, ranging from vesicular release of small ATP boluses upon membrane deformation, to leakage of ATP through resealable plasma membrane tears, to spillage of cellular content due to destructive forces. Correspondingly, different P2 receptors responsive to ATP will be activated according to their affinity at the site of mechanical stimulation. ATP is a small molecule that readily diffuses through the environment, bringing the signal to the surrounding cells. ATP is also degraded to ADP which can stimulate a distinct set of P2 receptors. We propose that depending on the magnitude of mechanical forces and distance from the site of their application, ATP/ADP profiles will be different, allowing the relay of information about tissue level injury and proximity. Lastly, ADP is degraded to adenosine acting via its P1 receptors. The presence of large amounts of adenosine without ATP, indicates that an active source of ATP release is no longer present, initiating the transition to the recovery phase. This model consolidates the knowledge regarding the individual components of the purinergic system into a conceptual framework of choreographed responses to physical forces. Cellular bioenergetic molecule ATP is released when cell is mechanically stimulated. ATP release is proportional to the amount of cellular damage. ATP diffusion and transformation to ADP indicates the proximity to the damage. Purinergic receptors form a network choreographing cell response to physical forces. Complete transformation of ATP to adenosine initiates the recovery phase.
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Affiliation(s)
- Chrisanne Dsouza
- Department of Experimental Surgery, McGill University, Montreal, QC H3G 1A4, Canada
- Shriners Hospitals for Children- Canada, Montreal, QC H4A 0A9, Canada
| | - Mahmoud S. Moussa
- Shriners Hospitals for Children- Canada, Montreal, QC H4A 0A9, Canada
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, QC H3A 1G1, Canada
| | - Nicholas Mikolajewicz
- Shriners Hospitals for Children- Canada, Montreal, QC H4A 0A9, Canada
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, QC H3A 1G1, Canada
| | - Svetlana V. Komarova
- Department of Experimental Surgery, McGill University, Montreal, QC H3G 1A4, Canada
- Shriners Hospitals for Children- Canada, Montreal, QC H4A 0A9, Canada
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, QC H3A 1G1, Canada
- Corresponding author.
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17
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Aryal SP, Xia M, Ortinski PI, Richards CI. Study of Calcium Signaling in Astrocytes with a Novel Endoplasmic Reticulum-Targeted GCaMP Sensor. Curr Protoc 2022; 2:e491. [PMID: 35938843 PMCID: PMC9373517 DOI: 10.1002/cpz1.491] [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] [Indexed: 06/15/2023]
Abstract
The endoplasmic reticulum (ER), the major organelle for the storage of Ca2+ , maintains a concentration of Ca2+ much higher than in the cytosol or other subcellular organelles, such as the mitochondria. A variety of tools have been developed for measuring Ca2+ activity in neuronal and glial cells, but most of these sensors target either the plasma membrane (PM) or the cytosol. Though these sensors are important for measuring Ca2+ transients, they lack the capability to measure activity in the periphery of the ER or to measure low-amplitude events resulting from Ca2+ exchange between the ER and other organelles, such as the mitochondria. We recently developed an ER-targeted GCaMP6f anchored to the cytosolic side of the ER that can measure minute calcium exchange occurring in this region. In this article, we discuss detailed methods to characterize the ER-GCaMP6f sensor, utilize it for calcium imaging in cultured astrocytes, and assess its expression and calcium imaging in astrocytes in rodent brains. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Expression and characterization of ER-GCaMP6f Support Protocol 1: ER-GCaMP6f-expressing stable cell line generation Basic Protocol 2: In vitro calcium imaging with ER-GCaMP6f Support Protocol 2: Imaging of drug-induced calcium activity Alternate Protocol 1: Transduction of astrocytes with ER-GCaMP6f AAV Alternate Protocol 2: Calcium imaging of astrocytes with Fluo-4 AM Basic Protocol 3: In vivo ER-GCaMP6f expression and slice calcium imaging Support Protocol 3: Pharmacological studies with 2-APB in brain slices.
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Affiliation(s)
- Surya P Aryal
- Department of Chemistry, University of Kentucky, Lexington, Kentucky
| | - Mengfan Xia
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky
| | - Pavel I Ortinski
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky
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18
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Oliveira JF, Araque A. Astrocyte regulation of neural circuit activity and network states. Glia 2022; 70:1455-1466. [PMID: 35460131 PMCID: PMC9232995 DOI: 10.1002/glia.24178] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 02/23/2022] [Accepted: 02/27/2022] [Indexed: 12/13/2022]
Abstract
Astrocytes are known to influence neuronal activity through different mechanisms, including the homeostatic control of extracellular levels of ions and neurotransmitters and the exchange of signaling molecules that regulate synaptic formation, structure, and function. While a great effort done in the past has defined many molecular mechanisms and cellular processes involved in astrocyte-neuron interactions at the cellular level, the consequences of these interactions at the network level in vivo have only relatively recently been identified. This review describes and discusses recent findings on the regulatory effects of astrocytes on the activity of neuronal networks in vivo. Accumulating but still limited, evidence indicates that astrocytes regulate neuronal network rhythmic activity and synchronization as well as brain states. These studies demonstrate a critical contribution of astrocytes to brain activity and are paving the way for a more thorough understanding of the cellular bases of brain function.
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Affiliation(s)
- João Filipe Oliveira
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Portugal.,IPCA-EST-2Ai, Polytechnic Institute of Cávado and Ave, Applied Artificial Intelligence Laboratory, Campus of IPCA, Barcelos, Portugal
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
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19
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Bistability and Chaos Emergence in Spontaneous Dynamics of Astrocytic Calcium Concentration. MATHEMATICS 2022. [DOI: 10.3390/math10081337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In this work, we consider a mathematical model describing spontaneous calcium signaling in astrocytes. Based on biologically relevant principles, this model simulates experimentally observed calcium oscillations and can predict the emergence of complicated dynamics. Using analytical and numerical analysis, various attracting sets were found and investigated. Employing bifurcation theory analysis, we examined steady state solutions, bistability, simple and complicated periodic limit cycles and also chaotic attractors. We found that astrocytes possess a variety of complex dynamical modes, including chaos and multistability, that can further provide different modulations of neuronal circuits, enhancing their plasticity and flexibility.
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20
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Yang J, Yin M, Hou Y, Li H, Guo Y, Yu H, Zhang K, Zhang C, Jia L, Zhang F, Li X, Bian H, Li Z. Role of ammonia for brain abnormal protein glycosylation during the development of hepatitis B virus-related liver diseases. Cell Biosci 2022; 12:16. [PMID: 35164881 PMCID: PMC8842931 DOI: 10.1186/s13578-022-00751-4] [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: 09/01/2021] [Accepted: 01/29/2022] [Indexed: 11/30/2022] Open
Abstract
Background Ammonia is the most typical neurotoxin in hepatic encephalopathy (HE), but the underlying pathophysiology between ammonia and aberrant glycosylation in HE remains unknown. Results Here, we used HBV transgenic mice and astrocytes to present a systems-based study of glycosylation changes and corresponding enzymes associated with the key factors of ammonia in HE. We surveyed protein glycosylation changes associated with the brain of HBV transgenic mice by lectin microarrays. Upregulation of Galβ1-3GalNAc mediated by core 1 β1,3-galactosyltransferase (C1GALT1) was identified as a result of ammonia stimulation. Using in vitro assays, we validated that upregulation of C1GALT1 is a driver of deregulates calcium (Ca2+) homeostasis by overexpression of inositol 1,4,5-trisphosphate receptor type 1 (IP3R1) in astrocytes. Conclusions We demonstrated that silencing C1GALT1 could depress the IP3R1 expression, an effective strategy to inhibit the ammonia-induced upregulation of Ca2+ activity, thereby C1GALT1 and IP3R1 may serve as therapeutic targets in hyperammonemia of HE. Supplementary Information The online version contains supplementary material available at 10.1186/s13578-022-00751-4.
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Affiliation(s)
- Jiajun Yang
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an, 710069, China
| | - Mengqi Yin
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an, 710069, China
| | - Yao Hou
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an, 710069, China
| | - Hao Li
- Cell Engineering Research Centre and Department of Cell Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Yonghong Guo
- Department of Infectious Diseases, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Hanjie Yu
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an, 710069, China
| | - Kun Zhang
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an, 710069, China
| | - Chen Zhang
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an, 710069, China
| | - Liyuan Jia
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an, 710069, China
| | - Fan Zhang
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an, 710069, China
| | - Xia Li
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an, 710069, China
| | - Huijie Bian
- Cell Engineering Research Centre and Department of Cell Biology, Fourth Military Medical University, Xi'an, 710032, China.
| | - Zheng Li
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an, 710069, China.
