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Harkins J, Langston J, Keith ZM, Munoz C, Acon-Chen C, Shih TM. Learning and memory function preserved by delayed A 1 adenosine receptor agonist treatment following soman intoxication in rats and a humanized esterase mouse model. Neuropharmacology 2024; 253:109983. [PMID: 38704023 PMCID: PMC11132435 DOI: 10.1016/j.neuropharm.2024.109983] [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: 01/09/2024] [Revised: 04/23/2024] [Accepted: 05/01/2024] [Indexed: 05/06/2024]
Abstract
Exposure to organophosphorus compounds, such as soman (GD), cause widespread toxic effects, sustained status epilepticus, neuropathology, and death. The A1 adenosine receptor agonist N-bicyclo-(2.2.1)-hept-2-yl-5'-chloro-5'-deoxyadenosine (ENBA), when given 1 min after GD exposure, provides neuroprotection and prevents behavioral impairments. Here, we tested the ability of ENBA at delayed treatment times to improve behavioral outcomes via a two-way active avoidance task in two male animal models, each consisting of saline and GD exposure groups. In a rat model, animals received medical treatments (atropine sulfate [A], 2-PAM [P], and midazolam [MDZ]) or AP + MDZ + ENBA at 15 or 30 min after seizure onset and were subjected to behavioral testing for up to 14 days. In a human acetylcholinesterase knock-in serum carboxylesterase knock-out mouse model, animals received AP, AP + MDZ, AP + ENBA, or AP + MDZ + ENBA at 15 min post seizure onset and were subjected to the behavioral task on days 7 and 14. In rats, the GD/AP + MDZ + ENBA group recovered to saline-exposed avoidance levels while the GD/AP + MDZ group did not. In mice, in comparison with GD/AP + MDZ group, the GD/AP + MDZ + ENBA showed decreases in escape latency, response latency, and pre-session crossings, as well as increases in avoidances. In both models, only ENBA-treated groups showed control level inter-trial interval crossings by day 14. Our findings suggest that ENBA, alone and as an adjunct to medical treatments, can improve behavioral and cognitive outcomes when given at delayed time points after GD intoxication.
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Affiliation(s)
- Joshua Harkins
- Medical Toxicology Research Division, U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD, 21010-5400, USA.
| | - Jeffrey Langston
- Medical Toxicology Research Division, U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD, 21010-5400, USA.
| | - Zora-Maya Keith
- Medical Toxicology Research Division, U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD, 21010-5400, USA.
| | - Crystal Munoz
- Medical Toxicology Research Division, U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD, 21010-5400, USA.
| | - Cindy Acon-Chen
- Medical Toxicology Research Division, U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD, 21010-5400, USA.
| | - Tsung-Ming Shih
- Medical Toxicology Research Division, U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD, 21010-5400, USA.
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Munoz C, Acon-Chen C, Keith ZM, Shih TM. Hypothermia as potential therapeutic approach to attenuating soman-induced seizure, neuropathology, and mortality with an adenosine A 1 receptor agonist and body cooling. Neuropharmacology 2024; 253:109966. [PMID: 38677446 PMCID: PMC11197881 DOI: 10.1016/j.neuropharm.2024.109966] [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: 01/04/2024] [Revised: 04/14/2024] [Accepted: 04/19/2024] [Indexed: 04/29/2024]
Abstract
Organophosphorus nerve agents, such as soman (GD), produce excitotoxic effects resulting in sustained status epilepticus (SSE) and brain damage. Previous work shows that neuronal inhibitory effects of A1 adenosine receptor (A1AR) agonists, such as N6- Bicyclo (2.2.1)-hept-2-yl-5'-chloro-5'-deoxyadenosine (Cl-ENBA), suppresses GD-induced SSE and improves neuropathology. Some other physiologic effects of these agonists are hypothermia, hypotension, and sedation. Hypothermia may also shield the brain from injury by slowing down chemical insults, lessening inflammation, and contributing to improved neurological outcomes. Therefore, we attempted to isolate the hypothermic effect from ENBA by assessing the neuroprotective efficacy of direct surface body cooling in a rat GD-induced SSE model, and comparing the effects on seizure termination, neuropathology, and survival. Male rats implanted with a body temperature (Tb) transponder and electroencephalographic (EEG) electrodes were primed with asoxime (HI-6), exposed to GD 30 min later, and then treated with Cl-ENBA or had Tb lowered directly via body cooling at 30 min after the onset of seizure activity. Afterwards, they were either allowed to develop hypothermia as expected, or received thermal support to maintain normothermic Tb for a period of 6-h. Neuropathology was assessed at 24 h. Regardless of Cl-ENBA or surface cooling, all hypothermic GD-exposed groups had significantly improved 24-h survival compared to rats with normothermic Tb (81% vs. 39%, p < 0.001). Cl-ENBA offered neuroprotection independently of hypothermic Tb. While hypothermia enhanced the overall efficacy of Cl-ENBA by improving survival outcomes, body cooling didn't reduce seizure activity or neuropathology following GD-induced SSE.
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Affiliation(s)
- Crystal Munoz
- Neuroscience Department, Medical Toxicology Research Division, U.S. Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, 21010-5400, USA
| | - Cindy Acon-Chen
- Neuroscience Department, Medical Toxicology Research Division, U.S. Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, 21010-5400, USA
| | - Zora-Maya Keith
- Neuroscience Department, Medical Toxicology Research Division, U.S. Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, 21010-5400, USA
| | - Tsung-Ming Shih
- Neuroscience Department, Medical Toxicology Research Division, U.S. Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, 21010-5400, USA.
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Zhang L, Liu J, Liu M. Transsynaptic degeneration of ventral horn motor neurons exists but plays a minor role in lower motor system dysfunction in acute ischemic rats. PLoS One 2024; 19:e0298006. [PMID: 38669239 PMCID: PMC11051614 DOI: 10.1371/journal.pone.0298006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 01/16/2024] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND As a leading cause of mortality and long-term disability, acute ischemic stroke can produce far-reaching pathophysiological consequences. Accumulating evidence has demonstrated abnormalities in the lower motor system following stroke, while the existence of Transsynaptic degeneration of contralateral spinal cord ventral horn (VH) neurons is still debated. METHODS Using a rat model of acute ischemic stroke, we analyzed spinal cord VH neuron counts contralaterally and ipsilaterally after stroke with immunofluorescence staining. Furthermore, we estimated the overall lower motor unit abnormalities after stroke by simultaneously measuring the modified neurological severity score (mNSS), compound muscle action potential (CMAP) amplitude, repetitive nerve stimulation (RNS), spinal cord VH neuron counts, and the corresponding muscle fiber morphology. The activation status of microglia and extracellular signal-regulated kinase 1/2 (ERK 1/2) in the spinal cord VH was also assessed. RESULTS At 7 days after stroke, the contralateral CMAP amplitudes declined to a nadir indicating lower motor function damage, and significant muscle disuse atrophy was observed on the same side; meanwhile, the VH neurons remained intact. At 14 days after focal stroke, lower motor function recovered with alleviated muscle disuse atrophy, while transsynaptic degeneration occurred on the contralateral side with elevated activation of ERK 1/2, along with the occurrence of neurogenic muscle atrophy. No apparent decrement of CMAP amplitude was observed with RNS during the whole experimental process. CONCLUSIONS This study offered an overview of changes in the lower motor system in experimental ischemic rats. We demonstrated that transsynaptic degeneration of contralateral VH neurons occurred when lower motor function significantly recovered, which indicated the minor role of transsynaptic degeneration in lower motor dysfunction during the acute and subacute phases of focal ischemic stroke.
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Affiliation(s)
- Lei Zhang
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Jingwen Liu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Mingsheng Liu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
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Grubišić V, Perez-Medina AL, Fried DE, Sévigny J, Robson SC, Galligan JJ, Gulbransen BD. NTPDase1 and -2 are expressed by distinct cellular compartments in the mouse colon and differentially impact colonic physiology and function after DSS colitis. Am J Physiol Gastrointest Liver Physiol 2019; 317:G314-G332. [PMID: 31188623 PMCID: PMC6774087 DOI: 10.1152/ajpgi.00104.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
ATP is both an important mediator of physiological gut functions such as motility and epithelial function, and a key danger signal that mediates cell death and tissue damage. The actions of extracellular ATP are regulated through the catalytic functions extracellular nucleoside triphosphate diphosphohydrolase-1 (NTPDase1), -2, -3, and -8, which ultimately generate nucleosides. Ectonucleotidases have distinct cellular associations, but the specific locations and functional roles of individual NTPDases in the intestine are still poorly understood. Here, we tested the hypothesis that differential and cell-selective regulation of purine hydrolysis by NTPDase1 and -2 plays important roles in gut physiology and disease. We studied Entpd1 and Entpd2 null mice in health and following colitis driven by 2% dextran sulfate sodium (DSS) administration using functional readouts of gut motility, epithelial barrier function, and neuromuscular communication. NTPDase1 is expressed by immune cells, and the ablation of Entpd1 altered glial numbers in the myenteric plexus. NTPDase2 is expressed by enteric glia, and the ablation of Entpd2 altered myenteric neuron numbers. Mice lacking either NTPDase1 or -2 exhibited decreased inhibitory neuromuscular transmission and altered components of inhibitory junction potentials. Ablation of Entpd2 increased gut permeability following inflammation. In conclusion, the location- and context-dependent extracellular nucleotide phosphohydrolysis by NTPDase1 and -2 substantially impacts gut function in health and disease.NEW & NOTEWORTHY Purines are important mediators of gastrointestinal physiology and pathophysiology. Nucleoside triphosphate diphosphohydrolases (NTPDases) regulate extracellular purines, but the roles of specific NTPDases in gut functions are poorly understood. Here, we used Entpd1- and Entpd2-deficient mice to show that the differential and cell-selective regulation of purine hydrolysis by NTPDase1 and -2 plays important roles in barrier function, gut motility, and neuromuscular communication in health and disease.
