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Leal-Nazaré CG, Arrifano GP, Lopes-Araújo A, Santos-Sacramento L, Barthelemy JL, Soares-Silva I, Crespo-Lopez ME, Augusto-Oliveira M. Methylmercury neurotoxicity: Beyond the neurocentric view. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 920:170939. [PMID: 38365040 DOI: 10.1016/j.scitotenv.2024.170939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/09/2024] [Accepted: 02/10/2024] [Indexed: 02/18/2024]
Abstract
Mercury is a highly toxic metal widely used in human activities worldwide, therefore considered a global public health problem. Many cases of mercury intoxication have occurred in history and represent a huge challenge nowadays. Of particular importance is its methylated form, methylmercury (MeHg). This mercurial species induces damage to several organs in the human body, especially to the central nervous system. Neurological impairments such as executive, memory, motor and visual deficits are associated with MeHg neurotoxicity. Molecular mechanisms involved in MeHg-induced neurotoxicity include excitotoxicity due to glutamatergic imbalance, disturbance in calcium homeostasis and oxidative balance, failure in synaptic support, and inflammatory response. Although neurons are largely affected by MeHg intoxication, they only represent half of the brain cells. Glial cells represent roughly 50 % of the brain cells and are key elements in the functioning of the central nervous system. Particularly, astrocytes and microglia are deeply involved in MeHg-induced neurotoxicity, resulting in distinct neurological outcomes depending on the context. In this review, we discuss the main findings on astroglial and microglial involvement as mediators of neuroprotective and neurotoxic responses to MeHg intoxication. The literature shows that these responses depend on chemical and morphophysiological features, thus, we present some insights for future investigations, considering the particularities of the context, including time and dose of exposure, brain region, and species of study.
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Affiliation(s)
- Caio Gustavo Leal-Nazaré
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil
| | - Gabriela P Arrifano
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil
| | - Amanda Lopes-Araújo
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil
| | - Leticia Santos-Sacramento
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil
| | - Jean Ludger Barthelemy
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil
| | - Isabela Soares-Silva
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil
| | - Maria Elena Crespo-Lopez
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
| | - Marcus Augusto-Oliveira
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
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2
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Li B, Yu W, Verkhratsky A. Trace metals and astrocytes physiology and pathophysiology. Cell Calcium 2024; 118:102843. [PMID: 38199057 DOI: 10.1016/j.ceca.2024.102843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/03/2024] [Accepted: 01/03/2024] [Indexed: 01/12/2024]
Abstract
Several trace metals, including iron, copper, manganese and zinc are essential for normal function of the nervous system. Both deficiency and excessive accumulation of these metals trigger neuropathological developments. The central nervous system (CNS) is in possession of dedicated homeostatic system that removes, accumulates, stores and releases these metals to fulfil nervous tissue demand. This system is mainly associated with astrocytes that act as dynamic reservoirs for trace metals, these being a part of a global system of CNS ionostasis. Here we overview physiological and pathophysiological aspects of astrocyte-cantered trace metals regulation.
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Affiliation(s)
- Baoman Li
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China; Liaoning Province Key Laboratory of Forensic Bio-Evidence Sciences, China; China Medical University Centre of Forensic Investigation, China
| | - Weiyang Yu
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China; Liaoning Province Key Laboratory of Forensic Bio-Evidence Sciences, China; China Medical University Centre of Forensic Investigation, China
| | - Alexei Verkhratsky
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK; Achucarro Center for Neuroscience, Ikerbasque, Bilbao 48011, Spain; Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius LT-01102, Lithuania.
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3
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Untiet V. Astrocytic chloride regulates brain function in health and disease. Cell Calcium 2024; 118:102855. [PMID: 38364706 DOI: 10.1016/j.ceca.2024.102855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/18/2024]
Abstract
Chloride ions (Cl-) play a pivotal role in synaptic inhibition in the central nervous system, primarily mediated through ionotropic mechanisms. A recent breakthrough emphathizes the significant influence of astrocytic intracellular chloride concentration ([Cl-]i) regulation, a field still in its early stages of exploration. Typically, the [Cl-]i in most animal cells is maintained at lower levels than the extracellular chloride [Cl-]o, a critical balance to prevent cell swelling due to osmotic pressure. Various Cl- transporters are expressed differently across cell types, fine-tuning the [Cl-]i, while Cl- gradients are utilised by several families of Cl- channels. Although the passive distribution of ions within cells is governed by basic biophysical principles, astrocytes actively expend energy to sustain [Cl-]i at much higher levels than those achieved passively, and much higher than neuronal [Cl-]i. Beyond the role in volume regulation, astrocytic [Cl-]i is dynamically linked to brain states and influences neuronal signalling in actively behaving animals. As a vital component of brain function, astrocytic [Cl-]i also plays a role in the development of disorders where inhibitory transmission is disrupted. This review synthesises the latest insights into astrocytic [Cl-]i, elucidating its role in modulating brain function and its implications in various pathophysiological conditions.
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Affiliation(s)
- Verena Untiet
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, University of Copenhagen, 2200 Copenhagen, Denmark.
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4
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González-González MA, Conde SV, Latorre R, Thébault SC, Pratelli M, Spitzer NC, Verkhratsky A, Tremblay MÈ, Akcora CG, Hernández-Reynoso AG, Ecker M, Coates J, Vincent KL, Ma B. Bioelectronic Medicine: a multidisciplinary roadmap from biophysics to precision therapies. Front Integr Neurosci 2024; 18:1321872. [PMID: 38440417 PMCID: PMC10911101 DOI: 10.3389/fnint.2024.1321872] [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: 10/16/2023] [Accepted: 01/10/2024] [Indexed: 03/06/2024] Open
Abstract
Bioelectronic Medicine stands as an emerging field that rapidly evolves and offers distinctive clinical benefits, alongside unique challenges. It consists of the modulation of the nervous system by precise delivery of electrical current for the treatment of clinical conditions, such as post-stroke movement recovery or drug-resistant disorders. The unquestionable clinical impact of Bioelectronic Medicine is underscored by the successful translation to humans in the last decades, and the long list of preclinical studies. Given the emergency of accelerating the progress in new neuromodulation treatments (i.e., drug-resistant hypertension, autoimmune and degenerative diseases), collaboration between multiple fields is imperative. This work intends to foster multidisciplinary work and bring together different fields to provide the fundamental basis underlying Bioelectronic Medicine. In this review we will go from the biophysics of the cell membrane, which we consider the inner core of neuromodulation, to patient care. We will discuss the recently discovered mechanism of neurotransmission switching and how it will impact neuromodulation design, and we will provide an update on neuronal and glial basis in health and disease. The advances in biomedical technology have facilitated the collection of large amounts of data, thereby introducing new challenges in data analysis. We will discuss the current approaches and challenges in high throughput data analysis, encompassing big data, networks, artificial intelligence, and internet of things. Emphasis will be placed on understanding the electrochemical properties of neural interfaces, along with the integration of biocompatible and reliable materials and compliance with biomedical regulations for translational applications. Preclinical validation is foundational to the translational process, and we will discuss the critical aspects of such animal studies. Finally, we will focus on the patient point-of-care and challenges in neuromodulation as the ultimate goal of bioelectronic medicine. This review is a call to scientists from different fields to work together with a common endeavor: accelerate the decoding and modulation of the nervous system in a new era of therapeutic possibilities.
