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Gargiulo MR, Argibay LM, Molina VA, Calfa GD, Bender CL. Role of amygdala astrocytes in different phases of contextual fear memory. Behav Brain Res 2024; 468:115017. [PMID: 38679145 DOI: 10.1016/j.bbr.2024.115017] [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: 02/09/2024] [Revised: 04/23/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
Growing evidence indicates a critical role of astrocytes in learning and memory. However, little is known about the role of basolateral amygdala complex (BLA-C) astrocytes in contextual fear conditioning (CFC), a paradigm relevant to understand and generate treatments for fear- and anxiety-related disorders. To get insights on the involvement of BLA-C astrocytes in fear memory, fluorocitrate (FLC), a reversible astroglial metabolic inhibitor, was applied at critical moments of the memory processing in order to target the acquisition, consolidation, retrieval and reconsolidation process of the fear memory. Adult Wistar male rats were bilaterally cannulated in BLA-C. Ten days later they were infused with different doses of FLC (0.5 or 1 nmol/0.5 µl) or saline before or after CFC and before or after retrieval. FLC impaired fear memory expression when administered before and shortly after CFC, but not one hour later. Infusion of FLC prior and after retrieval did not affect the memory. Our findings suggest that BLA-C astrocytes are critically involved in the acquisition/early consolidation of fear memory but not in the retrieval and reconsolidation. Furthermore, the extinction process was presumably not affected (considering that peri-retrieval administration could also affect this process).
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Affiliation(s)
- Melisa Riva Gargiulo
- Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET) - Departamento de Farmacología Otto Orsingher (FCQ-UNC), Córdoba, Argentina
| | - Lourdes María Argibay
- Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET) - Departamento de Farmacología Otto Orsingher (FCQ-UNC), Córdoba, Argentina
| | - Víctor Alejandro Molina
- Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET) - Departamento de Farmacología Otto Orsingher (FCQ-UNC), Córdoba, Argentina
| | - Gastón Diego Calfa
- Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET) - Departamento de Farmacología Otto Orsingher (FCQ-UNC), Córdoba, Argentina
| | - Crhistian Luis Bender
- Instituto de Farmacología Experimental de Córdoba (IFEC-CONICET) - Departamento de Farmacología Otto Orsingher (FCQ-UNC), Córdoba, Argentina.
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Selistre NG, Rodrigues L, Federhen BC, Gayger-Dias V, Taday J, Wartchow KM, Gonçalves CA. S100B Secretion in Astrocytes, Unlike C6 Glioma Cells, Is Downregulated by Lactate. Metabolites 2023; 14:7. [PMID: 38276297 PMCID: PMC10819463 DOI: 10.3390/metabo14010007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/14/2023] [Accepted: 12/18/2023] [Indexed: 01/27/2024] Open
Abstract
S100B is a calcium-binding protein produced and secreted by astrocytes in response to various extracellular stimuli. C6 glioma cells are a lineage commonly employed for astroglial studies due to the expression of astrocyte specific markers and behavior. However, in high-glucose medium, C6 S100B secretion increases, in contrast to the trend in primary astrocyte cultures. Additionally, S100B secretion decreases due to fluorocitrate (FC), a Krebs cycle inhibitor, highlighting a connection between S100B and metabolism. Herein, we investigate the impact of FC on S100B secretion in primary astrocyte cultures, acute hippocampal slices and C6 glioma cells, as well as lactate mediation. Our results demonstrated that C6 responded similarly to astrocytes in various parameters, despite the decrease in S100B secretion, which was inversely observed in astrocytes and slices. Furthermore, FC inversely altered extracellular lactate in both models, suggesting a role for lactate in S100B secretion. This was reinforced by a decrease in S100B secretion in hippocampal slices treated with lactate and its agonist, but not in C6 cells, despite HCAR1 expression. Our findings indicate that extracellular lactate mediates the decrease in S100B secretion in astrocytes exposed to FC. They also emphasize the differences in C6 glioma cells regarding energetic metabolism. The proposed mechanism via HCAR1 provides further compelling evidence of the relationship between S100B and glucose metabolism.
