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Jang MH, Song J. Adenosine and adenosine receptors in metabolic imbalance-related neurological issues. Biomed Pharmacother 2024; 177:116996. [PMID: 38897158 DOI: 10.1016/j.biopha.2024.116996] [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: 04/24/2024] [Revised: 06/08/2024] [Accepted: 06/15/2024] [Indexed: 06/21/2024] Open
Abstract
Metabolic syndromes (e.g., obesity) are characterized by insulin resistance, chronic inflammation, impaired glucose metabolism, and dyslipidemia. Recently, patients with metabolic syndromes have experienced not only metabolic problems but also neuropathological issues, including cognitive impairment. Several studies have reported blood-brain barrier (BBB) disruption and insulin resistance in the brain of patients with obesity and diabetes. Adenosine, a purine nucleoside, is known to regulate various cellular responses (e.g., the neuroinflammatory response) by binding with adenosine receptors in the central nervous system (CNS). Adenosine has four known receptors: A1R, A2AR, A2BR, and A3R. These receptors play distinct roles in various physiological and pathological processes in the brain, including endothelial cell homeostasis, insulin sensitivity, microglial activation, lipid metabolism, immune cell infiltration, and synaptic plasticity. Here, we review the recent findings on the role of adenosine receptor-mediated signaling in neuropathological issues related to metabolic imbalance. We highlight the importance of adenosine signaling in the development of therapeutic solutions for neuropathological issues in patients with metabolic syndromes.
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Affiliation(s)
- Mi-Hyeon Jang
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, United States.
| | - Juhyun Song
- Department of Anatomy, Chonnam National University Medical School, Hwasun 58128, Republic of Korea.
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2
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Daniels SD, Boison D. Bipolar mania and epilepsy pathophysiology and treatment may converge in purine metabolism: A new perspective on available evidence. Neuropharmacology 2023; 241:109756. [PMID: 37820933 PMCID: PMC10841508 DOI: 10.1016/j.neuropharm.2023.109756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 09/25/2023] [Accepted: 10/07/2023] [Indexed: 10/13/2023]
Abstract
Decreased ATPergic signaling is an increasingly recognized pathophysiology in bipolar mania disease models. In parallel, adenosine deficit is increasingly recognized in epilepsy pathophysiology. Under-recognized ATP and/or adenosine-increasing mechanisms of several antimanic and antiseizure therapies including lithium, valproate, carbamazepine, and ECT suggest a fundamental pathogenic role of adenosine deficit in bipolar mania to match the established role of adenosine deficit in epilepsy. The depletion of adenosine-derivatives within the purine cycle is expected to result in a compensatory increase in oxopurines (uric acid precursors) and secondarily increased uric acid, observed in both bipolar mania and epilepsy. Cortisol-based inhibition of purine conversion to adenosine-derivatives may be reflected in observed uric acid increases and the well-established contribution of cortisol to both bipolar mania and epilepsy pathology. Cortisol-inhibited conversion from IMP to AMP as precursor of both ATP and adenosine may represent a mechanism for treatment resistance common in both bipolar mania and epilepsy. Anti-cortisol therapies may therefore augment other treatments both in bipolar mania and epilepsy. Evidence linking (i) adenosine deficit with a decreased need for sleep, (ii) IMP/cGMP excess with compulsive hypersexuality, and (iii) guanosine excess with grandiose delusions may converge to suggest a novel theory of bipolar mania as a condition characterized by disrupted purine metabolism. The potential for disease-modification and prevention related to adenosine-mediated epigenetic changes in epilepsy may be mirrored in mania. Evaluating the purinergic effects of existing agents and validating purine dysregulation may improve diagnosis and treatment in bipolar mania and epilepsy and provide specific targets for drug development.
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Affiliation(s)
- Scott D Daniels
- Hutchings Psychiatric Center, New York State Office of Mental Health, Syracuse, NY, 13210, USA
| | - Detlev Boison
- Dept. of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA.
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3
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Lopes CR, Silva AC, Silva HB, Canas PM, Agostinho P, Cunha RA, Lopes JP. Adenosine A 2A Receptor Up-Regulation Pre-Dates Deficits of Synaptic Plasticity and of Memory in Mice Exposed to Aβ 1-42 to Model Early Alzheimer's Disease. Biomolecules 2023; 13:1173. [PMID: 37627238 PMCID: PMC10452250 DOI: 10.3390/biom13081173] [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: 06/16/2023] [Revised: 07/19/2023] [Accepted: 07/26/2023] [Indexed: 08/27/2023] Open
Abstract
The intracerebroventricular (icv) injection of amyloid peptides (Aβ) models Alzheimer's disease (AD) in mice, as typified by the onset within 15 days of deficits of memory and of hippocampal long-term potentiation (LTP) that are prevented by the blockade of adenosine A2A receptors (A2AR). Since A2AR overfunction is sufficient to trigger memory deficits, we tested if A2AR were upregulated in hippocampal synapses before the onset of memory deficits to support the hypothesis that A2AR overfunction could be a trigger of AD. Six to eight days after Aβ-icv injection, mice displayed no alterations of hippocampal dependent memory; however, they presented an increased excitability of hippocampal synapses, a slight increase in LTP magnitude in Schaffer fiber-CA1 pyramid synapses and an increased density of A2AR in hippocampal synapses. A2AR blockade with SCH58261 (50 nM) normalized excitability and LTP in hippocampal slices from mice sacrificed 7-8 days after Aβ-icv injection. Fifteen days after Aβ-icv injection, mice displayed evident deficits of hippocampal-dependent memory deterioration, with reduced hippocampal CA1 LTP but no hyperexcitability and a sustained increase in synaptic A2AR, which blockade restored LTP magnitude. This shows that the upregulation of synaptic A2AR precedes the onset of deterioration of memory and of hippocampal synaptic plasticity, supporting the hypothesis that the overfunction of synaptic A2AR could be a trigger of memory deterioration in AD.