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21
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Serrat R, Covelo A, Kouskoff V, Delcasso S, Ruiz-Calvo A, Chenouard N, Stella C, Blancard C, Salin B, Julio-Kalajzić F, Cannich A, Massa F, Varilh M, Deforges S, Robin LM, De Stefani D, Busquets-Garcia A, Gambino F, Beyeler A, Pouvreau S, Marsicano G. Astroglial ER-mitochondria calcium transfer mediates endocannabinoid-dependent synaptic integration. Cell Rep 2021; 37:110133. [PMID: 34936875 DOI: 10.1016/j.celrep.2021.110133] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/08/2021] [Accepted: 11/23/2021] [Indexed: 10/19/2022] Open
Abstract
Intracellular calcium signaling underlies the astroglial control of synaptic transmission and plasticity. Mitochondria-endoplasmic reticulum contacts (MERCs) are key determinants of calcium dynamics, but their functional impact on astroglial regulation of brain information processing is unexplored. We found that the activation of astrocyte mitochondrial-associated type-1 cannabinoid (mtCB1) receptors determines MERC-dependent intracellular calcium signaling and synaptic integration. The stimulation of mtCB1 receptors promotes calcium transfer from the endoplasmic reticulum to mitochondria through a specific molecular cascade, involving the mitochondrial calcium uniporter (MCU). Physiologically, mtCB1-dependent mitochondrial calcium uptake determines the dynamics of cytosolic calcium events in astrocytes upon endocannabinoid mobilization. Accordingly, electrophysiological recordings in hippocampal slices showed that conditional genetic exclusion of mtCB1 receptors or dominant-negative MCU expression in astrocytes blocks lateral synaptic potentiation, through which astrocytes integrate the activity of distant synapses. Altogether, these data reveal an endocannabinoid link between astroglial MERCs and the regulation of brain network functions.
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Affiliation(s)
- Roman Serrat
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France; INRAE, Nutrition and Integrative Neurobiology, UMR 1286, Bordeaux, France
| | - Ana Covelo
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Vladimir Kouskoff
- University of Bordeaux, 33077 Bordeaux, France; Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Sebastien Delcasso
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France; Institut de Biochimie et Genetique Cellulaires, CNRS UMR 5095, Bordeaux, France
| | - Andrea Ruiz-Calvo
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Nicolas Chenouard
- University of Bordeaux, 33077 Bordeaux, France; Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Carol Stella
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Corinne Blancard
- University of Bordeaux, 33077 Bordeaux, France; Institut de Biochimie et Genetique Cellulaires, CNRS UMR 5095, Bordeaux, France
| | - Benedicte Salin
- University of Bordeaux, 33077 Bordeaux, France; Institut de Biochimie et Genetique Cellulaires, CNRS UMR 5095, Bordeaux, France
| | - Francisca Julio-Kalajzić
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Astrid Cannich
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Federico Massa
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Marjorie Varilh
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Severine Deforges
- University of Bordeaux, 33077 Bordeaux, France; Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Laurie M Robin
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Arnau Busquets-Garcia
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Frederic Gambino
- University of Bordeaux, 33077 Bordeaux, France; Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Anna Beyeler
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Sandrine Pouvreau
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France; Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France.
| | - Giovanni Marsicano
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France.
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22
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Orts-Del'Immagine A, Dhanasekar M, Lejeune FX, Roussel J, Wyart C. A norepinephrine-dependent glial calcium wave travels in the spinal cord upon acoustovestibular stimuli. Glia 2021; 70:491-507. [PMID: 34773299 DOI: 10.1002/glia.24118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 10/27/2021] [Accepted: 11/01/2021] [Indexed: 02/06/2023]
Abstract
Although calcium waves have been widely observed in glial cells, their occurrence in vivo during behavior remains less understood. Here, we investigated the recruitment of glial cells in the hindbrain and spinal cord after acousto-vestibular (AV) stimuli triggering escape responses using in vivo population calcium imaging in larval zebrafish. We observed that gap-junction-coupled spinal glial network exhibits large and homogenous calcium increases that rose in the rostral spinal cord and propagated bi-directionally toward the spinal cord and toward the hindbrain. Spinal glial calcium waves were driven by the recruitment of neurons and in particular, of noradrenergic signaling acting through α-adrenergic receptors. Noradrenergic neurons of the medulla-oblongata (NE-MO) were revealed in the vicinity of where the calcium wave started. NE-MO were recruited upon AV stimulation and sent dense axonal projections in the rostro-lateral spinal cord, suggesting these cells could trigger the glial wave to propagate down the spinal cord. Altogether, our results revealed that a simple AV stimulation is sufficient to recruit noradrenergic neurons in the brainstem that trigger in the rostral spinal cord two massive glial calcium waves, one traveling caudally in the spinal cord and another rostrally into the hindbrain.
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Affiliation(s)
| | | | | | | | - Claire Wyart
- Institut du cerveau, Sorbonne Université, Paris, France
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23
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Critical Involvement of Glial Cells in Manganese Neurotoxicity. BIOMED RESEARCH INTERNATIONAL 2021; 2021:1596185. [PMID: 34660781 PMCID: PMC8514895 DOI: 10.1155/2021/1596185] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 09/16/2021] [Accepted: 09/21/2021] [Indexed: 12/13/2022]
Abstract
Over the years, most of the research concerning manganese exposure was restricted to the toxicity of neuronal cells. Manganese is an essential trace element that in high doses exerts neurotoxic effects. However, in the last two decades, efforts have shifted toward a more comprehensive approach that takes into account the involvement of glial cells in the development of neurotoxicity as a brain insult. Glial cells provide structural, trophic, and metabolic support to neurons. Nevertheless, these cells play an active role in adult neurogenesis, regulation of synaptogenesis, and synaptic plasticity. Disturbances in glial cell function can lead to neurological disorders, including neurodegenerative diseases. This review highlights the pivotal role that glial cells have in manganese-induced neurotoxicity as well as the most sounding mechanisms involved in the development of this phenomenon.
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24
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Semyanov A, Verkhratsky A. Astrocytic processes: from tripartite synapses to the active milieu. Trends Neurosci 2021; 44:781-792. [PMID: 34479758 DOI: 10.1016/j.tins.2021.07.006] [Citation(s) in RCA: 110] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/09/2021] [Accepted: 07/20/2021] [Indexed: 12/16/2022]
Abstract
We define a new concept of 'active milieu' that unifies all components of nervous tissue (neuronal and glial compartments, extracellular space, extracellular matrix, and vasculature) into a dynamic information processing system. Within this framework, we focus on the role of astrocytic processes, classified into organelle-containing branches and organelle-free leaflets. We argue that astrocytic branches with emanating leaflets are homologous to dendritic shafts with spines. Within the active milieu, astrocytic processes are engaged in reciprocal interactions with neuronal compartments and communication with other cellular and non-cellular elements of the nervous tissue.
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Affiliation(s)
- Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Faculty of Biology, Moscow State University, Moscow, Russia; Sechenov First Moscow State Medical University, Moscow, Russia.
| | - Alexei Verkhratsky
- Sechenov First Moscow State Medical University, Moscow, Russia; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain; Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.
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25
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Astrocytes in the Ventromedial Hypothalamus Involve Chronic Stress-Induced Anxiety and Bone Loss in Mice. Neural Plast 2021; 2021:7806370. [PMID: 34306063 PMCID: PMC8282369 DOI: 10.1155/2021/7806370] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 06/22/2021] [Indexed: 11/18/2022] Open
Abstract
Chronic stress is one of the main risk factors of bone loss. While the neurons and neural circuits of the ventromedial hypothalamus (VMH) mediate bone loss induced by chronic stress, the detailed intrinsic mechanisms within the VMH nucleus still need to be explored. Astrocytes in brain regions play important roles in the regulation of metabolism and anxiety-like behavior through interactions with surrounding neurons. However, whether astrocytes in the VMH affect neuronal activity and therefore regulate chronic stress-induced anxiety and bone loss remain elusive. In this study, we found that VMH astrocytes were activated during chronic stress-induced anxiety and bone loss. Pharmacogenetic activation of the Gi and Gq pathways in VMH astrocytes reduced and increased the levels of anxiety and bone loss, respectively. Furthermore, activation of VMH astrocytes by optogenetics induced depolarization in neighboring steroidogenic factor-1 (SF-1) neurons, which was diminished by administration of N-methyl-D-aspartic acid (NMDA) receptor blocker but not by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor blocker. These results suggest that there may be a functional "glial-neuron microcircuit" in VMH nuclei that mediates anxiety and bone loss induced by chronic stress. This study not only advances our understanding of glial cell function but also provides a potential intervention target for chronic stress-induced anxiety and bone loss therapy.