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Affiliation(s)
- Nicholas Guerini Selistre
- Biochemistry Post-Graduate Program, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre 90010-150, Brazil; (N.G.S.); (L.R.); (B.C.F.); (V.G.-D.); (J.T.); (C.-A.G.)
| | - Leticia Rodrigues
- Biochemistry Post-Graduate Program, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre 90010-150, Brazil; (N.G.S.); (L.R.); (B.C.F.); (V.G.-D.); (J.T.); (C.-A.G.)
| | - Barbara Carolina Federhen
- Biochemistry Post-Graduate Program, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre 90010-150, Brazil; (N.G.S.); (L.R.); (B.C.F.); (V.G.-D.); (J.T.); (C.-A.G.)
| | - Vitor Gayger-Dias
- Biochemistry Post-Graduate Program, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre 90010-150, Brazil; (N.G.S.); (L.R.); (B.C.F.); (V.G.-D.); (J.T.); (C.-A.G.)
| | - Jéssica Taday
- Biochemistry Post-Graduate Program, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre 90010-150, Brazil; (N.G.S.); (L.R.); (B.C.F.); (V.G.-D.); (J.T.); (C.-A.G.)
| | - Krista Mineia Wartchow
- Brain Health Imaging Institute, Department of Radiology, Weill Cornell Medicine, New York, NY 10044, USA
| | - Carlos-Alberto Gonçalves
- Biochemistry Post-Graduate Program, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre 90010-150, Brazil; (N.G.S.); (L.R.); (B.C.F.); (V.G.-D.); (J.T.); (C.-A.G.)
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3
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Wang T, Yang J, Wang G, Zhao F, Jin Y. Factors ameliorate pro-inflammatory microglia polarization through inhibition of reactive astrocytes induced by 2-chloroethanol. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 261:115130. [PMID: 37311391 DOI: 10.1016/j.ecoenv.2023.115130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 06/06/2023] [Accepted: 06/09/2023] [Indexed: 06/15/2023]
Abstract
Our previous studies have demonstrated that the crosstalk between astrocytes and microglia may trigger and amplify the neuroinflammatory response and, in turn, cause brain edema in 1,2-dichloroethane (1,2-DCE)-intoxicated mice. Moreover, findings from our in vitro studies showed that astrocytes are more sensitive to 2-chloroethanol (2-CE), an intermediate metabolite of 1,2-DCE, than microglia, and 2-CE-induced reactive astrocytes (RAs) can promote microglia polarization through releasing the pro-inflammatory mediators. Therefore, it is essential to explore therapeutic agents that may ameliorate microglia polarization through inhibition of 2-CE-induced RAs, which remains unclear till now. Results of this study revealed that exposure to 2-CE could induce RAs with pro-inflammatory effects, and fluorocitrate (FC), GIBH-130 (GI) and diacerein (Dia) pretreatment could all abolish the pro-inflammatory effects of 2-CE-induced RAs. FC and GI pretreatment might suppress 2-CE-induced RAs through inhibition of p38 mitogen-activated protein kinase (p38 MAPK)/activator protein-1 (AP-1) and nuclear factor-kappaB (NF-κB) signaling pathways, but Dia pretreatment might only inhibit p38 MAPK/NF-κB signaling pathway. FC, GI, and Dia pretreatment could all suppress the pro-inflammatory microglia polarization through inhibition of 2-CE-induced RAs. Meanwhile, GI and Dia pretreatment could also restored the anti-inflammatory microglia polarization via inhibition of 2-CE-induced RAs. However, FC pretreatment could not affect the anti-inflammatory polarization of microglia through inhibition of 2-CE-induced RAs. Taken together, findings from the present study demonstrated that FC, GI, and Dia might be the potential candidates with different characteristic for therapeutic use in 1,2-DCE poisoning.
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Affiliation(s)
- Tong Wang
- Department of Basic Medical Sciences, School of medicine, Taizhou University, Jiaojiang 318000, Zhejiang, China; Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China
| | - Jinhan Yang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China
| | - Gaoyang Wang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China
| | - Fenghong Zhao
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China
| | - Yaping Jin
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang 110122, China.