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Affiliation(s)
- María Alejandra González-González
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, United States
- Department of Pediatric Neurology, Baylor College of Medicine, Houston, TX, United States
| | - Silvia V. Conde
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NOVA University, Lisbon, Portugal
| | - Ramon Latorre
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Stéphanie C. Thébault
- Laboratorio de Investigación Traslacional en salud visual (D-13), Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, Mexico
| | - Marta Pratelli
- Neurobiology Department, Kavli Institute for Brain and Mind, UC San Diego, La Jolla, CA, United States
| | - Nicholas C. Spitzer
- Neurobiology Department, Kavli Institute for Brain and Mind, UC San Diego, La Jolla, CA, United States
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
- International Collaborative Center on Big Science Plan for Purinergic Signaling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada
| | - Cuneyt G. Akcora
- Department of Computer Science, University of Central Florida, Orlando, FL, United States
| | | | - Melanie Ecker
- Department of Biomedical Engineering, University of North Texas, Denton, TX, United States
| | | | - Kathleen L. Vincent
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX, United States
| | - Brandy Ma
- Stanley H. Appel Department of Neurology, Houston Methodist Hospital, Houston, TX, United States
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5
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Glaser T, Martins P, Beco R, Bento CA, Cappellari AR, La Banca Oliveira S, Merkel CA, Arnaud-Sampaio VF, Lameu C, Battastini AM, Ulrich H. Impairment of adenosine signaling disrupts early embryo development: unveiling the underlying mechanisms. Front Pharmacol 2024; 14:1328398. [PMID: 38313072 PMCID: PMC10834787 DOI: 10.3389/fphar.2023.1328398] [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: 10/26/2023] [Accepted: 12/15/2023] [Indexed: 02/06/2024] Open
Abstract
Purinergic signaling has been implicated in many biological functions, including development. In this study, we investigate the functions of extracellular adenosine and adenosine receptors using a mouse embryonic stem cell (ESC) line and morula stages isolated from mouse embryos. Feeder-free mouse ESC was investigated in the absence and presence of the leukemia inhibitory factor (LIF), configuring undifferentiated cells and cells undergoing spontaneous differentiation. High alkaline phosphatase (ALPL) and low CD73 levels resulting in low adenosine (eADO) levels were characteristic for pluripotent cells in the presence of the LIF, while LIF deprivation resulted in augmented adenosine levels and reduced pluripotency marker expression, which indicated differentiation. Tracing ESC proliferation by BrdU labeling revealed that the inhibition of ALPL by levamisole resulted in a decrease in proliferation due to less eADO accumulation. Furthermore, caffeine and levamisole treatment, inhibiting adenosine receptor and eADO accumulation, respectively, reduced ESC migration, similar to that observed in the absence of the LIF. Pharmacological approaches of selective adenosine receptor subtype inhibition triggered specific adenosine receptor activities, thus triggering calcium or MAP kinase pathways leading to differentiation. In line with the in vitro data, mouse embryos at the morula stage were sensitive to treatments with A1 and A3 receptor antagonists, leading to the conclusion that A1 receptor and A3 receptor inhibition impairs proliferation and self-renewal and triggers inappropriate differentiation, respectively. The findings herein define the functions of eADO signaling in early development with implications for developmental disorders, in which adenosine receptors or ectonucleotidase dysfunctions are involved, and which could lead to malformations and miscarriages, due to exposure to caffeine.
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Affiliation(s)
- Talita Glaser
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, SãoPaulo, Brazil
| | - Patrícia Martins
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, SãoPaulo, Brazil
| | - Renata Beco
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, SãoPaulo, Brazil
| | - Carolina Adriane Bento
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, SãoPaulo, Brazil
| | - Angelica R. Cappellari
- Department of Biochemistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | | | - Christian Albert Merkel
- Department of Health (São Paulo—State), Medical School of the University of São Paulo (HCFMUSP), SãoPaulo, Brazil
| | | | - Claudiana Lameu
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, SãoPaulo, Brazil
| | - Ana Maria Battastini
- Department of Biochemistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Henning Ulrich
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, SãoPaulo, Brazil
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6
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Sočan V, Dolinar K, Kržan M. Cortical and Striatal Astrocytes of Neonatal Rats Display Distinct Molecular and Pharmacological Characteristics of Dopamine Uptake. Int J Mol Sci 2024; 25:911. [PMID: 38255983 PMCID: PMC10815805 DOI: 10.3390/ijms25020911] [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: 12/12/2023] [Revised: 01/05/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Astrocytes are crucial in the regulation of neurotransmitter homeostasis, and while their involvement in the dopamine (DA) tripartite synapse is acknowledged, it necessitates a more comprehensive investigation. In the present study, experiments were conducted on primary astrocyte cultures from the striatum and cortex of neonatal rats. The pharmacological intricacies of DA uptake, including dependence on time, temperature, and concentration, were investigated using radiolabelled [3H]-DA. The mRNA expression of transporters DAT, NET, PMAT, and OCTs was evaluated by qPCR. Notably, astrocytes from both brain regions exhibited prominent mRNA expression of NET and PMAT, with comparatively lower expression of DAT and OCTs. The inhibition of DA uptake by the DAT inhibitor, GBR12909, and NET inhibitors, desipramine and nortriptyline, impeded DA uptake in striatal astrocytes more than in cortical astrocytes. The mRNA expression of NET and PMAT was significantly upregulated in cortical astrocytes in response to the DA receptor agonist apomorphine, while only the mRNA expression of NET exhibited changes in striatal astrocytes. Haloperidol, a DA receptor antagonist, and L-DOPA, a DA precursor, did not induce significant alterations in transporter mRNA expression. These findings underscore the intricate and region-specific mechanisms governing DA uptake in astrocytes, emphasizing the need for continued exploration to unravel the nuanced dynamics of astrocytic involvement in the DA tripartite synapse.
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Affiliation(s)
- Vesna Sočan
- Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
| | - Klemen Dolinar
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
| | - Mojca Kržan
- Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
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7
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Rose CR, Verkhratsky A. Sodium homeostasis and signalling: The core and the hub of astrocyte function. Cell Calcium 2024; 117:102817. [PMID: 37979342 DOI: 10.1016/j.ceca.2023.102817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 10/20/2023] [Indexed: 11/20/2023]
Abstract
Neuronal activity and neurochemical stimulation trigger spatio-temporal changes in the cytoplasmic concentration of Na+ ions in astrocytes. These changes constitute the substrate for Na+ signalling and are fundamental for astrocytic excitability. Astrocytic Na+ signals are generated by Na+ influx through neurotransmitter transporters, with primary contribution of glutamate transporters, and through cationic channels; whereas recovery from Na+ transients is mediated mainly by the plasmalemmal Na+/K+ ATPase. Astrocytic Na+ signals regulate the activity of plasmalemmal transporters critical for homeostatic function of astrocytes, thus providing real-time coordination between neuronal activity and astrocytic support.
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Affiliation(s)
- Christine R Rose
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.
| | - Alexej Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, United Kingdom; Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain; Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China; International Collaborative Center on Big Science Plan for Purinergic Signaling, Chengdu University of Traditional Chinese Medicine, Chengdu, China; Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102, Vilnius, Lithuania.
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8
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Khananshvili D. Neuronal and astrocyte NCX isoform/splice variants: How do they participate in Na + and Ca 2+ signalling? Cell Calcium 2023; 116:102818. [PMID: 37918135 DOI: 10.1016/j.ceca.2023.102818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 10/20/2023] [Accepted: 10/22/2023] [Indexed: 11/04/2023]
Abstract
NCX1, NCX2, and NCX3 gene isoforms and their splice variants are characteristically expressed in different regions of the brain. The tissue-specific splice variants of NCX1-3 isoforms show specific expression profiles in neurons and astrocytes, whereas the relevant NCX isoform/splice variants exhibit diverse allosteric modes of Na+- and Ca2+-dependent regulation. In general, overexpression of NCX1-3 genes leads to neuroprotective effects, whereas their ablation gains the opposite results. At this end, the partial contributions of NCX isoform/splice variants to neuroprotective effects remain unresolved. The glutamate-dependent Na+ entry generates Na+ transients (in response to neuronal cell activities), whereas the Na+-driven Ca2+ entry (through the reverse NCX mode) raises Ca2+ transients. This special mode of signal coupling translates Na+ transients into the Ca2+ signals while being a part of synaptic neurotransmission. This mechanism is of general interest since disease-related conditions (ischemia, metabolic stress, and stroke among many others) trigger Na+ and Ca2+ overload with deadly outcomes of downstream apoptosis and excitotoxicity. The recently discovered mechanisms of NCX allosteric regulation indicate that some NCX variants might play a critical role in the dynamic coupling of Na+-driven Ca2+ entry. In contrast, the others are less important or even could be dangerous under altered conditions (e.g., metabolic stress). This working hypothesis can be tested by applying advanced experimental approaches and highly focused computational simulations. This may allow the development of structure-based blockers/activators that can selectively modulate predefined NCX variants to lessen the life-threatening outcomes of excitotoxicity, ischemia, apoptosis, metabolic deprivation, brain injury, and stroke.
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Affiliation(s)
- Daniel Khananshvili
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel.