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Affiliation(s)
- Cátia R. Lopes
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (C.R.L.); (A.C.S.); (H.B.S.); (P.M.C.); (P.A.); (J.P.L.)
- Faculty of Medicine, University of Coimbra, 3000-370 Coimbra, Portugal
| | - António C. Silva
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (C.R.L.); (A.C.S.); (H.B.S.); (P.M.C.); (P.A.); (J.P.L.)
| | - Henrique B. Silva
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (C.R.L.); (A.C.S.); (H.B.S.); (P.M.C.); (P.A.); (J.P.L.)
| | - Paula M. Canas
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (C.R.L.); (A.C.S.); (H.B.S.); (P.M.C.); (P.A.); (J.P.L.)
| | - Paula Agostinho
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (C.R.L.); (A.C.S.); (H.B.S.); (P.M.C.); (P.A.); (J.P.L.)
- Faculty of Medicine, University of Coimbra, 3000-370 Coimbra, Portugal
| | - Rodrigo A. Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (C.R.L.); (A.C.S.); (H.B.S.); (P.M.C.); (P.A.); (J.P.L.)
- Faculty of Medicine, University of Coimbra, 3000-370 Coimbra, Portugal
| | - João Pedro Lopes
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (C.R.L.); (A.C.S.); (H.B.S.); (P.M.C.); (P.A.); (J.P.L.)
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4
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da Silva TC, da Silveira TL, Dos Santos LV, Arantes LP, Martins RP, Soares FAA, Dalla Corte CL. Exogenous Adenosine Modulates Behaviors and Stress Response in Caenorhabditis elegans. Neurochem Res 2023; 48:117-130. [PMID: 36018438 DOI: 10.1007/s11064-022-03727-5] [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: 01/19/2022] [Revised: 07/14/2022] [Accepted: 08/15/2022] [Indexed: 01/11/2023]
Abstract
Adenosine, a purine nucleoside with neuromodulatory actions, is part of the purinergic signaling system (PSS). Caenorhabditis elegans is a free-living nematode found in soil, used in biological research for its advantages as an alternative experimental model. Since there is a lack of evidence of adenosine's direct actions and the PSS's participation in this animal, such an investigation is necessary. In this research, we aimed to test the effects of acute and chronic adenosine at 1, 5, and 10 mM on nematode's behaviors, morphology, survival after stress conditions, and on pathways related to the response to oxidative stress (DAF-16/FOXO and SKN-1) and genes products downstream these pathways (SOD-3, HSP-16.2, and GCS-1). Acute or chronic adenosine did not alter the worms' morphology analyzed by the worms' length, width, and area, nor interfered with reproductive behavior. On the other hand, acute and chronic adenosine modulated the defecation rate, pharyngeal pumping rate, and locomotion, in addition, to interacting with stress response pathways in C. elegans. Adenosine interfered in the speed and mobility of the worms analyzed. In addition, both acute and chronic adenosine presented modulatory effects on oxidative stress response signaling. Acute adenosine prevented the heat-induced-increase of DAF-16 activation and SOD-3 levels, while chronic adenosine per se induced DAF-16 activation and prevented heat-induced-increase of HSP-16.2 and SKN-1 levels. Together, these results indicate that exogenous adenosine has physiological and biochemical effects on C. elegans and describes possible purinergic signaling in worms.
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Affiliation(s)
- Thayanara Cruz da Silva
- Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Av. Roraima nº 1000, Camobi, Santa Maria, RS, 97105-900, Brazil
| | - Tássia Limana da Silveira
- Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Av. Roraima nº 1000, Camobi, Santa Maria, RS, 97105-900, Brazil
| | - Luiza Venturini Dos Santos
- Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Av. Roraima nº 1000, Camobi, Santa Maria, RS, 97105-900, Brazil
| | - Leticia Priscila Arantes
- Instituto Latino-Americano de Ciências da Vida e da Natureza, Universidade Federal da Integração Latino-Americana, Foz do Iguaçu, Paraná, 85866-000, Brazil
| | - Rodrigo Pereira Martins
- Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Av. Roraima nº 1000, Camobi, Santa Maria, RS, 97105-900, Brazil
| | - Félix Alexandre Antunes Soares
- Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Av. Roraima nº 1000, Camobi, Santa Maria, RS, 97105-900, Brazil
| | - Cristiane Lenz Dalla Corte
- Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Av. Roraima nº 1000, Camobi, Santa Maria, RS, 97105-900, Brazil.
