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Baraibar AM, Colomer T, Moreno-García A, Bernal-Chico A, Sánchez-Martín E, Utrilla C, Serrat R, Soria-Gómez E, Rodríguez-Antigüedad A, Araque A, Matute C, Marsicano G, Mato S. Autoimmune inflammation triggers aberrant astrocytic calcium signaling to impair synaptic plasticity. Brain Behav Immun 2024; 121:192-210. [PMID: 39032542 DOI: 10.1016/j.bbi.2024.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 07/12/2024] [Accepted: 07/15/2024] [Indexed: 07/23/2024] Open
Abstract
Cortical pathology involving inflammatory and neurodegenerative mechanisms is a hallmark of multiple sclerosis and a correlate of disease progression and cognitive decline. Astrocytes play a pivotal role in multiple sclerosis initiation and progression but astrocyte-neuronal network alterations contributing to gray matter pathology remain undefined. Here we unveil deregulation of astrocytic calcium signaling and astrocyte-to-neuron communication as key pathophysiological mechanisms of cortical dysfunction in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis. Using two-photon imaging ex vivo and fiber photometry in freely behaving mice, we found that acute EAE was associated with the emergence of spontaneously hyperactive cortical astrocytes exhibiting dysfunctional responses to cannabinoid, glutamate and purinoreceptor agonists. Abnormal astrocyte signaling by Gi and Gq protein coupled receptors was observed in the inflamed cortex. This was mirrored by treatments with pro-inflammatory factors both in vitro and ex vivo, suggesting cell-autonomous effects of the cortical neuroinflammatory environment. Finally, deregulated astrocyte calcium activity was associated with an enhancement of glutamatergic gliotransmission and a shift of astrocyte-mediated short-term and long-term plasticity mechanisms towards synaptic potentiation. Overall, our data identify astrocyte-neuronal network dysfunctions as key pathological features of gray matter inflammation in multiple sclerosis and potentially additional neuroimmunological disorders.
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Affiliation(s)
- A M Baraibar
- Department of Neurosciences, University of the Basque Country UPV/EHU, 48940 Leioa, Spain; Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; Neuroinmunology Group, Biobizkaia Health Research Institute, 48903 Barakaldo, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28029 Madrid, Spain
| | - T Colomer
- Department of Neurosciences, University of the Basque Country UPV/EHU, 48940 Leioa, Spain; Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; Neuroinmunology Group, Biobizkaia Health Research Institute, 48903 Barakaldo, Spain
| | - A Moreno-García
- Department of Neurosciences, University of the Basque Country UPV/EHU, 48940 Leioa, Spain; Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; Neuroinmunology Group, Biobizkaia Health Research Institute, 48903 Barakaldo, Spain
| | - A Bernal-Chico
- Department of Neurosciences, University of the Basque Country UPV/EHU, 48940 Leioa, Spain; Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; Neuroinmunology Group, Biobizkaia Health Research Institute, 48903 Barakaldo, Spain
| | - E Sánchez-Martín
- Department of Neurosciences, University of the Basque Country UPV/EHU, 48940 Leioa, Spain; Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; Neuroinmunology Group, Biobizkaia Health Research Institute, 48903 Barakaldo, Spain
| | - C Utrilla
- Department of Neurosciences, University of the Basque Country UPV/EHU, 48940 Leioa, Spain; Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; Neuroinmunology Group, Biobizkaia Health Research Institute, 48903 Barakaldo, Spain
| | - R Serrat
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - E Soria-Gómez
- Department of Neurosciences, University of the Basque Country UPV/EHU, 48940 Leioa, Spain; Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain
| | - A Rodríguez-Antigüedad
- Department of Neurosciences, University of the Basque Country UPV/EHU, 48940 Leioa, Spain; Neuroinmunology Group, Biobizkaia Health Research Institute, 48903 Barakaldo, Spain
| | - A Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, 55455 MN, USA
| | - C Matute
- Department of Neurosciences, University of the Basque Country UPV/EHU, 48940 Leioa, Spain; Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28029 Madrid, Spain
| | - G Marsicano
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France.
| | - S Mato
- Department of Neurosciences, University of the Basque Country UPV/EHU, 48940 Leioa, Spain; Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; Neuroinmunology Group, Biobizkaia Health Research Institute, 48903 Barakaldo, Spain.
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Kazis D, Chatzikonstantinou S, Ciobica A, Kamal FZ, Burlui V, Calin G, Mavroudis I. Epidemiology, Risk Factors, and Biomarkers of Post-Traumatic Epilepsy: A Comprehensive Overview. Biomedicines 2024; 12:410. [PMID: 38398011 PMCID: PMC10886732 DOI: 10.3390/biomedicines12020410] [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: 01/23/2024] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
This paper presents an in-depth exploration of Post-Traumatic Epilepsy (PTE), a complex neurological disorder following traumatic brain injury (TBI), characterized by recurrent, unprovoked seizures. With TBI being a global health concern, understanding PTE is crucial for effective diagnosis, management, and prognosis. This study aims to provide a comprehensive overview of the epidemiology, risk factors, and emerging biomarkers of PTE, thereby informing clinical practice and guiding future research. The epidemiological aspect of the study reveals PTE as a significant contributor to acquired epilepsies, with varying incidence influenced by injury severity, age, and intracranial pathologies. The paper delves into the multifactorial nature of PTE risk factors, encompassing clinical, demographic, and genetic elements. Key insights include the association of injury severity, intracranial hemorrhages, and early seizures with increased PTE risk, and the roles of age, gender, and genetic predispositions. Advancements in neuroimaging, electroencephalography, and molecular biology are presented, highlighting their roles in identifying potential PTE biomarkers. These biomarkers, ranging from radiological signs to electroencephalography EEG patterns and molecular indicators, hold promise for enhancing PTE pathogenesis understanding, early diagnosis, and therapeutic guidance. The paper also discusses the critical roles of astrocytes and microglia in PTE, emphasizing the significance of neuroinflammation in PTE development. The insights from this review suggest potential therapeutic targets in neuroinflammation pathways. In conclusion, this paper synthesizes current knowledge in the field, emphasizing the need for continued research and a multidisciplinary approach to effectively manage PTE. Future research directions include longitudinal studies for a better understanding of TBI and PTE outcomes, and the development of targeted interventions based on individualized risk profiles. This research contributes significantly to the broader understanding of epilepsy and TBI.
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Affiliation(s)
- Dimitrios Kazis
- Third Department of Neurology, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece; (D.K.)
| | - Symela Chatzikonstantinou
- Third Department of Neurology, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece; (D.K.)
| | - Alin Ciobica
- Department of Biology, Faculty of Biology, Alexandru Ioan Cuza University of Iasi, 20th Carol I Avenue, 700506 Iasi, Romania;
- Center of Biomedical Research, Romanian Academy, Iasi Branch, Teodor Codrescu 2, 700481 Iasi, Romania
- Academy of Romanian Scientists, 3 Ilfov, 050044 Bucharest, Romania
| | - Fatima Zahra Kamal
- Higher Institute of Nursing Professions and Health Technical (ISPITS), Marrakech 40000, Morocco
- Laboratory of Physical Chemistry of Processes and Materials, Faculty of Sciences and Techniques, Hassan First University, Settat 26000, Morocco
| | - Vasile Burlui
- Department of Biomaterials, Faculty of Dental Medicine, Apollonia University, 700511 Iasi, Romania;
| | - Gabriela Calin
- Department of Biomaterials, Faculty of Dental Medicine, Apollonia University, 700511 Iasi, Romania;
| | - Ioannis Mavroudis
- Department of Neuroscience, Leeds Teaching Hospitals, Leeds LS2 9JT, UK
- Faculty of Medicine, Leeds University, Leeds LS2 9JT, UK
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Liu Z, Wang Z, Wei Y, Shi J, Shi T, Chen X, Li L. Transcriptomic Profiling of Tetrodotoxin-Induced Neurotoxicity in Human Cerebral Organoids. Mar Drugs 2023; 21:588. [PMID: 37999412 PMCID: PMC10672545 DOI: 10.3390/md21110588] [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: 10/02/2023] [Revised: 10/30/2023] [Accepted: 11/07/2023] [Indexed: 11/25/2023] Open
Abstract
Tetrodotoxin (TTX) is an exceedingly toxic non-protein biotoxin that demonstrates remarkable selectivity and affinity for sodium channels on the excitation membrane of nerves. This property allows TTX to effectively obstruct nerve conduction, resulting in nerve paralysis and fatality. Although the mechanistic aspects of its toxicity are well understood, there is a dearth of literature addressing alterations in the neural microenvironment subsequent to TTX poisoning. In this research endeavor, we harnessed human pluripotent induced stem cells to generate cerebral organoids-an innovative model closely mirroring the structural and functional intricacies of the human brain. This model was employed to scrutinize the comprehensive transcriptomic shifts induced by TTX exposure, thereby delving into the neurotoxic properties of TTX and its potential underlying mechanisms. Our findings revealed 455 differentially expressed mRNAs (DEmRNAs), 212 differentially expressed lncRNAs (DElncRNAs), and 18 differentially expressed miRNAs (DEmiRNAs) in the TTX-exposed group when juxtaposed with the control cohort. Through meticulous Gene Ontology (GO) annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and protein-protein interaction (PPI) analysis, we ascertained that these differential genes predominantly participate in the regulation of voltage-gated channels and synaptic homeostasis. A comprehensive ceRNA network analysis unveiled that DEmRNAs exert control over the expression of ion channels and neurocytokines, suggesting their potential role in mediating apoptosis.
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Affiliation(s)
- Zhanbiao Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China (J.S.)
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, Dalian Minzu University, Dalian 116600, China
| | - Zhe Wang
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, Dalian Minzu University, Dalian 116600, China
| | - Yue Wei
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China (J.S.)
| | - Jingjing Shi
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China (J.S.)
| | - Tong Shi
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China (J.S.)
| | - Xuejun Chen
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China (J.S.)
| | - Liqin Li
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China (J.S.)
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Aroniadou-Anderjaska V, Figueiredo TH, de Araujo Furtado M, Pidoplichko VI, Braga MFM. Mechanisms of Organophosphate Toxicity and the Role of Acetylcholinesterase Inhibition. TOXICS 2023; 11:866. [PMID: 37888716 PMCID: PMC10611379 DOI: 10.3390/toxics11100866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 10/11/2023] [Accepted: 10/17/2023] [Indexed: 10/28/2023]
Abstract
Organophosphorus compounds (OPs) have applications in agriculture (e.g., pesticides), industry (e.g., flame retardants), and chemical warfare (nerve agents). In high doses or chronic exposure, they can be toxic or lethal. The primary mechanism, common among all OPs, that initiates their toxic effects is the inhibition of acetylcholinesterase. In acute OP exposure, the subsequent surge of acetylcholine in cholinergic synapses causes a peripheral cholinergic crisis and status epilepticus (SE), either of which can lead to death. If death is averted without effective seizure control, long-term brain damage ensues. This review describes the mechanisms by which elevated acetylcholine can cause respiratory failure and trigger SE; the role of the amygdala in seizure initiation; the role of M1 muscarinic receptors in the early stages of SE; the neurotoxic pathways activated by SE (excitotoxicity/Ca++ overload/oxidative stress, neuroinflammation); and neurotoxic mechanisms linked to low-dose, chronic exposure (Ca++ dyshomeostasis/oxidative stress, inflammation), which do not depend on SE and do not necessarily involve acetylcholinesterase inhibition. The evidence so far indicates that brain damage from acute OP exposure is a direct result of SE, while the neurotoxic mechanisms activated by low-dose chronic exposure are independent of SE and may not be associated with acetylcholinesterase inhibition.
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Affiliation(s)
- Vassiliki Aroniadou-Anderjaska
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (V.A.-A.); (V.I.P.)
- Department of Psychiatry, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Taiza H. Figueiredo
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (V.A.-A.); (V.I.P.)
| | - Marcio de Araujo Furtado
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (V.A.-A.); (V.I.P.)
| | - Volodymyr I. Pidoplichko
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (V.A.-A.); (V.I.P.)
| | - Maria F. M. Braga
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (V.A.-A.); (V.I.P.)
- Department of Psychiatry, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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Korczowska-Łącka I, Słowikowski B, Piekut T, Hurła M, Banaszek N, Szymanowicz O, Jagodziński PP, Kozubski W, Permoda-Pachuta A, Dorszewska J. Disorders of Endogenous and Exogenous Antioxidants in Neurological Diseases. Antioxidants (Basel) 2023; 12:1811. [PMID: 37891890 PMCID: PMC10604347 DOI: 10.3390/antiox12101811] [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: 08/16/2023] [Revised: 09/19/2023] [Accepted: 09/27/2023] [Indexed: 10/29/2023] Open
Abstract
In diseases of the central nervous system, such as Alzheimer's disease (AD), Parkinson's disease (PD), stroke, amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and even epilepsy and migraine, oxidative stress load commonly surpasses endogenous antioxidative capacity. While oxidative processes have been robustly implicated in the pathogenesis of these diseases, the significance of particular antioxidants, both endogenous and especially exogenous, in maintaining redox homeostasis requires further research. Among endogenous antioxidants, enzymes such as catalase, superoxide dismutase, and glutathione peroxidase are central to disabling free radicals, thereby preventing oxidative damage to cellular lipids, proteins, and nucleic acids. Whether supplementation with endogenously occurring antioxidant compounds such as melatonin and glutathione carries any benefit, however, remains equivocal. Similarly, while the health benefits of certain exogenous antioxidants, including ascorbic acid (vitamin C), carotenoids, polyphenols, sulforaphanes, and anthocyanins are commonly touted, their clinical efficacy and effectiveness in particular neurological disease contexts need to be more robustly defined. Here, we review the current literature on the cellular mechanisms mitigating oxidative stress and comment on the possible benefit of the most common exogenous antioxidants in diseases such as AD, PD, ALS, HD, stroke, epilepsy, and migraine. We selected common neurological diseases of a basically neurodegenerative nature.