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4
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Nikkar R, Esmaeili-Bandboni A, Badrikoohi M, Babaei P. Effects of inhibiting astrocytes and BET/BRD4 chromatin reader on spatial memory and synaptic proteins in rats with Alzheimer's disease. Metab Brain Dis 2022; 37:1119-1131. [PMID: 35244824 DOI: 10.1007/s11011-022-00940-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/21/2022] [Indexed: 10/18/2022]
Abstract
Communication between astrocytes and neurons has a profound effect on the pathophysiology of Alzheimer's disease (AD). Astrocytes regulate homeostasis and increase synaptic plasticity in physiological situations, however, they become activated during the progression of AD. Whether or not these reactions are supportive or detrimental for the central nervous system have not been understood yet. Considering epigenetic regulation of neuroinflammatory genes by chromatin readers, particularly bromodomain and extraterminal domain (BET) family, here we examined the effect of chronic co-inhibition of astrocytes metabolism (with fluorocitrate) and also BRD4 (with JQ1) on cognition deficit at early stages of AD. Forty adult male Wistar rats underwent stereotaxic cannulation for inducing AD by intrahippocampal injection of Aβ1-42 (4 μg/8 μl/rat). Then animals were divided into five groups of Saline+DMSO, Aβ + saline+DMSO, Aβ + JQ1, Aβ + FC (fluorocitrate), and Aβ + JQ1 + FC and received the related treatments. Two weeks later, spatial memory was recorded by Morris Water Maze (MWM), and the levels of phosphorylated cyclic-AMP response element binding protein (CREB), postsynaptic density 95 (PSD95), synaptophysin (SYP), and tumor necrosis factor-alpha (TNF-α) were measured in the hippocampus by western blotting and RT-qPCR. Administration of JQ1 significantly improved both acquisition and retrieval of spatial memory, which were evident by decreased escape latency and increased total time spent (TTS) in target quadrant, and significant rise in p-CREB, PSD95, and synaptophysin compared with Aβ + saline+DMSO group. In contrast, both groups receiving FC demonstrated memory decline, and reduction in p-CREB, PSD95 and synaptophysin in parallel with increase in TNF-α. Our data indicate that chronic inhibition of BRD4 significantly restores memory impaired by amyloid β partly via CREB signaling and upregulating synaptic proteins of PSD95 and synaptophysin. However, inhibition of astrocytes nullifies the memory-boosting effects of JQ1 and reduces CREB/PSD95/synaptophysin levels in hippocampus.
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Affiliation(s)
- Rastin Nikkar
- Cellular &Molecular Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
- Neuroscience Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Aghil Esmaeili-Bandboni
- Department of Medical Genetics, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
- Medical Biotechnology Research Center, School of Paramedicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Mahshid Badrikoohi
- Cellular &Molecular Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
- Department of Physiology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Parvin Babaei
- Cellular &Molecular Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
- Neuroscience Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
- Department of Physiology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
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5
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Yuan M, Wang Y, Wen J, Jing F, Zou Q, Pu Y, Pan T, Cai Z. Dietary Salt Disrupts Tricarboxylic Acid Cycle and Induces Tau Hyperphosphorylation and Synapse Dysfunction during Aging. Aging Dis 2022; 13:1532-1545. [PMID: 36186135 PMCID: PMC9466974 DOI: 10.14336/ad.2022.0220] [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: 11/07/2021] [Accepted: 02/20/2022] [Indexed: 11/05/2022] Open
Abstract
Dietary salt causes synaptic deficits and tau hyperphosphorylation, which are detrimental to cognitive function. However, the specific effects of a high-salt diet on synapse and tau protein remain poorly understood. In this study, aged (15-month-old) C57BL/6 mice received a normal (0.5% NaCl) or high-salt (8% NaCl) diet for 3 months, and N2a cells were treated with normal culture medium or a NaCl medium (40 mM). Spatial learning and memory abilities were tested using the Morris water maze. The levels of metabolites and related enzymes in the tricarboxylic acid (TCA) cycle were confirmed using liquid chromatography-tandem mass spectrometry, western blotting, and immunofluorescence. We also investigated synapse morphology and the phosphorylation of tau protein. Under the high-salt diet, mice displayed impaired learning and memory compared to mice fed the normal diet. Furthermore, excessive salt intake disturbed the TCA cycle in both animals and cells compared to the respective normal controls. High dietary salt reduced postsynaptic density protein 95 (PSD95) and brain-derived neurotrophic factor (BDNF) expression, impaired neurons, and caused synaptic loss in the mice. We also detected tau hyperphosphorylation at different sites (Thr205, Thr231, and Thr181) without increasing total tau levels in response to high salt treatment, both in vivo and in vitro. We concluded that elevated salt intake impairs the TCA cycle and induces tau hyperphosphorylation and synapse dysfunction during aging, which ultimately results in cognitive impairment.
