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Belo do Nascimento I, Ates G, Desmet N, Beckers P, Massie A, Hermans E. AMPKα1 Deficiency in Astrocytes from a Rat Model of ALS Is Associated with an Altered Metabolic Resilience. Biomolecules 2023; 13:1183. [PMID: 37627248 PMCID: PMC10452650 DOI: 10.3390/biom13081183] [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: 07/03/2023] [Revised: 07/24/2023] [Accepted: 07/27/2023] [Indexed: 08/27/2023] Open
Abstract
Alterations in the activity of the regulator of cell metabolism AMP-activated protein kinase (AMPK) have been reported in motor neurons from patients and animal models of amyotrophic lateral sclerosis (ALS). Considering the key role played by astrocytes in modulating energy metabolism in the nervous system and their compromised support towards neurons in ALS, we examined whether a putative alteration in AMPK expression/activity impacted astrocytic functions such as their metabolic plasticity and glutamate handling capacity. We found a reduced expression of AMPK mRNA in primary cultures of astrocytes derived from transgenic rats carrying an ALS-associated mutated superoxide dismutase (hSOD1G93A). The activation of AMPK after glucose deprivation was reduced in hSOD1G93A astrocytes compared to non-transgenic. This was accompanied by a lower increase in ATP levels and increased vulnerability to this insult, although the ATP production rate did not differ between the two cell types. Furthermore, soliciting the activity of glutamate transporters was found to induce similar AMPK activity in these cells. However, manipulation of AMPK activity did not influence glutamate transport. Together, these results suggest that the altered AMPK responsiveness in ALS might be context dependent and may compromise the metabolic adaptation of astrocytes in response to specific cellular stress.
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Affiliation(s)
- Inês Belo do Nascimento
- Institute of Neuroscience, Université Catholique de Louvain, 1200 Brussels, Belgium; (I.B.d.N.); (N.D.); (P.B.)
| | - Gamze Ates
- Center for Neurosciences, Neuro-Aging & Viro-Immunotherapy, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium; (G.A.); (A.M.)
| | - Nathalie Desmet
- Institute of Neuroscience, Université Catholique de Louvain, 1200 Brussels, Belgium; (I.B.d.N.); (N.D.); (P.B.)
| | - Pauline Beckers
- Institute of Neuroscience, Université Catholique de Louvain, 1200 Brussels, Belgium; (I.B.d.N.); (N.D.); (P.B.)
| | - Ann Massie
- Center for Neurosciences, Neuro-Aging & Viro-Immunotherapy, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium; (G.A.); (A.M.)
| | - Emmanuel Hermans
- Institute of Neuroscience, Université Catholique de Louvain, 1200 Brussels, Belgium; (I.B.d.N.); (N.D.); (P.B.)
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Lee A, Klinkradt S, McCombe P, Pow D. Cloning of a new form of EAAT2/GLT-1 from human and rodent brains. Neurosci Lett 2022; 780:136637. [DOI: 10.1016/j.neulet.2022.136637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 04/08/2022] [Accepted: 04/13/2022] [Indexed: 11/15/2022]
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Yin X, Wang S, Qi Y, Wang X, Jiang H, Wang T, Yang Y, Wang Y, Zhang C, Feng H. Astrocyte elevated gene-1 is a novel regulator of astrogliosis and excitatory amino acid transporter-2 via interplaying with nuclear factor-κB signaling in astrocytes from amyotrophic lateral sclerosis mouse model with hSOD1 G93A mutation. Mol Cell Neurosci 2018; 90:1-11. [PMID: 29777762 DOI: 10.1016/j.mcn.2018.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 12/16/2022] Open
Abstract
AEG-1 has received extensive attention on cancer research. However, little is known about its roles in astrogliosis of Amyotrophic lateral sclerosis (ALS). In this study, we detected AEG-1 expression in hSOD1G93A-positive (mut-SOD1) astrocytes and wild type (wt-SOD1) astrocytes, and intend to elucidate its potential functions in ALS related astrogliosis and the always accompanied dysregulated glutamate clearance. Results showed elevated protein and mRNA levels of AEG-1 in mut-SOD1 astrocytes; Also, NF-κB signaling pathway related proteins and inflammatory cytokines were upregulated in mut-SOD1 astrocytes; AEG-1 knockdown attenuated astrocytes proliferation and pro-inflammatory release; also we found that AEG-1 silence inhibited translocation of p65 from cytoplasma to nuclear, which was associated with inhibited NF-κB signaling. Besides, excitatory amino acid transporter-2 (EAAT2) expression levels were significantly decreased, accompanied by impaired glutamate clearance ability, in mut-SOD1 astrocytes; yin yang 1 (YY1), a transcriptional inhibitor for EAAT2, increased in nucleus of mut-SOD1 astrocytes. AEG-1 silence inhibited translocation of YY1 to nucleus, increased EAAT2 expression levels, and enhanced astrocytic ability of glutamate clearance, ultimately exerted the neuronal protection. Findings from this study implicate potential function of AEG-1 in mut-SOD1 related astrogliosis and the accompanied excitatory cytotoxic mechanism in ALS.