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26
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Bjørnstad DM, Åbjørsbråten KS, Hennestad E, Cunen C, Hermansen GH, Bojarskaite L, Pettersen KH, Vervaeke K, Enger R. Begonia-A Two-Photon Imaging Analysis Pipeline for Astrocytic Ca 2+ Signals. Front Cell Neurosci 2021; 15:681066. [PMID: 34093134 PMCID: PMC8172593 DOI: 10.3389/fncel.2021.681066] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 04/21/2021] [Indexed: 11/13/2022] Open
Abstract
Imaging the intact brain of awake behaving mice without the dampening effects of anesthesia, has revealed an exceedingly rich repertoire of astrocytic Ca2+ signals. Analyzing and interpreting such complex signals pose many challenges. Traditional analyses of fluorescent changes typically rely on manually outlined static region-of-interests, but such analyses fail to capture the intricate spatiotemporal patterns of astrocytic Ca2+ dynamics. Moreover, all astrocytic Ca2+ imaging data obtained from awake behaving mice need to be interpreted in light of the complex behavioral patterns of the animal. Hence processing multimodal data, including animal behavior metrics, stimulation timings, and electrophysiological signals is needed to interpret astrocytic Ca2+ signals. Managing and incorporating these data types into a coherent analysis pipeline is challenging and time-consuming, especially if research protocols change or new data types are added. Here, we introduce Begonia, a MATLAB-based data management and analysis toolbox tailored for the analyses of astrocytic Ca2+ signals in conjunction with behavioral data. The analysis suite includes an automatic, event-based algorithm with few input parameters that can capture a high level of spatiotemporal complexity of astrocytic Ca2+ signals. The toolbox enables the experimentalist to quantify astrocytic Ca2+ signals in a precise and unbiased way and combine them with other types of time series data.
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Affiliation(s)
- Daniel M Bjørnstad
- GliaLab at the Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Knut S Åbjørsbråten
- GliaLab at the Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Eivind Hennestad
- Lab for Neural Computation, Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Céline Cunen
- Statistics and Data Science Group, Department of Mathematics, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Gudmund Horn Hermansen
- Statistics and Data Science Group, Department of Mathematics, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Laura Bojarskaite
- GliaLab at the Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Klas H Pettersen
- GliaLab at the Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,NORA-Norwegian Artificial Intelligence Research Consortium, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Koen Vervaeke
- Lab for Neural Computation, Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Rune Enger
- GliaLab at the Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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27
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Lim D, Semyanov A, Genazzani A, Verkhratsky A. Calcium signaling in neuroglia. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 362:1-53. [PMID: 34253292 DOI: 10.1016/bs.ircmb.2021.01.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glial cells exploit calcium (Ca2+) signals to perceive the information about the activity of the nervous tissue and the tissue environment to translate this information into an array of homeostatic, signaling and defensive reactions. Astrocytes, the best studied glial cells, use several Ca2+ signaling generation pathways that include Ca2+ entry through plasma membrane, release from endoplasmic reticulum (ER) and from mitochondria. Activation of metabotropic receptors on the plasma membrane of glial cells is coupled to an enzymatic cascade in which a second messenger, InsP3 is generated thus activating intracellular Ca2+ release channels in the ER endomembrane. Astrocytes also possess store-operated Ca2+ entry and express several ligand-gated Ca2+ channels. In vivo astrocytes generate heterogeneous Ca2+ signals, which are short and frequent in distal processes, but large and relatively rare in soma. In response to neuronal activity intracellular and inter-cellular astrocytic Ca2+ waves can be produced. Astrocytic Ca2+ signals are involved in secretion, they regulate ion transport across cell membranes, and are contributing to cell morphological plasticity. Therefore, astrocytic Ca2+ signals are linked to fundamental functions of the central nervous system ranging from synaptic transmission to behavior. In oligodendrocytes, Ca2+ signals are generated by plasmalemmal Ca2+ influx, or by release from intracellular stores, or by combination of both. Microglial cells exploit Ca2+ permeable ionotropic purinergic receptors and transient receptor potential channels as well as ER Ca2+ release. In this contribution, basic morphology of glial cells, glial Ca2+ signaling toolkit, intracellular Ca2+ signals and Ca2+-regulated functions are discussed with focus on astrocytes.
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Affiliation(s)
- Dmitry Lim
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale, Novara, Italy.
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia; Faculty of Biology, Moscow State University, Moscow, Russia; Sechenov First Moscow State Medical University, Moscow, Russia
| | - Armando Genazzani
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale, Novara, Italy
| | - Alexei Verkhratsky
- Sechenov First Moscow State Medical University, Moscow, Russia; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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28
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Denisov P, Popov A, Brazhe A, Lazareva N, Verkhratsky A, Semyanov A. Caloric restriction modifies spatiotemporal calcium dynamics in mouse hippocampal astrocytes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119034. [PMID: 33836176 DOI: 10.1016/j.bbamcr.2021.119034] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/18/2021] [Accepted: 03/29/2021] [Indexed: 11/17/2022]
Abstract
We analysed spatiotemporal properties of Ca2+ signals in protoplasmic astrocytes in the CA1 stratum radiatum of hippocampal slices from young (2-3 months old) mice housed in control conditions or exposed to a caloric restriction (CR) diet for one month. The astrocytic Ca2+ events became shorter in duration and smaller in size; they also demonstrated reduced velocity of expansion and shrinkage following CR. At the same time, Ca2+ signals in the astrocytes from the CR animals demonstrated higher amplitude and the faster rise and decay rates. These changes can be attributed to CR-induced morphological remodelling and uncoupling of astrocytes described in our previous study. CR-induced changes in the parameters of Ca2+ activity were partially reversed by inhibition of gap junctions/hemichannels with carbenoxolone (CBX). The effect of CBX on Ca2+ activity in CR-animals was unexpected because the diet already decreases gap junctional coupling in astrocytic syncytia. It may reflect the blockade of hemichannels also sensitive to this drug. Thus, CR-induced morphological remodelling of astrocytes is at least partly responsible for changes in the pattern of Ca2+ activity in the astrocytic network. How such changes in spatiotemporal Ca2+ landscape can translate into astrocytic physiology and neuron-glia interactions remains a matter for future studies.
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Affiliation(s)
- Pavel Denisov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow 117997, Russia; Faculty of Biology, Nizhny Novgorod University, Nizhny Novgorod, Russia
| | - Alexander Popov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow 117997, Russia; Faculty of Biology, Nizhny Novgorod University, Nizhny Novgorod, Russia
| | - Alexey Brazhe
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow 117997, Russia; Faculty of Biology, Moscow State University, Moscow, Russia
| | | | - Alexei Verkhratsky
- Sechenov First Moscow State Medical University, Moscow, Russia; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain; Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow 117997, Russia; Faculty of Biology, Moscow State University, Moscow, Russia; Sechenov First Moscow State Medical University, Moscow, Russia.
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29
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Iwai Y, Ozawa K, Yahagi K, Mishima T, Akther S, Vo CT, Lee AB, Tanaka M, Itohara S, Hirase H. Transient Astrocytic Gq Signaling Underlies Remote Memory Enhancement. Front Neural Circuits 2021; 15:658343. [PMID: 33828463 PMCID: PMC8019746 DOI: 10.3389/fncir.2021.658343] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 02/24/2021] [Indexed: 01/31/2023] Open
Abstract
Astrocytes elicit transient Ca2+ elevations induced by G protein-coupled receptors (GPCRs), yet their role in vivo remains unknown. To address this, transgenic mice with astrocytic expression of the optogenetic Gq-type GPCR, Optoα1AR, were established, in which transient Ca2+ elevations similar to those in wild type mice were induced by brief blue light illumination. Activation of cortical astrocytes resulted in an adenosine A1 receptor-dependent inhibition of neuronal activity. Moreover, sensory stimulation with astrocytic activation induced long-term depression of sensory evoked response. At the behavioral level, repeated astrocytic activation in the anterior cortex gradually affected novel open field exploratory behavior, and remote memory was enhanced in a novel object recognition task. These effects were blocked by A1 receptor antagonism. Together, we demonstrate that GPCR-triggered Ca2+ elevation in cortical astrocytes has causal impacts on neuronal activity and behavior.