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Affiliation(s)
- Minghao Yuan
- Chongqing Medical University, Chongqing, China.
- Department of Neurology, Chongqing School, University of Chinese Academy of Sciences, Chongqing, China.
- Department of Neurology, Chongqing General Hospital, Chongqing, China.
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China.
| | - Yangyang Wang
- Department of Neurology, Chongqing General Hospital, Chongqing, China.
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China.
| | - Jie Wen
- Guangdong Medical University, Guangdong, China.
| | - Feng Jing
- Chongqing Medical University, Chongqing, China.
- Department of Neurology, Chongqing School, University of Chinese Academy of Sciences, Chongqing, China.
- Department of Neurology, Chongqing General Hospital, Chongqing, China.
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China.
| | - Qian Zou
- Department of Neurology, Chongqing General Hospital, Chongqing, China.
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China.
| | - Yinshuang Pu
- Department of Neurology, Chongqing General Hospital, Chongqing, China.
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China.
| | - Tingyu Pan
- Department of Neurology, Chongqing General Hospital, Chongqing, China.
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China.
| | - Zhiyou Cai
- Chongqing Medical University, Chongqing, China.
- Department of Neurology, Chongqing School, University of Chinese Academy of Sciences, Chongqing, China.
- Department of Neurology, Chongqing General Hospital, Chongqing, China.
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China.
- Correspondence should be addressed to: Dr. Zhiyou Cai, Department of Neurology, Chongqing Medical University, Chongqing, Chongqing, 400016, China. .
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6
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Gonzalez-Sanchez L, Cobos-Fernandez MA, Lopez-Nieva P, Villa-Morales M, Stamatakis K, Cuezva JM, Marin-Rubio JL, Vazquez-Dominguez I, Gonzalez-Vasconcellos I, Salido E, Llamas P, Lopez-Lorenzo JL, Santos J, Fernandez-Piqueras J. Exploiting the passenger ACO1-deficiency arising from 9p21 deletions to kill T-cell lymphoblastic neoplasia cells. Carcinogenesis 2021; 41:1113-1122. [PMID: 31734690 DOI: 10.1093/carcin/bgz185] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 10/17/2019] [Accepted: 11/12/2019] [Indexed: 11/14/2022] Open
Abstract
Precursor T-cell lymphoblastic neoplasms are aggressive malignancies in need for more effective and specific therapeutic treatments. A significant fraction of these neoplasms harbor deletions on the locus 9p21, targeting the tumor suppressor CDKN2A but also deleting the aconitase 1 (ACO1) gene, a neighboring housekeeping gene involved in cytoplasm and mitochondrial metabolism. Here we show that reducing the aconitase activity with fluorocitrate decreases the viability of T-cell lymphoblastic neoplasia cells in correlation to the differential aconitase expression. The consequences of the treatment were evidenced in vitro using T-cell lymphoblastic neoplasia cell lines exhibiting 9p21 deletions and variable levels of ACO1 expression or activity. Similar results were observed in melanoma cell lines, suggesting a true potential for fluorocitrate in different cancer types. Notably, ectopic expression of ACO1 alleviated the susceptibility of cell lines to fluorocitrate and, conversely, knockdown experiments increased susceptibility of resistant cell lines. These findings were confirmed in vivo on athymic nude mice by using tumor xenografts derived from two T-cell lines with different levels of ACO1. Taken together, our results indicate that the non-targeted ACO1 deficiency induced by common deletions exerts a collateral cellular lethality that can be used as a novel therapeutic strategy in the treatment of several types of cancer.