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Affiliation(s)
- Vladimir Grubišić
- 1Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Alberto L. Perez-Medina
- 2Department of Pharmacology and Toxicology and Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - David E. Fried
- 1Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Jean Sévigny
- 3Centre de recherche du CHU de Québec–Université Laval, Québec City, Quebec, Canada,4Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec City, Quebec, Canada
| | - Simon C. Robson
- 5Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - James J. Galligan
- 2Department of Pharmacology and Toxicology and Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Brian D. Gulbransen
- 1Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan
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5
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Fleischer LM, Somaiya RD, Miller GM. Review and Meta-Analyses of TAAR1 Expression in the Immune System and Cancers. Front Pharmacol 2018; 9:683. [PMID: 29997511 PMCID: PMC6029583 DOI: 10.3389/fphar.2018.00683] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 06/06/2018] [Indexed: 12/29/2022] Open
Abstract
Since its discovery in 2001, the major focus of TAAR1 research has been on its role in monoaminergic regulation, drug-induced reward and psychiatric conditions. More recently, TAAR1 expression and functionality in immune system regulation and immune cell activation has become a topic of emerging interest. Here, we review the immunologically-relevant TAAR1 literature and incorporate open-source expression and cancer survival data meta-analyses. We provide strong evidence for TAAR1 expression in the immune system and cancers revealed through NCBI GEO datamining and discuss its regulation in a spectrum of immune cell types as well as in numerous cancers. We discuss connections and logical directions for further study of TAAR1 in immunological function, and its potential role as a mediator or modulator of immune dysregulation, immunological effects of psychostimulant drugs of abuse, and cancer progression.
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Affiliation(s)
- Lisa M Fleischer
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, United States
| | - Rachana D Somaiya
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, United States
| | - Gregory M Miller
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, United States.,Department of Chemical Engineering, Northeastern University, Boston, MA, United States.,Center for Drug Discovery, Northeastern University, Boston, MA, United States
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6
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Gubert C, Jacintho Moritz CE, Vasconcelos-Moreno MP, Quadros Dos Santos BTM, Sartori J, Fijtman A, Kauer-Sant'Anna M, Kapczinski F, Battastini AMO, Magalhães PVDS. Peripheral adenosine levels in euthymic patients with bipolar disorder. Psychiatry Res 2016; 246:421-426. [PMID: 27788463 DOI: 10.1016/j.psychres.2016.10.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 08/23/2016] [Accepted: 10/05/2016] [Indexed: 12/19/2022]
Abstract
Recent evidence points to the involvement of the purinergic signaling in the pathophysiology of bipolar disorder. The aim of this study was to assess the serum levels of adenosine and to evaluate its relation to functioning in 24 euthymic patients with bipolar disorder type I and in 25 matched healthy controls. Subjects were evaluated using the functioning assessment short test. Serum purine levels were measured by high pressure liquid chromatography. Our results show a decrease in serum adenosine levels in bipolar disorder patients compared with controls (t= -4.8, df= 43.96, p<0.001). Moreover, a significant negative correlation was found between patient adenosine levels and depression scale scores (r= -0.642, p= 0.001). Higher functional impairment was linked to lower levels of adenosine in patients (rho= -0.551, p= 0.008). Taken together, our results provide evidence for a purinergic imbalance in bipolar disorder, specifically an adenosinergic dysfunction. Our results also indicate a relation between adenosine levels and the functional impairment caused by the disorder, which could demonstrate a potential relation of adenosine levels in worsening of symptoms.
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Affiliation(s)
- Carolina Gubert
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, 90035-003 Porto Alegre, RS, Brazil
| | - Cesar Eduardo Jacintho Moritz
- Programa de Pós-Graduação em Medicina: Ciências Médicas, Universidade Federal do Rio Grande do Sul, Hospital de Clínicas de Porto Alegre, 90035-903, Porto Alegre, RS, Brazil
| | - Mirela Paiva Vasconcelos-Moreno
- Bipolar Disorder Program and Laboratory of Molecular Psychiatry, Hospital de Clínicas de Porto Alegre, 90035-003, Porto Alegre, RS, Brazil
| | | | - Juliana Sartori
- Bipolar Disorder Program and Laboratory of Molecular Psychiatry, Hospital de Clínicas de Porto Alegre, 90035-003, Porto Alegre, RS, Brazil
| | - Adam Fijtman
- Bipolar Disorder Program and Laboratory of Molecular Psychiatry, Hospital de Clínicas de Porto Alegre, 90035-003, Porto Alegre, RS, Brazil
| | - Márcia Kauer-Sant'Anna
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, 90035-003 Porto Alegre, RS, Brazil; Bipolar Disorder Program and Laboratory of Molecular Psychiatry, Hospital de Clínicas de Porto Alegre, 90035-003, Porto Alegre, RS, Brazil; INCT of Translational Medicine, Hospital de Clínicas de Porto Alegre, 90035-903 RS, Brazil; Departamento de Psiquiatria, Universidade Federal Rio Grande do Sul, 90035-903 RS, Brazil
| | - Flávio Kapczinski
- Bipolar Disorder Program and Laboratory of Molecular Psychiatry, Hospital de Clínicas de Porto Alegre, 90035-003, Porto Alegre, RS, Brazil; INCT of Translational Medicine, Hospital de Clínicas de Porto Alegre, 90035-903 RS, Brazil; Departamento de Psiquiatria, Universidade Federal Rio Grande do Sul, 90035-903 RS, Brazil
| | - Ana Maria Oliveira Battastini
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, 90035-003 Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Medicina: Ciências Médicas, Universidade Federal do Rio Grande do Sul, Hospital de Clínicas de Porto Alegre, 90035-903, Porto Alegre, RS, Brazil.
| | - Pedro Vieira da Silva Magalhães
- Bipolar Disorder Program and Laboratory of Molecular Psychiatry, Hospital de Clínicas de Porto Alegre, 90035-003, Porto Alegre, RS, Brazil; INCT of Translational Medicine, Hospital de Clínicas de Porto Alegre, 90035-903 RS, Brazil; Departamento de Psiquiatria, Universidade Federal Rio Grande do Sul, 90035-903 RS, Brazil.
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Caravan I, Sevastre Berghian A, Moldovan R, Decea N, Orasan R, Filip GA. Modulatory effects of caffeine on oxidative stress and anxiety-like behavior in ovariectomized rats. Can J Physiol Pharmacol 2016; 94:961-72. [DOI: 10.1139/cjpp-2015-0502] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Menopause is accompanied by enhanced oxidative stress and behavioral changes, effects attenuated by antioxidants. The aim of this study was to evaluate the effects of caffeine on behavior and oxidative stress in an experimental model of menopause. Female rats were divided into the following groups: sham-operated (CON), sham-operated and caffeine-treated (CAF), ovariectomized (OVX), ovariectomized and caffeine-treated (OVX+CAF). Caffeine (6 mg/kg) and vehicle were administered for 21 days (subchronic) and 42 days (chronic), using 2 experimental subsets. Behavioral tests and oxidative stress parameters in the blood, whole brain, and hippocampus were assessed. The subchronic administration of caffeine decreased the lipid peroxidation and improved the antioxidant defense in the blood and brain. The GSH/GGSG ratio in the brain was improved by chronic administration, with reduced activities of antioxidant enzymes and enhanced nitric oxide and malondialdehyde levels. In particular, the lipid peroxidation in the hippocampus decreased in both experiments. The rats became hyperactive after 21 days of treatment, but no effect was observed after chronic administration. In both experimental subsets, caffeine had anxiolytic effects as tested in elevated plus maze. The administration of low doses of caffeine, for a short period of time, may be a new therapeutic approach to modulating the oxidative stress and anxiety in menopause.