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Affiliation(s)
- Youichi Iwai
- Laboratory for Neuron-Glia Circuitry, RIKEN Center for Brain Science, Wako, Japan
| | - Katsuya Ozawa
- Laboratory for Neuron-Glia Circuitry, RIKEN Center for Brain Science, Wako, Japan
| | - Kazuko Yahagi
- Laboratory for Neuron-Glia Circuitry, RIKEN Center for Brain Science, Wako, Japan
| | - Tsuneko Mishima
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sonam Akther
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Camilla Trang Vo
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Ashley Bomin Lee
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mika Tanaka
- Laboratory for Neuron-Glia Circuitry, RIKEN Center for Brain Science, Wako, Japan
- Laboratory for Behavioral Genetics, RIKEN Center for Brain Science, Wako, Japan
| | - Shigeyoshi Itohara
- Laboratory for Behavioral Genetics, RIKEN Center for Brain Science, Wako, Japan
| | - Hajime Hirase
- Laboratory for Neuron-Glia Circuitry, RIKEN Center for Brain Science, Wako, Japan
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark
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30
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Popov A, Brazhe A, Denisov P, Sutyagina O, Li L, Lazareva N, Verkhratsky A, Semyanov A. Astrocyte dystrophy in ageing brain parallels impaired synaptic plasticity. Aging Cell 2021; 20:e13334. [PMID: 33675569 PMCID: PMC7963330 DOI: 10.1111/acel.13334] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 12/30/2020] [Accepted: 02/08/2021] [Indexed: 01/02/2023] Open
Abstract
Little is known about age-dependent changes in structure and function of astrocytes and of the impact of these on the cognitive decline in the senescent brain. The prevalent view on the age-dependent increase in reactive astrogliosis and astrocytic hypertrophy requires scrutiny and detailed analysis. Using two-photon microscopy in conjunction with 3D reconstruction, Sholl and volume fraction analysis, we demonstrate a significant reduction in the number and the length of astrocytic processes, in astrocytic territorial domains and in astrocyte-to-astrocyte coupling in the aged brain. Probing physiology of astrocytes with patch clamp, and Ca2+ imaging revealed deficits in K+ and glutamate clearance and spatiotemporal reorganisation of Ca2+ events in old astrocytes. These changes paralleled impaired synaptic long-term potentiation (LTP) in hippocampal CA1 in old mice. Our findings may explain the astroglial mechanisms of age-dependent decline in learning and memory.
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Affiliation(s)
- Alexander Popov
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Institute of NeuroscienceNizhny Novgorod UniversityNizhny NovgorodRussia
| | - Alexey Brazhe
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Faculty of BiologyMoscow State UniversityMoscowRussia
| | - Pavel Denisov
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Institute of NeuroscienceNizhny Novgorod UniversityNizhny NovgorodRussia
| | - Oksana Sutyagina
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Institute of NeuroscienceNizhny Novgorod UniversityNizhny NovgorodRussia
| | - Li Li
- Department of PhysiologyJiaxing University College of MedicineZhejiang ProChina
| | | | - Alexei Verkhratsky
- Sechenov First Moscow State Medical UniversityMoscowRussia
- Faculty of Biology, Medicine and HealthThe University of ManchesterManchesterUK
- Achucarro Center for NeuroscienceIKERBASQUEBasque Foundation for ScienceBilbaoSpain
- Department of NeurosciencesUniversity of the Basque Country UPV/EHU and CIBERNEDLeioaSpain
| | - Alexey Semyanov
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Faculty of BiologyMoscow State UniversityMoscowRussia
- Sechenov First Moscow State Medical UniversityMoscowRussia
- Department of PhysiologyJiaxing University College of MedicineZhejiang ProChina
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31
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Horvat A, Muhič M, Smolič T, Begić E, Zorec R, Kreft M, Vardjan N. Ca 2+ as the prime trigger of aerobic glycolysis in astrocytes. Cell Calcium 2021; 95:102368. [PMID: 33621899 DOI: 10.1016/j.ceca.2021.102368] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 02/05/2021] [Accepted: 02/08/2021] [Indexed: 12/17/2022]
Abstract
Astroglial aerobic glycolysis, a process during which d-glucose is converted to l-lactate, a brain fuel and signal, is regulated by the plasmalemmal receptors, including adrenergic receptors (ARs) and purinergic receptors (PRs), modulating intracellular Ca2+ and cAMP signals. However, the extent to which the two signals regulate astroglial aerobic glycolysis is poorly understood. By using agonists to stimulate intracellular α1-/β-AR-mediated Ca2+/cAMP signals, β-AR-mediated cAMP and P2R-mediated Ca2+ signals and genetically encoded fluorescence resonance energy transfer-based glucose and lactate nanosensors in combination with real-time microscopy, we show that intracellular Ca2+, but not cAMP, initiates a robust increase in the concentration of intracellular free d-glucose ([glc]i) and l-lactate ([lac]i), both depending on extracellular d-glucose, suggesting Ca2+-triggered glucose uptake and aerobic glycolysis in astrocytes. When the glycogen shunt, a process of glycogen remodelling, was inhibited, the α1-/β-AR-mediated increases in [glc]i and [lac]i were reduced by ∼65 % and ∼30 %, respectively, indicating that at least ∼30 % of the utilization of d-glucose is linked to glycogen remodelling and aerobic glycolysis. Additional activation of β-AR/cAMP signals aided to α1-/β-AR-triggered [lac]i increase, whereas the [glc]i increase was unaltered. Taken together, an increase in intracellular Ca2+ is the prime mechanism of augmented aerobic glycolysis in astrocytes, while cAMP has only a moderate role. The results provide novel information on the signals regulating brain metabolism and open new avenues to explore whether astroglial Ca2+ signals are dysregulated and contribute to neuropathologies with impaired brain metabolism.
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Affiliation(s)
- Anemari Horvat
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Marko Muhič
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Tina Smolič
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Ena Begić
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia; Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Nina Vardjan
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia.
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Piccialli I, Tedeschi V, Boscia F, Ciccone R, Casamassa A, de Rosa V, Grieco P, Secondo A, Pannaccione A. The Anemonia sulcata Toxin BDS-I Protects Astrocytes Exposed to Aβ 1-42 Oligomers by Restoring [Ca 2+] i Transients and ER Ca 2+ Signaling. Toxins (Basel) 2020; 13:20. [PMID: 33396295 PMCID: PMC7823622 DOI: 10.3390/toxins13010020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/22/2020] [Accepted: 12/24/2020] [Indexed: 12/28/2022] Open
Abstract
Intracellular calcium concentration ([Ca2+]i) transients in astrocytes represent a highly plastic signaling pathway underlying the communication between neurons and glial cells. However, how this important phenomenon may be compromised in Alzheimer's disease (AD) remains unexplored. Moreover, the involvement of several K+ channels, including KV3.4 underlying the fast-inactivating currents, has been demonstrated in several AD models. Here, the effect of KV3.4 modulation by the marine toxin blood depressing substance-I (BDS-I) extracted from Anemonia sulcata has been studied on [Ca2+]i transients in rat primary cortical astrocytes exposed to Aβ1-42 oligomers. We showed that: (1) primary cortical astrocytes expressing KV3.4 channels displayed [Ca2+]i transients depending on the occurrence of membrane potential spikes, (2) BDS-I restored, in a dose-dependent way, [Ca2+]i transients in astrocytes exposed to Aβ1-42 oligomers (5 µM/48 h) by inhibiting hyperfunctional KV3.4 channels, (3) BDS-I counteracted Ca2+ overload into the endoplasmic reticulum (ER) induced by Aβ1-42 oligomers, (4) BDS-I prevented the expression of the ER stress markers including active caspase 12 and GRP78/BiP in astrocytes treated with Aβ1-42 oligomers, and (5) BDS-I prevented Aβ1-42-induced reactive oxygen species (ROS) production and cell suffering measured as mitochondrial activity and lactate dehydrogenase (LDH) release. Collectively, we proposed that the marine toxin BDS-I, by inhibiting the hyperfunctional KV3.4 channels and restoring [Ca2+]i oscillation frequency, prevented Aβ1-42-induced ER stress and cell suffering in astrocytes.