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Affiliation(s)
- Izabela Korczowska-Łącka
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland (M.H.)
| | - Bartosz Słowikowski
- Department of Biochemistry and Molecular Biology, Poznan University of Medical Sciences, 61-701 Poznan, Poland; (B.S.); (P.P.J.)
| | - Thomas Piekut
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland (M.H.)
| | - Mikołaj Hurła
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland (M.H.)
| | - Natalia Banaszek
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland (M.H.)
| | - Oliwia Szymanowicz
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland (M.H.)
| | - Paweł P. Jagodziński
- Department of Biochemistry and Molecular Biology, Poznan University of Medical Sciences, 61-701 Poznan, Poland; (B.S.); (P.P.J.)
| | - Wojciech Kozubski
- Chair and Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland
| | - Agnieszka Permoda-Pachuta
- Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, 20-059 Lublin, Poland
| | - Jolanta Dorszewska
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland (M.H.)
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Umpierre AD, Li B, Ayasoufi K, Zhao S, Xie M, Thyen G, Hur B, Zheng J, Liang Y, Wu Z, Yu X, Sung J, Johnson AJ, Li Y, Wu LJ. Microglial P2Y 6 calcium signaling promotes phagocytosis and shapes neuroimmune responses in epileptogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.12.544691. [PMID: 37398001 PMCID: PMC10312639 DOI: 10.1101/2023.06.12.544691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Microglial calcium signaling is rare in a baseline state but shows strong engagement during early epilepsy development. The mechanism and purpose behind microglial calcium signaling is not known. By developing an in vivo UDP fluorescent sensor, GRABUDP1.0, we discovered that UDP release is a conserved response to seizures and excitotoxicity across brain regions. UDP signals to the microglial P2Y6 receptor for broad increases in calcium signaling during epileptogenesis. UDP-P2Y6 signaling is necessary for lysosome upregulation across limbic brain regions and enhances production of pro-inflammatory cytokines-TNFα and IL-1β. Failures in lysosome upregulation, observed in P2Y6 KO mice, can also be phenocopied by attenuating microglial calcium signaling in Calcium Extruder ("CalEx") mice. In the hippocampus, only microglia with P2Y6 expression can perform full neuronal engulfment, which substantially reduces CA3 neuron survival and impairs cognition. Our results demonstrate that calcium activity, driven by UDP-P2Y6 signaling, is a signature of phagocytic and pro-inflammatory function in microglia during epileptogenesis.
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Affiliation(s)
- Anthony D. Umpierre
- Department of Neurology, Mayo Clinic, Rochester, MN 55905
- These authors contributed equally
| | - Bohan Li
- State Key Laboratory of Membrane Biology, New Cornerstone Science Laboratory, Peking University School of Life Sciences, Beijing, CN 100871
- These authors contributed equally
| | | | - Shunyi Zhao
- Department of Neurology, Mayo Clinic, Rochester, MN 55905
- Neuroscience Track, Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN 55905
| | - Manling Xie
- Department of Neurology, Mayo Clinic, Rochester, MN 55905
- Neuroscience Track, Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN 55905
| | - Grace Thyen
- Department of Neurology, Mayo Clinic, Rochester, MN 55905
| | - Benjamin Hur
- Microbiome Program, Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905
- Division of Surgery Research, Department of Surgery, Mayo Clinic, Rochester, MN 55905
| | - Jiaying Zheng
- Department of Neurology, Mayo Clinic, Rochester, MN 55905
- Neuroscience Track, Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN 55905
| | - Yue Liang
- Department of Neurology, Mayo Clinic, Rochester, MN 55905
| | - Zhaofa Wu
- State Key Laboratory of Membrane Biology, New Cornerstone Science Laboratory, Peking University School of Life Sciences, Beijing, CN 100871
| | - Xinzhu Yu
- Department of Molecular and Integrative Physiology, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Jaeyun Sung
- Microbiome Program, Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905
- Division of Surgery Research, Department of Surgery, Mayo Clinic, Rochester, MN 55905
| | - Aaron J. Johnson
- Department of Neurology, Mayo Clinic, Rochester, MN 55905
- Department of Immunology, Mayo Clinic, Rochester, MN 55905
- Department of Molecular Medicine, Mayo Clinic, Rochester MN 55905
| | - Yulong Li
- State Key Laboratory of Membrane Biology, New Cornerstone Science Laboratory, Peking University School of Life Sciences, Beijing, CN 100871
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN 55905
- Department of Immunology, Mayo Clinic, Rochester, MN 55905
- Lead contact
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Figueiredo TH, Aroniadou-Anderjaska V, Apland JP, Rossetti K, Braga MFM. Delayed tezampanel and caramiphen treatment but not midazolam protects against long-term neuropathology after soman exposure. Exp Biol Med (Maywood) 2023; 248:612-623. [PMID: 37300407 PMCID: PMC10350803 DOI: 10.1177/15353702231171911] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 03/09/2023] [Indexed: 06/12/2023] Open
Abstract
Prolonged status epilepticus (SE) can cause brain damage; therefore, treatment must be administered promptly after seizure onset to limit SE duration and prevent neuropathology. Timely treatment of SE is not always feasible; this would be particularly true in a mass exposure to an SE-inducing agent such as a nerve agent. Therefore, the availability of anticonvulsant treatments that have neuroprotective efficacy even if administered with a delay after SE onset is an imperative. Here, we compared the long-term neuropathology resulting from acutely exposing 21-day-old male and female rats to the nerve agent soman, and treating them with midazolam (3 mg/kg) or co-administration of tezampanel (10 mg/kg) and caramiphen (50 mg/kg), at 1 h postexposure (~50 min after SE onset). Midazolam-treated rats had significant neuronal degeneration in limbic structures, mainly at one month postexposure, followed by neuronal loss in the basolateral amygdala and the CA1 hippocampal area. Neuronal loss resulted in significant amygdala and hippocampal atrophy, deteriorating from one to six months postexposure. Rats treated with tezampanel-caramiphen had no evidence of neuropathology, except for neuronal loss in the basolateral amygdala at the six-month timepoint. Anxiety was increased only in the midazolam-treated rats, at one, three, and six months postexposure. Spontaneous recurrent seizures appeared only in midazolam-treated rats, at three and six months postexposure in males and only at six months in females. These findings suggest that delayed treatment of nerve agent-induced SE with midazolam may result in long-lasting or permanent brain damage, while antiglutamatergic anticonvulsant treatment consisting of tezampanel and caramiphen may provide full neuroprotection.
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Affiliation(s)
- Taiza H Figueiredo
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Vassiliki Aroniadou-Anderjaska
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
- Department of Psychiatry, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - James P Apland
- Neuroscience Program, U.S. Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Katia Rossetti
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Maria FM Braga
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
- Department of Psychiatry, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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Purnell BS, Alves M, Boison D. Astrocyte-neuron circuits in epilepsy. Neurobiol Dis 2023; 179:106058. [PMID: 36868484 DOI: 10.1016/j.nbd.2023.106058] [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: 12/19/2022] [Revised: 02/20/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023] Open
Abstract
The epilepsies are a diverse spectrum of disease states characterized by spontaneous seizures and associated comorbidities. Neuron-focused perspectives have yielded an array of widely used anti-seizure medications and are able to explain some, but not all, of the imbalance of excitation and inhibition which manifests itself as spontaneous seizures. Furthermore, the rate of pharmacoresistant epilepsy remains high despite the regular approval of novel anti-seizure medications. Gaining a more complete understanding of the processes that turn a healthy brain into an epileptic brain (epileptogenesis) as well as the processes which generate individual seizures (ictogenesis) may necessitate broadening our focus to other cell types. As will be detailed in this review, astrocytes augment neuronal activity at the level of individual neurons in the form of gliotransmission and the tripartite synapse. Under normal conditions, astrocytes are essential to the maintenance of blood-brain barrier integrity and remediation of inflammation and oxidative stress, but in epilepsy these functions are impaired. Epilepsy results in disruptions in the way astrocytes relate to each other by gap junctions which has important implications for ion and water homeostasis. In their activated state, astrocytes contribute to imbalances in neuronal excitability due to their decreased capacity to take up and metabolize glutamate and an increased capacity to metabolize adenosine. Furthermore, due to their increased adenosine metabolism, activated astrocytes may contribute to DNA hypermethylation and other epigenetic changes that underly epileptogenesis. Lastly, we will explore the potential explanatory power of these changes in astrocyte function in detail in the specific context of the comorbid occurrence of epilepsy and Alzheimer's disease and the disruption in sleep-wake regulation associated with both conditions.
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Affiliation(s)
- Benton S Purnell
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America
| | - Mariana Alves
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America; Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin D02 YN77, Ireland
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America; Brain Health Institute, Rutgers University, Piscataway, NJ, United States of America.
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Lawrence JM, Schardien K, Wigdahl B, Nonnemacher MR. Roles of neuropathology-associated reactive astrocytes: a systematic review. Acta Neuropathol Commun 2023; 11:42. [PMID: 36915214 PMCID: PMC10009953 DOI: 10.1186/s40478-023-01526-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/08/2023] [Indexed: 03/16/2023] Open
Abstract
In the contexts of aging, injury, or neuroinflammation, activated microglia signaling with TNF-α, IL-1α, and C1q induces a neurotoxic astrocytic phenotype, classified as A1, A1-like, or neuroinflammatory reactive astrocytes. In contrast to typical astrocytes, which promote neuronal survival, support synapses, and maintain blood-brain barrier integrity, these reactive astrocytes downregulate supportive functions and begin to secrete neurotoxic factors, complement components like C3, and chemokines like CXCL10, which may facilitate recruitment of immune cells across the BBB into the CNS. The proportion of pro-inflammatory reactive astrocytes increases with age through associated microglia activation, and these pro-inflammatory reactive astrocytes are particularly abundant in neurodegenerative disorders. As the identification of astrocyte phenotypes progress, their molecular and cellular effects are characterized in a growing array of neuropathologies.
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Affiliation(s)
- Jill M Lawrence
- Molecular and Cell Biology and Genetics Graduate Program, Drexel University College of Medicine, Philadelphia, PA, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Kayla Schardien
- Molecular and Cell Biology and Genetics Graduate Program, Drexel University College of Medicine, Philadelphia, PA, USA
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Brian Wigdahl
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Michael R Nonnemacher
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA.
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA.
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA.
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10
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Naylor DE. In the fast lane: Receptor trafficking during status epilepticus. Epilepsia Open 2023; 8 Suppl 1:S35-S65. [PMID: 36861477 PMCID: PMC10173858 DOI: 10.1002/epi4.12718] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 02/23/2023] [Indexed: 03/03/2023] Open
Abstract
Status epilepticus (SE) remains a significant cause of morbidity and mortality and often is refractory to standard first-line treatments. A rapid loss of synaptic inhibition and development of pharmacoresistance to benzodiazepines (BZDs) occurs early during SE, while NMDA and AMPA receptor antagonists remain effective treatments after BZDs have failed. Multimodal and subunit-selective receptor trafficking within minutes to an hour of SE involves GABA-A, NMDA, and AMPA receptors and contributes to shifts in the number and subunit composition of surface receptors with differential impacts on the physiology, pharmacology, and strength of GABAergic and glutamatergic currents at synaptic and extrasynaptic sites. During the first hour of SE, synaptic GABA-A receptors containing γ2 subunits move to the cell interior while extrasynaptic GABA-A receptors with δ subunits are preserved. Conversely, NMDA receptors containing N2B subunits are increased at synaptic and extrasynaptic sites, and homomeric GluA1 ("GluA2-lacking") calcium permeant AMPA receptor surface expression also is increased. Molecular mechanisms, largely driven by NMDA receptor or calcium permeant AMPA receptor activation early during circuit hyperactivity, regulate subunit-specific interactions with proteins involved with synaptic scaffolding, adaptin-AP2/clathrin-dependent endocytosis, endoplasmic reticulum (ER) retention, and endosomal recycling. Reviewed here is how SE-induced shifts in receptor subunit composition and surface representation increase the excitatory to inhibitory imbalance that sustains seizures and fuels excitotoxicity contributing to chronic sequela such as "spontaneous recurrent seizures" (SRS). A role for early multimodal therapy is suggested both for treatment of SE and for prevention of long-term comorbidities.