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9
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Liu Y, Wang XR, Jiang YH, Li T, Ling S, Wang HY, Yu JW, Jia SW, Liu XY, Hou CM, Parpura V, Wang YF. Interactions between the Astrocytic Volume-Regulated Anion Channel and Aquaporin 4 in Hyposmotic Regulation of Vasopressin Neuronal Activity in the Supraoptic Nucleus. Cells 2023; 12:1723. [PMID: 37443757 PMCID: PMC10341125 DOI: 10.3390/cells12131723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/11/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023] Open
Abstract
We assessed interactions between the astrocytic volume-regulated anion channel (VRAC) and aquaporin 4 (AQP4) in the supraoptic nucleus (SON). Acute SON slices and cultures of hypothalamic astrocytes prepared from rats received hyposmotic challenge (HOC) with/without VRAC or AQP4 blockers. In acute slices, HOC caused an early decrease with a late rebound in the neuronal firing rate of vasopressin neurons, which required activity of astrocytic AQP4 and VRAC. HOC also caused a persistent decrease in the excitatory postsynaptic current frequency, supported by VRAC and AQP4 activity in early HOC; late HOC required only VRAC activity. These events were associated with the dynamics of glial fibrillary acidic protein (GFAP) filaments, the late retraction of which was mediated by VRAC activity; this activity also mediated an HOC-evoked early increase in AQP4 expression and late subside in GFAP-AQP4 colocalization. AQP4 activity supported an early HOC-evoked increase in VRAC levels and its colocalization with GFAP. In cultured astrocytes, late HOC augmented VRAC currents, the activation of which depended on AQP4 pre-HOC/HOC activity. HOC caused an early increase in VRAC expression followed by a late rebound, requiring AQP4 and VRAC, or only AQP4 activity, respectively. Astrocytic swelling in early HOC depended on AQP4 activity, and so did the early extension of GFAP filaments. VRAC and AQP4 activity supported late regulatory volume decrease, the retraction of GFAP filaments, and subside in GFAP-VRAC colocalization. Taken together, astrocytic morphological plasticity relies on the coordinated activities of VRAC and AQP4, which are mutually regulated in the astrocytic mediation of HOC-evoked modulation of vasopressin neuronal activity.
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Affiliation(s)
- Yang Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Xiao-Ran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Yun-Hao Jiang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Tong Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
- Neuroscience Laboratory for Translational Medicine, School of Mental Health, Qiqihar Medical University, Qiqihar 161006, China
| | - Shuo Ling
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Hong-Yang Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Jia-Wei Yu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Shu-Wei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Xiao-Yu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Chun-Mei Hou
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Vladimir Parpura
- International Translational Neuroscience Research Institute, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
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10
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Cervetto C, Maura G, Guidolin D, Amato S, Ceccoli C, Agnati LF, Marcoli M. Striatal astrocytic A2A-D2 receptor-receptor interactions and their role in neuropsychiatric disorders. Neuropharmacology 2023:109636. [PMID: 37321323 DOI: 10.1016/j.neuropharm.2023.109636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/26/2023] [Accepted: 06/11/2023] [Indexed: 06/17/2023]
Abstract
It is now generally accepted that astrocytes are active players in synaptic transmission, so that a neurocentric perspective of the integrative signal communication in the central nervous system is shifting towards a neuro-astrocentric perspective. Astrocytes respond to synaptic activity, release chemical signals (gliotransmitters) and express neurotransmitter receptors (G protein-coupled and ionotropic receptors), thus behaving as co-actors with neurons in signal communication in the central nervous system. The ability of G protein-coupled receptors to physically interact through heteromerization, forming heteromers and receptor mosaics with new distinct signal recognition and transduction pathways, has been intensively studied at neuronal plasma membrane, and has changed the view of the integrative signal communication in the central nervous system. One of the best-known examples of receptor-receptor interaction through heteromerization, with relevant consequences for both the physiological and the pharmacological points of view, is given by adenosine A2A and dopamine D2 receptors on the plasma membrane of striatal neurons. Here we review evidence that native A2A and D2 receptors can interact through heteromerization at the plasma membrane of astrocytes as well. Astrocytic A2A-D2 heteromers were found able to control the release of glutamate from the striatal astrocyte processes. A2A-D2 heteromers on striatal astrocytes and astrocyte processes are discussed as far as their potential relevance in the control of glutamatergic transmission in striatum is concerned, including potential roles in glutamatergic transmission dysregulation in pathological conditions including schizophrenia or the Parkinson's disease.
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Affiliation(s)
- Chiara Cervetto
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy; Center for Promotion of 3Rs in Teaching and Research (Centro 3R), Pisa, Italy.
| | - Guido Maura
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy.
| | - Diego Guidolin
- Department of Neuroscience, University of Padova, Italy.
| | - Sarah Amato
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy.
| | - Cristina Ceccoli
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy.
| | - Luigi F Agnati
- Department of Biochemical, Metabolic Sciences and Neuroscience, University of Modena and Reggio Emilia, Modena, Italy.
| | - Manuela Marcoli
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy; Center for Promotion of 3Rs in Teaching and Research (Centro 3R), Pisa, Italy; Center of Excellence for Biomedical Research, University of Genova, Italy.
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11
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Lin SS, Zhou B, Chen BJ, Jiang RT, Li B, Illes P, Semyanov A, Tang Y, Verkhratsky A. Electroacupuncture prevents astrocyte atrophy to alleviate depression. Cell Death Dis 2023; 14:343. [PMID: 37248211 DOI: 10.1038/s41419-023-05839-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/16/2023] [Accepted: 04/26/2023] [Indexed: 05/31/2023]
Abstract
Astrocyte atrophy is the main histopathological hallmark of major depressive disorder (MDD) in humans and in animal models of depression. Here we show that electroacupuncture prevents astrocyte atrophy in the prefrontal cortex and alleviates depressive-like behaviour in mice subjected to chronic unpredictable mild stress (CUMS). Treatment of mice with CUMS induced depressive-like phenotypes as confirmed by sucrose preference test, tail suspension test, and forced swimming test. These behavioural changes were paralleled with morphological atrophy of astrocytes in the prefrontal cortex, revealed by analysis of 3D reconstructions of confocal Z-stack images of mCherry expressing astrocytes. This morphological atrophy was accompanied by a decrease in the expression of cytoskeletal linker Ezrin, associated with formation of astrocytic leaflets, which form astroglial synaptic cradle. Electroacupuncture at the acupoint ST36, as well as treatment with anti-depressant fluoxetine, prevented depressive-like behaviours, astrocytic atrophy, and down-regulation of astrocytic ezrin. In conclusion, our data further strengthen the notion of a primary role of astrocytic atrophy in depression and reveal astrocytes as cellular target for electroacupuncture in treatment of depressive disorders.
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Affiliation(s)
- Si-Si Lin
- International Joint Research Centre on Purinergic Signalling of Sichuan Province /Research Centre on TCM-Rehabilitation and Neural Circuit, School of Acupuncture and Tuina/Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
| | - Bin Zhou
- Laboratory of Anaesthesia and Critical Care Medicine, Department of Anaesthesiology, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China
| | - Bin-Jie Chen
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
| | - Ruo-Tian Jiang
- Laboratory of Anaesthesia and Critical Care Medicine, Department of Anaesthesiology, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China
| | - Baoman Li
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
| | - Peter Illes
- International Joint Research Centre on Purinergic Signalling of Sichuan Province /Research Centre on TCM-Rehabilitation and Neural Circuit, School of Acupuncture and Tuina/Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany
| | - Alexey Semyanov
- College of Medicine, Jiaxing University, Jiaxing, China
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Yong Tang
- International Joint Research Centre on Purinergic Signalling of Sichuan Province /Research Centre on TCM-Rehabilitation and Neural Circuit, School of Acupuncture and Tuina/Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
- Acupuncture and Chronobiology Key Laboratory of Sichuan Province, Chengdu, China.
| | - Alexei Verkhratsky
- International Joint Research Centre on Purinergic Signalling of Sichuan Province /Research Centre on TCM-Rehabilitation and Neural Circuit, School of Acupuncture and Tuina/Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China.