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Affiliation(s)
- Ionut Caravan
- Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 1 Clinicilor Street, 400006 Cluj-Napoca, Romania
- Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 1 Clinicilor Street, 400006 Cluj-Napoca, Romania
| | - Alexandra Sevastre Berghian
- Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 1 Clinicilor Street, 400006 Cluj-Napoca, Romania
- Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 1 Clinicilor Street, 400006 Cluj-Napoca, Romania
| | - Remus Moldovan
- Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 1 Clinicilor Street, 400006 Cluj-Napoca, Romania
- Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 1 Clinicilor Street, 400006 Cluj-Napoca, Romania
| | - Nicoleta Decea
- Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 1 Clinicilor Street, 400006 Cluj-Napoca, Romania
- Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 1 Clinicilor Street, 400006 Cluj-Napoca, Romania
| | - Remus Orasan
- Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 1 Clinicilor Street, 400006 Cluj-Napoca, Romania
- Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 1 Clinicilor Street, 400006 Cluj-Napoca, Romania
| | - Gabriela Adriana Filip
- Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 1 Clinicilor Street, 400006 Cluj-Napoca, Romania
- Department of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 1 Clinicilor Street, 400006 Cluj-Napoca, Romania
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8
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Haghani M, Keshavarz S, Nazari M, Rafati A. Electrophysiology of cerebral ischemia and reperfusion: First evidence for the role of synapse in ischemic tolerance. Synapse 2016; 70:351-60. [PMID: 27124112 DOI: 10.1002/syn.21910] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 04/24/2016] [Accepted: 04/26/2016] [Indexed: 01/08/2023]
Abstract
OBJECTIVE The subthreshold brain-damaging stimulus may protect the brain from subsequent ischemia; this phenomenon has been named "ischemic tolerance" (IT). We focused on the synaptic properties of the neurons after mild and severe ischemia to determine the association between IT and synaptic efficacy. EXPERIMENTAL DESIGN Adult male rats were randomly divided into four experimental groups including control, sham, permanent ischemia (pI/R), and mild ischemia (mI/R). Middle cerebral artery occlusion (MCAO) method was applied to induce brain ischemia. Seven days after the insult, long-term potentiation (LTP) induced by high-frequency stimulation (HFS) and paired-pulse ratio (PPR) were monitored before and after the HFS delivery. RESULTS The field potential recording demonstrated that mild ischemia significantly increased the basal synaptic transmission. Additionally, the HFS produced a significant potentiation compared to its baseline level in the mI/R group. Moreover, mild ischemia prevented depression of PPR by HFS. This effect was accompanied by a significant increase in the normalized PPR (PPR after HFS/PPR before HFS) in this group. CONCLUSIONS Our data indicated that a mild reduction in brain perfusion without permanent lesion can dramatically increase the basal synaptic transmission. This effect may be associated with an increase in the neurotransmitter content of the pre-synaptic neurons. This hypothesis could provide a new insight into the relationship between IT and synaptic efficacy. Synapse 70:351-360, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Masoud Haghani
- Department of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran.,Histomorphometry and Stereology Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Somaye Keshavarz
- Department of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Maryam Nazari
- Department of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ali Rafati
- Department of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran.,Histomorphometry and Stereology Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran
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9
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Dar MS. Ethanol-Induced Cerebellar Ataxia: Cellular and Molecular Mechanisms. THE CEREBELLUM 2016; 14:447-65. [PMID: 25578036 DOI: 10.1007/s12311-014-0638-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The cerebellum is an important target of ethanol toxicity given that cerebellar ataxia is the most consistent physical manifestation of acute ethanol consumption. Despite the significance of the cerebellum in ethanol-induced cerebellar ataxia (EICA), the cellular and molecular mechanisms underlying EICA are incompletely understood. However, two important findings have shed greater light on this phenomenon. First, ethanol-induced blockade of cerebellar adenosine uptake in rodent models points to a role for adenosinergic A1 modulation of EICA. Second, the consistent observation that intracerebellar administration of nicotine in mice leads to antagonism of EICA provides evidence for a critical role of cerebellar nitric oxide (NO) in EICA reversal. Based on these two important findings, this review discusses the potential molecular events at two key synaptic sites (mossy fiber-granule cell-Golgi cell (MGG synaptic site) and granule cell parallel fiber-Purkinje cell (GPP synaptic site) that lead to EICA. Specifically, ethanol-induced neuronal NOS inhibition at the MGG synaptic site acts as a critical trigger for Golgi cell activation which leads to granule cell deafferentation. Concurrently, ethanol-induced inhibition of adenosine uptake at the GPP synaptic site produces adenosine accumulation which decreases glutamate release and leads to the profound activation of Purkinje cells (PCs). These molecular events at the MGG and GPP synaptic sites are mutually reinforcing and lead to cerebellar dysfunction, decreased excitatory output of deep cerebellar nuclei, and EICA. The critical importance of PCs as the sole output of the cerebellar cortex suggests normalization of PC function could have important therapeutic implications.
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Affiliation(s)
- M Saeed Dar
- Department of Pharmacology and Toxicology, Brody School of Medicine, East Carolina University, Greenville, NC, 27858, USA,
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10
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Carlin JL, Tosh DK, Xiao C, Piñol RA, Chen Z, Salvemini D, Gavrilova O, Jacobson KA, Reitman ML. Peripheral Adenosine A3 Receptor Activation Causes Regulated Hypothermia in Mice That Is Dependent on Central Histamine H1 Receptors. J Pharmacol Exp Ther 2016; 356:474-82. [PMID: 26606937 PMCID: PMC4746492 DOI: 10.1124/jpet.115.229872] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 11/23/2015] [Indexed: 11/22/2022] Open
Abstract
Adenosine can induce hypothermia, as previously demonstrated for adenosine A1 receptor (A1AR) agonists. Here we use the potent, specific A3AR agonists MRS5698, MRS5841, and MRS5980 to show that adenosine also induces hypothermia via the A3AR. The hypothermic effect of A3AR agonists is independent of A1AR activation, as the effect was fully intact in mice lacking A1AR but abolished in mice lacking A3AR. A3AR agonist-induced hypothermia was attenuated by mast cell granule depletion, demonstrating that the A3AR hypothermia is mediated, at least in part, via mast cells. Central agonist dosing had no clear hypothermic effect, whereas peripheral dosing of a non-brain-penetrant agonist caused hypothermia, suggesting that peripheral A3AR-expressing cells drive the hypothermia. Mast cells release histamine, and blocking central histamine H1 (but not H2 or H4) receptors prevented the hypothermia. The hypothermia was preceded by hypometabolism and mice with hypothermia preferred a cooler environmental temperature, demonstrating that the hypothermic state is a coordinated physiologic response with a reduced body temperature set point. Importantly, hypothermia is not required for the analgesic effects of A3AR agonists, which occur with lower agonist doses. These results support a mechanistic model for hypothermia in which A3AR agonists act on peripheral mast cells, causing histamine release, which stimulates central histamine H1 receptors to induce hypothermia. This mechanism suggests that A3AR agonists will probably not be useful for clinical induction of hypothermia.
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Affiliation(s)
- Jesse Lea Carlin
- Diabetes, Endocrinology, and Obesity Branch (J.L.C., C.X., R.A.P., M.L.R.), Molecular Recognition Section, Laboratory of Bioorganic Chemistry (D.K.T., K.A.J.), and Mouse Metabolism Core (O.G.), National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; and Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri (Z.C., D.S.)
| | - Dilip K Tosh
- Diabetes, Endocrinology, and Obesity Branch (J.L.C., C.X., R.A.P., M.L.R.), Molecular Recognition Section, Laboratory of Bioorganic Chemistry (D.K.T., K.A.J.), and Mouse Metabolism Core (O.G.), National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; and Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri (Z.C., D.S.)
| | - Cuiying Xiao
- Diabetes, Endocrinology, and Obesity Branch (J.L.C., C.X., R.A.P., M.L.R.), Molecular Recognition Section, Laboratory of Bioorganic Chemistry (D.K.T., K.A.J.), and Mouse Metabolism Core (O.G.), National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; and Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri (Z.C., D.S.)
| | - Ramón A Piñol
- Diabetes, Endocrinology, and Obesity Branch (J.L.C., C.X., R.A.P., M.L.R.), Molecular Recognition Section, Laboratory of Bioorganic Chemistry (D.K.T., K.A.J.), and Mouse Metabolism Core (O.G.), National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; and Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri (Z.C., D.S.)
| | - Zhoumou Chen
- Diabetes, Endocrinology, and Obesity Branch (J.L.C., C.X., R.A.P., M.L.R.), Molecular Recognition Section, Laboratory of Bioorganic Chemistry (D.K.T., K.A.J.), and Mouse Metabolism Core (O.G.), National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; and Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri (Z.C., D.S.)
| | - Daniela Salvemini
- Diabetes, Endocrinology, and Obesity Branch (J.L.C., C.X., R.A.P., M.L.R.), Molecular Recognition Section, Laboratory of Bioorganic Chemistry (D.K.T., K.A.J.), and Mouse Metabolism Core (O.G.), National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; and Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri (Z.C., D.S.)
| | - Oksana Gavrilova
- Diabetes, Endocrinology, and Obesity Branch (J.L.C., C.X., R.A.P., M.L.R.), Molecular Recognition Section, Laboratory of Bioorganic Chemistry (D.K.T., K.A.J.), and Mouse Metabolism Core (O.G.), National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; and Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri (Z.C., D.S.)
| | - Kenneth A Jacobson
- Diabetes, Endocrinology, and Obesity Branch (J.L.C., C.X., R.A.P., M.L.R.), Molecular Recognition Section, Laboratory of Bioorganic Chemistry (D.K.T., K.A.J.), and Mouse Metabolism Core (O.G.), National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; and Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri (Z.C., D.S.)
| | - Marc L Reitman
- Diabetes, Endocrinology, and Obesity Branch (J.L.C., C.X., R.A.P., M.L.R.), Molecular Recognition Section, Laboratory of Bioorganic Chemistry (D.K.T., K.A.J.), and Mouse Metabolism Core (O.G.), National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; and Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri (Z.C., D.S.)
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Bondan EF, Martins MDFM, Bernardi MM. Propentofylline reverses delayed remyelination in streptozotocin-induced diabetic rats. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2015; 59:47-53. [DOI: 10.1590/2359-3997000000009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Accepted: 10/16/2014] [Indexed: 11/22/2022]
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12
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Giunta S, Andriolo V, Castorina A. Dual blockade of the A1 and A2A adenosine receptor prevents amyloid beta toxicity in neuroblastoma cells exposed to aluminum chloride. Int J Biochem Cell Biol 2014; 54:122-36. [PMID: 25058312 DOI: 10.1016/j.biocel.2014.07.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 06/25/2014] [Accepted: 07/11/2014] [Indexed: 02/06/2023]
Abstract
In a previous work we have shown that exposure to aluminum (Al) chloride (AlCl3) enhanced the neurotoxicity of the amyloid beta(25-35) fragment (Abeta(25-35)) in neuroblastoma cells and affected the expression of Alzheimer's disease (AD)-related genes. Caffein, a compound endowed with beneficial effects against AD, exerts neuroprotection primarily through its antagonist activity on A2A adenosine receptors (A2AR), although it also inhibits A1Rs with similar potency. Still, studies on the specific involvement of these receptors in neuroprotection in a model of combined neurotoxicity (Abeta(25-35)+AlCl3) are missing. To address this issue, cultured SH-SY5Y cells exposed to Abeta(25-35)+AlCl3 were assessed for cell viability, morphology, intracellular ROS activity and expression of apoptosis-, stress- and AD-related proteins. To define the role of A1R and A2ARs, pretreatment with caffein, specific receptor antagonists (DPCPX or SCH58261) or siRNA-mediated gene knockdown were delivered. Results indicate that AlCl3 treatment exacerbated Abeta(25-35) toxicity, increased ROS production, lipid peroxidation, β-secretase-1 (BACE1) and amyloid precursor protein (APP). Interestingly, SCH58261 successfully prevented toxicity associated to Abeta(25-35) only, whereas pretreatment with both DPCPX and SCH58261 was required to fully avert Abeta(25-35)+AlCl3-induced damage, suggesting that A1Rs might also be critically involved in protection during combined toxicity. The effects of caffein were mimicked by both N-acetyl cysteine, an antioxidant, and desferrioxamine, likely acting through distinct mechanisms. Altogether, our data establish a novel protective function associated with A1R inhibition in the setting of combined Abeta(25-35)+AlCl3 neurotoxicity, and expand our current knowledge on the potential beneficial role of caffein to prevent AD progression in subjects environmentally exposed to aluminum.