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5
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Shen HY, Baer SB, Gesese R, Cook JM, Weltha L, Coffman SQ, Wu J, Chen JF, Gao M, Ji T. Adenosine-A 2A Receptor Signaling Plays a Crucial Role in Sudden Unexpected Death in Epilepsy. Front Pharmacol 2022; 13:910535. [PMID: 35754505 PMCID: PMC9218562 DOI: 10.3389/fphar.2022.910535] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/16/2022] [Indexed: 11/16/2022] Open
Abstract
Adenosinergic activities are suggested to participate in SUDEP pathophysiology; this study aimed to evaluate the adenosine hypothesis of SUDEP and specifically the role of adenosine A2A receptor (A2AR) in the development of a SUDEP mouse model with relevant clinical features. Using a combined paradigm of intrahippocampal and intraperitoneal administration of kainic acid (KA), we developed a boosted-KA model of SUDEP in genetically modified adenosine kinase (ADK) knockdown (Adk+/-) mice, which has reduced ADK in the brain. Seizure activity was monitored using video-EEG methods, and in vivo recording of local field potential (LFP) was used to evaluate neuronal activity within the nucleus tractus solitarius (NTS). Our boosted-KA model of SUDEP was characterized by a delayed, postictal sudden death in epileptic mice. We demonstrated a higher incidence of SUDEP in Adk+/- mice (34.8%) vs. WTs (8.0%), and the ADK inhibitor, 5-Iodotubercidin, further increased SUDEP in Adk+/- mice (46.7%). We revealed that the NTS level of ADK was significantly increased in epileptic WTs, but not in epileptic Adk+/- mutants, while the A2AR level in NTS was increased in epileptic (WT and Adk+/-) mice vs. non-epileptic controls. The A2AR antagonist, SCH58261, significantly reduced SUDEP events in Adk+/- mice. LFP data showed that SCH58261 partially restored KA injection-induced suppression of gamma oscillation in the NTS of epileptic WT mice, whereas SCH58261 increased theta and beta oscillations in Adk+/- mutants after KA injection, albeit with no change in gamma oscillations. These LFP findings suggest that SCH58261 and KA induced changes in local neuronal activities in the NTS of epileptic mice. We revealed a crucial role for NTS A2AR in SUDEP pathophysiology suggesting A2AR as a potential therapeutic target for SUDEP risk prevention.
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Affiliation(s)
- Hai-Ying Shen
- Department of Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - Sadie B Baer
- Department of Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - Raey Gesese
- Department of Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - John M Cook
- Department of Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - Landen Weltha
- Department of Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - Shayla Q Coffman
- Department of Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - Jie Wu
- Department of Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, United States
| | - Jiang-Fan Chen
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Ming Gao
- Department of Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, United States
| | - Teng Ji
- Department of Pediatric Neurology, Randall Children's Hospital, Legacy Emanuel Medical Center, Portland, OR, United States
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6
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Zhao J, Kumar M, Sharma J, Yuan Z. Arbutin effectively ameliorates the symptoms of Parkinson's disease: the role of adenosine receptors and cyclic adenosine monophosphate. Neural Regen Res 2021; 16:2030-2040. [PMID: 33642391 PMCID: PMC8343309 DOI: 10.4103/1673-5374.308102] [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] [Indexed: 12/15/2022] Open
Abstract
An antagonistic communication exists between adenosinergic and dopaminergic signaling in the basal ganglia, which suggests that the suppression of adenosine A2A receptors-cyclic adenosine monophosphate pathway may be able to restore the disrupted dopamine transmission that results in motor symptoms in Parkinson’s disease (PD). Arbutin is a natural glycoside that possesses antioxidant, anti-inflammatory, and neuroprotective properties. The purpose of this study was to investigate whether arbutin could ameliorate the symptoms of PD and to examine the underlying mechanism. In this study, Swiss albino mouse models of PD were established by the intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine for 4 successive days, with the concurrent intraperitoneal administration of arbutin (50 and 100 mg/kg) for 7 days. The results showed that arbutin significantly reduced lipid peroxidation, total nitrite levels, and inflammation in the substantia nigra and striatum of PD mouse models. In addition, arbutin decreased the activity of endogenous antioxidants, reduced the levels of dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid, and γ-aminobutyric acid, and minimized neurodegeneration in the striatum. Arbutin also reduced the abnormal performance of PD mouse models in the open field test, bar test, pole test, and rotarod test. The therapeutic efficacy of arbutin was similar to that of madopar. The intraperitoneal injection of the A2AR agonist CGS21680 (0.5 mg/kg) attenuated the therapeutic effects of arbutin, whereas the intraperitoneal injection of forskolin (3 mg/kg) enhanced arbutin-mediated improvements. These findings suggest that arbutin can improve the performance of PD mouse models by inhibiting the function of the A2AR and enhancing the effects of cyclic adenosine monophosphate. This study was approved by the Institutional Animal Ethics Committee (1616/PO/Re/S/12/CPCSEA) on November 17, 2019 (approval No. IAEC/2019/010).