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
- Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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12
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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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13
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Pressey JC, de Saint-Rome M, Raveendran VA, Woodin MA. Chloride transporters controlling neuronal excitability. Physiol Rev 2023; 103:1095-1135. [PMID: 36302178 DOI: 10.1152/physrev.00025.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Synaptic inhibition plays a crucial role in regulating neuronal excitability, which is the foundation of nervous system function. This inhibition is largely mediated by the neurotransmitters GABA and glycine that activate Cl--permeable ion channels, which means that the strength of inhibition depends on the Cl- gradient across the membrane. In neurons, the Cl- gradient is primarily mediated by two secondarily active cation-chloride cotransporters (CCCs), NKCC1 and KCC2. CCC-mediated regulation of the neuronal Cl- gradient is critical for healthy brain function, as dysregulation of CCCs has emerged as a key mechanism underlying neurological disorders including epilepsy, neuropathic pain, and autism spectrum disorder. This review begins with an overview of neuronal chloride transporters before explaining the dependent relationship between these CCCs, Cl- regulation, and inhibitory synaptic transmission. We then discuss the evidence for how CCCs can be regulated, including by activity and their protein interactions, which underlie inhibitory synaptic plasticity. For readers who may be interested in conducting experiments on CCCs and neuronal excitability, we have included a section on techniques for estimating and recording intracellular Cl-, including their advantages and limitations. Although the focus of this review is on neurons, we also examine how Cl- is regulated in glial cells, which in turn regulate neuronal excitability through the tight relationship between this nonneuronal cell type and synapses. Finally, we discuss the relatively extensive and growing literature on how CCC-mediated neuronal excitability contributes to neurological disorders.
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Affiliation(s)
- Jessica C Pressey
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Miranda de Saint-Rome
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Vineeth A Raveendran
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Melanie A Woodin
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
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14
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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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15
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Nordberg A, Semyanov A, Parpura V, Zorec R. Alexei Verkhratsky, the Philosopher of Neuroglia. Preface for the Honorary Issue of Neurochemical Research. Neurochem Res 2023; 48:1009-1014. [PMID: 36899208 DOI: 10.1007/s11064-023-03894-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Affiliation(s)
- Agneta Nordberg
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Alexey Semyanov
- Department of Physiology, Jiaxing University College of Medicine, Jiaxing, 314033, Zhejiang, China
| | - Vladimir Parpura
- International Translational Neuroscience Research Institute, Zhejiang Chinese Medical University, Hangzhou, China
| | - Robert Zorec
- Medical Faculty & Celica Biomedical, University of Ljubljana, Ljubljana, Slovenia.
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16
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Verkhratsky A, Pivoriūnas A. Astroglia support, regulate and reinforce brain barriers. Neurobiol Dis 2023; 179:106054. [PMID: 36842485 DOI: 10.1016/j.nbd.2023.106054] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/17/2023] [Accepted: 02/20/2023] [Indexed: 02/28/2023] Open
Abstract
Nervous system is segregated from the body by the complex system of barriers. The CNS is protected by (i) the blood-brain and blood-spinal cord barrier between the intracerebral and intraspinal blood vessels and the brain parenchyma; (ii) the arachnoid blood-cerebrospinal fluid barrier; (iii) the blood-cerebrospinal barrier of circumventricular organs made by tanycytes and (iv) the choroid plexus blood-CSF barrier formed by choroid ependymocytes. In the peripheral nervous system the nerve-blood barrier is secured by tight junctions between specialised glial cells known as perineural cells. In the CNS astroglia contribute to all barriers through the glia limitans, which represent the parenchymal portion of the barrier system. Astroglia through secretion of various paracrine factors regulate the permeability of endothelial vascular barrier; in pathology damage or asthenia of astrocytes may compromise brain barriers integrity.
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Affiliation(s)
- Alexei Verkhratsky
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102 Vilnius, Lithuania; 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; Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China.
| | - Augustas Pivoriūnas
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102 Vilnius, Lithuania.
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17
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Verkhratsky A, Semyanov A. Astrocytes in Ageing. Subcell Biochem 2023; 103:253-277. [PMID: 37120471 DOI: 10.1007/978-3-031-26576-1_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Ageing is associated with a morphological and functional decline of astrocytes with a prevalence of morphological atrophy and loss of function. In particular, ageing is manifested by the shrinkage of astrocytic processes: branches and leaflets, which decreases synaptic coverage. Astrocytic dystrophy affects multiple functions astrocytes play in the brain active milieu. In particular, and in combination with an age-dependent decline in the expression of glutamate transporters, astrocytic atrophy translates into deficient glutamate clearance and K+ buffering. Decreased astrocyte presence may contribute to age-dependent remodelling of brain extracellular space, hence affecting extrasynaptic signalling. Old astrocytes lose endfeet polarisation of AQP4 water channels, thus limiting the operation of the glymphatic system. In ageing, astrocytes down-regulate their antioxidant capacity leading to decreased neuroprotection. All these changes may contribute to an age-dependent cognitive decline.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
- Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China.
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania.
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- Sechenov First Moscow State Medical University, Moscow, Russia
- Department of Physiology, Jiaxing University College of Medicine, Jiaxing, Zhejiang Pro, China
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18
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Role of Microglia and Astrocytes in Alzheimer’s Disease: From Neuroinflammation to Ca2+ Homeostasis Dysregulation. Cells 2022; 11:cells11172728. [PMID: 36078138 PMCID: PMC9454513 DOI: 10.3390/cells11172728] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 12/12/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia worldwide, with a complex, poorly understood pathogenesis. Cerebral atrophy, amyloid-β (Aβ) plaques, and neurofibrillary tangles represent the main pathological hallmarks of the AD brain. Recently, neuroinflammation has been recognized as a prominent feature of the AD brain and substantial evidence suggests that the inflammatory response modulates disease progression. Additionally, dysregulation of calcium (Ca2+) homeostasis represents another early factor involved in the AD pathogenesis, as intracellular Ca2+ concentration is essential to ensure proper cellular and neuronal functions. Although growing evidence supports the involvement of Ca2+ in the mechanisms of neurodegeneration-related inflammatory processes, scant data are available on its contribution in microglia and astrocytes functioning, both in health and throughout the AD continuum. Nevertheless, AD-related aberrant Ca2+ signalling in astrocytes and microglia is crucially involved in the mechanisms underpinning neuroinflammatory processes that, in turn, impact neuronal Ca2+ homeostasis and brain function. In this light, we attempted to provide an overview of the current understanding of the interactions between the glia cells-mediated inflammatory responses and the molecular mechanisms involved in Ca2+ homeostasis dysregulation in AD.
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19
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The Involvement of Polyamines Catabolism in the Crosstalk between Neurons and Astrocytes in Neurodegeneration. Biomedicines 2022; 10:biomedicines10071756. [PMID: 35885061 PMCID: PMC9312548 DOI: 10.3390/biomedicines10071756] [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: 06/21/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 11/19/2022] Open
Abstract
In mammalian cells, the content of polyamines is tightly regulated. Polyamines, including spermine, spermidine and putrescine, are involved in many cellular processes. Spermine oxidase specifically oxidizes spermine, and its deregulated activity has been reported to be linked to brain pathologies involving neuron damage. Spermine is a neuromodulator of a number of ionotropic glutamate receptors and types of ion channels. In this respect, the Dach-SMOX mouse model overexpressing spermine oxidase in the neocortex neurons was revealed to be a model of chronic oxidative stress, excitotoxicity and neuronal damage. Reactive astrocytosis, chronic oxidative and excitotoxic stress, neuron loss and the susceptibility to seizure in the Dach-SMOX are discussed here. This genetic model would help researchers understand the linkage between polyamine dysregulation and neurodegeneration and unveil the roles of polyamines in the crosstalk between astrocytes and neurons in neuroprotection or neurodegeneration.
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20
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Li B, Zhang D, Verkhratsky A. Astrocytes in Post-traumatic Stress Disorder. Neurosci Bull 2022; 38:953-965. [PMID: 35349095 PMCID: PMC8960712 DOI: 10.1007/s12264-022-00845-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/07/2022] [Indexed: 01/15/2023] Open
Abstract
Although posttraumatic stress disorder (PTSD) is on the rise, traumatic events and their consequences are often hidden or minimized by patients for reasons linked to PTSD itself. Traumatic experiences can be broadly classified into mental stress (MS) and traumatic brain injury (TBI), but the cellular mechanisms of MS- or TBI-induced PTSD remain unknown. Recent evidence has shown that the morphological remodeling of astrocytes accompanies and arguably contributes to fearful memories and stress-related disorders. In this review, we summarize the roles of astrocytes in the pathogenesis of MS-PTSD and TBI-PTSD. Astrocytes synthesize and secrete neurotrophic, pro- and anti-inflammatory factors and regulate the microenvironment of the nervous tissue through metabolic pathways, ionostatic control, and homeostatic clearance of neurotransmitters. Stress or trauma-associated impairment of these vital astrocytic functions contribute to the pathophysiological evolution of PTSD and may present therapeutic targets.