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Affiliation(s)
- Salvatore Giunta
- Department of Bio-Medical Sciences, Section of Anatomy and Histology, University of Catania, Italy
| | - Violetta Andriolo
- Department of Pediatrics and Public Health Sciences, University of Turin, Italy
| | - Alessandro Castorina
- Department of Bio-Medical Sciences, Section of Anatomy and Histology, University of Catania, Italy.
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13
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Bjerring PN, Dale N, Larsen FS. Acute Hyperammonemia and Systemic Inflammation is Associated with Increased Extracellular Brain Adenosine in Rats: A Biosensor Study. Neurochem Res 2014; 40:258-64. [DOI: 10.1007/s11064-014-1357-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 05/22/2014] [Accepted: 06/03/2014] [Indexed: 02/07/2023]
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14
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Thomas TP, Shih TM. Stimulation of central A1 adenosine receptors suppresses seizure and neuropathology in a soman nerve agent seizure rat model. Toxicol Mech Methods 2014; 24:385-95. [DOI: 10.3109/15376516.2014.920450] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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15
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Purinergic neuron-glia interactions in sensory systems. Pflugers Arch 2014; 466:1859-72. [DOI: 10.1007/s00424-014-1510-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 03/26/2014] [Accepted: 03/26/2014] [Indexed: 02/06/2023]
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16
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Bondan EF, Martins MDFM, Menezes Baliellas DE, Monteiro Gimenez CF, Castro Poppe S, Martha Bernardi M. Effects of propentofylline on CNS remyelination in the rat brainstem. Microsc Res Tech 2013; 77:23-30. [PMID: 24185688 DOI: 10.1002/jemt.22308] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 10/07/2013] [Accepted: 10/15/2013] [Indexed: 11/10/2022]
Abstract
Propentofylline (PPF) is a xanthine derivative with pharmacological effects distinct from those of the classical methylxanthines. It depresses activation of microglial cells and astrocytes which is associated with neuronal damage during neural inflammation and hypoxia. The aim of this study was to evaluate whether PPF had the capacity of affecting glial cells behavior during the process of demyelination and remyelination following ethidium bromide (EB) gliotoxic injury. EB injection into the CNS is commonly used as an experimental demyelinating model inducing local oligodendroglial and astrocytic death, which results in primary demyelination, blood-brain barrier and glia limitans disruption and Schwann cells invasion. Sixty Wistar rats were divided into four different groups receiving 10 microlitres of 0.1% EB or 0.9% saline solution into the cisterna pontis and treated or not with the xanthine. PPF treatment was done using 12.5 mg/kg/day by the intraperitonial route for 31 days of the experimental period. The rats were euthanized from 7 to 31 days after EB injection and brainstem sections were collected and processed for light and transmission electron microscopy studies. Results from both groups were compared by using a semi-quantitative method developed for documenting in semithin sections the extent and nature of remyelination of demyelinating lesions. Results showed that PPF administration after EB injection significantly increased both oligodendroglial and Schwann cell remyelination at 31 days (mean remyelination scores of 3.67 ± 0.5 for oligodendrocytes and 1.27 ± 0.49 for Schwann cells) compared to untreated animals (scores of 3.19 ± 0.57 and 0.90 ± 0.33, respectively).
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Affiliation(s)
- Eduardo Fernandes Bondan
- Department of Environmental and Experimental Pathology, University Paulista, São Paulo, SP, Brazil; Department of Veterinary Medicine, University Cruzeiro do Sul, São Paulo, SP, Brazil
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17
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Saeed Dar M. Functional role for mouse cerebellar NO/cGMP/KATP pathway in ethanol-induced ataxia. Alcohol Clin Exp Res 2013; 38:100-7. [PMID: 23905929 DOI: 10.1111/acer.12219] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 05/11/2013] [Indexed: 01/18/2023]
Abstract
BACKGROUND We have previously shown that brain adenosine A1 receptors and nitric oxide (NO) play an important role in ethanol (EtOH)-induced cerebellar ataxia (EICA) through glutamate/NO/cGMP pathway. I now report possible modulation of EICA by the cerebellar NO/cGMP/K(ATP) pathway. METHODS EICA was evaluated by Rotorod in CD-1 male mice. All drugs (K(ATP) activators pinacidil, 0.05, 0.1, 0.5 nmol; minoxidil, 0.01, 0.1, 1.0 pmol; antagonists glipizide/glibenclamide, 0.01, 0.05, 0.1 nmol; NO donor l-arginine, 20 nmol; NOS inhibitors [iNOS] inhibitor L-NAME, 50 nmol; glutamate, 1.5 nmol; adenosine A1 receptor agonist N(6) -cyclohexyladenosine [CHA], 6, 12 pmol; antagonist DPCPX, 0.1 or 0.4 nmol) were given by direct intracerebellar microinfusion via stereotaxically implanted guide cannulas, except EtOH (2 g/kg, i.p.). RESULTS Pinacidil and minoxidil dose-dependently accentuated, whereas glipizide and glibenclamide markedly attenuated EICA, indicating tonic participation of K(ATP) channels. Glipizide abolished the pinacidil potentiation of EICA, which confirmed both drugs acted via K(ATP) channels. A possible link between K(ATP) channels and glutamate/NO pathway was suggested when (i) CHA (12 pmol) totally abolished l-arginine-induced attenuation of EICA; (ii) L-NAME abolished l-arginine-induced attenuation of EICA associated with further increase in EICA; and (iii) the combined l-arginine and glutamate infusion virtually abolished EICA. Also, whereas CHA abolished glibenclamide-induced attenuation and potentiated pinacidil/minoxidil-induced accentuation of EICA, the effects of DPCPX were just the opposite to those of CHA. CONCLUSIONS The results with CHA therefore suggest a functional link between K(ATP) and A1 receptors and between K(ATP) and glutamate/NO and as an extension may involve participation of NO/cGMP/K(ATP) pathway in EICA.
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Affiliation(s)
- M Saeed Dar
- Department of Pharmacology, Brody School of Medicine, East Carolina University, Greenville, North Carolina
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18
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Zhong Y, Yang Z, Huang WC, Luo X. Adenosine, adenosine receptors and glaucoma: An updated overview. Biochim Biophys Acta Gen Subj 2013; 1830:2882-90. [DOI: 10.1016/j.bbagen.2013.01.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 12/21/2012] [Accepted: 01/07/2013] [Indexed: 01/30/2023]
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Genetically controlled upregulation of adenosine A(1) receptor expression enhances the survival of primary cortical neurons. Mol Neurobiol 2012; 46:535-44. [PMID: 22899189 DOI: 10.1007/s12035-012-8321-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 08/02/2012] [Indexed: 12/20/2022]
Abstract
Adenosine has a key endogenous neuroprotective role in the brain, predominantly mediated by the adenosine A(1) receptor (A(1)R). This has been mainly explored using pharmacological tools and/or receptor knockout mice strains. It has long been suggested that the neuroprotective effects of A(1)R are increased following receptor upregulation, thus attenuating neuronal damage in pathological conditions. We have previously shown that the neuroprotective and neuromodulatory actions of the cytokines IL-6 and oncostatin M are mediated by induction of neuronal A(1)R expression. In order to investigate the direct effects of A(1)R upregulation in neurons, we have generated a tetracycline-regulated expression system with a bidirectional promoter, directing the simultaneous expression of the mouse A(1)R and GFP/mCherry reporter genes. In a first step, we tested the efficacy of the system in transiently transfected human embryonic kidney 293 cells. In addition, we confirmed the functional integrity of the expressed A(1)R by whole-cell patch clamp recordings. We demonstrated that A(1)R-transfected primary neurons show enhanced survival against N-methyl-D-aspartate-induced excitotoxicity. Pretreatment with an A(1)R-selective agonist additionally strongly decreased neuronal cell death, while an A(1)R antagonist completely abolished the neuroprotective effects of A(1)R upregulation. The presented data provide for the first time direct evidence that the upregulation of A(1)R enhances neuronal survival.
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Abstract
Brain and spinal cord traumas include blunt and penetrating trauma, disease, and required surgery. Such traumas trigger events such as inflammation, infiltration of inflammatory and other cells, oxidative stress, acidification, excitotoxicity, ischemia, and the loss of calcium homeostasis, all of which cause neurotoxicity and neuron death. To prevent trauma-induced neurological deficits and death, each of the many neurotoxic events that occur in parallel or sequentially must be minimized or prevented. Although neuroprotective techniques have been developed that block single neurotoxic events, most provide only limited neuroprotection and are only applied singly. However, because many neurotoxicity triggers arise from common events, an approach for invoking more effective neuroprotection is to apply multiple neuroprotective methods simultaneously before the many neurotoxic triggers and cascades are initiated and become irreversible. This paper first discusses some triggers of neurotoxicity and neuroprotective mechanisms that block them, including hypothermia, alkalinization, and the administration of adenosine. It then examines how the simultaneous application of these techniques provides significantly greater neuroprotection than is provided by any technique alone. The paper also stresses the importance of determining whether the neuroprotection provided by these techniques can be further enhanced by combining them with additional techniques, such as the systemic administration of glucocorticoids. Finally, the paper stresses the absolute critical importance of applying these techniques within the "golden hour" following trauma, before the many neurotoxic events and cascades are manifest and before the neurotoxic cascades become irreversible.