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Affiliation(s)
- Jie Zhao
- Department of Neurology, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan Province, China
| | - Manish Kumar
- Department of Pharmacology, Swift School of Pharmacy, Rajpura (Patiala), Punjab, India
| | - Jeevan Sharma
- Department of Pharmacology, Swift School of Pharmacy, Rajpura (Patiala), Punjab, India
| | - Zhihai Yuan
- Department of Neurosurgery, The Second Affiliated Hospital of Xi'an Medical University, Xi'an, Shaanxi Province, China
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Nguyen MD, Wang Y, Ganesana M, Venton BJ. Transient Adenosine Release Is Modulated by NMDA and GABA B Receptors. ACS Chem Neurosci 2017; 8:376-385. [PMID: 28071892 DOI: 10.1021/acschemneuro.6b00318] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Adenosine is a neuroprotective agent that modulates neurotransmission and is modulated by other neurotransmitters. Spontaneous, transient adenosine is a recently discovered mode of signaling where adenosine is released and cleared from the extracellular space quickly, in less than three seconds. Spontaneous adenosine release is regulated by adenosine A1 and A2a receptors, but regulation by other neurotransmitter receptors has not been studied. Here, we examined the effect of glutamate and GABA receptors on the concentration and frequency of spontaneous, transient adenosine release by measuring adenosine with fast-scan cyclic voltammetry in the rat caudate-putamen. The glutamate NMDA antagonist, 3-(R-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP, 6.25 mg/kg i.p.), increased the frequency of adenosine transients and the concentration of individual transients, but NMDA (agonist, 50 mg/kg, i.p.) did not change the frequency. In contrast, antagonists of other glutamate receptors had no effect on the frequency or concentration of transient adenosine release, including the AMPA antagonist NBQX (15 mg/kg i.p.) and the mGlu2/3 glutamate receptor antagonist LY 341495 (5 mg/kg i.p.). The GABAB antagonist CGP 52432 (30 mg/kg i.p.) significantly decreased the number of adenosine release events while the GABAB agonist baclofen (4 mg/kg i.p.) increased the frequency of adenosine release. The GABAA antagonist bicuculline (5 mg/kg i.p.) had no significant effects on adenosine. NMDA and GABAB likely act presynaptically, affecting the overall cell excitability for vesicular release. The ability to regulate adenosine with NMDA and GABAB receptors will help control the modulatory effects of transient adenosine release.
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Affiliation(s)
- Michael D. Nguyen
- Department
of Chemistry and
Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Ying Wang
- Department
of Chemistry and
Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Mallikarjunarao Ganesana
- Department
of Chemistry and
Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia 22904, United States
| | - B. Jill Venton
- Department
of Chemistry and
Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia 22904, United States
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8
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Ruan L, Wang Y, Chen SC, Zhao T, Huang Q, Hu ZL, Xia NZ, Liu JJ, Chen WJ, Zhang Y, Cheng JL, Gao HC, Yang YJ, Sun HZ. Metabolite changes in the ipsilateral and contralateral cerebral hemispheres in rats with middle cerebral artery occlusion. Neural Regen Res 2017; 12:931-937. [PMID: 28761426 PMCID: PMC5514868 DOI: 10.4103/1673-5374.208575] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Cerebral ischemia not only causes pathological changes in the ischemic areas but also induces a series of secondary changes in more distal brain regions (such as the contralateral cerebral hemisphere). The impact of supratentorial lesions, which are the most common type of lesion, on the contralateral cerebellum has been studied in patients by positron emission tomography, single photon emission computed tomography, magnetic resonance imaging and diffusion tensor imaging. In the present study, we investigated metabolite changes in the contralateral cerebral hemisphere after supratentorial unilateral ischemia using nuclear magnetic resonance spectroscopy-based metabonomics. The permanent middle cerebral artery occlusion model of ischemic stroke was established in rats. Rats were randomly divided into the middle cerebral artery occlusion 1-, 3-, 9- and 24-hour groups and the sham group. 1H nuclear magnetic resonance spectroscopy was used to detect metabolites in the left and right cerebral hemispheres. Compared with the sham group, the concentrations of lactate, alanine, γ-aminobutyric acid, choline and glycine in the ischemic cerebral hemisphere were increased in the acute stage, while the concentrations of N-acetyl aspartate, creatinine, glutamate and aspartate were decreased. This demonstrates that there is an upregulation of anaerobic glycolysis (shown by the increase in lactate), a perturbation of choline metabolism (suggested by the increase in choline), neuronal cell damage (shown by the decrease in N-acetyl aspartate) and neurotransmitter imbalance (evidenced by the increase in γ-aminobutyric acid and glycine and by the decrease in glutamate and aspartate) in the acute stage of cerebral ischemia. In the contralateral hemisphere, the concentrations of lactate, alanine, glycine, choline and aspartate were increased, while the concentrations of γ-aminobutyric acid, glutamate and creatinine were decreased. This suggests that there is a difference in the metabolite changes induced by ischemic injury in the contralateral and ipsilateral cerebral hemispheres. Our findings demonstrate the presence of characteristic changes in metabolites in the contralateral hemisphere and suggest that they are most likely caused by metabolic changes in the ischemic hemisphere.