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Affiliation(s)
- Ilaria Piccialli
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, 80131 Napoli, Italy; (I.P.); (V.T.); (F.B.); (R.C.); (A.C.); (V.d.R.)
| | - Valentina Tedeschi
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, 80131 Napoli, Italy; (I.P.); (V.T.); (F.B.); (R.C.); (A.C.); (V.d.R.)
| | - Francesca Boscia
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, 80131 Napoli, Italy; (I.P.); (V.T.); (F.B.); (R.C.); (A.C.); (V.d.R.)
| | - Roselia Ciccone
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, 80131 Napoli, Italy; (I.P.); (V.T.); (F.B.); (R.C.); (A.C.); (V.d.R.)
| | - Antonella Casamassa
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, 80131 Napoli, Italy; (I.P.); (V.T.); (F.B.); (R.C.); (A.C.); (V.d.R.)
| | - Valeria de Rosa
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, 80131 Napoli, Italy; (I.P.); (V.T.); (F.B.); (R.C.); (A.C.); (V.d.R.)
| | - Paolo Grieco
- Department of Pharmacy, School of Medicine, Federico II Universityof Naples, 80131 Napoli, Italy;
| | - Agnese Secondo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, 80131 Napoli, Italy; (I.P.); (V.T.); (F.B.); (R.C.); (A.C.); (V.d.R.)
| | - Anna Pannaccione
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, 80131 Napoli, Italy; (I.P.); (V.T.); (F.B.); (R.C.); (A.C.); (V.d.R.)
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Mitroshina EV, Krivonosov MI, Burmistrov DE, Savyuk MO, Mishchenko TA, Ivanchenko MV, Vedunova MV. Signatures of the Consolidated Response of Astrocytes to Ischemic Factors In Vitro. Int J Mol Sci 2020; 21:E7952. [PMID: 33114758 PMCID: PMC7672566 DOI: 10.3390/ijms21217952] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/20/2020] [Accepted: 10/23/2020] [Indexed: 12/20/2022] Open
Abstract
Whether and under what conditions astrocytes can mount a collective network response has recently become one of the central questions in neurobiology. Here, we address this problem, investigating astrocytic reactions to different biochemical stimuli and ischemic-like conditions in vitro. Identifying an emergent astrocytic network is based on a novel mathematical approach that extracts calcium activity from time-lapse fluorescence imaging and estimates the connectivity of astrocytes. The developed algorithm represents the astrocytic network as an oriented graph in which the nodes correspond to separate astrocytes, and the edges indicate high dynamical correlations between astrocytic events. We demonstrate that ischemic-like conditions decrease network connectivity in primary cultures in vitro, although calcium events persist. Importantly, we found that stimulation under normal conditions with 10 µM ATP increases the number of long-range connections and the degree of corresponding correlations in calcium activity, apart from the frequency of calcium events. This result indicates that astrocytes can form a large functional network in response to certain stimuli. In the post-ischemic interval, the response to ATP stimulation is not manifested, which suggests a deep lesion in functional astrocytic networks. The blockade of Connexin 43 during ischemic modeling preserves the connectivity of astrocytes in the post-hypoxic period.
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Affiliation(s)
- Elena V. Mitroshina
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhni Novgorod, 23 Prospekt Gagarina, 603950 Nizhny Novgorod, Russia; (D.E.B.); (M.O.S.); (T.A.M.)
| | - Mikhail I. Krivonosov
- Institute of Information, Technology, Mathematics and Mechanics, Lobachevsky State University of Nizhni Novgorod, 23 Prospekt Gagarina, 603950 Nizhny Novgorod, Russia; (M.I.K.); (M.V.I.)
| | - Dmitriy E. Burmistrov
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhni Novgorod, 23 Prospekt Gagarina, 603950 Nizhny Novgorod, Russia; (D.E.B.); (M.O.S.); (T.A.M.)
| | - Maria O. Savyuk
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhni Novgorod, 23 Prospekt Gagarina, 603950 Nizhny Novgorod, Russia; (D.E.B.); (M.O.S.); (T.A.M.)
| | - Tatiana A. Mishchenko
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhni Novgorod, 23 Prospekt Gagarina, 603950 Nizhny Novgorod, Russia; (D.E.B.); (M.O.S.); (T.A.M.)
| | - Mikhail V. Ivanchenko
- Institute of Information, Technology, Mathematics and Mechanics, Lobachevsky State University of Nizhni Novgorod, 23 Prospekt Gagarina, 603950 Nizhny Novgorod, Russia; (M.I.K.); (M.V.I.)
| | - Maria V. Vedunova
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhni Novgorod, 23 Prospekt Gagarina, 603950 Nizhny Novgorod, Russia; (D.E.B.); (M.O.S.); (T.A.M.)
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Verkhratsky A, Augusto-Oliveira M, Pivoriūnas A, Popov A, Brazhe A, Semyanov A. Astroglial asthenia and loss of function, rather than reactivity, contribute to the ageing of the brain. Pflugers Arch 2020; 473:753-774. [PMID: 32979108 DOI: 10.1007/s00424-020-02465-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/05/2020] [Accepted: 09/09/2020] [Indexed: 12/13/2022]
Abstract
Astroglia represent a class of heterogeneous, in form and function, cells known as astrocytes, which provide for homoeostasis and defence of the central nervous system (CNS). Ageing is associated with morphological and functional remodelling of astrocytes with a prevalence of morphological atrophy and loss of function. In particular, ageing is associated with (i) decrease in astroglial synaptic coverage, (ii) deficits in glutamate and potassium clearance, (iii) reduced astroglial synthesis of synaptogenic factors such as cholesterol, (iv) decrease in aquaporin 4 channels in astroglial endfeet with subsequent decline in the glymphatic clearance, (v) decrease in astroglial metabolic support through the lactate shuttle, (vi) dwindling adult neurogenesis resulting from diminished proliferative capacity of radial stem astrocytes, (vii) decline in the astroglial-vascular coupling and deficient blood-brain barrier and (viii) decrease in astroglial ability to mount reactive astrogliosis. Decrease in reactive capabilities of astroglia are associated with rise of age-dependent neurodegenerative diseases. Astroglial morphology and function can be influenced and improved by lifestyle interventions such as intellectual engagement, social interactions, physical exercise, caloric restriction and healthy diet. These modifications of lifestyle are paramount for cognitive longevity.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK. .,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain. .,Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.
| | - Marcus Augusto-Oliveira
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, 66075-110, Brazil
| | - Augustas Pivoriūnas
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102, Vilnius, Lithuania
| | - Alexander Popov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, Russia, 117997
| | - Alexey Brazhe
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, Russia, 117997.,Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, Russia, 117997. .,Sechenov First Moscow State Medical University, Moscow, Russia.
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Mitochondrial Calcium Deregulation in the Mechanism of Beta-Amyloid and Tau Pathology. Cells 2020; 9:cells9092135. [PMID: 32967303 PMCID: PMC7564294 DOI: 10.3390/cells9092135] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/18/2020] [Accepted: 09/19/2020] [Indexed: 02/06/2023] Open
Abstract
Aggregation and deposition of β-amyloid and/or tau protein are the key neuropathological features in neurodegenerative disorders such as Alzheimer's disease (AD) and other tauopathies including frontotemporal dementia (FTD). The interaction between oxidative stress, mitochondrial dysfunction and the impairment of calcium ions (Ca2+) homeostasis induced by misfolded tau and β-amyloid plays an important role in the progressive neuronal loss occurring in specific areas of the brain. In addition to the control of bioenergetics and ROS production, mitochondria are fine regulators of the cytosolic Ca2+ homeostasis that induce vital signalling mechanisms in excitable cells such as neurons. Impairment in the mitochondrial Ca2+ uptake through the mitochondrial Ca2+ uniporter (MCU) or release through the Na+/Ca2+ exchanger may lead to mitochondrial Ca2+ overload and opening of the permeability transition pore inducing neuronal death. Recent evidence suggests an important role for these mechanisms as the underlying causes for neuronal death in β-amyloid and tau pathology. The present review will focus on the mechanisms that lead to cytosolic and especially mitochondrial Ca2+ disturbances occurring in AD and tau-induced FTD, and propose possible therapeutic interventions for these disorders.