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Affiliation(s)
- Xiang Yin
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, PR China; Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun 130021, People's Republic of China
| | - Shuyu Wang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, PR China
| | - Yan Qi
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, PR China
| | - Xudong Wang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, PR China
| | - Hongquan Jiang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, PR China
| | - Tianhang Wang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, PR China
| | - Yueqing Yang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, PR China
| | - Ying Wang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, PR China
| | - Chunting Zhang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, PR China
| | - Honglin Feng
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, PR China.
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Vidal-Taboada JM, Pugliese M, Salvadó M, Gámez J, Mahy N, Rodríguez MJ. K ATP Channel Expression and Genetic Polymorphisms Associated with Progression and Survival in Amyotrophic Lateral Sclerosis. Mol Neurobiol 2018; 55:7962-7972. [PMID: 29492846 DOI: 10.1007/s12035-018-0970-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 02/16/2018] [Indexed: 02/06/2023]
Abstract
The ATP-sensitive potassium (KATP) channel directly regulates the microglia-mediated inflammatory response following CNS injury. To determine the putative role of the KATP channel in amyotrophic lateral sclerosis (ALS) pathology, we investigated whether ALS induces changes in KATP channel expression in the spinal cord and motor cortex. We also characterized new functional variants of human ABCC8, ABCC9, KCNJ8, and KCNJ11 genes encoding for the KATP channel and analyzed their association with ALS risk, rate of progression, and survival in a Spanish ALS cohort. The expression of ABCC8 and KCNJ8 genes was enhanced in the spinal cord of ALS samples, and KCNJ11 increased in motor cortex of ALS samples, as determined by real-time polymerase chain reaction. We then sequenced the exons and regulatory regions of KATP channel genes from a subset of 28 ALS patients and identified 50 new genetic variants. For the case-control association analysis, we genotyped five selected polymorphisms with predicted functional relevance in 185 Spanish ALS (134 spinal ALS and 51 bulbar ALS) patients and 493 controls. We found that bulbar ALS patients presenting the G/G genotype of the rs4148646 variant of ABCC8 and the T/T genotype of the rs5219 variant of KCNJ11 survived longer than other ALS patients presenting other genotypes. Also, the C/C genotype of the rs4148642 variant of ABCC8 and the T/C genotype of the rs148416760 variant of ABCC9 modified the progression rate in spinal ALS patients. Our results suggest that the KATP channel plays a role in the pathophysiological mechanisms of ALS.
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Affiliation(s)
- José M Vidal-Taboada
- Department of Biomedical Sciences, Institut de Neurociències, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Universitat de Barcelona, Barcelona, Spain
| | - Marco Pugliese
- Department of Biomedical Sciences, Institut de Neurociències, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Universitat de Barcelona, Barcelona, Spain
| | - Maria Salvadó
- ALS Unit, Department of Neurology, Hospital Universitari Vall d'Hebron - VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Josep Gámez
- ALS Unit, Department of Neurology, Hospital Universitari Vall d'Hebron - VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Nicole Mahy
- Department of Biomedical Sciences, Institut de Neurociències, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Universitat de Barcelona, Barcelona, Spain
| | - Manuel J Rodríguez
- Department of Biomedical Sciences, Institut de Neurociències, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Universitat de Barcelona, Barcelona, Spain. .,Unitat de Bioquímica i Biologia Molecular, Department of Biomedicina, Facultat de Medicina, UB, c/ Casanova 143, E-08036, Barcelona, Spain.