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Affiliation(s)
- Lei Ruan
- Department of Radiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Yan Wang
- Department of Radiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Shu-Chao Chen
- Department of Radiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Tian Zhao
- Department of Radiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Qun Huang
- Department of Radiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Zi-Long Hu
- Department of Radiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Neng-Zhi Xia
- Department of Radiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Jin-Jin Liu
- Department of Radiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Wei-Jian Chen
- Department of Radiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Yong Zhang
- Department of Radiology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Jing-Liang Cheng
- Department of Radiology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Hong-Chang Gao
- School of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Yun-Jun Yang
- Department of Radiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Hou-Zhang Sun
- Department of Radiology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China
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9
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Rombo DM, Ribeiro JA, Sebastião AM. Hippocampal GABAergic transmission: a new target for adenosine control of excitability. J Neurochem 2016; 139:1056-1070. [PMID: 27778347 DOI: 10.1111/jnc.13872] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 09/30/2016] [Accepted: 10/21/2016] [Indexed: 01/01/2023]
Abstract
Physiological network functioning in the hippocampus is dependent on a balance between glutamatergic cell excitability and the activity of diverse local circuit neurons that release the inhibitory neurotransmitter γ-aminobutyric acid (GABA). Tuners of neuronal communication such as adenosine, an endogenous modulator of synapses, control hippocampal network operations by regulating excitability. Evidence has been recently accumulating on the influence of adenosine on different aspects of GABAergic transmission to shape hippocampal function. This review addresses how adenosine, through its high-affinity A1 (A1 R) and A2A receptors (A2A R), interferes with different GABA-mediated forms of inhibition in the hippocampus to regulate neuronal excitability. Adenosine-mediated modulation of phasic/tonic inhibitory transmission, of GABA transport mechanisms and its interference with other modulatory systems are discussed together with the putative implications for neuronal function in physiological and pathological conditions. This article is part of a mini review series: 'Synaptic Function and Dysfunction in Brain Diseases'.
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Affiliation(s)
- Diogo M Rombo
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Joaquim A Ribeiro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
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10
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Arosio B, Casati M, Gussago C, Ferri E, Abbate C, Scortichini V, Colombo E, Rossi PD, Mari D. Adenosine Type A2A Receptor in Peripheral Cell from Patients with Alzheimer’s Disease, Vascular Dementia, and Idiopathic Normal Pressure Hydrocephalus: A New/Old Potential Target. J Alzheimers Dis 2016; 54:417-25. [DOI: 10.3233/jad-160324] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Beatrice Arosio
- Geriatric Unit, Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
- Fondazione Ca’ Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | - Martina Casati
- Geriatric Unit, Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
- Nutritional Sciences, University of Milan, Milan, Italy
| | - Cristina Gussago
- Geriatric Unit, Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
| | - Evelyn Ferri
- Geriatric Unit, Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
- Nutritional Sciences, University of Milan, Milan, Italy
| | - Carlo Abbate
- Fondazione Ca’ Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | | | - Elena Colombo
- Geriatric Unit, Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
| | | | - Daniela Mari
- Geriatric Unit, Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
- Fondazione Ca’ Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy
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11
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Pedata F, Dettori I, Coppi E, Melani A, Fusco I, Corradetti R, Pugliese AM. Purinergic signalling in brain ischemia. Neuropharmacology 2015; 104:105-30. [PMID: 26581499 DOI: 10.1016/j.neuropharm.2015.11.007] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 11/04/2015] [Accepted: 11/06/2015] [Indexed: 12/18/2022]
Abstract
Ischemia is a multifactorial pathology characterized by different events evolving in the time. After ischemia a primary damage due to the early massive increase of extracellular glutamate is followed by activation of resident immune cells, i.e microglia, and production or activation of inflammation mediators. Protracted neuroinflammation is now recognized as the predominant mechanism of secondary brain injury progression. Extracellular concentrations of ATP and adenosine in the brain increase dramatically during ischemia in concentrations able to stimulate their respective specific P2 and P1 receptors. Both ATP P2 and adenosine P1 receptor subtypes exert important roles in ischemia. Although adenosine exerts a clear neuroprotective effect through A1 receptors during ischemia, the use of selective A1 agonists is hampered by undesirable peripheral effects. Evidence up to now in literature indicate that A2A receptor antagonists provide protection centrally by reducing excitotoxicity, while agonists at A2A (and possibly also A2B) and A3 receptors provide protection by controlling massive infiltration and neuroinflammation in the hours and days after brain ischemia. Among P2X receptors most evidence indicate that P2X7 receptor contribute to the damage induced by the ischemic insult due to intracellular Ca(2+) loading in central cells and facilitation of glutamate release. Antagonism of P2X7 receptors might represent a new treatment to attenuate brain damage and to promote proliferation and maturation of brain immature resident cells that can promote tissue repair following cerebral ischemia. Among P2Y receptors, antagonists of P2Y12 receptors are of value because of their antiplatelet activity and possibly because of additional anti-inflammatory effects. Moreover strategies that modify adenosine or ATP concentrations at injury sites might be of value to limit damage after ischemia. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.