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Affiliation(s)
- Damien P Kuffler
- Institute of Neurobiology, University of Puerto Rico, San Juan, Puerto Rico
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21
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Colak G, Johnson GVW. Complete transglutaminase 2 ablation results in reduced stroke volumes and astrocytes that exhibit increased survival in response to ischemia. Neurobiol Dis 2011; 45:1042-50. [PMID: 22198379 DOI: 10.1016/j.nbd.2011.12.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 12/02/2011] [Accepted: 12/06/2011] [Indexed: 02/09/2023] Open
Abstract
Transglutaminase 2 (TG2) is a very multifunctional protein that is ubiquitously expressed in the body. It is a Ca(2+)-dependent transamidating enzyme, a GTPase, as well as a scaffolding protein. TG2 is the predominant form of transglutaminase expressed in the mammalian nervous system. Previously, it was shown that TG2 can affect both cell death and cell survival mechanisms depending on the cell type and the stressor. In the case of ischemic stress, TG2 was previously shown to play a protective role in the models used. For example in hTG2 transgenic mice, where TG2 is overexpressed only in neurons, middle cerebral artery ligation (MCAL) resulted in smaller infarct volumes compared to wild type mice. In this study TG2 knock out mice were used to determine how endogenous TG2 affected stroke volumes. Intriguingly, infarct volumes in TG2 knock out mice were significantly smaller compared to wild type mice. As expected, primary neurons isolated from TG2 knock out mice showed decreased viability in response to oxygen-glucose deprivation. However, primary astrocytes that were isolated from TG2 knock out mice were resistant to oxygen-glucose deprivation in situ. Both wild type and knock out neurons were protected against oxygen glucose deprivation when they were co-cultured with astrocytes from TG2 knockout mice. Therefore, the decreased stroke volumes observed in TG2 knock out mice after MCAL, can be correlated with the protective effects of TG2 knock out in astrocytes in response to oxygen glucose deprivation in situ. These findings suggest that neuron-astrocyte crosstalk plays a significant role in mediating ischemic cell death and that TG2 differentially impacts cell survival depending on cell context.
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Affiliation(s)
- Gozde Colak
- Department of Pharmacology and Physiology, 601 Elmwood Avenue, Box 711, University of Rochester, Rochester, NY 14642, USA
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Czarnecka J, Roszek K, Jabłoński A, Smoliński DJ, Komoszyński M. Some aspects of purinergic signaling in the ventricular system of porcine brain. Acta Vet Scand 2011; 53:54. [PMID: 21995888 PMCID: PMC3213016 DOI: 10.1186/1751-0147-53-54] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Accepted: 10/13/2011] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Numerous signaling pathways function in the brain ventricular system, including the most important - GABAergic, glutaminergic and dopaminergic signaling. Purinergic signalization system - comprising nucleotide receptors, nucleotidases, ATP and adenosine and their degradation products - are also present in the brain. However, the precise role of nucleotide signalling pathway in the ventricular system has been not elucidated so far. The aim of our research was the identification of all three elements of purinergic signaling pathway in the porcine brain ventricular system. RESULTS Besides nucleotide receptors on the ependymocytes surface, we studied purines and pyrimidines in the CSF, including mechanisms of nucleotide signaling in the swine model (Sus scrofa domestica). The results indicate presence of G proteins coupled P2Y receptors on ependymocytes and also P2X receptors engaged in fast signal transmission. Additionally we found in CSF nucleotides and adenosine in the concentration sufficient to P receptors activation. These extracellular nucleotides are metabolised by adenylate kinase and nucleotidases from at least two families: NTPDases and NPPases. A low activity of these nucleotide metabolising enzymes maintains nucleotides concentration in ventricular system in micromolar range. ATP is degraded into adenosine and inosine. CONCLUSIONS Our results confirm the thesis about cross-talking between brain and ventricular system functioning in physiological as well as pathological conditions. The close interaction of brain and ventricular system may elicit changes in qualitative and quantitative composition of purines and pyrimidines in CSF. These changes can be dependent on the physiological state of brain, including pathological processes in CNS.
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Moidunny S, Dias RB, Wesseling E, Sekino Y, Boddeke HWGM, Sebastião AM, Biber K. Interleukin-6-type cytokines in neuroprotection and neuromodulation: oncostatin M, but not leukemia inhibitory factor, requires neuronal adenosine A1 receptor function. J Neurochem 2010; 114:1667-77. [DOI: 10.1111/j.1471-4159.2010.06881.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Malik A, Buck LT. Adenosinergic modulation of neuronal activity in the pond snail Lymnaea stagnalis. J Exp Biol 2010; 213:1126-32. [DOI: 10.1242/jeb.033894] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
SUMMARY
Adenosine has been termed a retaliatory metabolite and its neuroprotective effects have been implicated in the hypoxia tolerance of several species; however, its role in the invertebrate CNS remains unclear. To determine if adenosine modulates neuronal activity in invertebrate neurons, we conducted whole-cell recordings from neurons in the central ring ganglia of the anoxia-tolerant pond snail Lymnaea stagnalis during exposure to adenosine and pharmacological compounds known to modulate the type I subclass of adenosine receptors (A1R). Action potential (AP) frequency and membrane potential (Vm) were unchanged under control conditions, and addition of adenosine decreased AP frequency by 47% (from 1.08±0.22 to 0.57±0.14 Hz) and caused significant hyperpolarization of Vm. The A1R agonist cyclopentyladenosine (CPA) mimicked the results obtained with adenosine whereas antagonism of the A1R with 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) had no effect on AP frequency or Vm but prevented the adenosine and CPA-mediated decreases in neuronal activity. Furthermore, Ca2+ measurements with fluo-4 revealed that A1R activation led to a 12% increase in intracellular Ca2+ concentration and this elevation was also antagonized by DPCPX. Our results suggest that adenosine acting via the adenosine receptor (type I subclass) depresses neuronal activity in the adult L. stagnalis CNS and this depression is correlated with an increase in cytosolic Ca2+ levels.
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Affiliation(s)
- Aqsa Malik
- Department of Cell and Systems Biology, University of Toronto, ON, Canada
| | - Leslie Thomas Buck
- Department of Cell and Systems Biology, University of Toronto, ON, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, ON, Canada
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Pereira MR, Hang VR, Vardiero E, de Mello FG, Paes-de-Carvalho R. Modulation of A1 adenosine receptor expression by cell aggregation and long-term activation of A2a receptors in cultures of avian retinal cells: involvement of the cyclic AMP/PKA pathway. J Neurochem 2010; 113:661-73. [PMID: 20163523 DOI: 10.1111/j.1471-4159.2010.06641.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The expression of A1 and A2a adenosine receptors is developmentally regulated in the chick retina, but little is known about the factors important for this regulation. Here, we show that cell aggregation and cAMP analogs promote a dramatic increase in A1 receptor expression. Importantly, a long-term stimulation of A2a receptors also promotes an increase of A1 receptor expression accompanied by a down-regulation of A2a receptors. Chick embryo retina cultures grown in the form of aggregates or dispersed cells accumulate cAMP when stimulated with dopamine or the adenosine agonist 2-chloroadenosine. However, inhibition of dopamine-dependent cAMP accumulation by 2-chloroadenosine was observed in aggregate cultures but not in dispersed cell cultures. Accordingly, A1 receptor binding sites were detected in aggregate cultures, but were low or absent from dispersed cell cultures. Interestingly, an increase of A1 binding sites was detected when dispersed cell cultures were treated for 5 days with permeable cAMP analogs, the adenylyl cyclase activator forskolin or A2a receptor agonists. Although a significant amount of A1 receptor protein was detected in dispersed cell cultures by western blot or immunocytochemistry, the long-term stimulation of A2a receptors also promoted an increase of the A1 receptor protein and mRNA, indicating that A2a receptors and cAMP were regulating transcription and/or translation of A1 receptors. We also found an increase of A1 receptors in locations in or near the membrane after treatment with A2a agonist. The long-term stimulation of retinal explants with A2a agonist also promoted an increase of A1 receptor protein. The results indicate that A2a receptors and the cAMP-dependent protein kinase pathway are involved in the regulation of A1 receptor expression during retinal development.
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Affiliation(s)
- Mariana R Pereira
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, Brazil
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Morelli M, Carta AR, Kachroo A, Schwarzschild MA. Pathophysiological roles for purines: adenosine, caffeine and urate. PROGRESS IN BRAIN RESEARCH 2010; 183:183-208. [PMID: 20696321 PMCID: PMC3102301 DOI: 10.1016/s0079-6123(10)83010-9] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The motor symptoms of Parkinson's disease (PD) are primarily due to the degeneration of the dopaminergic neurons in the nigrostriatal pathway. However, several other brain areas and neurotransmitters other than dopamine such as noradrenaline, 5-hydroxytryptamine and acetylcholine are affected in the disease. Moreover, adenosine because of the extensive interaction of its receptors with the dopaminergic system has been implicated in the pathophysiology of the disease. Based on the involvement of these non-dopaminergic neurotransmitters in PD and the sometimes severe adverse effects that limit the mainstay use of dopamine-based anti-parkinsonian treatments, recent assessments have called for a broadening of therapeutic options beyond the traditional dopaminergic drug arsenal. In this review we describe the interactions between dopamine and adenosine receptors that underpin the pre-clinical and clinical rationale for pursuing adenosine A(2A) receptor antagonists as symptomatic and potentially neuroprotective treatment of PD. The review will pay particular attention to recent results regarding specific A(2A) receptor-receptor interactions and recent findings identifying urate, the end product of purine metabolism, as a novel prognostic biomarker and candidate neuroprotectant in PD.
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Affiliation(s)
- Micaela Morelli
- Department of Toxicology, University of Cagliari, Cagliari, Italy.