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Affiliation(s)
- Baoman Li
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, 110122, China
| | - Dianjun Zhang
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, 110122, China
| | - Alexei Verkhratsky
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, 110122, China.
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK.
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, 01102, Vilnius, Lithuania.
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21
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Marcoli M, Cervetto C, Amato S, Fiorucci C, Maura G, Mariottini P, Cervelli M. Transgenic Mouse Overexpressing Spermine Oxidase in Cerebrocortical Neurons: Astrocyte Dysfunction and Susceptibility to Epileptic Seizures. Biomolecules 2022; 12:204. [PMID: 35204705 PMCID: PMC8961639 DOI: 10.3390/biom12020204] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 02/06/2023] Open
Abstract
Polyamines are organic polycations ubiquitously present in living cells. Polyamines are involved in many cellular processes, and their content in mammalian cells is tightly controlled. Among their function, these molecules modulate the activity of several ion channels. Spermine oxidase, specifically oxidized spermine, is a neuromodulator of several types of ion channel and ionotropic glutamate receptors, and its deregulated activity has been linked to several brain pathologies, including epilepsy. The Dach-SMOX mouse line was generated using a Cre/loxP-based recombination approach to study the complex and critical functions carried out by spermine oxidase and spermine in the mammalian brain. This mouse genetic model overexpresses spermine oxidase in the neocortex and is a chronic model of excitotoxic/oxidative injury and neuron vulnerability to oxidative stress and excitotoxic, since its phenotype revealed to be more susceptible to different acute oxidative insults. In this review, the molecular mechanisms underlined the Dach-SMOX phenotype, linked to reactive astrocytosis, neuron loss, chronic oxidative and excitotoxic stress, and susceptibility to seizures have been discussed in detail. The Dach-SMOX mouse model overexpressing SMOX may help in shedding lights on the susceptibility to epileptic seizures, possibly helping to understand the mechanisms underlying epileptogenesis in vulnerable individuals and contributing to provide new molecular mechanism targets to search for novel antiepileptic drugs.
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Affiliation(s)
- Manuela Marcoli
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genoa, Italy; (S.A.); (G.M.)
- Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research (Centro 3R), Lucio Lazzarino 1, 56122 Pisa, Italy
| | - Chiara Cervetto
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genoa, Italy; (S.A.); (G.M.)
- Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research (Centro 3R), Lucio Lazzarino 1, 56122 Pisa, Italy
| | - Sarah Amato
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genoa, Italy; (S.A.); (G.M.)
| | - Cristian Fiorucci
- Department of Science, University of Rome “Roma Tre”, Viale Marconi 446, 00146 Rome, Italy; (C.F.); (P.M.)
| | - Guido Maura
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genoa, Italy; (S.A.); (G.M.)
| | - Paolo Mariottini
- Department of Science, University of Rome “Roma Tre”, Viale Marconi 446, 00146 Rome, Italy; (C.F.); (P.M.)
| | - Manuela Cervelli
- Department of Science, University of Rome “Roma Tre”, Viale Marconi 446, 00146 Rome, Italy; (C.F.); (P.M.)
- Neurodevelopment, Neurogenetics and Molecular Neurobiology Unit, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy
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22
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Bancroft EA, Srinivasan R. Emerging Roles for Aberrant Astrocytic Calcium Signals in Parkinson's Disease. Front Physiol 2022; 12:812212. [PMID: 35087422 PMCID: PMC8787054 DOI: 10.3389/fphys.2021.812212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/09/2021] [Indexed: 11/25/2022] Open
Abstract
Astrocytes display a plethora of spontaneous Ca2+ signals that modulate vital functions of the central nervous system (CNS). This suggests that astrocytic Ca2+ signals also contribute to pathological processes in the CNS. In this context, the molecular mechanisms by which aberrant astrocytic Ca2+ signals trigger dopaminergic neuron loss during Parkinson's disease (PD) are only beginning to emerge. Here, we provide an evidence-based perspective on potential mechanisms by which aberrant astrocytic Ca2+ signals can trigger dysfunction in three distinct compartments of the brain, viz., neurons, microglia, and the blood brain barrier, thereby leading to PD. We envision that the coming decades will unravel novel mechanisms by which aberrant astrocytic Ca2+ signals contribute to PD and other neurodegenerative processes in the CNS.
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Affiliation(s)
- Eric A. Bancroft
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University College of Medicine, Bryan, TX, United States
| | - Rahul Srinivasan
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University College of Medicine, Bryan, TX, United States
- Texas A&M Institute for Neuroscience (TAMIN), College Station, TX, United States
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23
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Astroglial Serotonin Receptors as the Central Target of Classic Antidepressants. ADVANCES IN NEUROBIOLOGY 2021; 26:317-347. [PMID: 34888840 DOI: 10.1007/978-3-030-77375-5_13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Major depressive disorder (MDD) presents multiple clinical phenotypes and has complex underlying pathological mechanisms. Existing theories cannot completely explain the pathophysiological mechanism(s) of MDD, while the pharmacology of current antidepressants is far from being fully understood. Astrocytes, the homeostatic and defensive cells of the central nervous system, contribute to shaping behaviors, and regulating mood and emotions. A detailed introduction on the role of astrocytes in depressive disorders is thus required, to which this chapter is dedicated. We also focus on the interactions between classic antidepressants and serotonin receptors, overview the role of astrocytes in the pharmacological mechanisms of various antidepressants, and present astrocytes as targets for the treatment of bipolar disorder. We provide a foundation of knowledge on the role of astrocytes in depressive disorders and astroglial 5-HT2B receptors as targets for selective serotonin reuptake inhibitors in vivo and in vitro.
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24
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Verkhratsky A, Li B, Scuderi C, Parpura V. Principles of Astrogliopathology. ADVANCES IN NEUROBIOLOGY 2021; 26:55-73. [PMID: 34888830 DOI: 10.1007/978-3-030-77375-5_3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The role of astrocytes in the nervous system pathology was early on embraced by neuroscientists at end of the nineteenth and the beginning of the twentieth century, only to be pushed aside by neurone-centric dogmas during most of the twentieth century. However, the last decade of the twentieth century and the twenty-first century have brought the astroglial "renaissance", which has put astroglial cells as key players in pathophysiology of most if not all disorders of the nervous system and has regarded astroglia as a fertile ground for therapeutic intervention.Astrocytic contribution to neuropathology can be primary, whereby cell-autonomous changes, such as mutations in gene encoding for glial fibrillary acidic protein, can drive the pathologic progression, in this example, Alexander disease. They can also be secondary, when astrocytes respond to a variety of insults to the nervous tissue. Regardless of their origin, being cell-autonomous or not, changes in astroglia that occur in pathology, that is, astrogliopathology, can be contemporary and arbitrary classified into four forms: (i) reactive astrogliosis, (ii) astrocytic atrophy with loss of function, (iii) pathological remodelling of astrocytes and (iv) astrodegeneration morphologically manifested as clasmatodendrosis. Inevitably, as with any other classification, this classification of astrogliopathology awaits its revision that shall be rooted in new discoveries and concepts.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
| | - Baoman Li
- Practical Teaching Center, School of Forensic Medicine, China Medical University, Shenyang, China
| | - Caterina Scuderi
- Department of Physiology and Pharmacology "Vittorio Erspamer", SAPIENZA University of Rome, Rome, Italy
| | - Vladimir Parpura
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
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Verkhratsky A, Parpura V, Li B, Scuderi C. Astrocytes: The Housekeepers and Guardians of the CNS. ADVANCES IN NEUROBIOLOGY 2021; 26:21-53. [PMID: 34888829 DOI: 10.1007/978-3-030-77375-5_2] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Astroglia are a diverse group of cells in the central nervous system. They are of the ectodermal, neuroepithelial origin and vary in morphology and function, yet, they can be collectively defined as cells having principle function to maintain homeostasis of the central nervous system at all levels of organisation, including homeostasis of ions, pH and neurotransmitters; supplying neurones with metabolic substrates; supporting oligodendrocytes and axons; regulating synaptogenesis, neurogenesis, and formation and maintenance of the blood-brain barrier; contributing to operation of the glymphatic system; and regulation of systemic homeostasis being central chemosensors for oxygen, CO2 and Na+. Their basic physiological features show a lack of electrical excitability (inapt to produce action potentials), but display instead a rather active excitability based on variations in cytosolic concentrations of Ca2+ and Na+. It is expression of neurotransmitter receptors, pumps and transporters at their plasmalemma, along with transports on the endoplasmic reticulum and mitochondria that exquisitely regulate the cytosolic levels of these ions, the fluctuation of which underlies most, if not all, astroglial homeostatic functions.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
| | - Vladimir Parpura
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Baoman Li
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
| | - Caterina Scuderi
- Department of Physiology and Pharmacology "Vittorio Erspamer", SAPIENZA University of Rome, Rome, Italy
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Schulte A, Bieniussa L, Gupta R, Samtleben S, Bischler T, Doering K, Sodmann P, Rittner H, Blum R. Homeostatic calcium fluxes, ER calcium release, SOCE, and calcium oscillations in cultured astrocytes are interlinked by a small calcium toolkit. Cell Calcium 2021; 101:102515. [PMID: 34896701 DOI: 10.1016/j.ceca.2021.102515] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 11/29/2021] [Accepted: 11/30/2021] [Indexed: 12/27/2022]
Abstract
How homeostatic ER calcium fluxes shape cellular calcium signals is still poorly understood. Here we used dual-color calcium imaging (ER-cytosol) and transcriptome analysis to link candidates of the calcium toolkit of astrocytes with homeostatic calcium signals. We found molecular and pharmacological evidence that P/Q-type channel Cacna1a contributes to depolarization-dependent calcium entry in astrocytes. For stimulated ER calcium release, the cells express the phospholipase Cb3, IP3 receptors Itpr1 and Itpr2, but no ryanodine receptors (Ryr1-3). After IP3-induced calcium release, Stim1/2 - Orai1/2/3 most likely mediate SOCE. The Serca2 (Atp2a2) is the candidate for refilling of the ER calcium store. The cells highly express adenosine receptor Adora1a for IP3-induced calcium release. Accordingly, adenosine induces fast ER calcium release and subsequent ER calcium oscillations. After stimulation, calcium refilling of the ER depends on extracellular calcium. In response to SOCE, astrocytes show calcium-induced calcium release, notably even after ER calcium was depleted by extracellular calcium removal in unstimulated cells. In contrast, spontaneous ER-cytosol calcium oscillations were not fully dependent on extracellular calcium, as ER calcium oscillations could persist over minutes in calcium-free solution. Additionally, cell-autonomous calcium oscillations show a second-long spatial and temporal delay in the signal dynamics of ER and cytosolic calcium. Our data reveal a rather strong contribution of homeostatic calcium fluxes in shaping IP3-induced and calcium-induced calcium release as well as spatiotemporal components of intracellular calcium oscillations.