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Affiliation(s)
- Felicita Pedata
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy.
| | - Ilaria Dettori
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
| | - Elisabetta Coppi
- Department of Health Sciences, University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
| | - Alessia Melani
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
| | - Irene Fusco
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
| | - Renato Corradetti
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
| | - Anna Maria Pugliese
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
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12
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Adenosine A2A receptors modulate acute injury and neuroinflammation in brain ischemia. Mediators Inflamm 2014; 2014:805198. [PMID: 25165414 PMCID: PMC4138795 DOI: 10.1155/2014/805198] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 06/26/2014] [Accepted: 07/10/2014] [Indexed: 01/07/2023] Open
Abstract
The extracellular concentration of adenosine in the brain increases dramatically during ischemia. Adenosine A2A receptor is expressed in neurons and glial cells and in inflammatory cells (lymphocytes and granulocytes). Recently, adenosine A2A receptor emerged as a potential therapeutic attractive target in ischemia. Ischemia is a multifactorial pathology characterized by different events evolving in the time. After ischemia the early massive increase of extracellular glutamate is followed by activation of resident immune cells, that is, microglia, and production or activation of inflammation mediators. Proinflammatory cytokines, which upregulate cell adhesion molecules, exert an important role in promoting recruitment of leukocytes that in turn promote expansion of the inflammatory response in ischemic tissue. Protracted neuroinflammation is now recognized as the predominant mechanism of secondary brain injury progression. A2A receptors present on central cells and on blood cells account for important effects depending on the time-related evolution of the pathological condition. Evidence suggests that A2A receptor antagonists provide early protection via centrally mediated control of excessive excitotoxicity, while A2A receptor agonists provide protracted protection by controlling massive blood cell infiltration in the hours and days after ischemia. Focus on inflammatory responses provides for adenosine A2A receptor agonists a wide therapeutic time-window of hours and even days after stroke.
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Increased adenosine levels in mice expressing mutant glial fibrillary acidic protein in astrocytes result in failure of induction of LTP reversal (depotentiation) in hippocampal CA1 neurons. Brain Res 2014; 1578:1-13. [DOI: 10.1016/j.brainres.2014.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 06/23/2014] [Accepted: 07/03/2014] [Indexed: 11/20/2022]
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Lee HU, Yamazaki Y, Tanaka KF, Furuya K, Sokabe M, Hida H, Takao K, Miyakawa T, Fujii S, Ikenaka K. Increased astrocytic ATP release results in enhanced excitability of the hippocampus. Glia 2012; 61:210-24. [PMID: 23018918 DOI: 10.1002/glia.22427] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 09/04/2012] [Indexed: 11/05/2022]
Abstract
Astrocytes, a major subtype of glia, interact with neurons as a supportive partner supplying energy sources and growth factors. Astrocytes regulate the activity of neighboring neurons by releasing chemical transmitters (gliotransmitters). However, the precise role of gilotransmitters in regulating neuronal activity is still under debate. Here, we report that a subtle enhancement in the release of one gliotransmitter, ATP, affects synaptic potentiation from an analysis of mice containing an astrocyte-selective (GFAP) mutation. We found that, relative to normal mice, weaker stimulation induced long-term potentiation (LTP) in mutant mice, indicating that the threshold to induce LTP was lowered in the mutant. While excitatory transmission was normal in the mutant, inhibitory GABAergic transmission was suppressed. We found that a low concentration of adenosine selectively attenuated inhibitory neuronal activity and lowered the threshold to induce LTP in wild type mice. In comparison, adenosine A(1) receptor antagonism reversed the lowered LTP threshold back to normal in the mutant mouse. We verified that adenosine levels in the cerebrospinal fluid of mutant mice were slightly elevated compared to wild type mice. This was apparently caused by an increase in ATP release from mutant astrocytes that could provide a source of augmented adenosine levels in the mutant. ATP is thought to suppress the excitability of neuronal circuits; however, a small increase in ATP release can result in a suppressed inhibitory tone and enhanced excitability of neuronal circuitry. These findings demonstrate that ATP released from astrocytes acts in a bidirectional fashion to regulate neuronal excitability depending on concentration.