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Affiliation(s)
- David E Naylor
- VA Greater Los Angeles Healthcare System, Department of Neurology, David Geffen School of Medicine at UCLA, and The Lundquist Institute at Harbor-UCLA Medical Center, Los Angeles, California, USA
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11
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Dahal A, Govindarajan K, Kar S. Administration of Kainic Acid Differentially Alters Astrocyte Markers and Transiently Enhanced Phospho-tau Level in Adult Rat Hippocampus. Neuroscience 2023; 516:27-41. [PMID: 36805001 DOI: 10.1016/j.neuroscience.2023.02.010] [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: 07/28/2022] [Revised: 02/04/2023] [Accepted: 02/12/2023] [Indexed: 02/18/2023]
Abstract
Kainic acid (KA), an analogue of the excitatory neurotransmitter glutamate, when administered systemically can trigger seizures and neuronal loss in a manner that mirrors the neuropathology of human mesial temporal lobe epilepsy (mTLE), which affects ∼50 million people globally. Evidence suggests that changes in astrocytes which precede neuronal damage play an important role in the degeneration of neurons and/or development of seizures in TLE pathogenesis. Additionally, a role for microtubule associated tau protein, involved in various neurodegenerative diseases including Alzheimer's disease, has also been suggested in the development of seizure and/or neurodegeneration in TLE pathogenesis. At present, possible alterations of different subtypes of astrocytes and their association, if any, with tau protein in TLE remain unclear. In this study, we evaluated alterations of different subtypes of astrocytes and phospho-/cleaved-tau levels in KA-treated rat model of TLE. Our results reveal that levels/expression of various astrocyte markers such as GFAP, vimentin, S100B, Aldh1L1, but not GS, are increased in the hippocampus of KA-treated rats. The levels/expression of both A1(C3+) and A2(S100A10+)-like astrocytes are also increased in KA-treated rats. Concurrently, the total (Tau1 and Tau5) and phospho-tau (AT270 and PHF1) levels are transiently enhanced following KA administration. Furthermore, the level/expression of cleaved-tau, which is apparent in a subset of GFAP-, S100B- and A2-positive astrocytes, are increased in KA-treated rats. These results, taken together, suggest a differential role for various astrocytic subpopulations and tau protein in the development of seizure and/or loss of neurons in KA model of TLE and possibly in human mTLE pathogenesis.
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Affiliation(s)
- Abhishek Dahal
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta T6G 2M8, Canada; Centre for Prions and Protein Folding Disease, University of Alberta, Edmonton, Alberta T6G 2M8, Canada
| | - Karthivashan Govindarajan
- Centre for Prions and Protein Folding Disease, University of Alberta, Edmonton, Alberta T6G 2M8, Canada; Department of Medicine, University of Alberta, Edmonton, Alberta T6G 2M8, Canada
| | - Satyabrata Kar
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta T6G 2M8, Canada; Centre for Prions and Protein Folding Disease, University of Alberta, Edmonton, Alberta T6G 2M8, Canada; Department of Medicine, University of Alberta, Edmonton, Alberta T6G 2M8, Canada.
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12
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Walters GC, Usachev YM. Mitochondrial calcium cycling in neuronal function and neurodegeneration. Front Cell Dev Biol 2023; 11:1094356. [PMID: 36760367 PMCID: PMC9902777 DOI: 10.3389/fcell.2023.1094356] [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: 11/10/2022] [Accepted: 01/12/2023] [Indexed: 01/26/2023] Open
Abstract
Mitochondria are essential for proper cellular function through their critical roles in ATP synthesis, reactive oxygen species production, calcium (Ca2+) buffering, and apoptotic signaling. In neurons, Ca2+ buffering is particularly important as it helps to shape Ca2+ signals and to regulate numerous Ca2+-dependent functions including neuronal excitability, synaptic transmission, gene expression, and neuronal toxicity. Over the past decade, identification of the mitochondrial Ca2+ uniporter (MCU) and other molecular components of mitochondrial Ca2+ transport has provided insight into the roles that mitochondrial Ca2+ regulation plays in neuronal function in health and disease. In this review, we discuss the many roles of mitochondrial Ca2+ uptake and release mechanisms in normal neuronal function and highlight new insights into the Ca2+-dependent mechanisms that drive mitochondrial dysfunction in neurologic diseases including epilepsy, Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. We also consider how targeting Ca2+ uptake and release mechanisms could facilitate the development of novel therapeutic strategies for neurological diseases.
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Affiliation(s)
- Grant C. Walters
- Department of Neuroscience and Pharmacology, Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, United States
| | - Yuriy M. Usachev
- Department of Neuroscience and Pharmacology, Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, United States
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13
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Senn L, Costa AM, Avallone R, Socała K, Wlaź P, Biagini G. Is the peroxisome proliferator-activated receptor gamma a putative target for epilepsy treatment? Current evidence and future perspectives. Pharmacol Ther 2023; 241:108316. [PMID: 36436690 DOI: 10.1016/j.pharmthera.2022.108316] [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: 09/14/2022] [Revised: 11/20/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022]
Abstract
The peroxisome proliferator-activated receptor gamma (PPARγ), which belongs to the family of nuclear receptors, has been mainly studied as an important factor in metabolic disorders. However, in recent years the potential role of PPARγ in different neurological diseases has been increasingly investigated. Especially, in the search of therapeutic targets for patients with epilepsy the question of the involvement of PPARγ in seizure control has been raised. Epilepsy is a chronic neurological disorder causing a major impact on the psychological, social, and economic conditions of patients and their families, besides the problems of the disease itself. Considering that the world prevalence of epilepsy ranges between 0.5% - 1.0%, this condition is the fourth for importance among the other neurological disorders, following migraine, stroke, and dementia. Among others, temporal lobe epilepsy (TLE) is the most common form of epilepsy in adult patients. About 65% of individuals who receive antiseizure medications (ASMs) experience seizure independence. For those in whom seizures still recur, investigating PPARγ could lead to the development of novel ASMs. This review focuses on the most important findings from recent investigations about the potential intracellular PPARγ-dependent processes behind different compounds that exhibited anti-seizure effects. Additionally, recent clinical investigations are discussed along with the promising results found for PPARγ agonists and the ketogenic diet (KD) in various rodent models of epilepsy.
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Affiliation(s)
- Lara Senn
- Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; PhD School of Clinical and Experimental Medicine (CEM), University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Anna-Maria Costa
- Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Rossella Avallone
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Katarzyna Socała
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Maria Curie-Skłodowska University, PL 20-033 Lublin, Poland
| | - Piotr Wlaź
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Maria Curie-Skłodowska University, PL 20-033 Lublin, Poland
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy.
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14
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GRIN2A-related epilepsy and speech disorders: A comprehensive overview with a focus on the role of precision therapeutics. Epilepsy Res 2023; 189:107065. [PMID: 36516565 DOI: 10.1016/j.eplepsyres.2022.107065] [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: 08/18/2022] [Revised: 10/27/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
Language dysfunction is a common and serious comorbidity of epilepsy, especially in individuals with epilepsy aphasia spectrum syndromes. Childhood epilepsy with centrotemporal spikes is on the mild end of the spectrum, while epileptic encephalopathy with continuous spike-and-wave during sleep syndrome is on the severe end. Traditional antiseizure medicines and immunotherapy are currently used to treat severely affected patients, but the results are usually disappointing. The discovery that GRIN2A is the primary monogenic etiology of these diseases has opened the door to precision treatments. The GRIN2A gene encodes GluN2A protein, which constitutes a subunit of the NMDA receptor (NMDAR). The GRIN2A pathogenic variants cause gain or loss of function of NMDAR; the former can be treated with uncompetitive NMDAR antagonists, such as memantine, while the latter with NMDAR co-agonist serine. Hyper-precision therapies with various other effective agents are likely to be developed shortly to target the diverse functional effects of different variants. Precision treatments for GRIN2A-related disorders will benefit those who suffer from the condition and pave the way for new therapeutic approaches to a variety of other NMDAR-linked neurodegenerative and psychiatric diseases (schizophrenia, Parkinson's disease, Alzheimer's disease, and so on). Furthermore, more research into GRIN2A-related disorders will help us better understand the neuroinflammatory and neuroimmunological basis of epilepsy, as well as the pathological and physiological network activation mechanisms that cause sleep activation of central-temporal spikes and language impairment.
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15
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Tiberi A, Carucci NM, Testa G, Rizzi C, Pacifico P, Borgonovo G, Arisi I, D’Onofrio M, Brandi R, Gan WB, Capsoni S, Cattaneo A. Reduced levels of NGF shift astrocytes toward a neurotoxic phenotype. Front Cell Dev Biol 2023; 11:1165125. [PMID: 37143894 PMCID: PMC10151754 DOI: 10.3389/fcell.2023.1165125] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 03/16/2023] [Indexed: 05/06/2023] Open
Abstract
Nerve growth factor (NGF) is critical for neuronal physiology during development and adulthood. Despite the well-recognized effect of NGF on neurons, less is known about whether NGF can actually affect other cell types in the central nervous system (CNS). In this work, we show that astrocytes are susceptible to changes in ambient levels of NGF. First, we observe that interfering with NGF signaling in vivo via the constitutive expression of an antiNGF antibody induces astrocytic atrophy. A similar asthenic phenotype is encountered in an uncleavable proNGF transgenic mouse model (TgproNGF#72), effectively increasing the brain proNGF levels. To examine whether this effect on astrocytes is cell-autonomous, we cultured wild-type primary astrocytes in the presence of antiNGF antibodies, uncovering that a short incubation period is sufficient to potently and rapidly trigger calcium oscillations. Acute induction of calcium oscillations by antiNGF antibodies is followed by progressive morphological changes similar to those observed in antiNGF AD11 mice. Conversely, incubation with mature NGF has no effect on either calcium activity nor on astrocytic morphology. At longer timescales, transcriptomic analysis revealed that NGF-deprived astrocytes acquire a proinflammatory profile. In particular, antiNGF-treated astrocytes show upregulation of neurotoxic transcripts and downregulation of neuroprotective mRNAs. Consistent with that data, culturing wild-type neurons in the presence of NGF-deprived astrocytes leads to neuronal cell death. Finally, we report that in both awake and anesthetized mice, astrocytes in layer I of the motor cortex respond with an increase in calcium activity to acute NGF inhibition using either NGF-neutralizing antibodies or a TrkA-Fc NGF scavenger. Moreover, in vivo calcium imaging in the cortex of the 5xFAD neurodegeneration mouse model shows an increased level of spontaneous calcium activity in astrocytes, which is significantly reduced after acute administration of NGF. In conclusion, we unveil a novel neurotoxic mechanism driven by astrocytes, triggered by their sensing and reacting to changes in the levels of ambient NGF.
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Affiliation(s)
- Alexia Tiberi
- BIO@SNS, Scuola Normale Superiore, Pisa, Italy
- Skirball Institute of Biomolecular Medicine, Langone Medical Center, New York University, New York, NY, United States
| | | | | | | | | | | | - Ivan Arisi
- European Brain Research Institute - Fondazione Rita Levi-Montalcini, Rome, Italy
| | - Mara D’Onofrio
- European Brain Research Institute - Fondazione Rita Levi-Montalcini, Rome, Italy
| | - Rossella Brandi
- European Brain Research Institute - Fondazione Rita Levi-Montalcini, Rome, Italy
| | - Wen-Biao Gan
- Skirball Institute of Biomolecular Medicine, Langone Medical Center, New York University, New York, NY, United States
- Shenzhen Bay Laboratory, Shenzhen, China
| | - Simona Capsoni
- BIO@SNS, Scuola Normale Superiore, Pisa, Italy
- Institute of Physiology, Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
| | - Antonino Cattaneo
- BIO@SNS, Scuola Normale Superiore, Pisa, Italy
- European Brain Research Institute - Fondazione Rita Levi-Montalcini, Rome, Italy
- *Correspondence: Antonino Cattaneo,
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16
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Zhang LY, Kim AY, Cheer JF. Regulation of glutamate homeostasis in the nucleus accumbens by astrocytic CB1 receptors and its role in cocaine-motivated behaviors. ADDICTION NEUROSCIENCE 2022; 3:100022. [PMID: 36419922 PMCID: PMC9681119 DOI: 10.1016/j.addicn.2022.100022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Cannabinoid type 1 receptors (CB1Rs) orchestrate brain reward circuitry and are prevalent neurobiological targets for endocannabinoids and cannabis in the mammalian brain. Decades of histological and electrophysiological studies have established CB1R as presynaptic G-protein coupled receptors (GPCRs) that inhibit neurotransmitter release through retrograde signaling mechanisms. Recent seminal work demonstrates CB1R expression on astrocytes and the pivotal function of glial cells in endocannabinoid-mediated modulation of neuron-astrocyte signaling. Here, we review key facets of CB1R-mediated astroglia regulation of synaptic glutamate transmission in the nucleus accumbens with a specific emphasis on cocaine-directed behaviors.