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27
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Yang L, Li F, Zhang H, Ge W, Mi C, Sun R, Liu C. Astrocyte activation and memory impairment in the repetitive febrile seizures model. Epilepsy Res 2009; 86:209-20. [DOI: 10.1016/j.eplepsyres.2009.07.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 06/15/2009] [Accepted: 07/02/2009] [Indexed: 10/20/2022]
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Su CK, Ho CM, Kuo HH, Wen YC, Chai CY. Sympathetic-correlated c-Fos expression in the neonatal rat spinal cord in vitro. J Biomed Sci 2009; 16:44. [PMID: 19409080 PMCID: PMC2687431 DOI: 10.1186/1423-0127-16-44] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Accepted: 05/01/2009] [Indexed: 02/07/2023] Open
Abstract
An isolated thoracic spinal cord of the neonatal rat in vitro spontaneously generates sympathetic nerve discharge (SND) at ~25 degrees C, but it fails in SND genesis at < or = 10 degrees C. Basal levels of the c-Fos expression in the spinal cords incubated at < or = 10 degrees C and ~25 degrees C were compared to determine the anatomical substrates that might participate in SND genesis. Cells that exhibited c-Fos immunoreactivity were virtually absent in the spinal cords incubated at < or = 10 degrees C. However, in the spinal cords incubated at ~25 degrees C, c-Fos-positive cells were found in the dorsal laminae, the white matter, lamina X, and the intermediolateral cell column (IML). Cell identities were verified by double labeling of c-Fos with neuron-specific nuclear protein (NeuN), glial fibrillary acidic protein (GFAP), or choline acetyltransferase (ChAT). The c-Fos-positive cells distributed in the white matter and lamina X were NeuN-negative or GFAP-positive and were glial cells. Endogenously active neurons showing c-Fos and NeuN double labeling were scattered in the dorsal laminae and concentrated in the IML. Double labeling of c-Fos and ChAT confirmed the presence of active sympathetic preganglionic neurons (SPNs) in the IML. Suppression of SND genesis by tetrodotoxin (TTX) or mecamylamine (MECA, nicotinic receptor blocker) almost abolished c-Fos expression in dorsal laminae, but only mildly affected c-Fos expression in the SPNs. Therefore, c-Fos expression in some SPNs does not require synaptic activation. Our results suggest that spinal SND genesis is initiated from some spontaneously active SPNs, which are capable of TTX- or MECA-resistant c-Fos expression.
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Affiliation(s)
- Chun-Kuei Su
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, Republic of China
| | - Chiu-Ming Ho
- Department of Anesthesiology, Taipei Veterans General Hospital and National Yang-Ming University, Taipei 112, Taiwan, Republic of China
| | - Hsiao-Hui Kuo
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, Republic of China
- Department of Anesthesiology, Taipei Veterans General Hospital and National Yang-Ming University, Taipei 112, Taiwan, Republic of China
| | - Yu-Chuan Wen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, Republic of China
| | - Chok-Yung Chai
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, Republic of China
- Department of Physiology and Biophysics, National Defense Medical Center, Taipei 114, Taiwan, Republic of China
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Izadpanah F, Mojtahedzadeh M, Aghamir SMK, Atharikia D, Dashti S, Abbasi A. Effect of Intravenous Pentoxifylline in Inflammatory Response in Patients Undergoing Nephrolithotomy. J Endourol 2009; 23:323-8. [DOI: 10.1089/end.2008.0474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Fatemeh Izadpanah
- Departments of Anesthesiology and Clinical Pharmacy, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mojtaba Mojtahedzadeh
- Departments of Anesthesiology and Clinical Pharmacy, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Mohammad Kazem Aghamir
- Department of Urology, Urology Research Center, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Davood Atharikia
- Department of Urology, Urology Research Center, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Simin Dashti
- Departments of Anesthesiology and Clinical Pharmacy, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Abbasi
- Department of Basic and Clinical Research, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran
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Abstract
Advances in radiotracer chemistry have resulted in the development of novel molecular imaging probes for adenosine receptors (ARs). With the availability of these molecules, the function of ARs in human pathophysiology as well as the safety and efficacy of approaches to the different AR targets can now be determined. Molecular imaging is a rapidly growing field of research that allows the identification of molecular targets and functional processes in vivo. It is therefore gaining increasing interest as a tool in drug development because it permits the process of evaluating promising therapeutic targets to be stratified. Further, molecular imaging has the potential to evolve into a useful diagnostic tool, particularly for neurological and psychiatric disorders. This chapter focuses on currently available AR ligands that are suitable for molecular neuroimaging and describes first applications in healthy subjects and patients using positron emission tomography (PET).
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Affiliation(s)
- Andreas Bauer
- Institute of Neuroscience and Biophysics (INB-3), Research Center Jülich, 52425 Jülich, Germany.
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Migita H, Kominami K, Higashida M, Maruyama R, Tuchida N, McDonald F, Shimada F, Sakurada K. Activation of adenosine A1receptor-induced neural stem cell proliferation via MEK/ERK and Akt signaling pathways. J Neurosci Res 2008; 86:2820-8. [DOI: 10.1002/jnr.21742] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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32
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Morita K. High salt culture conditions inhibit serum- and NGF- but not PMA-induced Egr-1 gene transcription in rat C6 glioma cells. J Mol Neurosci 2008; 33:216-23. [PMID: 17917080 DOI: 10.1007/s12031-007-9000-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Revised: 11/30/1999] [Accepted: 08/10/2007] [Indexed: 12/24/2022]
Abstract
Recent studies have suggested that glial cells may play a physiologically important role in the retention and restoration of neuronal cell integrity, proposing the possibility that the proliferation and/or differentiation of glial cells may be related to pathological changes in neural functions in neurodegenerative diseases, and hence, it seems interesting to investigate the expression of genes related to the proliferation and differentiation of glial cells. Following this basic concept, we have previously examined the influence of culture conditions on egr-1 gene expression in rat C6 glioma cells and have shown that brief exposure of these cells to high salt culture medium can induce the down-regulation of egr-1 gene expression. In contrast, the long-term culture of these cells in high salt medium has been shown to primarily reduce their proliferation and secondarily elevate egr-1 gene transcription as a consequence of arresting the cell-cycle progression. Therefore, the effect of high salt culture medium on egr-1 gene expression seems practically unconfirmed, and remains to be further investigated. Then, the effects of various egr-1 gene inducers, such as serum, NGF and phorbol ester PMA, on Egr-1 mRNA levels in the glioma cells were examined under the high salt culture conditions. The brief exposure to high salt culture medium inhibited the elevation of Egr-1 mRNA levels induced by serum replenishment and NGF, but not induced by PMA. These results suggest that the suppression of serum action on egr-1 gene transcription may be the primary and essential event leading to the down-regulation of egr-1 gene expression under the high salt culture conditions.
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Affiliation(s)
- Kyoji Morita
- Department of Pharmacology, Tokushima University School of Medicine, 3-18-15 Kuramoto, Tokushima, Japan.
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33
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Chen JF, Sonsalla PK, Pedata F, Melani A, Domenici MR, Popoli P, Geiger J, Lopes LV, de Mendonça A. Adenosine A2A receptors and brain injury: Broad spectrum of neuroprotection, multifaceted actions and “fine tuning” modulation. Prog Neurobiol 2007; 83:310-31. [DOI: 10.1016/j.pneurobio.2007.09.002] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Revised: 08/10/2007] [Accepted: 09/21/2007] [Indexed: 10/22/2022]
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Abstract
This paper presents an overview of the current knowledge of the neurophysiology and cellular pharmacology of sleep mechanisms. It is written from the perspective that recent years have seen a remarkable development of knowledge about sleep mechanisms, due to the capability of current cellular neurophysiological, pharmacological and molecular techniques to provide focused, detailed, and replicable studies that have enriched and informed the knowledge of sleep phenomenology and pathology derived from electroencephalographic (EEG) analysis. This chapter has a cellular and neurophysiological/neuropharmacological focus, with an emphasis on rapid eye movement (REM) sleep mechanisms and non-REM (NREM) sleep phenomena attributable to adenosine. The survey of neuronal and neurotransmitter-related brainstem mechanisms of REM includes monoamines, acetylcholine, the reticular formation, a new emphasis on GABAergic mechanisms and a discussion of the role of orexin/hypcretin in diurnal consolidation of REM sleep. The focus of the NREM sleep discussion is on the basal forebrain and adenosine as a mediator of homeostatic control. Control is through basal forebrain extracellular adenosine accumulation during wakefulness and inhibition of wakefulness-active neurons. Over longer periods of sleep loss, there is a second mechanism of homeostatic control through transcriptional modification. Adenosine acting at the A1 receptor produces an up-regulation of A1 receptors, which increases inhibition for a given level of adenosine, effectively increasing the gain of the sleep homeostat. This second mechanism likely occurs in widespread cortical areas as well as in the basal forebrain. Finally, the results of a new series of experimental paradigms in rodents to measure the neurocognitive effects of sleep loss and sleep interruption (modeling sleep apnea) provide animal model data congruent with those in humans.
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Affiliation(s)
- Robert W McCarley
- Neuroscience Laboratory, VA Boston Healthcare System, 940 Belmont St., Brockton, MA 02301, USA.