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EAAT2 and the Molecular Signature of Amyotrophic Lateral Sclerosis. ADVANCES IN NEUROBIOLOGY 2017; 16:117-136. [PMID: 28828608 DOI: 10.1007/978-3-319-55769-4_6] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapid and fatal neurodegenerative disease, primarily affecting upper and lower motor neurons. It is an extremely heterogeneous disease in both cause and symptom development, and its mechanisms of pathogenesis remain largely unknown. Excitotoxicity, a process caused by excessive glutamate signaling, is believed to play a substantial role, however. Excessive glutamate release, changes in postsynaptic glutamate receptors, and reduction of functional astrocytic glutamate transporters contribute to excitotoxicity in ALS. Here, we explore the roles of each, with a particular emphasis on glutamate transporters and attempts to increase them as therapy for ALS. Screening strategies have been employed to find compounds that increase the functional excitatory amino acid transporter EAAT2 (GLT1), which is responsible for the vast majority of glutamate clearance. One such compound, ceftriaxone, was recently tested in clinical trials but unfortunately did not modify disease course, though its effect on EAAT2 expression in patients was not measured.
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Ma D, Shuler JM, Kumar A, Stanford QR, Tungtur S, Nishimune H, Stanford JA. Effects of Tongue Force Training on Bulbar Motor Function in the Female SOD1-G93A Rat Model of Amyotrophic Lateral Sclerosis. Neurorehabil Neural Repair 2016; 31:147-156. [PMID: 27573800 DOI: 10.1177/1545968316666956] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND The use of exercise in amyotrophic lateral sclerosis (ALS) is controversial. Although moderate exercise appears to be beneficial for limb muscles in ALS, the effects of exercise on bulbar muscles such as the tongue have not been studied. OBJECTIVE To determine the effects of tongue force training on bulbar motor function in the SOD1-G93A rat model of ALS. METHODS We compared the effects of tongue force training on bulbar motor function and neuromuscular junction innervation in female SOD1-G93A rats and age-matched female wild-type controls. Half of each group underwent afternoon tongue force training sessions, and all rats were tested under minimal force conditions in the mornings. RESULTS Tongue force did not differ between the SOD1-G93A rats and healthy controls during the morning testing sessions, nor was it affected by training. Surprisingly, decreases in tongue motility, the number of licks per session, and body weight were greater in the tongue force-trained SOD1-G93A rats. Forelimb grip force, survival, and denervation of the genioglossus (GG) muscle did not differ between the trained and untrained SOD1-G93A rats. GG innervation was correlated with changes in tongue force but not tongue motility in SOD1-G93A rats at end stage. CONCLUSIONS The results indicate a potential deleterious effect of tongue force training on tongue motility in female SOD1-G93A rats. The lack of a relationship between GG innervation and tongue motility suggests that factors other than lower-motor neuron integrity likely accounted for this effect.