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Affiliation(s)
- Lan-Yuan Zhang
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Andrew Y. Kim
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Joseph F. Cheer
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States of America
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, United States of America
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, United States of America
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17
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Shasaltaneh MD, Naghdi N, Ramezani S, Alizadeh L, Riazi GH. Protection of Beta Boswellic Acid against Streptozotocin-induced Alzheimer's Model by Reduction of Tau Phosphorylation Level and Enhancement of Reelin Expression. PLANTA MEDICA 2022; 88:367-379. [PMID: 34116571 DOI: 10.1055/a-1502-7083] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Alzheimer's disease is a growing general health concern with huge implications for individuals and society. Beta boswellic acid, a major compound of the Boswellia serrata plant, has long been used for the treatment of various inflammatory diseases. The exact mechanism of beta boswellic acid action in Alzheimer's disease pathogenesis remains unclear. In the current study, the protective effect of beta boswellic acid on streptozotocin-induced sporadic Alzheimer's disease was surveyed. Alzheimer's disease model was induced using streptozotocin followed by an assessment of the treatment effects of beta boswellic acid in the presence of streptozotocin. The prevention effect of beta boswellic acid on Alzheimer's disease induction by streptozotocin was evaluated. Behavioral activities in the treated rats were evaluated. Histological analysis was performed. Phosphorylation of tau protein at residues Ser396 and Ser404 and the expression of reelin protein were determined. Glial fibrillary acidic protein immunofluorescence staining was applied in the hippocampus regions. Our findings indicated that beta boswellic acid decreased traveled distance and escape latency in the prevention (beta boswellic acid + streptozotocin) and treatment (streptozotocin + beta boswellic acid) groups compared to control during the acquisition test. It increased "time spent" (%) in the target quadrant. Reelin level was enhanced in rats treated with beta boswellic acid. Tau hyperphosphorylation (p-tau404) and glial fibrillary acidic protein were decreased in the prevention group while the expression of reelin protein in both groups was increased. We could suggest that the anti-inflammatory property of beta boswellic acid is one of the main factors involving in the improvement of learning and memory in rats. Therefore the antineurodegenerative effect of beta boswellic acid may be due to its ability to reactivate reelin protein.
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Affiliation(s)
| | - Nasser Naghdi
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran
| | - Sadrollah Ramezani
- Zanjan Pharmaceutical Biotechnology Research Center, Zanjan University of Medical Sciences, Zanjan, Iran
- University of Sistan and Baluchestan, Zahedan, Iran
| | - Leila Alizadeh
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran
| | - Gholam Hossein Riazi
- Laboratory of Neuro-organic Chemistry, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
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18
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Schroeder ME, Bassett DS, Meaney DF. A multilayer network model of neuron-astrocyte populations in vitro reveals mGluR5 inhibition is protective following traumatic injury. Netw Neurosci 2022; 6:499-527. [PMID: 35733423 PMCID: PMC9208011 DOI: 10.1162/netn_a_00227] [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: 01/11/2021] [Accepted: 01/04/2022] [Indexed: 11/16/2022] Open
Abstract
Astrocytes communicate bidirectionally with neurons, enhancing synaptic plasticity and promoting the synchronization of neuronal microcircuits. Despite recent advances in understanding neuron-astrocyte signaling, little is known about astrocytic modulation of neuronal activity at the population level, particularly in disease or following injury. We used high-speed calcium imaging of mixed cortical cultures in vitro to determine how population activity changes after disruption of glutamatergic signaling and mechanical injury. We constructed a multilayer network model of neuron-astrocyte connectivity, which captured distinct topology and response behavior from single-cell-type networks. mGluR5 inhibition decreased neuronal activity, but did not on its own disrupt functional connectivity or network topology. In contrast, injury increased the strength, clustering, and efficiency of neuronal but not astrocytic networks, an effect that was not observed in networks pretreated with mGluR5 inhibition. Comparison of spatial and functional connectivity revealed that functional connectivity is largely independent of spatial proximity at the microscale, but mechanical injury increased the spatial-functional correlation. Finally, we found that astrocyte segments of the same cell often belong to separate functional communities based on neuronal connectivity, suggesting that astrocyte segments function as independent entities. Our findings demonstrate the utility of multilayer network models for characterizing the multiscale connectivity of two distinct but functionally dependent cell populations. Astrocytes communicate bidirectionally with neurons, enhancing synaptic plasticity and promoting the synchronization of neuronal microcircuits. We constructed a multilayer network model of neuron-astrocyte connectivity based on calcium activity in mixed cortical cultures, and used this model to evaluate the effect of glutamatergic inhibition and mechanical injury on network topology. We found that injury increased the strength, clustering, and efficiency of neuronal but not astrocytic networks, an effect that was not observed in injured networks pretreated with a glutamate receptor antagonist. Our findings demonstrate the utility of multilayer network models for characterizing the multiscale connectivity of two distinct but functionally dependent cell populations.
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Affiliation(s)
- Margaret E. Schroeder
- Department of Bioengineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, USA
| | - Danielle S. Bassett
- Department of Bioengineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, USA
- Department of Physics & Astronomy, College of Arts & Sciences, University of Pennsylvania, Philadelphia, PA, USA
- Department of Electrical & Systems Engineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David F. Meaney
- Department of Bioengineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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19
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Lundquist AJ, Llewellyn GN, Kishi SH, Jakowec NA, Cannon PM, Petzinger GM, Jakowec MW. Knockdown of Astrocytic Monocarboxylate Transporter 4 in the Motor Cortex Leads to Loss of Dendritic Spines and a Deficit in Motor Learning. Mol Neurobiol 2021; 59:1002-1017. [PMID: 34822124 DOI: 10.1007/s12035-021-02651-z] [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: 08/09/2021] [Accepted: 11/16/2021] [Indexed: 10/19/2022]
Abstract
Monocarboxylate transporters (MCTs) shuttle molecules, including L-lactate, involved in metabolism and cell signaling of the central nervous system. Astrocyte-specific MCT4 is a key component of the astrocyte-neuron lactate shuttle (ANLS) and is important for neuroplasticity and learning of the hippocampus. However, the importance of astrocyte-specific MCT4 in neuroplasticity of the M1 primary motor cortex remains unknown. In this study, we investigated astrocyte-specific MCT4 in motor learning and neuroplasticity of the M1 primary motor cortex using a cell-type specific shRNA knockdown of MCT4. Knockdown of astrocyte-specific MCT4 resulted in impaired motor performance and learning on the accelerating rotarod. In addition, MCT4 knockdown was associated with a reduction of neuronal dendritic spine density and spine width and decreased protein expression of PSD95, Arc, and cFos. Using near-infrared-conjugated 2-deoxyglucose uptake as a surrogate marker for neuronal activity, MCT4 knockdown was also associated with decreased neuronal activity in the M1 primary motor cortex and associated motor regions including the dorsal striatum and ventral thalamus. Our study supports a potential role for astrocyte-specific MCT4 and the ANLS in the neuroplasticity of the M1 primary motor cortex. Targeting MCT4 may serve to enhance neuroplasticity and motor repair in several neurological disorders, including Parkinson's disease and stroke.
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Affiliation(s)
- Adam J Lundquist
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90033, USA. .,Department of Neurology, University of Southern California, 1333 San Pablo St, MCA-241, Los Angeles, CA, 90033, USA.
| | - George N Llewellyn
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Susan H Kishi
- Department of Neurology, University of Southern California, 1333 San Pablo St, MCA-241, Los Angeles, CA, 90033, USA
| | - Nicolaus A Jakowec
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.,Molecular and Cellular Biology Graduate Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90033, USA
| | - Paula M Cannon
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Giselle M Petzinger
- Department of Neurology, University of Southern California, 1333 San Pablo St, MCA-241, Los Angeles, CA, 90033, USA
| | - Michael W Jakowec
- Department of Neurology, University of Southern California, 1333 San Pablo St, MCA-241, Los Angeles, CA, 90033, USA
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20
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Lalo U, Koh W, Lee CJ, Pankratov Y. The tripartite glutamatergic synapse. Neuropharmacology 2021; 199:108758. [PMID: 34433089 DOI: 10.1016/j.neuropharm.2021.108758] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 07/25/2021] [Accepted: 08/20/2021] [Indexed: 12/31/2022]
Abstract
Astroglial cells were long considered as structural and metabolic supporting cells are which do not directly participate in information processing in the brain. Discoveries of responsiveness of astrocytes to synaptically-released glutamate and their capability to release agonists of glutamate receptors awakened extensive studies of glia-neuron communications and led to the revolutionary changes in our understanding of brain cellular networks. Nowadays, astrocytes are widely acknowledged as inseparable element of glutamatergic synapses and role for glutamatergic astrocyte-neuron interactions in the brain computation is emerging. Astroglial glutamate receptors, in particular of NMDA, mGluR3 and mGluR5 types, can activate a variety of molecular cascades leading astroglial-driven modulation of extracellular levels of glutamate and activity of neuronal glutamate receptors. Their preferential location to the astroglial perisynaptic processes facilitates interaction of astrocytes with individual excitatory synapses. Bi-directional glutamatergic communication between astrocytes and neurons underpins a complex, spatially-distributed modulation of synaptic signalling thus contributing to the enrichment of information processing by the neuronal networks. Still, further research is needed to bridge the substantial gaps in our understanding of mechanisms and physiological relevance of astrocyte-neuron glutamatergic interactions, in particular ability of astrocytes directly activate neuronal glutamate receptors by releasing glutamate and, arguably, d-Serine. An emerging roles for aberrant changes in glutamatergic astroglial signalling, both neuroprotective and pathogenic, in neurological and neurodegenerative diseases also require further investigation. This article is part of the special Issue on 'Glutamate Receptors - The Glutamatergic Synapse'.
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Affiliation(s)
- Ulyana Lalo
- School of Life Sciences, Immanuel Kant Baltic Federal University, Kaliningrad, Russia
| | - Wuhyun Koh
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, 34126, South Korea
| | - C Justin Lee
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, 34126, South Korea
| | - Yuriy Pankratov
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom.
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21
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Green JL, Dos Santos WF, Fontana ACK. Role of glutamate excitotoxicity and glutamate transporter EAAT2 in epilepsy: Opportunities for novel therapeutics development. Biochem Pharmacol 2021; 193:114786. [PMID: 34571003 DOI: 10.1016/j.bcp.2021.114786] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 12/21/2022]
Abstract
Epilepsy is a complex neurological syndrome characterized by seizures resulting from neuronal hyperexcitability and sudden and synchronized bursts of electrical discharges. Impaired astrocyte function that results in glutamate excitotoxicity has been recognized to play a key role in the pathogenesis of epilepsy. While there are 26 drugs marketed as anti-epileptic drugs no current treatments are disease modifying as they only suppress seizures rather than the development and progression of epilepsy. Excitatory amino acid transporters (EAATs) are critical for maintaining low extracellular glutamate concentrations and preventing excitotoxicity. When extracellular glutamate concentrations rise to abnormal levels, glutamate receptor overactivation and the subsequent excessive influx of calcium into the post-synaptic neuron can trigger cell death pathways. In this review we discuss targeting EAAT2, the predominant glutamate transporter in the CNS, as a promising approach for developing therapies for epilepsy. EAAT2 upregulation via transcriptional and translational regulation has proven successful in vivo in reducing spontaneous recurrent seizures and offering neuroprotective effects. Another approach to regulate EAAT2 activity is through positive allosteric modulation (PAM). Novel PAMs of EAAT2 have recently been identified and are under development, representing a promising approach for the advance of novel therapeutics for epilepsy.
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Affiliation(s)
- Jennifer Leigh Green
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, 19102, United States
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22
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Tanaka M, Shigetomi E, Parajuli B, Nagatomo H, Shinozaki Y, Hirayama Y, Saito K, Kubota Y, Danjo Y, Lee JH, Kim SK, Nabekura J, Koizumi S. Adenosine A 2B receptor down-regulates metabotropic glutamate receptor 5 in astrocytes during postnatal development. Glia 2021; 69:2546-2558. [PMID: 34339538 DOI: 10.1002/glia.24006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/30/2021] [Accepted: 04/01/2021] [Indexed: 11/07/2022]
Abstract
Metabotropic glutamate receptor 5 (mGluR5) in astrocytes is a key molecule for controlling synapse remodeling. Although mGluR5 is abundant in neonatal astrocytes, its level is gradually down-regulated during development and is almost absent in the adult. However, in several pathological conditions, mGluR5 re-emerges in adult astrocytes and contributes to disease pathogenesis by forming uncontrolled synapses. Thus, controlling mGluR5 expression in astrocyte is critical for several diseases, but the mechanism that regulates mGluR5 expression remains unknown. Here, we show that adenosine triphosphate (ATP)/adenosine-mediated signals down-regulate mGluR5 in astrocytes. First, in situ Ca2+ imaging of astrocytes in acute cerebral slices from post-natal day (P)7-P28 mice showed that Ca2+ responses evoked by (S)-3,5-dihydroxyphenylglycine (DHPG), a mGluR5 agonist, decreased during development, whereas those evoked by ATP or its metabolite, adenosine, increased. Second, ATP and adenosine suppressed expression of the mGluR5 gene, Grm5, in cultured astrocytes. Third, the decrease in the DHPG-evoked Ca2+ responses was associated with down-regulation of Grm5. Interestingly, among several adenosine (P1) receptor and ATP (P2) receptor genes, only the adenosine A2B receptor gene, Adora2b, was up-regulated in the course of development. Indeed, we observed that down-regulation of Grm5 was suppressed in Adora2b knockout astrocytes at P14 and in situ Ca2+ imaging from Adora2b knockout mice indicated that the A2B receptor inhibits mGluR5 expression in astrocytes. Furthermore, deletion of A2B receptor increased the number of excitatory synapse in developmental stage. Taken together, the A2B receptor is critical for down-regulation of mGluR5 in astrocytes, which would contribute to terminate excess synaptogenesis during development.