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Affiliation(s)
- Hae Ung Lee
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki 444-8787, Japan
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Saransaari P, Oja SS. Mechanisms of Inhibitory Amino Acid Release in the Brain Stem Under Normal and Ischemic Conditions. Neurochem Res 2010; 35:1948-56. [DOI: 10.1007/s11064-010-0265-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2010] [Indexed: 12/23/2022]
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Saransaari P, Oja SS. Adenosine receptor agonists affect taurine release from mouse brain stem slices in ischemia. Amino Acids 2009; 38:1387-93. [DOI: 10.1007/s00726-009-0351-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Accepted: 09/09/2009] [Indexed: 12/22/2022]
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18
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Mohammad-Zadeh M, Mirnajafi-Zadeh J, Fathollahi Y, Javan M, Jahanshahi A, Noorbakhsh SM, Motamedi F. The role of adenosine A(1) receptors in mediating the inhibitory effects of low frequency stimulation of perforant path on kindling acquisition in rats. Neuroscience 2008; 158:1632-43. [PMID: 19041928 DOI: 10.1016/j.neuroscience.2008.11.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 11/03/2008] [Accepted: 11/04/2008] [Indexed: 10/21/2022]
Abstract
Low frequency stimulation (LFS) has an inhibitory effect on rapid perforant path kindling acquisition. In the present study the role of adenosine A(1) and A(2A) receptors in mediating this inhibitory effect was investigated. Rats were kindled by perforant path stimulation using rapid kindling procedures (12 stimulations per day). LFS (0.1 ms pulse duration at 1 Hz, 200 pulses, and 50-150 muA) was applied to the perforant path immediately after termination of each rapid kindling stimulation. 1,3-Dimethyl-8-cyclopenthylxanthine (CPT; 50 muM), a selective A(1) antagonist and ZM241385 (ZM, 200 muM), a selective A(2A) antagonist were daily microinjected into the lateral ventricle 5 min before kindling stimulations. LFS had an inhibitory effect on kindling development. Pretreatment of animals with CPT reduced the inhibitory effect of LFS on kindling rate and suppressed the effects of LFS on potentiation of population EPSP during kindling acquisition. In addition, CPT was able to antagonize the effects of LFS on kindling-induced increase in early (10-50 ms intervals) and late (300-1000 ms intervals) paired pulse depression. ZM pretreatment had no effect on antiepileptogenic effects of LFS in kindling acquisition. In addition, LFS prevented the kindling-induced elevation of cyclic AMP (cAMP) levels in kindled animals. Based on these results, we suggest that the antiepileptogenic effects of LFS on perforant path kindling might be mediated through activation of adenosine A(1), but not A(2A) receptors. Moreover, modulation of cAMP levels by LFS may potentially be an important mechanism which explains the anticonvulsant effects of LFS in kindled seizures.
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Affiliation(s)
- M Mohammad-Zadeh
- Department of Physiology, School of Medical Sciences, Tarbiat Modares University, Tehran, IR Iran
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Hertz L. Bioenergetics of cerebral ischemia: a cellular perspective. Neuropharmacology 2008; 55:289-309. [PMID: 18639906 DOI: 10.1016/j.neuropharm.2008.05.023] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 05/14/2008] [Accepted: 05/14/2008] [Indexed: 12/27/2022]
Abstract
In cerebral ischemia survival of neurons, astrocytes, oligodendrocytes and endothelial cells is threatened during energy deprivation and/or following re-supply of oxygen and glucose. After a brief summary of characteristics of different cells types, emphasizing the dependence of all on oxidative metabolism, the bioenergetics of focal and global ischemia is discussed, distinguishing between events during energy deprivation and subsequent recovery attempt after re-circulation. Gray and white matter ischemia are described separately, and distinctions are made between mature and immature brains. Next comes a description of bioenergetics in individual cell types in culture during oxygen/glucose deprivation or exposure to metabolic inhibitors and following re-establishment of normal aerated conditions. Due to their expression of NMDA and non-NMDA receptors neurons and oligodendrocytes are exquisitely sensitive to excitotoxicity by glutamate, which reaches high extracellular concentrations in ischemic brain for several reasons, including failing astrocytic uptake. Excitotoxicity kills brain cells by energetic exhaustion (due to Na(+) extrusion after channel-mediated entry) combined with mitochondrial Ca(2+)-mediated injury and formation of reactive oxygen species. Many (but not all) astrocytes survive energy deprivation for extended periods, but after return to aerated conditions they are vulnerable to mitochondrial damage by cytoplasmic/mitochondrial Ca(2+) overload and to NAD(+) deficiency. Ca(2+) overload is established by reversal of Na(+)/Ca(2+) exchangers following Na(+) accumulation during Na(+)-K(+)-Cl(-) cotransporter stimulation or pH regulation, compensating for excessive acid production. NAD(+) deficiency inhibits glycolysis and eventually oxidative metabolism, secondary to poly(ADP-ribose)polymerase (PARP) activity following DNA damage. Hyperglycemia can be beneficial for neurons but increases astrocytic death due to enhanced acidosis.
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Affiliation(s)
- Leif Hertz
- College of Basic Medical Sciences, China Medical University, Shenyang, PR China.