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Affiliation(s)
- Delin Ma
- 1 Huazhong University of Science and Technology, Wuhan, Hubei Province, China
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Differential regulation of two isoforms of the glial glutamate transporter EAAT2 by DLG1 and CaMKII. J Neurosci 2015; 35:5260-70. [PMID: 25834051 DOI: 10.1523/jneurosci.4365-14.2015] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The gene for EAAT2, the major astrocytic glutamate transporter, generates two carrier isoforms (EAAT2a and EAAT2b) that vary at their C termini as a consequence of alternative RNA splicing. The EAAT2b cytoplasmic C terminus contains a postsynaptic density-95/Discs large/zona occludens-1 (PDZ) ligand, which is absent in EAAT2a. To understand how the distinct C termini might affect transporter trafficking and surface localization, we generated Madin-Darby canine kidney (MDCK) cells that stably express EGFP-EAAT2a or EGFP-EAAT2b and found robust basolateral membrane expression of the EAAT2b isoform. In contrast, EAAT2a displayed a predominant distribution within intracellular vesicle compartments, constitutively cycling to and from the membrane. Addition of the PDZ ligand to EAAT2a as well as its deletion from EAAT2b confirmed the importance of the motif for cell-surface localization. Using EAAT2 constructs with an extracellular biotin acceptor tag to directly assess surface proteins, we observed significant PDZ ligand-dependent EAAT2b surface expression in cultured astrocytes, consistent with observations in cell lines. Discs large homolog 1 (DLG1; SAP97), a PDZ protein prominent in both astrocytes and MDCK cells, colocalized and coimmunoprecipitated with EAAT2b. shRNA knockdown of DLG1 expression decreased surface EAAT2b in both MDCK cells and cultured astrocytes, suggesting that the DLG scaffolding protein stabilizes EAAT2b at the surface. DLG1 can be phosphorylated by Ca(2+)/calmodulin-dependent protein kinase (CaMKII), resulting in disruption of its PDZ-mediated interaction. In murine astrocytes and acute brain slices, activation of CaMKII decreases EAAT2b surface expression but does not alter the distribution of EAAT2a. These data indicate that the surface expression and function of EAAT2b can be rapidly modulated through the disruption of its interaction with DLG1 by CaMKII activation.
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Battaglia G, Riozzi B, Bucci D, Di Menna L, Molinaro G, Pallottino S, Nicoletti F, Bruno V. Activation of mGlu3 metabotropic glutamate receptors enhances GDNF and GLT-1 formation in the spinal cord and rescues motor neurons in the SOD-1 mouse model of amyotrophic lateral sclerosis. Neurobiol Dis 2015; 74:126-36. [DOI: 10.1016/j.nbd.2014.11.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 10/29/2014] [Accepted: 11/19/2014] [Indexed: 11/28/2022] Open
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Dumont AO, Goursaud S, Desmet N, Hermans E. Differential regulation of glutamate transporter subtypes by pro-inflammatory cytokine TNF-α in cortical astrocytes from a rat model of amyotrophic lateral sclerosis. PLoS One 2014; 9:e97649. [PMID: 24836816 PMCID: PMC4023965 DOI: 10.1371/journal.pone.0097649] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 04/22/2014] [Indexed: 12/14/2022] Open
Abstract
Dysregulation of the astroglial glutamate transporters GLAST and GLT-1 has been implicated in several neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) where a loss of GLT-1 protein expression and activity is reported. Furthermore, the two principal C-terminal splice variants of GLT-1 (namely GLT-1a and GLT-1b) show altered expression ratio in animal models of this disease. Considering the putative link between inflammation and excitotoxicity, we have here characterized the influence of TNF-α on glutamate transporters in cerebral cortical astrocyte cultures from wild-type rats and from a rat model of ALS (hSOD1G93A). Contrasting with the down-regulation of GLAST, a 72 h treatment with TNF-α substantially increased the expression of GLT-1a and GLT-1b in both astrocyte cultures. However, as the basal level of GLT-1a appeared considerably lower in hSOD1G93A astrocytes, its up-regulation by TNF-α was insufficient to recapitulate the expression observed in wild-type astrocytes. Also the glutamate uptake activity after TNF-α treatment was lower for hSOD1G93A astrocytes as compared to wild-type astrocytes. In the presence of the protein synthesis inhibitor cycloheximide, TNF-α did not influence GLT-1 isoform expression, suggesting an active role of dynamically regulated protein partners in the adaptation of astrocytes to the inflammatory environment. Confirming the influence of inflammation on the control of glutamate transmission by astrocytes, these results shed light on the regulation of glutamate transporter isoforms in neurodegenerative disorders.
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Affiliation(s)
- Amélie O. Dumont
- Institute of Neuroscience, Group of Neuropharmacology, Université Catholique de Louvain, Brussels, Belgium
| | - Stéphanie Goursaud
- Institute of Neuroscience, Group of Neuropharmacology, Université Catholique de Louvain, Brussels, Belgium
| | - Nathalie Desmet
- Institute of Neuroscience, Group of Neuropharmacology, Université Catholique de Louvain, Brussels, Belgium
| | - Emmanuel Hermans
- Institute of Neuroscience, Group of Neuropharmacology, Université Catholique de Louvain, Brussels, Belgium
- * E-mail:
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