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Affiliation(s)
- Masayoshi Tanaka
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Eiji Shigetomi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Bijay Parajuli
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Hiroaki Nagatomo
- Center for Life Science Research, University of Yamanashi, Yamanashi, Japan
| | - Youichi Shinozaki
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Yuri Hirayama
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Kozo Saito
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Yuto Kubota
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Yosuke Danjo
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Ji Hwan Lee
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Sun Kwang Kim
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul, South Korea.,Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi, Japan
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
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23
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Kyriatzis G, Bernard A, Bôle A, Pflieger G, Chalas P, Masse M, Lécorché P, Jacquot G, Ferhat L, Khrestchatisky M. Neurotensin receptor 2 is induced in astrocytes and brain endothelial cells in relation to neuroinflammation following pilocarpine-induced seizures in rats. Glia 2021; 69:2618-2643. [PMID: 34310753 DOI: 10.1002/glia.24062] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 06/30/2021] [Accepted: 07/09/2021] [Indexed: 12/14/2022]
Abstract
Neurotensin (NT) acts as a primary neurotransmitter and neuromodulator in the CNS and has been involved in a number of CNS pathologies including epilepsy. NT mediates its central and peripheral effects by interacting with the NTSR1, NTSR2, and Sort1/NTSR3 receptor subtypes. To date, little is known about the precise expression of the NT receptors in brain neural cells and their regulation in pathology. In the present work, we studied the cellular distribution of the NTSR2 protein in the rat hippocampus and questioned whether its expression was modulated in conditions of neuroinflammation using a model of temporal lobe epilepsy induced by pilocarpine. This model is characterized by a rapid and intense inflammatory reaction with reactive gliosis in the hippocampus. We show that NTSR2 protein is expressed in hippocampal astrocytes and its expression increases together with astrocyte reactivity following induction of status epilepticus. NTSR2 immunoreactivity is also increased in astrocytes proximal to blood vessels and their end-feet, and in endothelial cells. Proinflammatory factors such as IL1β and LPS induced NTSR2 mRNA and protein in cultured astroglial cells. Antagonizing NTSR2 with SR142948A decreased NTSR2 expression as well as astroglial reactivity. Together, our results suggest that NTSR2 is implicated in astroglial and gliovascular inflammation and that targeting the NTSR2 receptor may open new avenues in the regulation of neuroinflammation in CNS diseases.
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Affiliation(s)
- Grigorios Kyriatzis
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Anne Bernard
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Angélique Bôle
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Guillaume Pflieger
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Petros Chalas
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Maxime Masse
- VECT-HORUS, Faculté de Médecine, Marseille Cedex, France
| | | | | | - Lotfi Ferhat
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Michel Khrestchatisky
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
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24
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Heuser K, Enger R. Astrocytic Ca 2+ Signaling in Epilepsy. Front Cell Neurosci 2021; 15:695380. [PMID: 34335188 PMCID: PMC8320018 DOI: 10.3389/fncel.2021.695380] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/16/2021] [Indexed: 01/10/2023] Open
Abstract
Epilepsy is one of the most common neurological disorders – estimated to affect at least 65 million worldwide. Most of the epilepsy research has so far focused on how to dampen neuronal discharges and to explain how changes in intrinsic neuronal activity or network function cause seizures. As a result, pharmacological therapy has largely been limited to symptomatic treatment targeted at neurons. Given the expanding spectrum of functions ascribed to the non-neuronal constituents of the brain, in both physiological brain function and in brain disorders, it is natural to closely consider the roles of astrocytes in epilepsy. It is now widely accepted that astrocytes are key controllers of the composition of the extracellular fluids, and may directly interact with neurons by releasing gliotransmitters. A central tenet is that astrocytic intracellular Ca2+ signals promote release of such signaling substances, either through synaptic or non-synaptic mechanisms. Accruing evidence suggests that astrocytic Ca2+ signals play important roles in both seizures and epilepsy, and this review aims to highlight the current knowledge of the roles of this central astrocytic signaling mechanism in ictogenesis and epileptogenesis.
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Affiliation(s)
- Kjell Heuser
- Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Rune Enger
- Letten Centre and GliaLab, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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25
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Saito K, Shigetomi E, Koizumi S. [Alexander disease: diversity of cell population and interactions between neuron and glia]. Nihon Yakurigaku Zasshi 2021; 156:239-243. [PMID: 34193704 DOI: 10.1254/fpj.21028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Alexander disease (AxD) is a rare neurodegenerative disorder caused by the mutations in glial fibrillary acidic protein (GFAP) gene. Rosenthal fiber formations in astrocytes are the pathological hallmarks of AxD. Astrocyte dysfunction in the AxD brain is considered to be involved in its pathogenesis. We have previously reported that in AxD model mice aberrant Ca2+ signals in astrocytes were associated with the upregulation of reactive phenotype. Reactive astrocytes are conditions that lead to morphological, functional, and molecular changes by responding to various pathological insults (trauma, inflammation, ischemia), and environmental stimuli. Recent technological advances in single-cell gene expression analysis have revealed that astrocytes have heterogeneity by indicating that they form sub population with different characteristics depending on the brain region, the growth development, aging stage, and the pathological condition. AxD astrocytes are also thought to constitute a heterogeneous population with diverse properties and functions. Moreover, it is presumed that AxD pathogenesis occur due to interactions with neurons and other glial cells, as well as the microenvironment in tissues. Research strategies based on these perspectives will help us understand AxD pathology better and may lead to the elucidation of disease modifiers and clinical diversity.
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Affiliation(s)
- Kozo Saito
- Department of Neuropharmcology, Interdisciplinary Graduate School of Medicine
| | - Eiji Shigetomi
- Department of Neuropharmcology, Interdisciplinary Graduate School of Medicine
| | - Schuichi Koizumi
- Department of Neuropharmcology, Interdisciplinary Graduate School of Medicine
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26
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Zaitsev АV, Amakhin DV, Dyomina AV, Zakharova MV, Ergina JL, Postnikova TY, Diespirov GP, Magazanik LG. Synaptic Dysfunction in Epilepsy. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s002209302103008x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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27
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Sano F, Shigetomi E, Shinozaki Y, Tsuzukiyama H, Saito K, Mikoshiba K, Horiuchi H, Cheung DL, Nabekura J, Sugita K, Aihara M, Koizumi S. Reactive astrocyte-driven epileptogenesis is induced by microglia initially activated following status epilepticus. JCI Insight 2021; 6:135391. [PMID: 33830944 PMCID: PMC8262323 DOI: 10.1172/jci.insight.135391] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/25/2021] [Indexed: 12/22/2022] Open
Abstract
Extensive activation of glial cells during a latent period has been well documented in various animal models of epilepsy. However, it remains unclear whether activated glial cells contribute to epileptogenesis, i.e., the chronically persistent process leading to epilepsy. Particularly, it is not clear whether interglial communication between different types of glial cells contributes to epileptogenesis, because past literature has mainly focused on one type of glial cell. Here, we show that temporally distinct activation profiles of microglia and astrocytes collaboratively contributed to epileptogenesis in a drug-induced status epilepticus model. We found that reactive microglia appeared first, followed by reactive astrocytes and increased susceptibility to seizures. Reactive astrocytes exhibited larger Ca2+ signals mediated by IP3R2, whereas deletion of this type of Ca2+ signaling reduced seizure susceptibility after status epilepticus. Immediate, but not late, pharmacological inhibition of microglial activation prevented subsequent reactive astrocytes, aberrant astrocyte Ca2+ signaling, and the enhanced seizure susceptibility. These findings indicate that the sequential activation of glial cells constituted a cause of epileptogenesis after status epilepticus. Thus, our findings suggest that the therapeutic target to prevent epilepsy after status epilepticus should be shifted from microglia (early phase) to astrocytes (late phase).
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Affiliation(s)
- Fumikazu Sano
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine.,Department of Pediatrics, Faculty of Medicine, and.,Yamanashi GLIA Center, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Eiji Shigetomi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine.,Yamanashi GLIA Center, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Youichi Shinozaki
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine.,Yamanashi GLIA Center, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Haruka Tsuzukiyama
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine
| | - Kozo Saito
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine.,Yamanashi GLIA Center, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Katsuhiko Mikoshiba
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Hiroshi Horiuchi
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Japan
| | - Dennis Lawrence Cheung
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Japan
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Japan
| | - Kanji Sugita
- Department of Pediatrics, Faculty of Medicine, and
| | - Masao Aihara
- Department of Pediatrics, Faculty of Medicine, and
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine.,Yamanashi GLIA Center, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
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28
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Adrenergic inhibition facilitates normalization of extracellular potassium after cortical spreading depolarization. Sci Rep 2021; 11:8150. [PMID: 33854148 PMCID: PMC8047013 DOI: 10.1038/s41598-021-87609-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/31/2021] [Indexed: 01/31/2023] Open
Abstract
Cortical spreading depolarization (CSD) is a propagating wave of tissue depolarization characterized by a large increase of extracellular potassium concentration and prolonged subsequent electrical silencing of neurons. Waves of CSD arise spontaneously in various acute neurological settings, including migraine aura and ischemic stroke. Recently, we have reported that pan-inhibition of adrenergic receptors (AdRs) facilitates the normalization of extracellular potassium after acute photothrombotic stroke in mice. Here, we have extended that mechanistic study to ask whether AdR antagonists also modify the dynamics of KCl-induced CSD and post-CSD recovery in vivo. Spontaneous neural activity and KCl-induced CSD were visualized by cortex-wide transcranial Ca2+ imaging in G-CaMP7 transgenic mice. AdR antagonism decreased the recurrence of CSD waves and accelerated the post-CSD recovery of neural activity. Two-photon imaging revealed that astrocytes exhibited aberrant Ca2+ signaling after passage of the CSD wave. This astrocytic Ca2+ activity was diminished by the AdR antagonists. Furthermore, AdR pan-antagonism facilitated the normalization of the extracellular potassium level after CSD, which paralleled the recovery of neural activity. These observations add support to the proposal that neuroprotective effects of AdR pan-antagonism arise from accelerated normalization of extracellular K+ levels in the setting of acute brain injury.
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29
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Restoring glutamate homeostasis in the nucleus accumbens via endocannabinoid-mimetic drug prevents relapse to cocaine seeking behavior in rats. Neuropsychopharmacology 2021; 46:970-981. [PMID: 33514875 PMCID: PMC8115336 DOI: 10.1038/s41386-021-00955-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 12/13/2020] [Accepted: 12/29/2020] [Indexed: 12/23/2022]
Abstract
Impaired glutamate homeostasis is a key characteristic of the neurobiology of drug addiction in rodent models and contributes to the vulnerability to relapse to drug seeking. Although disrupted astrocytic and presynaptic regulation of glutamate release has been considered to constitute with impaired glutamate homeostasis in rodent model of drug relapse, the involvement of endocannabinoids (eCBs) in this neurobiological process has remained largely unknown. Here, using cocaine self-administration in rats, we investigated the role of endocannabinoids in impaired glutamate homeostasis in the core of nucleus accumbens (NAcore), which was indicated by augmentation of spontaneous synaptic glutamate release, downregulation of metabotropic glutamate receptor 2/3 (mGluR2/3), and mGluR5-mediated astrocytic glutamate release. We found that the endocannabinoid, anandamide (AEA), rather than 2-arachidonoylglycerol elicited glutamate release through presynaptic transient receptor potential vanilloid 1 (TRPV1) and astrocytic cannabinoid type-1 receptors (CB1Rs) in the NAcore of saline-yoked rats. In rats with a history of cocaine self-administration and extinction training, AEA failed to alter synaptic glutamate release in the NAcore, whereas CB1R-mediated astrocytic glutamate release by AEA remained functional. In order to induce increased astrocytic glutamate release via exogenous AEA, (R)-methanandamide (methAEA, a metabolically stable form of AEA) was chronically infused in the NAcore via osmotic pumps during extinction training. Restoration of mGluR2/3 function and mGluR5-mediated astrocytic glutamate release was observed after chronic methAEA infusion. Additionally, priming or cue-induced reinstatement of cocaine seeking was inhibited in methAEA-infused rats. These results demonstrate that enhancing endocannabinoid signaling is a potential pathway to restore glutamate homeostasis and may represent a promising therapeutic strategy for preventing cocaine relapse.
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30
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Alcoreza OB, Patel DC, Tewari BP, Sontheimer H. Dysregulation of Ambient Glutamate and Glutamate Receptors in Epilepsy: An Astrocytic Perspective. Front Neurol 2021; 12:652159. [PMID: 33828523 PMCID: PMC8019783 DOI: 10.3389/fneur.2021.652159] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/24/2021] [Indexed: 12/16/2022] Open
Abstract
Given the important functions that glutamate serves in excitatory neurotransmission, understanding the regulation of glutamate in physiological and pathological states is critical to devising novel therapies to treat epilepsy. Exclusive expression of pyruvate carboxylase and glutamine synthetase in astrocytes positions astrocytes as essential regulators of glutamate in the central nervous system (CNS). Additionally, astrocytes can significantly alter the volume of the extracellular space (ECS) in the CNS due to their expression of the bi-directional water channel, aquaporin-4, which are enriched at perivascular endfeet. Rapid ECS shrinkage has been observed following epileptiform activity and can inherently concentrate ions and neurotransmitters including glutamate. This review highlights our emerging knowledge on the various potential contributions of astrocytes to epilepsy, particularly supporting the notion that astrocytes may be involved in seizure initiation via failure of homeostatic responses that lead to increased ambient glutamate. We also review the mechanisms whereby ambient glutamate can influence neuronal excitability, including via generation of the glutamate receptor subunit GluN2B-mediated slow inward currents, as well as indirectly affect neuronal excitability via actions on metabotropic glutamate receptors that can potentiate GluN2B currents and influence neuronal glutamate release probabilities. Additionally, we discuss evidence for upregulation of System x c - , a cystine/glutamate antiporter expressed on astrocytes, in epileptic tissue and changes in expression patterns of glutamate receptors.