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Bernardi A, Bavaresco L, Wink MR, Jacques-Silva MC, Delgado-Cañedo A, Lenz G, Battastini AMO. Indomethacin stimulates activity and expression of ecto-5'-nucleotidase/CD73 in glioma cell lines. Eur J Pharmacol 2007; 569:8-15. [PMID: 17568578 DOI: 10.1016/j.ejphar.2007.04.058] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Revised: 04/16/2007] [Accepted: 04/21/2007] [Indexed: 01/23/2023]
Abstract
Gliomas are the most common and devastating primary tumors of the central nervous system. Ecto-NTPDases and ecto-5'-nucleotidase/CD73 can control extracellular ATP/adenosine levels, which have been described as proliferation factors. Here, we investigate the influence of indomethacin on the enzyme cascade that catalyses the interconversion of purine nucleotides in U138-MG and C6 glioma cell lines. Exposure of glioma cells to 100 microM indomethacin for 48 h caused increases of 52% (P < 0.05) and 62% (P < 0.05) in the AMP hydrolysis rate in C6 and U138-MG cell lines, respectively. Indomethacin treatments also increased ATP hydrolysis. Significant increase in ecto-5'-nucleotidase/CD73 mRNA and protein levels were observed after treatment with indomethacin. Pretreatment of glioma cells with a specific antagonist of the adenosine A(3) receptor, MRS1220 (1 microM; 9-Chloro-2-(2-furanyl)-5-((phenylacetyl)amino)-[1,2,4]triazolo[1,5-c]quinazoline), significantly reduced the inhibition of cell proliferation induced by indomethacin. In addition, a significant increase in mRNA levels of the adenosine A(3) receptor was observed after treatment with indomethacin. In conclusion, our data indicate that adenosine A(3) receptors and the enzyme, ecto-5'-nucleotidase/CD73, are involved in the anti-proliferative effect of indomethacin in glioma cells.
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Affiliation(s)
- Andressa Bernardi
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Av. Ramiro Barcelos, 2600-anexo, CEP 90035-003, Porto Alegre, RS, Brazil
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Tabata T, Kawakami D, Hashimoto K, Kassai H, Yoshida T, Hashimotodani Y, Fredholm BB, Sekino Y, Aiba A, Kano M. G protein-independent neuromodulatory action of adenosine on metabotropic glutamate signalling in mouse cerebellar Purkinje cells. J Physiol 2007; 581:693-708. [PMID: 17379632 PMCID: PMC2075187 DOI: 10.1113/jphysiol.2007.129866] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Adenosine receptors (ARs) are G protein-coupled receptors (GPCRs) mediating the neuromodulatory actions of adenosine that influence emotional, cognitive, motor, and other functions in the central nervous system (CNS). Previous studies show complex formation between ARs and metabotropic glutamate receptors (mGluRs) in heterologous systems and close colocalization of ARs and mGluRs in several central neurons. Here we explored the possibility of intimate functional interplay between G(i/o) protein-coupled A(1)-subtype AR (A1R) and type-1 mGluR (mGluR1) naturally occurring in cerebellar Purkinje cells. Using a perforated-patch voltage-clamp technique, we found that both synthetic and endogenous agonists for A1R induced continuous depression of a mGluR1-coupled inward current. A1R agonists also depressed mGluR1-coupled intracellular Ca(2+) mobilization monitored by fluorometry. A1R indeed mediated this depression because genetic depletion of A1R abolished it. Surprisingly, A1R agonist-induced depression persisted after blockade of G(i/o) protein. The depression appeared to involve neither the cAMP-protein kinase A cascade downstream of the alpha subunits of G(i/o) and G(s) proteins, nor cytoplasmic Ca(2+) that is suggested to be regulated by the beta-gamma subunit complex of G(i/o) protein. Moreover, A1R did not appear to affect G(q) protein which mediates the mGluR1-coupled responses. These findings suggest that A1R modulates mGluR1 signalling without the aid of the major G proteins. In this respect, the A1R-mediated depression of mGluR1 signalling shown here is clearly distinguished from the A1R-mediated neuronal responses described so far. These findings demonstrate a novel neuromodulatory action of adenosine in central neurons.
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Affiliation(s)
- Toshihide Tabata
- Department of Cellular Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
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D'Alimonte I, Ballerini P, Nargi E, Buccella S, Giuliani P, Di Iorio P, Caciagli F, Ciccarelli R. Staurosporine-induced apoptosis in astrocytes is prevented by A1 adenosine receptor activation. Neurosci Lett 2007; 418:66-71. [PMID: 17400382 DOI: 10.1016/j.neulet.2007.02.061] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Revised: 02/13/2007] [Accepted: 02/27/2007] [Indexed: 12/23/2022]
Abstract
Astrocyte apoptosis occurs in acute and chronic pathological processes at the central nervous system and the prevention of astrocyte death may represent an efficacious intervention in protecting neurons against degeneration. Our research shows that rat astrocyte exposure to 100 nM staurosporine for 3h caused apoptotic death accompanied by caspase-3, p38 mitogen-ed protein kinase (MAPK) and glycogen synthase kinase-3beta (GSK3beta) activation. N(6)-chlorocyclopentyladenosine (CCPA, 2.5-75 nM), a selective agonist of A(1) adenosine receptors, added to the cultures 1h prior to staurosporine, induced a dose-dependent anti-apoptotic effect, which was inhibited by the A(1) receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine. CCPA also caused a dose- and time-dependent phosphorylation/activation of Akt, a downstream effector of cell survival promoting phosphatidylinositol 3-kinase (PI3K) pathway, which in turn led to inhibition of staurosporine-induced GSK3beta and p38 MAPK activity. Accordingly, the anti-apoptotic effect of CCPA was abolished by culture pre-treatment with LY294002, a selective PI3K inhibitor, pointing out the prevailing role played by PI3K pathway in the protective effect exerted by A(1) receptor activation. Since an abnormal p38 and GSK3beta activity is implicated in acute (stroke) and chronic (Alzheimer's disease) neurodegenerative diseases, the results of the present study provide a hint to better understand adenosine relevance in these disorders.
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Affiliation(s)
- Iolanda D'Alimonte
- Department of Biomedical Sciences, G. D'Annunzio University, Chieti, Italy
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Joosen MJA, van Helden HPM. Correlations between acetylcholinesterase inhibition, acetylcholine levels and EEG changes during perfusion with neostigmine and N6-cyclopentyladenosine in rat brain. Eur J Pharmacol 2007; 555:122-8. [PMID: 17113068 DOI: 10.1016/j.ejphar.2006.10.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 09/29/2006] [Accepted: 10/05/2006] [Indexed: 10/24/2022]
Abstract
Organophosphate poisoning can result in seizures and subsequent neuropathology. In order to improve treatment strategies in organophosphate intoxication, the relationship between acetylcholinesterase inhibition, extracellular levels of acetylcholine, and electroencephalogram (EEG) changes was investigated during local perfusion of the reversible acetylcholinesterase inhibitor neostigmine in the hippocampus and striatum of freely moving rats. Acetylcholinesterase activity and acetylcholine levels were measured by microdialysis, and EEG signals were recorded from an electrode placed near the microdialysis probe. A non-linear relationship between the acetylcholinesterase activity and the extracellular amount of acetylcholine was found, the latter being approximately three times higher in the striatum than in the hippocampus upon infusion with 10(-4) M neostigmine. Highly accumulated extracellular acetylcholine significantly correlated with significant relative power increases of the EEG-gamma2-band and a significant relative power decrease in the beta2-band. Co-infusion of the adenosine A1 agonist N6-cyclopentyladenosine partly prevented acetylcholine accumulation, rendered both powers towards control values, and abolished the acetylcholine-EEG correlation. In view of the latter relationship, it is concluded that prevention of acetylcholine accumulation as a concept for neuroprotection in case of organophosphate poisoning, is worth to be further investigated.
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Affiliation(s)
- Marloes J A Joosen
- TNO Defence, Security and Safety, BU Biological and Chemical Protection, Department Diagnosis and Therapy, Rijswijk, The Netherlands.
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Rodríguez A, Martín M, Albasanz JL, Barrachina M, Espinosa JC, Torres JM, Ferrer I. Adenosine A1 Receptor Protein Levels and Activity Is Increased in the Cerebral Cortex in Creutzfeldt-Jakob Disease and in Bovine Spongiform Encephalopathy-Infected Bovine-PrP Mice. J Neuropathol Exp Neurol 2006; 65:964-75. [PMID: 17021401 DOI: 10.1097/01.jnen.0000235120.59935.f5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Prion diseases are characterized by neuronal loss, astrocytic gliosis, spongiform change, and abnormal protease-resistant prion protein (PrP) deposition. Creutzfeldt-Jakob disease (CJD) is the most prevalent human prion disease, whereas scrapie and bovine spongiform encephalopathy (BSE) are the most common animal prion diseases. Several candidates have been proposed as mediators of degeneration in prion diseases, one of them glutamate. Recent studies have shown reduced metabotropic glutamate receptor/phospholipase C signaling in the cerebral cortex in CJD, suggesting that this important neuromodulator and neuroprotector pathway is attenuated in CJD. Adenosine is involved in the regulation of different metabolic processes under physiological and pathologic conditions. Adenosine function is mediated by adenosine receptors, which are categorized into 4 types: A1, A2A, A2B, and A3. A1Rs are G-protein-coupled receptors that induce the inhibition of adenylyl cyclase activity. The most dramatic inhibitory actions of adenosine receptors are on the glutamatergic system. For these reasons, we examined the levels of A1Rs in the frontal cortex of 12 patients with CJD and 6 age-matched controls and in BSE-infected bovine-PrP transgenic mice (BoPrP-Tg110 mice) at different postincubation times to address modifications in A1Rs with disease progression. A significant increase in the protein levels of A1Rs was found in the cerebral cortex in CJD and in the murine BSE model at advanced stages of the disease and coincidental with the appearance of PrP expression. In addition, the activity of A1Rs was analyzed by in vitro assays with isolated membranes of the frontal cortex in CJD. Increased activity of the receptor, as revealed by the decreased forskolin-stimulated cAMP production in response to the A1R agonists cyclohexyl adenosine and cyclopentyl adenosine, was observed in CJD cases when compared with controls. Finally, mRNA A1R levels were similar in CJD and control cases, thus suggesting abnormal A1R turnover or dysregulation of raft-associated signaling pathways in CJD. These results show, for the first time, sensitization of A1Rs in prion diseases.