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Affiliation(s)
- Annemarie Schulte
- Department of Neurology, University Hospital of Würzburg, Würzburg, 97080 Germany; Institute of Clinical Neurobiology, University Hospital of Würzburg, Würzburg, 97078 Germany
| | - Linda Bieniussa
- Institute of Clinical Neurobiology, University Hospital of Würzburg, Würzburg, 97078 Germany; Department of Otorhinolaryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, University Hospital Würzburg, Germany
| | - Rohini Gupta
- Department of Neurology, University Hospital of Würzburg, Würzburg, 97080 Germany; Institute of Clinical Neurobiology, University Hospital of Würzburg, Würzburg, 97078 Germany
| | - Samira Samtleben
- Institute of Clinical Neurobiology, University Hospital of Würzburg, Würzburg, 97078 Germany; Department of Cell Biology, University of Alberta, MSM, Edmonton, T6G 2H7 Canada
| | - Thorsten Bischler
- Core Unit Systems Medicine, University of Würzburg, Würzburg, 97080 Germany
| | - Kristina Doering
- Core Unit Systems Medicine, University of Würzburg, Würzburg, 97080 Germany; Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
| | - Philipp Sodmann
- Department of Internal Medicine II, University Hospital of Würzburg, Würzburg, 97080 Germany
| | - Heike Rittner
- Department of Anesthesiology, Intensive Care, Emergency Medicine and Pain Therapy, University Hospital of Würzburg, Würzburg, 97074 Germany
| | - Robert Blum
- Department of Neurology, University Hospital of Würzburg, Würzburg, 97080 Germany; Institute of Clinical Neurobiology, University Hospital of Würzburg, Würzburg, 97078 Germany.
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Zhang X, Alnafisah RS, Hamoud ARA, Shukla R, Wen Z, McCullumsmith RE, O'Donovan SM. Role of Astrocytes in Major Neuropsychiatric Disorders. Neurochem Res 2021; 46:2715-2730. [PMID: 33411227 DOI: 10.1007/s11064-020-03212-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/17/2020] [Accepted: 12/21/2020] [Indexed: 12/30/2022]
Abstract
Astrocytes are the primary homeostatic cells of the central nervous system, essential for normal neuronal development and function, metabolism and response to injury and inflammation. Here, we review postmortem studies examining changes in astrocytes in subjects diagnosed with the neuropsychiatric disorders schizophrenia (SCZ), major depressive disorder (MDD), and bipolar disorder (BPD). We discuss the astrocyte-related changes described in the brain in these disorders and the potential effects of psychotropic medication on these findings. Finally, we describe emerging tools that can be used to study the role of astrocytes in neuropsychiatric illness.
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Affiliation(s)
- Xiaolu Zhang
- Department of Neurosciences, University of Toledo College of Medicine, Block Health Science Building, 3000 Arlington Avenue, Toledo, OH, 43614, USA
| | - Rawan S Alnafisah
- Department of Neurosciences, University of Toledo College of Medicine, Block Health Science Building, 3000 Arlington Avenue, Toledo, OH, 43614, USA
| | - Abdul-Rizaq A Hamoud
- Department of Neurosciences, University of Toledo College of Medicine, Block Health Science Building, 3000 Arlington Avenue, Toledo, OH, 43614, USA
| | - Rammohan Shukla
- Department of Neurosciences, University of Toledo College of Medicine, Block Health Science Building, 3000 Arlington Avenue, Toledo, OH, 43614, USA
| | - Zhexing Wen
- Departments of Psychiatry and Behavioral Sciences, Cell Biology, and Neurology, Emory University School of Medicine, Atlanta, GA, USA
| | - Robert E McCullumsmith
- Department of Neurosciences, University of Toledo College of Medicine, Block Health Science Building, 3000 Arlington Avenue, Toledo, OH, 43614, USA.,Neurosciences Institute, ProMedica, Toledo, OH, USA
| | - Sinead M O'Donovan
- Department of Neurosciences, University of Toledo College of Medicine, Block Health Science Building, 3000 Arlington Avenue, Toledo, OH, 43614, USA.
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Pirnat S, Božić M, Dolanc D, Horvat A, Tavčar P, Vardjan N, Verkhratsky A, Zorec R, Stenovec M. Astrocyte arborization enhances Ca 2+ but not cAMP signaling plasticity. Glia 2021; 69:2899-2916. [PMID: 34406698 PMCID: PMC9290837 DOI: 10.1002/glia.24076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 08/02/2021] [Accepted: 08/06/2021] [Indexed: 01/07/2023]
Abstract
The plasticity of astrocytes is fundamental for their principal function, maintaining homeostasis of the central nervous system throughout life, and is associated with diverse exposomal challenges. Here, we used cultured astrocytes to investigate at subcellular level basic cell processes under controlled environmental conditions. We compared astroglial functional and signaling plasticity in standard serum‐containing growth medium, a condition mimicking pathologic conditions, and in medium without serum, favoring the acquisition of arborized morphology. Using opto−/electrophysiologic techniques, we examined cell viability, expression of astroglial markers, vesicle dynamics, and cytosolic Ca2+ and cAMP signaling. The results revealed altered vesicle dynamics in arborized astrocytes that was associated with increased resting [Ca2+]i and increased subcellular heterogeneity in [Ca2+]i, whereas [cAMP]i subcellular dynamics remained stable in both cultures, indicating that cAMP signaling is less prone to plastic remodeling than Ca2+ signaling, possibly also in in vivo contexts.