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Affiliation(s)
- Laura Gonzalez-Sanchez
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CBMSO), Madrid, Spain.,Division of Hematology and Hemotherapy, IIS Fundación Jiménez Díaz, Madrid, Spain.,Consorcio de Investigación Biomédica de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Maria A Cobos-Fernandez
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CBMSO), Madrid, Spain.,Division of Hematology and Hemotherapy, IIS Fundación Jiménez Díaz, Madrid, Spain
| | - Pilar Lopez-Nieva
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CBMSO), Madrid, Spain.,Division of Hematology and Hemotherapy, IIS Fundación Jiménez Díaz, Madrid, Spain.,Consorcio de Investigación Biomédica de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Maria Villa-Morales
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CBMSO), Madrid, Spain.,Division of Hematology and Hemotherapy, IIS Fundación Jiménez Díaz, Madrid, Spain.,Consorcio de Investigación Biomédica de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Konstantinos Stamatakis
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CBMSO), Madrid, Spain
| | - Jose M Cuezva
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CBMSO), Madrid, Spain.,Consorcio de Investigación Biomédica de Enfermedades Raras (CIBERER), Madrid, Spain.,Division of Cancer, Instituto de Investigación Hospital 12 de Octubre, Madrid, Spain
| | - Jose L Marin-Rubio
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CBMSO), Madrid, Spain
| | - Irene Vazquez-Dominguez
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CBMSO), Madrid, Spain
| | - Iria Gonzalez-Vasconcellos
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CBMSO), Madrid, Spain
| | - Eduardo Salido
- Consorcio de Investigación Biomédica de Enfermedades Raras (CIBERER), Madrid, Spain.,Department of Pathology, Hospital Universitario de Canarias, ITB, Universidad de La Laguna, La Cuesta, Spain
| | - Pilar Llamas
- Division of Hematology and Hemotherapy, IIS Fundación Jiménez Díaz, Madrid, Spain
| | - Jose L Lopez-Lorenzo
- Division of Hematology and Hemotherapy, IIS Fundación Jiménez Díaz, Madrid, Spain
| | - Javier Santos
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CBMSO), Madrid, Spain.,Division of Hematology and Hemotherapy, IIS Fundación Jiménez Díaz, Madrid, Spain.,Consorcio de Investigación Biomédica de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Jose Fernandez-Piqueras
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CBMSO), Madrid, Spain.,Division of Hematology and Hemotherapy, IIS Fundación Jiménez Díaz, Madrid, Spain.,Consorcio de Investigación Biomédica de Enfermedades Raras (CIBERER), Madrid, Spain
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Glial ATP and Large Pore Channels Modulate Synaptic Strength in Response to Chronic Inactivity. Mol Neurobiol 2020; 57:2856-2869. [PMID: 32388797 DOI: 10.1007/s12035-020-01919-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 04/14/2020] [Indexed: 01/08/2023]
Abstract
A key feature of neurotransmission is its ability to adapt to changes in neuronal environment, which is essential for many brain functions. Homeostatic synaptic plasticity (HSP) emerges as a compensatory mechanism used by neurons to adjust their excitability in response to changes in synaptic activity. Recently, glial cells emerged as modulators for neurotransmission by releasing gliotransmitters into the synaptic cleft through pathways that include P2X7 receptors (P2X7R), connexons, and pannexons. However, the role of gliotransmission in the activity-dependent adjustment of presynaptic strength is still an open question. Here, we investigated whether glial cells participate in HSP upon chronic inactivity and the role of adenosine triphosphate (ATP), connexin43 hemichannels (Cx43HCs), and pannexin1 (Panx1) channels in this process. We used immunocytochemistry against vesicular glutamate transporter 1 (vGlut1) to estimate changes in synaptic strength in hippocampal dissociated cultures. Pharmacological manipulations indicate that glial-derived ATP and P2X7R are required for HSP. In addition, inhibition of Cx43 and Panx1 channels reveals a pivotal role for these channels in the compensatory adjustment of synaptic strength, emerging as new pathways for ATP release upon inactivity. The involvement of Panx1 channels was confirmed by using Panx1-deficient animals. Lacking Panx1 in neurons is sufficient to prevent the P2X7R-dependent upregulation of presynaptic strength; however, the P2X7R-dependent compensatory adjustment of synapse density requires both neuronal and glial Panx1. Together, our data supports an essential role for glial ATP signaling and Cx43HCs and Panx1 channels in the homeostatic adjustment of synaptic strength in hippocampal cultures upon chronic inactivity.