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Affiliation(s)
- Oscar B Alcoreza
- Glial Biology in Health, Disease, and Cancer Center, Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, VA, United States.,School of Medicine, Virginia Tech Carilion, Roanoke, VA, United States.,Translational Biology, Medicine and Health, Virginia Tech, Blacksburg, VA, United States
| | - Dipan C Patel
- Glial Biology in Health, Disease, and Cancer Center, Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, VA, United States
| | - Bhanu P Tewari
- Glial Biology in Health, Disease, and Cancer Center, Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, VA, United States
| | - Harald Sontheimer
- Glial Biology in Health, Disease, and Cancer Center, Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, VA, United States
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31
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Cocaine Triggers Astrocyte-Mediated Synaptogenesis. Biol Psychiatry 2021; 89:386-397. [PMID: 33069367 PMCID: PMC7854999 DOI: 10.1016/j.biopsych.2020.08.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 07/28/2020] [Accepted: 08/11/2020] [Indexed: 12/30/2022]
Abstract
BACKGROUND Synaptogenesis is essential in forming new neurocircuits during development, and this is mediated in part by astrocyte-released thrombospondins (TSPs) and activation of their neuronal receptor, α2δ-1. Here, we show that this developmental synaptogenic mechanism is utilized during cocaine experience to induce spinogenesis and the generation of AMPA receptor-silent glutamatergic synapses in the adult nucleus accumbens shell (NAcSh). METHODS Using multidisciplinary approaches including astrocyte Ca2+ imaging, genetic mouse lines, viral-mediated gene transfer, and operant behavioral procedures, we monitor the response of NAcSh astrocytes to cocaine administration and examine the role of astrocytic TSP-α2δ-1 signaling in cocaine-induced silent synapse generation as well as the behavioral impact of astrocyte-mediated synaptogenesis and silent synapse generation. RESULTS Cocaine administration acutely increases Ca2+ events in NAcSh astrocytes, while decreasing astrocytic Ca2+ blocks cocaine-induced generation of silent synapses. Furthermore, knockout of TSP2, or pharmacological inhibition or viral-mediated knockdown of α2δ-1, prevents cocaine-induced generation of silent synapses. Moreover, disrupting TSP2-α2δ-1-mediated spinogenesis and synapse generation in NAcSh decreases cue-induced cocaine seeking after withdrawal from cocaine self-administration and cue-induced reinstatement of cocaine seeking after drug extinction. CONCLUSIONS These results establish that silent synapses are generated by an astrocyte-mediated synaptogenic mechanism in response to cocaine experience and embed critical cue-associated memory traces that promote cocaine relapse.
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32
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Juvale IIA, Che Has AT. Possible interplay between the theories of pharmacoresistant epilepsy. Eur J Neurosci 2020; 53:1998-2026. [PMID: 33306252 DOI: 10.1111/ejn.15079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 11/22/2020] [Accepted: 12/04/2020] [Indexed: 02/06/2023]
Abstract
Epilepsy is one of the oldest known neurological disorders and is characterized by recurrent seizure activity. It has a high incidence rate, affecting a broad demographic in both developed and developing countries. Comorbid conditions are frequent in patients with epilepsy and have detrimental effects on their quality of life. Current management options for epilepsy include the use of anti-epileptic drugs, surgery, or a ketogenic diet. However, more than 30% of patients diagnosed with epilepsy exhibit drug resistance to anti-epileptic drugs. Further, surgery and ketogenic diets do little to alleviate the symptoms of patients with pharmacoresistant epilepsy. Thus, there is an urgent need to understand the underlying mechanisms of pharmacoresistant epilepsy to design newer and more effective anti-epileptic drugs. Several theories of pharmacoresistant epilepsy have been suggested over the years, the most common being the gene variant hypothesis, network hypothesis, multidrug transporter hypothesis, and target hypothesis. In our review, we discuss the main theories of pharmacoresistant epilepsy and highlight a possible interconnection between their mechanisms that could lead to the development of novel therapies for pharmacoresistant epilepsy.
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Affiliation(s)
- Iman Imtiyaz Ahmed Juvale
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia
| | - Ahmad Tarmizi Che Has
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia
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Shen W, Chen S, Xiang Y, Yao Z, Chen Z, Wu X, Li L, Zeng LH. Astroglial adrenoreceptors modulate synaptic transmission and contextual fear memory formation in dentate gyrus. Neurochem Int 2020; 143:104942. [PMID: 33340594 DOI: 10.1016/j.neuint.2020.104942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/30/2020] [Accepted: 12/13/2020] [Indexed: 11/16/2022]
Abstract
Astrocytes perform various supporting functions, including ion buffering, metabolic supplying and neurotransmitter clearance. They can also sense neuronal activity owing to the presence of specific receptors for neurotransmitters. In turn, astrocytes can regulate synaptic activity through the release of gliotransmitters. Evidence has shown that astrocytes are very sensitive to the locus coeruleus (LC) afferents. However, little is known about how LC neuromodulatory norepinephrine (NE) modulates synaptic transmission through astrocytic activity. In mouse dentate gyrus (DG), we demonstrated an increase in the frequency of miniature excitatory postsynaptic currents (mEPSC) in response to NE, which required the release of glutamate from astrocytes. The rise in glutamate release probability is likely due to the activation of presynaptic GluN2B-containing NMDA receptors. Moreover, we showed that the activation of NE signaling in DG is necessary for the formation of contextual learning memory. Thus, NE signaling activation during fear conditioning training contributed to enduring changes in the frequency of mEPSC in DG. Our results strongly support the physiological neuromodulatory role of NE signaling, which is derived from activation of astrocytes.
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Affiliation(s)
- Weida Shen
- Department of Pharmacology, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, 310015, China.
| | - Shishuo Chen
- Department of Pharmacology, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, 310015, China; Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Yingchun Xiang
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Zheyu Yao
- Department of Pharmacology, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, 310015, China
| | - Zhitao Chen
- Department of Pharmacology, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, 310015, China
| | - Xitian Wu
- Department of Pharmacology, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, 310015, China
| | - Ling Li
- Department of Pharmacology, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, 310015, China
| | - Ling-Hui Zeng
- Department of Pharmacology, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, 310015, China; Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
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das Neves SP, Sousa JC, Sousa N, Cerqueira JJ, Marques F. Altered astrocytic function in experimental neuroinflammation and multiple sclerosis. Glia 2020; 69:1341-1368. [PMID: 33247866 DOI: 10.1002/glia.23940] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/14/2020] [Accepted: 11/17/2020] [Indexed: 12/11/2022]
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) that affects about 2.5 million people worldwide. In MS, the patients' immune system starts to attack the myelin sheath, leading to demyelination, neurodegeneration, and, ultimately, loss of vital neurological functions such as walking. There is currently no cure for MS and the available treatments only slow the initial phases of the disease. The later-disease mechanisms are poorly understood and do not directly correlate with the activity of immune system cells, the main target of the available treatments. Instead, evidence suggests that disease progression and disability are better correlated with the maintenance of a persistent low-grade inflammation inside the CNS, driven by local glial cells, like astrocytes and microglia. Depending on the context, astrocytes can (a) exacerbate inflammation or (b) promote immunosuppression and tissue repair. In this review, we will address the present knowledge that exists regarding the role of astrocytes in MS and experimental animal models of the disease.
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Affiliation(s)
- Sofia Pereira das Neves
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - João Carlos Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal.,Clinical Academic Center, Braga, Portugal
| | - João José Cerqueira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal.,Clinical Academic Center, Braga, Portugal
| | - Fernanda Marques
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
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Caudal LC, Gobbo D, Scheller A, Kirchhoff F. The Paradox of Astroglial Ca 2 + Signals at the Interface of Excitation and Inhibition. Front Cell Neurosci 2020; 14:609947. [PMID: 33324169 PMCID: PMC7726216 DOI: 10.3389/fncel.2020.609947] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 11/03/2020] [Indexed: 12/15/2022] Open
Abstract
Astroglial networks constitute a non-neuronal communication system in the brain and are acknowledged modulators of synaptic plasticity. A sophisticated set of transmitter receptors in combination with distinct secretion mechanisms enables astrocytes to sense and modulate synaptic transmission. This integrative function evolved around intracellular Ca2+ signals, by and large considered as the main indicator of astrocyte activity. Regular brain physiology meticulously relies on the constant reciprocity of excitation and inhibition (E/I). Astrocytes are metabolically, physically, and functionally associated to the E/I convergence. Metabolically, astrocytes provide glutamine, the precursor of both major neurotransmitters governing E/I in the central nervous system (CNS): glutamate and γ-aminobutyric acid (GABA). Perisynaptic astroglial processes are structurally and functionally associated with the respective circuits throughout the CNS. Astonishingly, in astrocytes, glutamatergic as well as GABAergic inputs elicit similar rises in intracellular Ca2+ that in turn can trigger the release of glutamate and GABA as well. Paradoxically, as gliotransmitters, these two molecules can thus strengthen, weaken or even reverse the input signal. Therefore, the net impact on neuronal network function is often convoluted and cannot be simply predicted by the nature of the stimulus itself. In this review, we highlight the ambiguity of astrocytes on discriminating and affecting synaptic activity in physiological and pathological state. Indeed, aberrant astroglial Ca2+ signaling is a key aspect of pathological conditions exhibiting compromised network excitability, such as epilepsy. Here, we gather recent evidence on the complexity of astroglial Ca2+ signals in health and disease, challenging the traditional, neuro-centric concept of segregating E/I, in favor of a non-binary, mutually dependent perspective on glutamatergic and GABAergic transmission.
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Affiliation(s)
- Laura C Caudal
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine, University of Saarland, Homburg, Germany
| | - Davide Gobbo
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine, University of Saarland, Homburg, Germany
| | - Anja Scheller
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine, University of Saarland, Homburg, Germany
| | - Frank Kirchhoff
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine, University of Saarland, Homburg, Germany
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Vezzani B, Carinci M, Patergnani S, Pasquin MP, Guarino A, Aziz N, Pinton P, Simonato M, Giorgi C. The Dichotomous Role of Inflammation in the CNS: A Mitochondrial Point of View. Biomolecules 2020; 10:E1437. [PMID: 33066071 PMCID: PMC7600410 DOI: 10.3390/biom10101437] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/07/2020] [Accepted: 10/10/2020] [Indexed: 12/14/2022] Open
Abstract
Innate immune response is one of our primary defenses against pathogens infection, although, if dysregulated, it represents the leading cause of chronic tissue inflammation. This dualism is even more present in the central nervous system, where neuroinflammation is both important for the activation of reparatory mechanisms and, at the same time, leads to the release of detrimental factors that induce neurons loss. Key players in modulating the neuroinflammatory response are mitochondria. Indeed, they are responsible for a variety of cell mechanisms that control tissue homeostasis, such as autophagy, apoptosis, energy production, and also inflammation. Accordingly, it is widely recognized that mitochondria exert a pivotal role in the development of neurodegenerative diseases, such as multiple sclerosis, Parkinson's and Alzheimer's diseases, as well as in acute brain damage, such in ischemic stroke and epileptic seizures. In this review, we will describe the role of mitochondria molecular signaling in regulating neuroinflammation in central nervous system (CNS) diseases, by focusing on pattern recognition receptors (PRRs) signaling, reactive oxygen species (ROS) production, and mitophagy, giving a hint on the possible therapeutic approaches targeting mitochondrial pathways involved in inflammation.
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Affiliation(s)
- Bianca Vezzani
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
| | - Marianna Carinci
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
| | - Simone Patergnani
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
| | - Matteo P. Pasquin
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
| | - Annunziata Guarino
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
- Department of BioMedical and Specialist Surgical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Nimra Aziz
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
- Department of BioMedical and Specialist Surgical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Paolo Pinton
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
- Maria Cecilia Hospital, GVM Care & Research, 48033 Cotignola (RA), Italy
| | - Michele Simonato
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
- Department of BioMedical and Specialist Surgical Sciences, University of Ferrara, 44121 Ferrara, Italy
- School of Medicine, University Vita-Salute San Raffaele, 20132 Milan, Italy
| | - Carlotta Giorgi
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
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Mukhtar I. Inflammatory and immune mechanisms underlying epileptogenesis and epilepsy: From pathogenesis to treatment target. Seizure 2020; 82:65-79. [PMID: 33011590 DOI: 10.1016/j.seizure.2020.09.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 02/06/2023] Open
Abstract
Epilepsy is a brain disease associated with epileptic seizures as well as with neurobehavioral outcomes of this condition. In the last century, inflammation emerged as a crucial factor in epilepsy etiology. Various brain insults through activation of neuronal and non-neuronal brain cells initiate a series of inflammatory events. Growing observations strongly suggest that abnormal activation of critical inflammatory processes contributes to epileptogenesis, a gradual process by which a normal brain transforms into the epileptic brain. Increased knowledge of inflammatory pathways in epileptogenesis has unveiled mechanistic targets for novel antiepileptic therapies. Molecules specifically targeting the pivotal inflammatory pathways may serve as promising candidates to halt the development of epilepsy. The present paper reviews the pieces of evidence conceptually supporting the potential role of inflammatory mechanisms and the relevant blood-brain barrier (BBB) disruption in epileptogenesis. Also, it discusses the mechanisms underlying inflammation-induced neuronal-glial network impairment and highlights innovative neuroregulatory actions of typical inflammatory molecules. Finally, it presents a brief analysis of observations supporting the therapeutic role of inflammation-targeting tiny molecules in epileptic seizures.