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Cunha-Reis D, Ribeiro JA, Sebastião AM. A1 and A2A receptor activation by endogenous adenosine is required for VIP enhancement of K+-evoked [3H]-GABA release from rat hippocampal nerve terminals. Neurosci Lett 2008; 430:207-12. [DOI: 10.1016/j.neulet.2007.10.037] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 10/10/2007] [Accepted: 10/30/2007] [Indexed: 11/28/2022]
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GABA Release Under Normal and Ischemic Conditions. Neurochem Res 2007; 33:962-9. [DOI: 10.1007/s11064-007-9499-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Accepted: 08/31/2007] [Indexed: 11/26/2022]
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Saransaari P, Oja SS. Characteristics of GABA Release Induced by Free Radicals in Mouse Hippocampal Slices. Neurochem Res 2007; 33:384-93. [PMID: 17712630 DOI: 10.1007/s11064-007-9439-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2007] [Accepted: 07/09/2007] [Indexed: 10/22/2022]
Abstract
The release of the inhibitory neurotransmitter GABA is generally enhanced under potentially cell-damaging conditions. The properties and regulation of preloaded [3H]GABA release from mouse hippocampal slices were now studied in free radical-containing medium in a superfusion system. Free radical production was induced by 0.01% of H2O2 in the medium. H2O2 markedly potentiated GABA release, which was further enhanced about 1.5-fold by K+ stimulation (50 mM). In Ca2+-free media this stimulation was not altered, indicating that the release was mostly Ca2+-independent. Moreover, omission of Na+ increased the release, suggesting that it is mediated by Na+-dependent transporters operating outwards, a conception confirmed by the enhancement with GABA homoexchange. Inhibition of the release with the ion channel inhibitors diisothiocyanostilbene-2,2'-disulphonate and 4-acetamido-4'-isothiocyanostilbene-2,2'-disulphonate indicates that Cl(-) channels also participate in the process. This release was not modified by the adenosine receptor (A1 and A2a) agonists and ionotropic glutamate receptor agonists kainate, N-methy-D: -aspartate and 2-amino-3-hydroxy-5-methyl-4-isoxazolepropionate, whereas the agonists of metabotropic glutamate receptors of group I [(S)-3,5-dihydroxyphenylglycine] and of group II [(2R,4R)-4-aminopyrrolidine-2,4-dicarboxylate] enhanced it by receptor-mediated mechanisms, the effects being abolished by their respective antagonists. The group III agonist L+-2-amino-4-phosphonobutyrate reduced the evoked GABA release, but this was not affected by the antagonist. Furthermore, the release was reduced by activation of protein kinase C by 4 beta-phorbol 12-myristate 13-acetate and by inhibition of tyrosine kinase by genistein and of phoshoplipase by quinacrine. On the other hand, increasing cGMP levels with the phosphodiesterase inhibitor zaprinast, selective for PDE5, 6 and 9, and NO production with the NO-generating compounds hydroxylamine, sodium nitroprusside and S-nitroso-N-penicillamine enhanced the release. The regulation of GABA release induced by free radical production proved thus to be rather complex. Under potentially cell-damaging conditions, the potentiation of GABA release may be a mechanism to counteract hyperactivity and reduce the effects of excitatory amino acid release. On the other hand, reduction of GABA release could be harmful and contribute to excitotoxic damage and neuronal degeneration.
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Affiliation(s)
- Pirjo Saransaari
- Tampere Brain Research Center, Medical School, University of Tampere, Tampere 33014, Finland.
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Taranukhin AG, Taranukhina EY, Saransaari P, Djatchkova IM, Pelto-Huikko M, Oja SS. Taurine reduces caspase-8 and caspase-9 expression induced by ischemia in the mouse hypothalamic nuclei. Amino Acids 2007; 34:169-74. [PMID: 17297564 DOI: 10.1007/s00726-006-0405-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2006] [Accepted: 08/23/2006] [Indexed: 02/03/2023]
Abstract
Taurine is a sulphur-containing amino acid abundant in the nervous system. It protects cells from ischemia-induced apoptosis, but the mechanism underlying this is not well established. The aim of our study was to explore the effects of taurine on two main pathways of apoptosis induced by ischemia: receptor-mediated and mitochondrial cell death. Brain slices containing the supraoptic (SON) and paraventricular (PVN) nuclei of the hypothalamus were incubated in vitro under control and simulated ischemic (oxygen-glucose deprivation for 30 min) conditions in the absence and presence of 20 mM taurine. Brain slices were harvested after the 180-min "postischemic" period and fixed in 4% paraformaldehyde. To estimate apoptosis, immunostaining was done for caspase-8 and caspase-9 in paraffin-embedded sections. Immunoreactive caspase-8 and caspase-9 cells were observed in SON and PVN in all experimental groups, but in the "ischemic" group the expression of caspase-8 and caspase-9 and the number of immunoreactive cells was significantly increased in both hypothalamic nuclei. Addition of taurine (20 mM) to the incubation medium induced a marked decrease in caspase-8 and caspase-9 immunoreactivity after ischemia in SON and PVN when compared with the taurine-untreated "ischemic" group. Taurine reduces ischemia-induced caspase-8 and caspase-9 expression, the key inductors of apoptosis in SON and PVN.
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Affiliation(s)
- A G Taranukhin
- Brain Research Center, University of Tampere Medical School, Tampere, Finland.
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