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8
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Luo Z, Wang H, Fang S, Li L, Li X, Shi J, Zhu M, Tan Z, Lu Z. Annexin-1 Mimetic Peptide Ac2-26 Suppresses Inflammatory Mediators in LPS-Induced Astrocytes and Ameliorates Pain Hypersensitivity in a Rat Model of Inflammatory Pain. Cell Mol Neurobiol 2019; 40:569-585. [PMID: 31722050 DOI: 10.1007/s10571-019-00755-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 10/31/2019] [Indexed: 12/11/2022]
Abstract
Ac2-26, a mimetic peptide of Annexin-A1, plays a vital role in the anti-inflammatory response mediated by astrocytes. In this study, we aimed to explore the underlying mechanisms of Ac2-26-mediated anti-inflammatory effect. Specifically, we investigated the inhibitory effects of Ac2-26 on lipopolysaccharide (LPS)-induced astrocyte migration and on pro-inflammatory cytokines and chemokines expressions, as well as one glutathione (GSH) reductase mRNA and total intracellular GSH levels in LPS-induced astrocytes. Additionally, we investigated whether mitogen-activated protein kinases (MAPK) and nuclear factor kappa-B (NF-κB) signaling pathway were involved in this process. Finally, we evaluated the analgesic effect of Ac2-26 in complete Freund's adjuvant (CFA)-induced inflammatory pain model. Our results demonstrated that Ac2-26 inhibited LPS-induced astrocytes migration, reduced the production of pro-inflammatory mediators [tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1 (MIP-1α)] and upregulated GSH reductase mRNA and GSH levels in LPS-induced astrocytes in vitro. This process was mediated through the p38, JNK-MAPK signaling pathway, but not dependent on the NF-κB pathway. Furthermore, the p38 and JNK inhibitors mimicked the effects of Ac2-26, whereas a p38 and JNK activator anisomycin partially reversed its function. Finally, Ac2-26 treatment reduced CFA-induced activation of astrocytes and production of inflammatory mediators in the spinal cord. These results suggest that Ac2-26 attenuates pain by inhibiting astrocyte activation and the production of inflammatory mediators; thus, this work presents Ac2-26 as a potential drug to treat neuropathic pain.
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Affiliation(s)
- Zhenzhao Luo
- Department of Medical Laboratory, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, 26 Shengli St., Jiangan District, Wuhan, 430014, China
| | - Hui Wang
- Department of Medical Laboratory, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, 26 Shengli St., Jiangan District, Wuhan, 430014, China
| | - Shiqiang Fang
- Department of Medical Laboratory, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, 26 Shengli St., Jiangan District, Wuhan, 430014, China
| | - Li Li
- Department of Pathology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, 26 Shengli St., Jiangan District, Wuhan, 430014, China
| | - Xing Li
- Department of Neurobiology, The School of Basic Medical Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jing Shi
- Department of Neurobiology, The School of Basic Medical Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Man Zhu
- Department of Medical Laboratory, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, 26 Shengli St., Jiangan District, Wuhan, 430014, China
| | - Zheqiong Tan
- Department of Medical Laboratory, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, 26 Shengli St., Jiangan District, Wuhan, 430014, China
| | - Zhongxin Lu
- Department of Medical Laboratory, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, 26 Shengli St., Jiangan District, Wuhan, 430014, China.