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36
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Semyanov A, Henneberger C, Agarwal A. Making sense of astrocytic calcium signals — from acquisition to interpretation. Nat Rev Neurosci 2020; 21:551-564. [DOI: 10.1038/s41583-020-0361-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2020] [Indexed: 12/31/2022]
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37
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Jurisch-Yaksi N, Yaksi E, Kizil C. Radial glia in the zebrafish brain: Functional, structural, and physiological comparison with the mammalian glia. Glia 2020; 68:2451-2470. [PMID: 32476207 DOI: 10.1002/glia.23849] [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] [Received: 04/01/2020] [Revised: 05/07/2020] [Accepted: 05/13/2020] [Indexed: 02/01/2023]
Abstract
The neuroscience community has witnessed a tremendous expansion of glia research. Glial cells are now on center stage with leading roles in the development, maturation, and physiology of brain circuits. Over the course of evolution, glia have highly diversified and include the radial glia, astroglia or astrocytes, microglia, oligodendrocytes, and ependymal cells, each having dedicated functions in the brain. The zebrafish, a small teleost fish, is no exception to this and recent evidences point to evolutionarily conserved roles for glia in the development and physiology of its nervous system. Due to its small size, transparency, and genetic amenability, the zebrafish has become an increasingly prominent animal model for brain research. It has enabled the study of neural circuits from individual cells to entire brains, with a precision unmatched in other vertebrate models. Moreover, its high neurogenic and regenerative potential has attracted a lot of attention from the research community focusing on neural stem cells and neurodegenerative diseases. Hence, studies using zebrafish have the potential to provide fundamental insights about brain development and function, and also elucidate neural and molecular mechanisms of neurological diseases. We will discuss here recent discoveries on the diverse roles of radial glia and astroglia in neurogenesis, in modulating neuronal activity and in regulating brain homeostasis at the brain barriers. By comparing insights made in various animal models, particularly mammals and zebrafish, our goal is to highlight the similarities and differences in glia biology among species, which could set new paradigms relevant to humans.
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Affiliation(s)
- Nathalie Jurisch-Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Neurology and Clinical Neurophysiology, St Olav University Hospital, Trondheim, Norway
| | - Emre Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Trondheim, Norway
| | - Caghan Kizil
- German Center for Neurodegenerative Diseases (DZNE), Helmholtz Association, Dresden, Germany.,Center for Molecular and Cellular Bioengineering (CMCB), TU Dresden, Dresden, Germany
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38
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Whitwell HJ, Bacalini MG, Blyuss O, Chen S, Garagnani P, Gordleeva SY, Jalan S, Ivanchenko M, Kanakov O, Kustikova V, Mariño IP, Meyerov I, Ullner E, Franceschi C, Zaikin A. The Human Body as a Super Network: Digital Methods to Analyze the Propagation of Aging. Front Aging Neurosci 2020; 12:136. [PMID: 32523526 PMCID: PMC7261843 DOI: 10.3389/fnagi.2020.00136] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 04/22/2020] [Indexed: 12/13/2022] Open
Abstract
Biological aging is a complex process involving multiple biological processes. These can be understood theoretically though considering them as individual networks-e.g., epigenetic networks, cell-cell networks (such as astroglial networks), and population genetics. Mathematical modeling allows the combination of such networks so that they may be studied in unison, to better understand how the so-called "seven pillars of aging" combine and to generate hypothesis for treating aging as a condition at relatively early biological ages. In this review, we consider how recent progression in mathematical modeling can be utilized to investigate aging, particularly in, but not exclusive to, the context of degenerative neuronal disease. We also consider how the latest techniques for generating biomarker models for disease prediction, such as longitudinal analysis and parenclitic analysis can be applied to as both biomarker platforms for aging, as well as to better understand the inescapable condition. This review is written by a highly diverse and multi-disciplinary team of scientists from across the globe and calls for greater collaboration between diverse fields of research.
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Affiliation(s)
- Harry J Whitwell
- Department of Chemical Engineering, Imperial College London, London, United Kingdom
| | | | - Oleg Blyuss
- School of Physics, Astronomy and Mathematics, University of Hertfordshire, Harfield, United Kingdom.,Department of Paediatrics and Paediatric Infectious Diseases, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Shangbin Chen
- Britton Chance Centre for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
| | - Paolo Garagnani
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Susan Yu Gordleeva
- Laboratory of Systems Medicine of Healthy Aging, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Sarika Jalan
- Complex Systems Laboratory, Discipline of Physics, Indian Institute of Technology Indore, Indore, India.,Centre for Bio-Science and Bio-Medical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Mikhail Ivanchenko
- Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Oleg Kanakov
- Laboratory of Systems Medicine of Healthy Aging, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Valentina Kustikova
- Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Ines P Mariño
- Department of Biology and Geology, Physics and Inorganic Chemistry, Universidad Rey Juan Carlos, Madrid, Spain
| | - Iosif Meyerov
- Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Ekkehard Ullner
- Department of Physics (SUPA), Institute for Complex Systems and Mathematical Biology, University of Aberdeen, Aberdeen, United Kingdom
| | - Claudio Franceschi
- Laboratory of Systems Medicine of Healthy Aging, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia.,Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Alexey Zaikin
- Department of Paediatrics and Paediatric Infectious Diseases, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia.,Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia.,Department of Mathematics, Institute for Women's Health, University College London, London, United Kingdom
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Popov A, Denisov P, Bychkov M, Brazhe A, Lyukmanova E, Shenkarev Z, Lazareva N, Verkhratsky A, Semyanov A. Caloric restriction triggers morphofunctional remodeling of astrocytes and enhances synaptic plasticity in the mouse hippocampus. Cell Death Dis 2020; 11:208. [PMID: 32231202 PMCID: PMC7105492 DOI: 10.1038/s41419-020-2406-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/15/2020] [Accepted: 02/18/2020] [Indexed: 11/22/2022]
Abstract
Calorie-restricted (CR) diet has multiple beneficial effects on brain function. Here we report morphological and functional changes in hippocampal astrocytes in 3-months-old mice subjected to 1 month of the diet. Whole-cell patch-clamp recordings were performed in the CA1 stratum (str.) radiatum astrocytes of hippocampal slices. The cells were also loaded with fluorescent dye through the patch pipette. CR did not affect the number of astrocytic branches but increased the volume fraction (VF) of distal perisynaptic astrocytic leaflets. The astrocyte growth did not lead to a decrease in the cell input resistance, which may be attributed to a decrease in astrocyte coupling through the gap junctions. Western blotting revealed a decrease in the expression of Cx43 but not Cx30. Immunocytochemical analysis demonstrated a decrease in the density and size of Cx43 clusters. Cx30 cluster density did not change, while their size increased in the vicinity of astrocytic soma. CR shortened K+ and glutamate transporter currents in astrocytes in response to 5 × 50 Hz Schaffer collateral stimulation. However, no change in the expression of astrocytic glutamate transporter 1 (GLT-1) was observed, while the level of glutamine synthetase (GS) decreased. These findings suggest that enhanced enwrapping of synapses by the astrocytic leaflets reduces glutamate and K+ spillover. Reduced spillover led to a decreased contribution of extrasynaptic N2B containing N-methyl-D-aspartate receptors (NMDARs) to the tail of burst-induced EPSCs. The magnitude of long-term potentiation (LTP) in the glutamatergic CA3–CA1 synapses was significantly enhanced after CR. This enhancement was abolished by N2B-NMDARs antagonist. Our findings suggest that astrocytic morphofunctional remodeling is responsible for enhanced synaptic plasticity, which provides a basis for improved learning and memory reported after CR.
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Affiliation(s)
- Alexander Popov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Pavel Denisov
- University of Nizhny Novgorod, Gagarin Ave. 23, Nizhny Novgorod, 603950, Russia
| | - Maxim Bychkov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Alexey Brazhe
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia.,Faculty of Biology, Moscow State University, Leninskie Gory 1/12, Moscow, 119234, Russia
| | - Ekaterina Lyukmanova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Zakhar Shenkarev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Natalia Lazareva
- Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya, 19с1, Moscow, 119146, Russia
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK. .,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia. .,Faculty of Biology, Moscow State University, Leninskie Gory 1/12, Moscow, 119234, Russia. .,Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya, 19с1, Moscow, 119146, Russia.