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Affiliation(s)
- Samo Pirnat
- Laboratory of Cell Engineering, Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
| | - Mićo Božić
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
| | - Dorian Dolanc
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
| | - Anemari Horvat
- Laboratory of Cell Engineering, Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
| | - Petra Tavčar
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
| | - Nina Vardjan
- Laboratory of Cell Engineering, Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
| | - Alexei Verkhratsky
- Laboratory of Cell Engineering, Celica BIOMEDICAL, Ljubljana, Slovenia.,Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,Achucarro Center for Neuroscience, IKERBASQUE, Bilbao, Spain
| | - Robert Zorec
- Laboratory of Cell Engineering, Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
| | - Matjaž Stenovec
- Laboratory of Cell Engineering, Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
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29
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Verkhratsky A, Schousboe A, Zorec R. Preface for the Vladimir Parpura Honorary Issue of Neurochemical Research. Neurochem Res 2021; 46:2507-2511. [PMID: 34405370 DOI: 10.1007/s11064-021-03426-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK. .,Achucarro Center for Neuroscience, IKERBASQUE, 48011, Bilbao, Spain. .,Celica BIOMEDICAL, Tehnološki park 24, 1000, Ljubljana, Slovenia.
| | - Arne Schousboe
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - Robert Zorec
- Celica BIOMEDICAL, Tehnološki park 24, 1000, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
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30
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Revisiting Astrocytic Roles in Methylmercury Intoxication. Mol Neurobiol 2021; 58:4293-4308. [PMID: 33990914 DOI: 10.1007/s12035-021-02420-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 05/04/2021] [Indexed: 02/06/2023]
Abstract
Intoxication by heavy metals such as methylmercury (MeHg) is recognized as a global health problem, with strong implications in central nervous system pathologies. Most of these neuropathological conditions involve vascular, neurotransmitter recycling, and oxidative balance disruption leading to accelerated decline in fine balance, and learning, memory, and visual processes as main outcomes. Besides neurons, astrocytes are involved in virtually all the brain processes and perform important roles in neurological response following injuries. Due to astrocytes' strategic functions in brain homeostasis, these cells became the subject of several studies on MeHg intoxication. The most heterogenous glial cells, astrocytes, are composed of plenty of receptors and transporters to dialogue with neurons and other cells and to monitor extracellular environment responding tightly through fluctuation of cytosolic ions. The overall toxicity of MeHg might be determined on the basis of the balance between MeHg-mediated injury to neurons and protective responses from astrocytes. Although the role of neurons in MeHg intoxication is relatively well-established, the role of the astrocytes is only beginning to be understood. In this review, we update the information on astroglial modulation of the MeHg-induced neurotoxicity, providing remarks on their protective and deleterious roles and insights for future studies.
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31
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Astrocyte-Endotheliocyte Axis in the Regulation of the Blood-Brain Barrier. Neurochem Res 2021; 46:2538-2550. [PMID: 33961207 DOI: 10.1007/s11064-021-03338-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/01/2021] [Accepted: 05/03/2021] [Indexed: 12/18/2022]
Abstract
The evolution of blood-brain barrier paralleled centralisation of the nervous system: emergence of neuronal masses required control over composition of the interstitial fluids. The barriers were initially created by glial cells, which employed septate junctions to restrict paracellular diffusion in the invertebrates and tight junctions in some early vertebrates. The endothelial barrier, secured by tight and adherent junctions emerged in vertebrates and is common in mammals. Astrocytes form the parenchymal part of the blood-brain barrier and commutate with endothelial cells through secretion of growth factors, morphogens and extracellular vesicles. These secreted factors control the integrity of the blood-brain barrier through regulation of expression of tight junction proteins. The astrocyte-endotheliocyte communications are particularly important in various neurological diseases associated with impairments to the blood-brain barrier. Molecular mechanisms supporting astrocyte-endotheliocyte axis in health and disease are in need of detailed characterisation.
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32
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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: 31] [Impact Index Per Article: 10.3] [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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33
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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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34
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González-García I, Gruber T, García-Cáceres C. Insulin action on astrocytes: From energy homeostasis to behaviour. J Neuroendocrinol 2021; 33:e12953. [PMID: 33724579 DOI: 10.1111/jne.12953] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 12/14/2022]
Abstract
Astrocytes are specialised glial cells that integrate distinct inputs arising from neurones, other glial cells and the microcirculation to regulate diverse aspects of brain function. A growing body of emerging evidence supports that astrocytes, similar to neurones, also play active roles in the neuroendocrine control of metabolism by responding to afferent nutritional and hormonal cues and translating these metabolic cues into neuronal inputs. Specifically, insulin action in astrocytes has received special emphasis given its newly discovered regulatory role in brain glucose uptake, which until recently was assumed to be an insulin independent process. We now know that insulin signalling in astrocytes regulates metabolic processes and behavioural responses through coupling brain glucose uptake with nutrient availability to maintain energy balance and systemic glucose homeostasis. Moreover, genetic ablation of the insulin receptor in astrocytes is associated with anxiety- and depressive-like behaviours, confirming that these glial cells are involved in the regulation of cognition and mood via insulin action. Here, we provide a comprehensive review of the most relevant findings that have been made over the course of the last few years linking insulin signalling in astrocytes with the pathogenesis of brain metabolic and neurodegenerative diseases; a still unexplored field, but with a high translational potential for developing therapies.
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Affiliation(s)
- Ismael González-García
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Tim Gruber
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Cristina García-Cáceres
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Medizinische Klinik and Poliklinik IV, Klinikum der Universität, Ludwig-Maximilians-Universität München, Munich, Germany
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35
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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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Preman P, Alfonso-Triguero M, Alberdi E, Verkhratsky A, Arranz AM. Astrocytes in Alzheimer's Disease: Pathological Significance and Molecular Pathways. Cells 2021; 10:540. [PMID: 33806259 PMCID: PMC7999452 DOI: 10.3390/cells10030540] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/17/2021] [Accepted: 02/22/2021] [Indexed: 12/12/2022] Open
Abstract
Astrocytes perform a wide variety of essential functions defining normal operation of the nervous system and are active contributors to the pathogenesis of neurodegenerative disorders such as Alzheimer's among others. Recent data provide compelling evidence that distinct astrocyte states are associated with specific stages of Alzheimer´s disease. The advent of transcriptomics technologies enables rapid progress in the characterisation of such pathological astrocyte states. In this review, we provide an overview of the origin, main functions, molecular and morphological features of astrocytes in physiological as well as pathological conditions related to Alzheimer´s disease. We will also explore the main roles of astrocytes in the pathogenesis of Alzheimer´s disease and summarize main transcriptional changes and altered molecular pathways observed in astrocytes during the course of the disease.
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Affiliation(s)
- Pranav Preman
- VIB Center for Brain & Disease Research, 3000 Leuven, Belgium;
- Laboratory for the Research of Neurodegenerative Diseases, Department of Neurosciences, Leuven Brain Institute (LBI), KU Leuven (University of Leuven), 3000 Leuven, Belgium
| | - Maria Alfonso-Triguero
- Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; (M.A.-T.); (E.A.)
- Department of Neurosciences, Universidad del País Vasco (UPV/EHU), 48940 Leioa, Spain
| | - Elena Alberdi
- Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; (M.A.-T.); (E.A.)
- Department of Neurosciences, Universidad del País Vasco (UPV/EHU), 48940 Leioa, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 48940 Leioa, Spain
| | - Alexei Verkhratsky
- Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; (M.A.-T.); (E.A.)
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK
- Ikerbasque Basque Foundation for Science, 48009 Bilbao, Spain
| | - Amaia M. Arranz
- Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; (M.A.-T.); (E.A.)
- Ikerbasque Basque Foundation for Science, 48009 Bilbao, Spain
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Verkhratsky A, Dayanithi G. When day meets night: Subsiding calcium signalling translates daylight into new neurones. Cell Calcium 2021; 95:102385. [PMID: 33750576 DOI: 10.1016/j.ceca.2021.102385] [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: 02/18/2021] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 11/29/2022]
Abstract
Day/night cycle controls neurogenesis; melatonin released from pineal gland in darkness stimulates intracellular Ca2+ dynamics thus decreasing proliferation of neural stem cells. In the daylight intracellular Ca2+ activity subsides, which stimulates neural stem cells division and increases generation of newborn neurones.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain.
| | - Govindan Dayanithi
- Molecular Mechanisms in Neurodegenerative Diseases Laboratory, MMDN, University of Montpellier, EPHE-Sorbonne, INSERM, UMR-S1198, Place Eugène Bataillon, F-34095 Montpellier Cedex 5, France
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Charvériat M, Mouthon F, Rein W, Verkhratsky A. Connexins as therapeutic targets in neurological and neuropsychiatric disorders. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166098. [PMID: 33545299 DOI: 10.1016/j.bbadis.2021.166098] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 01/06/2021] [Accepted: 01/19/2021] [Indexed: 12/16/2022]
Abstract
Astrocytes represent the reticular part of the central nervous system; gap junctions formed by connexins Cx43, Cx30- and Cx26 provide for homocellular astrocyte-astrocyte coupling, whereas connexins Cx30, Cx32, Cx43, and Cx47 connect astrocytes and oligodendrocytes. Astroglial networks are anatomically and functionally segregated being homologous to neuronal ensembles. Connexons, gap junctions and hemichannels (unpaired connexons) are affected in various neuropathologies from neuropsychiatric to neurodegenerative diseases. Manipulation of astrocytic connexins modulates the size and outreach of astroglial syncytia thus affecting astroglial homeostatic support. Modulation of astrocytic connexin significantly modifies pharmacological profile of many CNS drugs, which represents an innovative therapeutic approach for CNS disorders; this approach is now actively tested in pre-clinical and clinical studies. Wide combination of connexin modulators with CNS drugs open new promising perspectives for fundamental studies and therapeutic strategies.