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9
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Inhibition of Reactive Astrocytes with Fluorocitrate Ameliorates Learning and Memory Impairment Through Upregulating CRTC1 and Synaptophysin in Ischemic Stroke Rats. Cell Mol Neurobiol 2019; 39:1151-1163. [PMID: 31270712 DOI: 10.1007/s10571-019-00709-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 06/19/2019] [Indexed: 12/12/2022]
Abstract
Ischemic stroke often causes motor and cognitive deficits. Deregulated glia gap junction communication, which is reflected by increased protein levels of glial fibrillary acidic protein (GFAP) and connexin 43 (Cx43), has been observed in ischemic hippocampus and has been associated with cognitive impairment in animal stroke models. Here, we tested the hypothesis that reactive astrocytes-mediated loss of synaptophysin (SYP) and CREB-regulated transcription coactivator 1 (CRTC1) contribute to dysfunction in glia gap junction communication and memory impairment after ischemic stroke. Male Sprague-Dawley rats were subjected to a 90-min middle cerebral artery occlusion (MCAO) with 7-day reperfusion. Fluorocitrate (1 nmol), the reversible inhibitor of the astrocytic tricarboxylic acid cycle, was injected into the right lateral ventricle of MCAO rats once every 2 days starting immediately before reperfusion. The Morris water maze was used to assess memory in conjunction with western blotting and immunostaining to detect protein expression and distribution in the hippocampus. Our results showed that ischemic stroke caused significant memory impairment accompanied by increased protein levels of GFAP and Cx43 in hippocampal tissue. In addition, the levels of several key memory-related important proteins including SYP, CRTC1, myelin basic protein and high-mobility group-box-1 were significantly reduced in the hippocampal tissue. Of note, inhibition of reactive astrocytes with fluorocitrate was shown to significantly reverse the above noted changes induced by ischemic stroke. Taken together, our findings demonstrate that inhibiting reactive astrocytes with fluorocitrate immediately before reperfusion may protect against ischemic stroke-induced memory impairment through the upregulation of CRTC1 and SYP.
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Role of astrocytes-derived d-serine in PFOS-induced neurotoxicity through NMDARs in the rat primary hippocampal neurons. Toxicology 2019; 422:14-24. [PMID: 31004706 DOI: 10.1016/j.tox.2019.04.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 03/05/2019] [Accepted: 04/16/2019] [Indexed: 12/30/2022]
Abstract
Perfluorooctane sulfonate (PFOS) is one of the perfluorinated compounds (PFCs), and has been used in industrial and consumer products. It has already been shown that PFOS could be detected in the environmental media and biological species including humans, due to its resistance to environmental degradation. PFOS is known to induce a series of adverse impacts on human health, e.g., as a potential neurotoxic substance. Recent studies suggest that astrocytes act as the mediator in PFOS-induced neurotoxicity; however, the underlying molecular mechanism needs further investigation. Under the physiological condition, astrocytes play an important role in maintaining brain functions through releasing and up-taking of neurotransmitters between astrocytes and neurons. In the present study, astrocytes-derived d-serine was shown to be involved in PFOS-induced apoptosis and death in the rat primary hippocampal neurons. Significant alterations in d-serine were found in astrocytes, mediated by the molecules in d-serine synthesis (serine racemase), metabolism (d-amino acid oxidase) and delivery (calcium, vacuolar type H+-ATPase, alanine-serine-cysteine transporter and connexin 43 hemichannels). Meanwhile, the N-methyl-d-aspartate receptor (NMDAR) subunits (NR1, NR2 A and NR2B) gene and protein expressions were significantly increased in the hippocampal neurons exposed to the PFOS-activated astrocytes-conditional medium (ACM). Further, the adverse effects of PFOS could be attenuated by the fluorocitrate (an inhibitor for d-serine up-taken by the glial cells) application. Our data indicated that astrocytes-derived d-serine was involved in PFOS-induced neurotoxicity through the NMDARs in the rat primary hippocampal neurons.
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Peña-Ortega F, Rivera-Angulo AJ, Lorea-Hernández JJ. Pharmacological Tools to Study the Role of Astrocytes in Neural Network Functions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 949:47-66. [DOI: 10.1007/978-3-319-40764-7_3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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