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40
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Martinez-Banaclocha M. Astroglial Isopotentiality and Calcium-Associated Biomagnetic Field Effects on Cortical Neuronal Coupling. Cells 2020; 9:cells9020439. [PMID: 32069981 PMCID: PMC7073214 DOI: 10.3390/cells9020439] [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: 01/18/2020] [Revised: 02/07/2020] [Accepted: 02/10/2020] [Indexed: 01/01/2023] Open
Abstract
Synaptic neurotransmission is necessary but does not sufficiently explain superior cognitive faculties. Growing evidence has shown that neuron-astroglial chemical crosstalk plays a critical role in the processing of information, computation, and memory. In addition to chemical and electrical communication among neurons and between neurons and astrocytes, other nonsynaptic mechanisms called ephaptic interactions can contribute to the neuronal synchronization from different brain regions involved in the processing of information. New research on brain astrocytes has clearly shown that the membrane potential of these cells remains very stable among neighboring and distant astrocytes due to the marked bioelectric coupling between them through gap junctions. This finding raises the possibility that the neocortical astroglial network exerts a guiding template modulating the excitability and synchronization of trillions of neurons by astroglial Ca2+-associated bioelectromagnetic interactions. We propose that bioelectric and biomagnetic fields of the astroglial network equalize extracellular local field potentials (LFPs) and associated local magnetic field potentials (LMFPs) in the cortical layers of the brain areas involved in the processing of information, contributing to the adequate and coherent integration of external and internal signals. This article reviews the current knowledge of ephaptic interactions in the cerebral cortex and proposes that the isopotentiality of cortical astrocytes is a prerequisite for the maintenance of the bioelectromagnetic crosstalk between neurons and astrocytes in the neocortex.
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41
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Hernandez E, MacNamee SE, Kaplan LR, Lance K, Garcia-Verdugo HD, Farhadi DS, Deer C, Lee SW, Oland LA. The astrocyte network in the ventral nerve cord neuropil of the Drosophila third-instar larva. J Comp Neurol 2020; 528:1683-1703. [PMID: 31909826 DOI: 10.1002/cne.24852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 12/19/2019] [Accepted: 12/20/2019] [Indexed: 11/10/2022]
Abstract
Understanding neuronal function at the local and circuit level requires understanding astrocyte function. We have provided a detailed analysis of astrocyte morphology and territory in the Drosophila third-instar ventral nerve cord where there already exists considerable understanding of the neuronal network. Astrocyte shape varies more than previously reported; many have bilaterally symmetrical partners, many have a high percentage of their arborization in adjacent segments, and many have branches that follow structural features. Taken together, our data are consistent with, but not fully explained by, a model of a developmental growth process dominated by competitive or repulsive interactions between astrocytes. Our data suggest that the model should also include cell-autonomous aspects, as well as the use of structural features for growth. Variation in location of arborization territory for identified astrocytes was great enough that a standardized scheme of neuropil division among the six astrocytes that populate each hemi-segment is not possible at the third instar. The arborizations of the astrocytes can extend across neuronal functional domains. The ventral astrocyte in particular, whose territory can extend well into the proprioceptive region of the neuropil, has no obvious branching pattern that correlates with domains of particular sensory modalities, suggesting that the astrocyte would respond to neuronal activity in any of the sensory modalities, perhaps integrating across them. This study sets the stage for future studies that will generate a robust, functionally oriented connectome that includes both partners in neuronal circuits-the neurons and the glial cells, providing the foundation necessary for studies to elucidate neuron-glia interactions in this neuropil.
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Key Words
- RRID:Abcam Cat# ab6953, RRID:AB_955010
- RRID:BDSC Cat# 30125, RRID:BDSC_30125
- RRID:BDSC Cat# 38760, RRID:BDSC_38760
- RRID:BDSC Cat# 4775, RRID:BDSC_4775
- RRID:BDSC Cat# 5692, RRID:BDSC_5692
- RRID:BDSC Cat# 64085, RRID:BDSC_64085
- RRID:BDSC Cat# 6938, RRID:BDSC_6938
- RRID:Bio-rad Cat # MCA1360, RRID:AB_322378
- RRID:Cell Signaling Technology Cat # 3724, RRID:AB_1549585
- RRID:DSHB Cat# 1D4, RRID:AB_528235
- RRID:DSHB Cat# nc82, RRID:AB_2314866
- RRID:Jackson ImmunoResearch Labs Cat# 115-167-003, RRID:AB_2338709
- RRID:Molecular Probes Cat# 6455, RRID:AB_2314543
- RRID:Molecular Probes Cat# A-21236, RRID:AB_141725
- RRID:Novus Cat # NBP1-06712, RRID:AB_1625981
- RRID:Thermo Fisher Scientific Cat# A-11034, RRID:AB_2576217.
- glial cells
- neuron-glia interaction
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Affiliation(s)
- Ernesto Hernandez
- Department of Neuroscience, University of Arizona, Tucson, Arizona.,University of Illinois at Chicago School of Medicine, Rockford, Illinois
| | - Sarah E MacNamee
- Department of Neuroscience, University of Arizona, Tucson, Arizona.,Inscopix, Palo Alto, California
| | - Leah R Kaplan
- Department of Neuroscience, University of Arizona, Tucson, Arizona.,Consortium for Science, Policy & Outcomes, Arizona State University, Washington, DC, Washington
| | - Kim Lance
- Department of Neuroscience, University of Arizona, Tucson, Arizona
| | | | - Dara S Farhadi
- Department of Neuroscience, University of Arizona, Tucson, Arizona.,College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona
| | - Christine Deer
- Department of Neuroscience, University of Arizona, Tucson, Arizona.,Research Technologies Group, Data Visualization Team, University of Arizona, University Information Technology Service, Tucson, Arizona
| | - Si W Lee
- Department of Neuroscience, University of Arizona, Tucson, Arizona
| | - Lynne A Oland
- Department of Neuroscience, University of Arizona, Tucson, Arizona
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42
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Rose CR, Ziemens D, Verkhratsky A. On the special role of NCX in astrocytes: Translating Na +-transients into intracellular Ca 2+ signals. Cell Calcium 2019; 86:102154. [PMID: 31901681 DOI: 10.1016/j.ceca.2019.102154] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 12/02/2019] [Accepted: 12/02/2019] [Indexed: 10/25/2022]
Abstract
As a solute carrier electrogenic transporter, the sodium/calcium exchanger (NCX1-3/SLC8A1-A3) links the trans-plasmalemmal gradients of sodium and calcium ions (Na+, Ca2+) to the membrane potential of astrocytes. Classically, NCX is considered to serve the export of Ca2+ at the expense of the Na+ gradient, defined as a "forward mode" operation. Forward mode NCX activity contributes to Ca2+ extrusion and thus to the recovery from intracellular Ca2+ signals in astrocytes. The reversal potential of the NCX, owing to its transport stoichiometry of 3 Na+ to 1 Ca2+, is, however, close to the astrocytes' membrane potential and hence even small elevations in the astrocytic Na+ concentration or minor depolarisations switch it into the "reverse mode" (Ca2+ import/Na+ export). Notably, transient Na+ elevations in the millimolar range are induced by uptake of glutamate or GABA into astrocytes and/or by the opening of Na+-permeable ion channels in response to neuronal activity. Activity-related Na+ transients result in NCX reversal, which mediates Ca2+ influx from the extracellular space, thereby generating astrocyte Ca2+ signalling independent from InsP3-mediated release from intracellular stores. Under pathological conditions, reverse NCX promotes cytosolic Ca2+ overload, while dampening Na+ elevations of astrocytes. This review provides an overview on our current knowledge about this fascinating transporter and its special functional role in astrocytes. We shall delineate that Na+-driven, reverse NCX-mediated astrocyte Ca2+ signals are involved neurone-glia interaction. Na+ transients, translated by the NCX into Ca2+ elevations, thereby emerge as a new signalling pathway in astrocytes.
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Affiliation(s)
- Christine R Rose
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Duesseldorf, 40225, Duesseldorf, Germany.
| | - Daniel Ziemens
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Duesseldorf, 40225, Duesseldorf, Germany
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK; Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain
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43
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NCX activity generates spontaneous Ca 2+ oscillations in the astrocytic leaflet microdomain. Cell Calcium 2019; 86:102137. [PMID: 31838438 DOI: 10.1016/j.ceca.2019.102137] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 12/01/2019] [Accepted: 12/01/2019] [Indexed: 12/13/2022]
Abstract
The synergy between synaptic Glu release and astrocytic Glu-Na+ symport is essential to the signalling function of the tripartite synapse. Here we used kinetic data of astrocytic Glu transporters (EAAT) and the Na+/Ca2+ exchanger (NCX) to simulate Glu release, Glu uptake and subsequent Na+ and Ca2+ dynamics in the astrocytic leaflet microdomain following single release event. Model simulations show that Glu-Na+ symport differently affect intracellular [Na+] in synapses with different extent of astrocytic coverage. Surprisingly, NCX activity alone has been shown to generate markedly stable, spontaneous Ca2+ oscillation in the astrocytic leaflet. These on-going oscillations appear when NCX operates either in the forward or reverse direction. We conjecture that intrinsic NCX activity may play a prominent role in the generation of astrocytic Ca2+ oscillations.