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Affiliation(s)
- Iqra Mukhtar
- H.E.J Research Institute of Chemistry, International Center For Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan; Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, University of Karachi, Karachi, 75270, Pakistan.
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Luo Z, Wang J, Tang S, Zheng Y, Zhou X, Tian F, Xu Z. Dynamic-related protein 1 inhibitor eases epileptic seizures and can regulate equilibrative nucleoside transporter 1 expression. BMC Neurol 2020; 20:353. [PMID: 32962663 PMCID: PMC7507736 DOI: 10.1186/s12883-020-01921-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 09/08/2020] [Indexed: 01/05/2023] Open
Abstract
Background Dynamic-related protein 1 (Drp1) is a key protein involved in the regulation of mitochondrial fission, and it could affect the dynamic balance of mitochondria and appears to be protective against neuronal injury in epileptic seizures. Equilibrative nucleoside transporter 1 (ENT1) is expressed and functional in the mitochondrial membrane that equilibrates adenosine concentration across membranes. Whether Drp1 participates in the pathogenesis of epileptic seizures via regulating function of ENT1 remains unclear. Methods In the present study, we used pilocarpine to induce status epilepticus (SE) in rats, and we used mitochondrial division inhibitor 1 (Mdivi-1), a selective inhibitor to Drp1, to suppress mitochondrial fission in pilocarpine-induced SE model. Mdivi-1administered by intraperitoneal injection before SE induction, and the latency to firstepileptic seizure and the number of epileptic seizures was thereafter observed. The distribution of Drp1 was detected by immunofluorescence, and the expression patterns of Drp1 and ENT1 were detected by Western blot. Furthermore, the mitochondrial ultrastructure of neurons in the hippocampal CA1 region was observed by transmission electron microscopy. Results We found that Drp1 was expressed mainly in neurons and Drp1 expression was significantly upregulated in the hippocampal and temporal neocortex tissues at 6 h and 24 h after induction of SE. Mitochondrial fission inhibitor 1 attenuated epileptic seizures after induction of SE, reduced mitochondrial damage and ENT1 expression. Conclusions These data indicate that Drp1 is upregulated in hippocampus and temporal neocortex after pilocarpine-induced SE and the inhibition of Drp1 may lead to potential therapeutic target for SE by regulating ENT1 after pilocarpine-induced SE.
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Affiliation(s)
- Zhong Luo
- Department of Neurology, The Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Zunyi, 563003, Guizhou, China
| | - Jing Wang
- Department of Neurology, The Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Zunyi, 563003, Guizhou, China
| | - Shirong Tang
- Department of Neurology, The Thirteenth People's Hospital of Chongqing, Chongqing, 400053, China
| | - Yongsu Zheng
- Department of Neurology, The Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Zunyi, 563003, Guizhou, China
| | - Xuejiao Zhou
- Department of Neurology, The Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Zunyi, 563003, Guizhou, China
| | - Fei Tian
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
| | - Zucai Xu
- Department of Neurology, The Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Zunyi, 563003, Guizhou, China.
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Peterson AR, Binder DK. Astrocyte Glutamate Uptake and Signaling as Novel Targets for Antiepileptogenic Therapy. Front Neurol 2020; 11:1006. [PMID: 33013665 PMCID: PMC7505989 DOI: 10.3389/fneur.2020.01006] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 07/30/2020] [Indexed: 12/14/2022] Open
Abstract
Astrocytes regulate and respond to extracellular glutamate levels in the central nervous system (CNS) via the Na+-dependent glutamate transporters glutamate transporter-1 (GLT-1) and glutamate aspartate transporter (GLAST) and the metabotropic glutamate receptors (mGluR) 3 and mGluR5. Both impaired astrocytic glutamate clearance and changes in metabotropic glutamate signaling could contribute to the development of epilepsy. Dysregulation of astrocytic glutamate transporters, GLT-1 and GLAST, is a common finding across patients and preclinical seizure models. Astrocytic metabotropic glutamate receptors, particularly mGluR5, have been shown to be dysregulated in both humans and animal models of temporal lobe epilepsy (TLE). In this review, we synthesize the available evidence regarding astrocytic glutamate homeostasis and astrocytic mGluRs in the development of epilepsy. Modulation of astrocyte glutamate uptake and/or mGluR activation could lead to novel glial therapeutics for epilepsy.
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Affiliation(s)
- Allison R Peterson
- Division of Biomedical Sciences, Center for Glial-Neuronal Interactions, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Devin K Binder
- Division of Biomedical Sciences, Center for Glial-Neuronal Interactions, School of Medicine, University of California, Riverside, Riverside, CA, United States
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Chemically Functionalized Water-Soluble Single-Walled Carbon Nanotubes Obstruct Vesicular/Plasmalemmal Recycling in Astrocytes Down-Stream of Calcium Ions. Cells 2020; 9:cells9071597. [PMID: 32630262 PMCID: PMC7408470 DOI: 10.3390/cells9071597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 06/24/2020] [Accepted: 06/27/2020] [Indexed: 01/24/2023] Open
Abstract
We used single-walled carbon nanotubes chemically functionalized with polyethylene glycol (SWCNT-PEG) to assess the effects of this nanomaterial on astrocytic endocytosis and exocytosis. We observed that the SWCNT-PEG do not affect the adenosine triphosphate (ATP)-evoked Ca2+ elevations in astrocytes but significantly reduce the Ca2+-dependent glutamate release. There was a significant decrease in the endocytic load of the recycling dye during constitutive and ATP-evoked recycling. Furthermore, SWCNT-PEG hampered ATP-evoked exocytotic release of the loaded recycling dye. Thus, by functionally obstructing evoked vesicular recycling, SWCNT-PEG reduced glutamate release from astrocytes via regulated exocytosis. These effects implicate SWCNT-PEG as a modulator of Ca2+-dependent exocytosis in astrocytes downstream of Ca2+, likely at the level of vesicle fusion with/pinching off the plasma membrane.
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Mukherjee S, Arisi GM, Mims K, Hollingsworth G, O'Neil K, Shapiro LA. Neuroinflammatory mechanisms of post-traumatic epilepsy. J Neuroinflammation 2020; 17:193. [PMID: 32552898 PMCID: PMC7301453 DOI: 10.1186/s12974-020-01854-w] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 05/25/2020] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Traumatic brain injury (TBI) occurs in as many as 64-74 million people worldwide each year and often results in one or more post-traumatic syndromes, including depression, cognitive, emotional, and behavioral deficits. TBI can also increase seizure susceptibility, as well as increase the incidence of epilepsy, a phenomenon known as post-traumatic epilepsy (PTE). Injury type and severity appear to partially predict PTE susceptibility. However, a complete mechanistic understanding of risk factors for PTE is incomplete. MAIN BODY From the earliest days of modern neuroscience, to the present day, accumulating evidence supports a significant role for neuroinflammation in the post-traumatic epileptogenic progression. Notably, substantial evidence indicates a role for astrocytes, microglia, chemokines, and cytokines in PTE progression. Although each of these mechanistic components is discussed in separate sections, it is highly likely that it is the totality of cellular and neuroinflammatory interactions that ultimately contribute to the epileptogenic progression following TBI. CONCLUSION This comprehensive review focuses on the neuroinflammatory milieu and explores putative mechanisms involved in the epileptogenic progression from TBI to increased seizure-susceptibility and the development of PTE.
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Affiliation(s)
- Sanjib Mukherjee
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Gabriel M Arisi
- Department of Physiology, Federal University of Sao Paulo - Escola Paulista de Medicina, Sao Paulo, Brazil.
| | - Kaley Mims
- Texas A&M University, College Station, TX, USA
| | | | | | - Lee A Shapiro
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA.
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Immunotherapy for GRIN2A and GRIN2D-related epileptic encephalopathy. Epilepsy Res 2020; 163:106325. [PMID: 32289570 DOI: 10.1016/j.eplepsyres.2020.106325] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 03/22/2020] [Accepted: 03/26/2020] [Indexed: 12/24/2022]
Abstract
BACKGROUND GRIN-related developmental-epileptic encephalopathies are associated with a spectrum of neurodevelopmental disorders, including intellectual disability, epilepsy including continuous spike-and-wave during sleep syndrome (CSWS), or epilepsy-aphasia spectrum phenotypes such as in Landau-Kleffner syndrome. Efficacy of IVIG treatment was recently reported in a patient with LKS related to GRIN2A mutation. AIM AND METHODS We describe the efficacy of Immunotherapy in 5 consecutive patients (4 males, age range 6 months-13 years) with molecularly confirmed GRIN-related epileptic encephalopathy (4 with GRIN2A- related epilepsy-aphasia spectrum/epileptic encephalopathy with CSWS, accompanied by verbal, communicative and behavioural regression, and one patient with GRIN2D - related infantile developmental-epileptic encephalopathy). All patients had global developmental delay/ intellectual disability in various degrees, and were resistant to anticonvulsants, but none of the patients had frequent clinical seizures. All patients received monthly infusion of IVIG 2 g/ kg for 6 months; 2 patients were also treated with high-dose corticosteroids. RESULTS Normalization or near normalization of the EEG was noted in 3 patients, from whom 2 had mild improvement in verbal abilities and communication skills. Perceptual/spatial abilities, as well as executive functions and attention span, remained significantly impaired. CONCLUSION according to this preliminary, open-label study, Immunotherapy may lead to a clinical and electrographic improvement in patients with GRIN-related developmental-epileptic encephalopathies. Further studies to validate the efficacy of immunotherapy and the potential role of autoimmunity in GRIN-related disorders are needed.
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Kofuji P, Araque A. G-Protein-Coupled Receptors in Astrocyte-Neuron Communication. Neuroscience 2020; 456:71-84. [PMID: 32224231 DOI: 10.1016/j.neuroscience.2020.03.025] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/13/2020] [Accepted: 03/18/2020] [Indexed: 12/11/2022]
Abstract
Astrocytes, a major type of glial cell, are known to play key supportive roles in brain function, contributing to ion and neurotransmitter homeostasis, maintaining the blood-brain barrier and providing trophic and metabolic support for neurons. Besides these support functions, astrocytes are emerging as important elements in brain physiology through signaling exchange with neurons at tripartite synapses. Astrocytes express a wide variety of neurotransmitter transporters and receptors that allow them to sense and respond to synaptic activity. Principal among them are the G-protein-coupled receptors (GPCRs) in astrocytes because their activation by synaptically released neurotransmitters leads to mobilization of intracellular calcium. In turn, activated astrocytes release neuroactive substances called gliotransmitters, such as glutamate, GABA, and ATP/adenosine that lead to synaptic regulation through activation of neuronal GPCRs. In this review we will present and discuss recent evidence demonstrating the critical roles played by GPCRs in the bidirectional astrocyte-neuron signaling, and their crucial involvement in the astrocyte-mediated regulation of synaptic transmission and plasticity.
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Affiliation(s)
- Paulo Kofuji
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA.
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Riquelme J, Wellmann M, Sotomayor-Zárate R, Bonansco C. Gliotransmission: A Novel Target for the Development of Antiseizure Drugs. Neuroscientist 2020; 26:293-309. [PMID: 31976817 DOI: 10.1177/1073858420901474] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
For more than a century, epilepsy has remained an incapacitating neurological disorder with a high incidence worldwide. Mesial temporal lobe epilepsy (TLE) is a common type of epilepsy without an effective pharmacological treatment. An increase in excitability and hypersynchrony of electrical neuronal activity during development are typically associated with an excitatory/inhibitory imbalance in the neuronal network. Astrocytes release gliotransmitters, which can regulate neuronal excitability and synaptic transmission; therefore, the classical neurocentric vision of the cellular basis of epileptogenesis has begun to change. Growing evidence suggests that the key contribution of astrocyte-to-neuron signaling in the mechanisms underlies the initiation, propagation, and recurrence of seizure activity. The aim of this review was to summarize current evidence obtained from experimental models that suggest how alterations in astroglial modulation of synaptic transmission and neuronal activity contribute to the development of this brain disease. In this article, we will summarize the main pharmacological, Ca2+-imaging, and electrophysiological findings in the gliotransmitter-mediated modulation of neuronal activity and their possible regulation as a novel cellular target for the development of pharmacological strategies for treating refractory epilepsies.