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Affiliation(s)
| | | | | | - A Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK; Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
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Nguyen H, Zerimech S, Baltan S. Astrocyte Mitochondria in White-Matter Injury. Neurochem Res 2021; 46:2696-2714. [PMID: 33527218 DOI: 10.1007/s11064-021-03239-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 12/11/2022]
Abstract
This review summarizes the diverse structure and function of astrocytes to describe the bioenergetic versatility required of astrocytes that are situated at different locations. The intercellular domain of astrocyte mitochondria defines their roles in supporting and regulating astrocyte-neuron coupling and survival against ischemia. The heterogeneity of astrocyte mitochondria, and how subpopulations of astrocyte mitochondria adapt to interact with other glia and regulate axon function, require further investigation. It has become clear that mitochondrial permeability transition pores play a key role in a wide variety of human diseases, whose common pathology may be based on mitochondrial dysfunction triggered by Ca2+ and potentiated by oxidative stress. Reactive oxygen species cause axonal degeneration and a reduction in axonal transport, leading to axonal dystrophies and neurodegeneration including Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, and Huntington's disease. Developing new tools to allow better investigation of mitochondrial structure and function in astrocytes, and techniques to specifically target astrocyte mitochondria, can help to unravel the role of mitochondrial health and dysfunction in a more inclusive context outside of neuronal cells. Overall, this review will assess the value of astrocyte mitochondria as a therapeutic target to mitigate acute and chronic injury in the CNS.
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Affiliation(s)
- Hung Nguyen
- Anesthesiology and Peri-Operative Medicine (APOM), Oregon Health and Science University, Portland, OR, 97239, USA
| | - Sarah Zerimech
- Anesthesiology and Peri-Operative Medicine (APOM), Oregon Health and Science University, Portland, OR, 97239, USA
| | - Selva Baltan
- Anesthesiology and Peri-Operative Medicine (APOM), Oregon Health and Science University, Portland, OR, 97239, USA.
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The Association Between Antidepressant Effect of SSRIs and Astrocytes: Conceptual Overview and Meta-analysis of the Literature. Neurochem Res 2021; 46:2731-2745. [PMID: 33527219 DOI: 10.1007/s11064-020-03225-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 12/19/2022]
Abstract
Major depressive disorders (MDD) a worldwide psychiatric disease, is yet to be adequately controlled by therapies; while the mechanisms of action of antidepressants are yet to be fully characterised. In the last two decades, an increasing number of studies have demonstrated the role of astrocytes in the pathophysiology and therapy of MDD. Selective serotonin reuptake inhibitors (SSRIs) are the most widely used antidepressants. It is generally acknowledged that SSRIs increase serotonin levels in the central nervous system by inhibiting serotonin transporters, although the SSRIs action is not ideal. The SSRIs antidepressant effect develops with considerable delay; their efficacy is low and frequent relapses are common. Neither cellular nor molecular pharmacological mechanisms of SSRIs are fully characterised; in particular their action on astrocytes remain underappreciated. In this paper we overview potential therapeutic mechanisms of SSRIs associated with astroglia and report the results of meta-analysis of studies dedicated to MDD, SSRIs and astrocytes. In particular, we argue that fluoxetine, the representative SSRI, improves depressive-like behaviours in animals treated with chronic mild stress and reverses depression-associated decrease in astrocytic glial fibrillary acidic protein (GFAP) expression. In addition, fluoxetine upregulates astrocytic mRNA expression of 5-hydroxytriptamin/serotonin2B receptors (5-HT2BR). In summary, we infer that SSRIs exert their anti-depressant effect by regulating several molecular and signalling pathways in astrocytes.
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Hanani M, Verkhratsky A. Satellite Glial Cells and Astrocytes, a Comparative Review. Neurochem Res 2021; 46:2525-2537. [PMID: 33523395 DOI: 10.1007/s11064-021-03255-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/19/2022]
Abstract
Astroglia are neural cells, heterogeneous in form and function, which act as supportive elements of the central nervous system; astrocytes contribute to all aspects of neural functions in health and disease. Through their highly ramified processes, astrocytes form close physical contacts with synapses and blood vessels, and are integrated into functional syncytia by gap junctions. Astrocytes interact among themselves and with other cells types (e.g., neurons, microglia, blood vessel cells) by an elaborate repertoire of chemical messengers and receptors; astrocytes also influence neural plasticity and synaptic transmission through maintaining homeostasis of neurotransmitters, K+ buffering, synaptic isolation and control over synaptogenesis and synaptic elimination. Satellite glial cells (SGCs) are the most abundant glial cells in sensory ganglia, and are believed to play major roles in sensory functions, but so far research into SGCs attracted relatively little attention. In this review we compare SGCs to astrocytes with the purpose of using the vast knowledge on astrocytes to explore new aspects of SGCs. We survey the main properties of these two cells types and highlight similarities and differences between them. We conclude that despite the much greater diversity in morphology and signaling mechanisms of astrocytes, there are some parallels between them and SGCs. Both types serve as boundary cells, separating different compartments in the nervous system, but much more needs to be learned on this aspect of SGCs. Astrocytes and SGCs employ chemical messengers and calcium waves for intercellular signaling, but their significance is still poorly understood for both cell types. Both types undergo major changes under pathological conditions, which have a protective function, but an also contribute to disease, and chronic pain in particular. The knowledge obtained on astrocytes is likely to benefit future research on SGCs.
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Affiliation(s)
- Menachem Hanani
- Laboratory of Experimental Surgery, Hadassah-Hebrew University Medical Center and Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK.,Achucarro Center for Neuroscience, IKERBASQUE, 48011, Bilbao, Spain
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Verkhratsky A, Sun D, Tanaka J. Snapshot of microglial physiological functions. Neurochem Int 2021; 144:104960. [PMID: 33460721 DOI: 10.1016/j.neuint.2021.104960] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 01/11/2021] [Indexed: 02/08/2023]
Abstract
Microglia as a defensive arm of the nervous system emerged early in evolution. The surveilling microglia with motile and ramified processes are the main phenotype in the healthy CNS; the surveilling microglial patrol neuronal somata, dendrites, dendritic spines and axons. Increasing evidence suggests that microglia play fundamental roles in development, maturation and ageing of the brain, as well as contribute to a variety of physiological brain processes including sleep and circadian rhythm. Physiological state of microglia is tightly regulated by brain microenvironment and controlled by a sophisticated system of receptors and signalling cascades including ionotropic and metabotropic purinoceptors, pattern-recognition receptors, and receptors for chemokines and cytokines. Microglia also utilise ion channels and transporters in regulating ionic homeostasis and various aspects of microglial function. The major ion transporters expressed by microglia include Na+/H+ exchanger 1 and Na+/Ca2+ exchangers, which are involved in regulation of pHi and Ca2+ homeostasis during microglial physiological responses. Microglial cells control development, maturation and plasticity of neuronal ensembles through controlled physiological phagocytosis of synapses or synaptic fragments - processes known as synaptic pruning and trogocytosis. This special issue on "Physiological roles of microglia" is an assembly of papers written by the leading experts in this research field. We start this special issue with this snapshot of microglial physiological functions as a prelude to the indepth discussion of microglia in physiological processes in the nervous system.
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Affiliation(s)
- 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.
| | - Dandan Sun
- Department of Neurology and Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Veterans Affairs Pittsburgh Health Care System, Geriatric Research, Educational and Clinical Center, Pittsburgh, PA, 15213, USA.
| | - Junya Tanaka
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Ehime, 791-0295, Japan.
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