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44
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Abstract
Cl- is the major extracellular (Cl-out) and intracellular (Cl-in) anion whose concentration is actively regulated by multiple transporters. These transporters generate Cl- gradients across the plasma membrane and between the cytoplasm and intracellular organelles. [Cl-]in changes rapidly in response to cell stimulation and influences many physiological functions, as well as cellular and systemic homeostasis. However, less appreciated is the signaling function of Cl-. Cl- interacts with multiple proteins to directly modify their activity. This review highlights the signaling function of Cl- and argues that Cl- is a bona fide signaling ion, a function deserving extensive exploration.
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Affiliation(s)
- Benjamin P Lüscher
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Laura Vachel
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Ehud Ohana
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
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45
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Vardjan N, Parpura V, Verkhratsky A, Zorec R. Gliocrine System: Astroglia as Secretory Cells of the CNS. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1175:93-115. [PMID: 31583585 DOI: 10.1007/978-981-13-9913-8_4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Astrocytes are secretory cells, actively participating in cell-to-cell communication in the central nervous system (CNS). They sense signaling molecules in the extracellular space, around the nearby synapses and also those released at much farther locations in the CNS, by their cell surface receptors, get excited to then release their own signaling molecules. This contributes to the brain information processing, based on diffusion within the extracellular space around the synapses and on convection when locales relatively far away from the release sites are involved. These functions resemble secretion from endocrine cells, therefore astrocytes were termed to be a part of the gliocrine system in 2015. An important mechanism, by which astrocytes release signaling molecules is the merger of the vesicle membrane with the plasmalemma, i.e., exocytosis. Signaling molecules stored in astroglial secretory vesicles can be discharged into the extracellular space after the vesicle membrane fuses with the plasma membrane. This leads to a fusion pore formation, a channel that must widen to allow the exit of the Vesiclal cargo. Upon complete vesicle membrane fusion, this process also integrates other proteins, such as receptors, transporters and channels into the plasma membrane, determining astroglial surface signaling landscape. Vesiclal cargo, together with the whole vesicle can also exit astrocytes by the fusion of multivesicular bodies with the plasma membrane (exosomes) or by budding of vesicles (ectosomes) from the plasma membrane into the extracellular space. These astroglia-derived extracellular vesicles can later interact with various target cells. Here, the characteristics of four types of astroglial secretory vesicles: synaptic-like microvesicles, dense-core vesicles, secretory lysosomes, and extracellular vesicles, are discussed. Then machinery for vesicle-based exocytosis, second messenger regulation and the kinetics of exocytotic vesicle content discharge or release of extracellular vesicles are considered. In comparison to rapidly responsive, electrically excitable neurons, the receptor-mediated cytosolic excitability-mediated astroglial exocytotic vesicle-based transmitter release is a relatively slow process.
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Affiliation(s)
- Nina Vardjan
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, 1000, Ljubljana, Slovenia. .,Celica Biomedical, 1000, Ljubljana, Slovenia.
| | - Vladimir Parpura
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK.,Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark.,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, 1000, Ljubljana, Slovenia. .,Celica Biomedical, 1000, Ljubljana, Slovenia.
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46
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Verkhratsky A, Rodrigues JJ, Pivoriunas A, Zorec R, Semyanov A. Astroglial atrophy in Alzheimer’s disease. Pflugers Arch 2019; 471:1247-1261. [DOI: 10.1007/s00424-019-02310-2] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/23/2019] [Accepted: 09/03/2019] [Indexed: 12/11/2022]
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47
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Song S, Luo L, Sun B, Sun D. Roles of glial ion transporters in brain diseases. Glia 2019; 68:472-494. [PMID: 31418931 DOI: 10.1002/glia.23699] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/22/2019] [Accepted: 07/26/2019] [Indexed: 12/21/2022]
Abstract
Glial ion transporters are important in regulation of ionic homeostasis, cell volume, and cellular signal transduction under physiological conditions of the central nervous system (CNS). In response to acute or chronic brain injuries, these ion transporters can be activated and differentially regulate glial functions, which has subsequent impact on brain injury or tissue repair and functional recovery. In this review, we summarized the current knowledge about major glial ion transporters, including Na+ /H+ exchangers (NHE), Na+ /Ca2+ exchangers (NCX), Na+ -K+ -Cl- cotransporters (NKCC), and Na+ -HCO3 - cotransporters (NBC). In acute neurological diseases, such as ischemic stroke and traumatic brain injury (TBI), these ion transporters are rapidly activated and play significant roles in regulation of the intra- and extracellular pH, Na+ , K+ , and Ca2+ homeostasis, synaptic plasticity, and myelin formation. However, overstimulation of these ion transporters can contribute to glial apoptosis, demyelination, inflammation, and excitotoxicity. In chronic brain diseases, such as glioma, Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS), glial ion transporters are involved in the glioma Warburg effect, glial activation, neuroinflammation, and neuronal damages. These findings suggest that glial ion transporters are involved in tissue structural and functional restoration, or brain injury and neurological disease development and progression. A better understanding of these ion transporters in acute and chronic neurological diseases will provide insights for their potential as therapeutic targets.
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Affiliation(s)
- Shanshan Song
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Lanxin Luo
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania.,School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, China.,School of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang, China
| | - Baoshan Sun
- School of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang, China.,Pólo Dois Portos, Instituto National de Investigação Agrária e Veterinária, Dois Portos, Portugal
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania.,Veterans Affairs Pittsburgh Health Care System, Geriatric Research, Educational and Clinical Center, Pittsburgh, Pennsylvania
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48
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Verkhratsky A, Semyanov A. Astroglial Ca 2+ signals trigger pathological behaviour in optogenetic mouse. Cell Calcium 2019; 82:102062. [PMID: 31374418 DOI: 10.1016/j.ceca.2019.102062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 07/04/2019] [Indexed: 11/16/2022]
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain; Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia; Sechenov First Moscow State Medical University, Moscow, Russia
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49
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Verkhratsky A. Astroglial Calcium Signaling in Aging and Alzheimer's Disease. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a035188. [PMID: 31110130 DOI: 10.1101/cshperspect.a035188] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Astrocytes are the homeostatic and protective cells of the central nervous system (CNS). In neurological diseases, astrocytes undergo complex changes, which are subclassified into (1) reactive astrogliosis, an evolutionary conserved defensive rearrangement of cellular phenotype aimed at neuroprotection; (2) pathological remodeling, when astrocytes acquire new features driving pathology; and (3) astrodegeneration, which is manifested by astroglial atrophy and loss of homeostatic functions. In aging brains as well as in the brains affected by Alzheimer's disease (AD), astrocytes acquire both atrophic and reactive phenotypes in a region- and disease-stage-dependent manner. Prevalence of atrophy overreactivity, observed in certain brain regions and in terminal stages of the disease, arguably facilitates the development of neurological deficits. Astrocytes exhibit ionic excitability mediated by changes in intracellular concentration of ions, most importantly of Ca2+ and Na+, with intracellular ion dynamics triggered by the activity of neural networks. AD astrocytes associated with senile plaques demonstrate Ca2+ hyperactivity in the form of aberrant Ca2+ oscillations and pathological long-range Ca2+ waves. Astroglial Ca2+ signaling originating from Ca2+ release from the endoplasmic reticulum is a key factor in initiating astrogliotic response; deficient Ca2+ signaling toolkits observed in entorhinal and prefrontal cortices of AD model animals may account for vulnerability of these regions to the pathology.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, United Kingdom.,Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark.,Achucarro Center for Neuroscience, Ikerbasque, Basque Foundation for Science, 48011 Bilbao, Spain
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50
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Verkhratsky A, Chvátal A. NMDA Receptors in Astrocytes. Neurochem Res 2019; 45:122-133. [DOI: 10.1007/s11064-019-02750-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 01/22/2019] [Accepted: 02/05/2019] [Indexed: 12/12/2022]
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