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Affiliation(s)
- Julio Riquelme
- Escuela de Medicina, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Servicio de Neurología, Hospital Carlos Van Buren, Valparaíso, Chile
| | - Mario Wellmann
- Escuela de Fonoaudiología, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Centro de Neurobiología y Fisiología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Ramón Sotomayor-Zárate
- Centro de Neurobiología y Fisiología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Christian Bonansco
- Centro de Neurobiología y Fisiología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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Nikolic L, Nobili P, Shen W, Audinat E. Role of astrocyte purinergic signaling in epilepsy. Glia 2019; 68:1677-1691. [DOI: 10.1002/glia.23747] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 10/08/2019] [Accepted: 10/25/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Ljiljana Nikolic
- Institute for Biological Research Siniša Stanković, University of Belgrade Serbia
| | | | - Weida Shen
- Zhejiang University City College Zhejiang Hangzhou China
| | - Etienne Audinat
- Institute for Functional Genomics (IGF), University of Montpellier, CNRS, INSERM Montpellier France
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Edwards III GA, Gamez N, Escobedo Jr. G, Calderon O, Moreno-Gonzalez I. Modifiable Risk Factors for Alzheimer's Disease. Front Aging Neurosci 2019; 11:146. [PMID: 31293412 PMCID: PMC6601685 DOI: 10.3389/fnagi.2019.00146] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 05/31/2019] [Indexed: 01/03/2023] Open
Abstract
Since first described in the early 1900s, Alzheimer's disease (AD) has risen exponentially in prevalence and concern. Research still drives to understand the etiology and pathogenesis of this disease and what risk factors can attribute to AD. With a majority of AD cases being of sporadic origin, the increasing exponential growth of an aged population and a lack of treatment, it is imperative to discover an easy accessible preventative method for AD. Some risk factors can increase the propensity of AD such as aging, sex, and genetics. Moreover, there are also modifiable risk factors-in terms of treatable medical conditions and lifestyle choices-that play a role in developing AD. These risk factors have their own biological mechanisms that may contribute to AD etiology and pathological consequences. In this review article, we will discuss modifiable risk factors and discuss the current literature of how each of these factors interplay into AD development and progression and if strategically analyzed and treated, could aid in protection against this neurodegenerative disease.
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Affiliation(s)
- George A. Edwards III
- The Mitchell Center for Alzheimer’s Disease and Related Brain Disorders, Department of Neurology, The University of Texas Houston Health Science Center at Houston, Houston, TX, United States
| | - Nazaret Gamez
- The Mitchell Center for Alzheimer’s Disease and Related Brain Disorders, Department of Neurology, The University of Texas Houston Health Science Center at Houston, Houston, TX, United States
- Networking Research Center on Neurodegenerative Diseases (CIBERNED), Department of Cell Biology, Facultad Ciencias, Universidad de Malaga, Malaga, Spain
| | - Gabriel Escobedo Jr.
- The Mitchell Center for Alzheimer’s Disease and Related Brain Disorders, Department of Neurology, The University of Texas Houston Health Science Center at Houston, Houston, TX, United States
| | - Olivia Calderon
- The Mitchell Center for Alzheimer’s Disease and Related Brain Disorders, Department of Neurology, The University of Texas Houston Health Science Center at Houston, Houston, TX, United States
| | - Ines Moreno-Gonzalez
- The Mitchell Center for Alzheimer’s Disease and Related Brain Disorders, Department of Neurology, The University of Texas Houston Health Science Center at Houston, Houston, TX, United States
- Networking Research Center on Neurodegenerative Diseases (CIBERNED), Department of Cell Biology, Facultad Ciencias, Universidad de Malaga, Malaga, Spain
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Abstract
Conditional Knockout of mGluR5 From Astrocytes During Epilepsy Development Impairs High-Frequency Glutamate Uptake Umpierre AD, West PJ, White JA, et al. J Neurosci. 2019;39(4):727-742. doi:10.1523/JNEUROSCI.1148-18.2018 Astrocyte expression of metabotropic glutamate receptor 5 (mGluR5) is consistently observed in resected tissue from patients with epilepsy and is equally prevalent in animal models of epilepsy. However, little is known about the functional signaling properties or downstream consequences of astrocyte mGluR5 activation during epilepsy development. In the rodent brain, astrocyte mGluR5 expression is developmentally regulated and confined in expression/function to the first weeks of life, with similar observations made in human control tissue. Herein, we demonstrate that mGluR5 expression and function dramatically increase in a mouse model of temporal lobe epilepsy. Interestingly, in both male and female mice, mGluR5 function persists in the astrocyte throughout the process of epileptogenesis following status epilepticus. However, mGluR5 expression and function are transient in animals that do not develop epilepsy over an equivalent time period, suggesting that patterns of mGluR5expression may signify continuing epilepsy development or its resolution. We demonstrate that, during epileptogenesis, astrocytes reacquire mGluR5-dependent calcium transients following agonist application or synaptic glutamate release, a feature of astrocyte-neuron communication absent since early development. Finally, we find that the selective and conditional knockout of mGluR5 signaling from astrocytes during epilepsy development slows the rate of glutamate clearance through astrocyte glutamate transporters under high-frequency stimulation conditions, a feature that suggests astrocyte mGluR5 expression during epileptogenesis may recapitulate earlier developmental roles in regulating glutamate transporter function.
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Li J, Khankan RR, Caneda C, Godoy MI, Haney MS, Krawczyk MC, Bassik MC, Sloan SA, Zhang Y. Astrocyte-to-astrocyte contact and a positive feedback loop of growth factor signaling regulate astrocyte maturation. Glia 2019; 67:1571-1597. [PMID: 31033049 PMCID: PMC6557696 DOI: 10.1002/glia.23630] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 03/31/2019] [Accepted: 04/05/2019] [Indexed: 01/09/2023]
Abstract
Astrocytes are critical for the development and function of the central nervous system. In developing brains, immature astrocytes undergo morphological, molecular, cellular, and functional changes as they mature. Although the mechanisms that regulate the maturation of other major cell types in the central nervous system such as neurons and oligodendrocytes have been extensively studied, little is known about the cellular and molecular mechanisms that control astrocyte maturation. Here, we identified molecular markers of astrocyte maturation and established an in vitro assay for studying the mechanisms of astrocyte maturation. Maturing astrocytes in vitro exhibit similar molecular changes and represent multiple molecular subtypes of astrocytes found in vivo. Using this system, we found that astrocyte‐to‐astrocyte contact strongly promotes astrocyte maturation. In addition, secreted signals from microglia, oligodendrocyte precursor cells, or endothelial cells affect a small subset of astrocyte genes but do not consistently change astrocyte maturation. To identify molecular mechanisms underlying astrocyte maturation, we treated maturing astrocytes with molecules that affect the function of tumor‐associated genes. We found that a positive feedback loop of heparin‐binding epidermal growth factor‐like growth factor (HBEGF) and epidermal growth factor receptor (EGFR) signaling regulates astrocytes maturation. Furthermore, HBEGF, EGFR, and tumor protein 53 (TP53) affect the expression of genes important for cilium development, the circadian clock, and synapse function. These results revealed cellular and molecular mechanisms underlying astrocytes maturation with implications for the understanding of glioblastoma.
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Affiliation(s)
- Jiwen Li
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at the University of California, Los Angeles, California
| | - Rana R Khankan
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at the University of California, Los Angeles, California
| | - Christine Caneda
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at the University of California, Los Angeles, California
| | - Marlesa I Godoy
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at the University of California, Los Angeles, California
| | - Michael S Haney
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Mitchell C Krawczyk
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at the University of California, Los Angeles, California
| | - Michael C Bassik
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Steven A Sloan
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia
| | - Ye Zhang
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at the University of California, Los Angeles, California.,Intellectual and Developmental Disabilities Research Center at UCLA, Los Angeles, California.,Brain Research Institute at UCLA, Los Angeles, California.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, Los Angeles, California.,Molecular Biology Institute at UCLA, Los Angeles, California
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49
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Ma T, Wu Y, Chen B, Zhang W, Jin L, Shen C, Wang Y, Liu Y. D-Serine Contributes to Seizure Development via ERK Signaling. Front Neurosci 2019; 13:254. [PMID: 30971878 PMCID: PMC6443828 DOI: 10.3389/fnins.2019.00254] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/04/2019] [Indexed: 12/22/2022] Open
Abstract
A seizure is one of the leading neurological disorders. NMDA receptor-mediated neuronal excitation has been thought to be essential for epileptogenesis. As an endogenous co-agonist of the NMDA receptor, D-serine has been suggested to play a role in epileptogenesis. However, the underlying mechanisms remain unclear. In the current study, we investigated the effects of antagonizing two key enzymes in D-serine metabolism on the development of seizures and the downstream signaling. Our results showed that serine racemase (SR), a key enzyme in regulating the L-to-D-serine conversion, was significantly up-regulated in hippocampal astrocytes in rats and patients who experienced seizure, in comparison with control rats and patients. L-aspartic acid β-hydroxamate (LaaβH), an inhibitor of SR, significantly prolonged the latencies of seizures, shortened the durations of seizures, and decreased the total EEG power in rats. In contrast, D-amino acid oxidase inhibitor 5-chlorobenzo[d]isoxazol-3-ol (CBIO), which can increase D-serine levels, showed the opposite effects. Furthermore, our data showed that LaaβH and CBIO significantly affected the phosphorylation of Extracellular Signal-regulated Kinase (ERK). Antagonizing or activating ERK could significantly block the effects of LaaβH/CBIO on the occurrence of seizures. In summary, our study revealed that D-serine is involved in the development of epileptic seizures, partially through ERK signaling, indicating that the metabolism of D-serine may be targeted for the treatment of epilepsy.
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Affiliation(s)
- Tie Ma
- Department of Neurology, Xijing Hospital, Air Force Military Medical University, Xi'an, China.,Department of Neurology, The Seventh Medical Center of PLA General Hospital, Beijing, China
| | - Yin Wu
- Department of Pharmacy, Xi'an High-tech Hospital, Xi'an, China
| | - Beibei Chen
- Department of Neurology, Xijing Hospital, Air Force Military Medical University, Xi'an, China
| | - Wenjuan Zhang
- Department of Neurology, Xijing Hospital, Air Force Military Medical University, Xi'an, China
| | - Lang Jin
- Department of Neurology, Xijing Hospital, Air Force Military Medical University, Xi'an, China
| | - Chenxi Shen
- Department of Neurology, Xijing Hospital, Air Force Military Medical University, Xi'an, China
| | - Yazhou Wang
- Department of Neurobiology and Institute of Neurosciences, School of Basic Medicine, Air Force Medical University, Xi'an, China
| | - Yonghong Liu
- Department of Neurology, Xijing Hospital, Air Force Military Medical University, Xi'an, China
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50
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Kou ZW, Mo JL, Wu KW, Qiu MH, Huang YL, Tao F, Lei Y, Lv LL, Sun FY. Vascular endothelial growth factor increases the function of calcium-impermeable AMPA receptor GluA2 subunit in astrocytes via activation of protein kinase C signaling pathway. Glia 2019; 67:1344-1358. [PMID: 30883902 PMCID: PMC6594043 DOI: 10.1002/glia.23609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 01/23/2019] [Accepted: 02/19/2019] [Indexed: 01/11/2023]
Abstract
Astrocytic calcium signaling plays pivotal roles in the maintenance of neural functions and neurovascular coupling in the brain. Vascular endothelial growth factor (VEGF), an original biological substance of vessels, regulates the movement of calcium and potassium ions across neuronal membrane. In this study, we investigated whether and how VEGF regulates glutamate-induced calcium influx in astrocytes. We used cultured astrocytes combined with living cell imaging to detect the calcium influx induced by glutamate. We found that VEGF quickly inhibited the glutamate/hypoxia-induced calcium influx, which was blocked by an AMPA receptor antagonist CNQX, but not D-AP5 or UBP310, NMDA and kainate receptor antagonist, respectively. VEGF increased phosphorylation of PKCα and AMPA receptor subunit GluA2 in astrocytes, and these effects were diminished by SU1498 or calphostin C, a PKC inhibitor. With the pHluorin assay, we observed that VEGF significantly increased membrane insertion and expression of GluA2, but not GluA1, in astrocytes. Moreover, siRNA-produced knockdown of GluA2 expression in astrocytes reversed the inhibitory effect of VEGF on glutamate-induced calcium influx. Together, our results suggest that VEGF reduces glutamate-induced calcium influx in astrocytes via enhancing PKCα-mediated GluA2 phosphorylation, which in turn promotes the membrane insertion and expression of GluA2 and causes AMPA receptors to switch from calcium-permeable to calcium-impermeable receptors, thereby inhibiting astrocytic calcium influx. The present study reveals that excitatory neurotransmitter glutamate-mediated astrocytic calcium influx can be regulated by vascular biological factor via activation of AMPA receptor GluA2 subunit and uncovers a novel coupling mechanism between astrocytes and endothelial cells within the neurovascular unit.
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Affiliation(s)
- Zeng-Wei Kou
- Department of Neurobiology and State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China.,Institute for Basic Research on Aging and Medicine of School of Basic Medical Sciences and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Jia-Lin Mo
- Department of Neurobiology and State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China.,Institute for Basic Research on Aging and Medicine of School of Basic Medical Sciences and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Kun-Wei Wu
- Department of Neurobiology and State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China.,Department of System Biology for Medicine, Institute of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Mei-Hong Qiu
- Department of Neurobiology and State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China.,Institute for Basic Research on Aging and Medicine of School of Basic Medical Sciences and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Ya-Lin Huang
- Department of Neurobiology and State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China.,Department of System Biology for Medicine, Institute of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Feng Tao
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas
| | - Yu Lei
- Department of Neurobiology and State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China.,Institute for Basic Research on Aging and Medicine of School of Basic Medical Sciences and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Ling-Ling Lv
- Department of Neurobiology and State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China.,Institute for Basic Research on Aging and Medicine of School of Basic Medical Sciences and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Feng-Yan Sun
- Department of Neurobiology and State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China.,Institute for Basic Research on Aging and Medicine of School of Basic Medical Sciences and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, PR China.,Department of System Biology for Medicine, Institute of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China
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