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Affiliation(s)
- Agustín Rodríguez
- Institut de Neuropatologia, Servei Anatomia Patològica, IDIBELL-Hospital Universitari de Bellvitge, Universitat de Barcelona, 08907 Hospitalet de Llobregat, Spain
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Tamura Y, Monden M, Shintani M, Kawai A, Shiomi H. Neuroprotective effects of hibernation-regulating substances against low-temperature-induced cell death in cultured hamster hippocampal neurons. Brain Res 2006; 1108:107-16. [PMID: 16854391 DOI: 10.1016/j.brainres.2006.06.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Revised: 06/01/2006] [Accepted: 06/05/2006] [Indexed: 01/20/2023]
Abstract
The neuroprotective effects of hibernation-regulating substances (HRS) such as adenosine (ADO), opioids, histamine and thyrotropin-releasing hormone (TRH) on low-temperature-induced cell death (LTCD) were examined using primary cultured hamster hippocampal neurons. LTCD was induced when cultures were maintained at <22 degrees C for 7 days. ADO (10-100 microM) protected cultured neurons from LTCD in a dose-dependent manner. The neuroprotective effects of ADO were reversed by both 8-cyclopenthyltheophilline (CPT; A(1) receptor antagonist) and 3,7-dimethyl-1-propargylxanthine (DMPX; A(2) receptor antagonist). Morphine (a non-selective opioid receptor agonist) was also effective in attenuating LTCD at an in vitro dose range of 10-100 muM. The neuroprotective effects of morphine were antagonized by naloxone (a non-selective opioid receptor antagonist). In addition, although [D-Ala(2), N-Me-Phe(4), Gly-ol(5)]-enkephalin (DAMGO; mu-opioid receptor agonist), [D-Pen(2,5)]-enkephalin (DPDPE; delta-opioid receptor agonist) and U-69593 (kappa-opioid receptor agonist) were also effective, LTCD of cultured hippocampal neurons was not affected by TRH. Furthermore, histamine produced hypothermia in Syrian hamsters and protected hippocampal neurons in vitro at 100 microM. The neuroprotective effect of histamine was reversed by pyrilamine (H(1) receptor antagonist). Apoptosis was probably involved in LTCD. These results suggest that ADO protected hippocampal neurons in vitro via its agonistic actions on both A(1) and A(2) receptors, whereas morphine probably elicited its neuroprotective effects via agonistic effects on the mu-, delta- and kappa-opioid receptors. In addition, histamine also protected hippocampal neurons via its agonistic action on the H(1) receptor. Thus, HRS-like adenosine-, opioid- and histamine-like hypothermic actions would most likely induce neuroprotective effects against LTCD in vitro.
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Affiliation(s)
- Yutaka Tamura
- Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Fukuyama, Hiroshima 729-0292, Japan
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Benfenati V, Caprini M, Nobile M, Rapisarda C, Ferroni S. Guanosine promotes the up-regulation of inward rectifier potassium current mediated by Kir4.1 in cultured rat cortical astrocytes. J Neurochem 2006; 98:430-45. [PMID: 16805837 DOI: 10.1111/j.1471-4159.2006.03877.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Guanosine (Guo) is an endogenous neuroprotective molecule of the CNS, which has various acute and long-term effects on both neurones and astroglial cells. Whether Guo also modulates the activity/expression of ion channels involved in homeostatic control of extracellular potassium by the astrocytic syncytium is still unknown. Here we provide electrophysiological evidence that chronic exposure (48 h) to Guo (500 microm) promotes the functional expression of an inward rectifier K+ (Kir) conductance in primary cultured rat cortical astrocytes. Molecular screening indicated that Guo promotes the up-regulation of the Kir4.1 channel, the major component of the Kir current in astroglia in vivo. Furthermore, the properties of astrocytic Kir current overlapped those of the recombinant Kir4.1 channel expressed in a heterologous system, strongly suggesting that the Guo-induced Kir conductance is mainly gated by Kir4.1. In contrast, the expression levels of two other Kir channel proteins were either unchanged (Kir2.1) or decreased (Kir5.1). Finally, we showed that inhibition of translational process, but not depression of transcription, prevents the Guo-induced up-regulation of Kir4.1, indicating that this nucleoside acts through de novo protein synthesis. Because accumulating data indicate that down-regulation of astroglial Kir current contributes to the pathogenesis of neurodegenerative diseases associated with dysregulation of extracellular K+ homeostasis, these results support the notion that Guo might be a molecule of therapeutic interest for counteracting the detrimental effect of K+-buffering impairment of the astroglial syncytium that occurs in pathological conditions.
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Affiliation(s)
- Valentina Benfenati
- Department of Human and General Physiology, University of Bologna, Bologna, Italy
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Xu K, Puchowicz MA, Lust WD, LaManna JC. Adenosine treatment delays postischemic hippocampal CA1 loss after cardiac arrest and resuscitation in rats. Brain Res 2006; 1071:208-17. [PMID: 16412392 DOI: 10.1016/j.brainres.2005.11.060] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2005] [Revised: 11/09/2005] [Accepted: 11/11/2005] [Indexed: 10/25/2022]
Abstract
Resuscitation from cardiac arrest results in reperfusion injury that leads to increased postresuscitation mortality and delayed neuronal death. One of the many consequences of resuscitation from cardiac arrest is a derangement of energy metabolism and the loss of adenylates, impairing the tissue's ability to regain proper energy balance. In this study, we investigated the effects of adenosine (ADO) on the recovery of the brain from 12 min of ischemia using a rat model of cardiac arrest and resuscitation. Compared to the untreated group, treatment with adenosine (7.2 mg/kg) initiated immediately after resuscitation increased the proportion of rats surviving to 4 days and significantly delayed hippocampal CA1 neuronal loss. Brain blood flow was increased significantly in the adenosine-treated rats 1 h after cardiac arrest and resuscitation. Adenosine-treated rats exhibited less edema in cortex, brainstem and hippocampus during the first 48 h of recovery. Adenosine treatment significantly lowered brain temperature during recovery, and a part of the neuroprotective effects of adenosine treatment could be ascribed to adenosine-induced hypothermia. With this dose, adenosine may have a delayed transient effect on the restoration of the adenylate pool (AXP = ATP + ADP + AMP) 24 h after cardiac arrest and resuscitation. Our findings suggested that improved postischemic brain blood flow and ADO-induced hypothermia, rather than adenylate supplementation, may be the two major contributors to the neuroprotective effects of adenosine following cardiac arrest and resuscitation. Although adenosine did not prevent eventual CA1 neuronal loss in the long term, it did delay neuronal loss and promoted long-term survival. Thus, adenosine or specific agonists of adenosine receptors should be evaluated as adjuncts to broaden the window of opportunity in the treatment of the reperfusion injury following cardiac arrest and resuscitation.
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Affiliation(s)
- Kui Xu
- Department of Anatomy, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA
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López-Herrera A, Liu Y, Rugeles MT, He JJ. HIV-1 interaction with human mannose receptor (hMR) induces production of matrix metalloproteinase 2 (MMP-2) through hMR-mediated intracellular signaling in astrocytes. Biochim Biophys Acta Mol Basis Dis 2005; 1741:55-64. [PMID: 15955449 DOI: 10.1016/j.bbadis.2004.12.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2004] [Revised: 11/05/2004] [Accepted: 12/02/2004] [Indexed: 11/16/2022]
Abstract
Astrocytes are susceptible to HIV-1 infection. We have recently demonstrated that human mannose receptor (hMR) is directly involved in CD4-independent HIV-1 infection of astrocytes. The apparent paradox between the vivid binding affinity of HIV-1 gp120 protein to hMR and the low efficiency of hMR-mediated HIV-1 infection raises the possibility that HIV-1 binding to hMR alone may negatively affect astrocyte function. In this study, we examined the relationship between HIV-1 interaction with hMR and the production of matrix metalloproteinases (MMPs) in astrocytes. We took advantage of an astroglial cell line U87.MR stably expressing hMR as an in vitro astrocyte model system and human primary astrocytes, and demonstrated that HIV-1 binding to astrocytes induced the production of MMP-2. This induction appeared to be most potent with M-tropic HIV-1 viruses. Increased MMP-2 production was not due to hMR-mediated HIV-1 entry and/or HIV-1 viral gene expression, as the transfection of HIV-1 proviral DNA did not result in MMP-2 production, and the infection of AT-2-treated HIV-1 viruses did not inhibit MMP-2 production. Direct involvement of hMR in HIV-induced MMP-2 production was confirmed by the inhibition of the yeast mannan, an hMR ligand antagonist, and an anti-hMR serum. Furthermore, HIV-induced MMP-2 production in astrocytes was shown to involve hMR-mediated intracellular signaling. Taken together, these results suggest that HIV-1 binding to astrocytes in the absence of HIV-1 viral entry is sufficient to alter astrocyte function through hMR-mediated intracellular signaling. In addition, these results provide new evidence to support the notion that hMR is capable of eliciting intracellular signaling upon ligand binding.
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Affiliation(s)
- Albeiro López-Herrera
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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44
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Fiebich BL, Akundi RS, Biber K, Hamke M, Schmidt C, Butcher RD, van Calker D, Willmroth F. IL-6 expression induced by adenosine A2b receptor stimulation in U373 MG cells depends on p38 mitogen activated kinase and protein kinase C. Neurochem Int 2005; 46:501-12. [PMID: 15769552 DOI: 10.1016/j.neuint.2004.11.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2004] [Revised: 11/26/2004] [Accepted: 11/29/2004] [Indexed: 02/02/2023]
Abstract
Adenosine binds to a class of G-protein coupled receptors, which are further distinguished as A(1), A(2a), A(2b) and A(3) adenosine receptors. As we have shown earlier, the stable adenosine analogue NECA (N6-(R)-phenylisopropyladenosine) stimulates IL-6 expression in the human astrocytoma cell line U373 MG via the A(2b) receptor. The mechanism by which NECA promotes astrocytic IL-6 expression has not been identified. By using various inhibitors of signal transduction, we found that p38 mitogen-activated protein kinases (MAPK) activation (inhibitor SB202190), but not extracellular signal-regulated kinase (ERK) (PD98059) and c-jun N-terminal kinase (JNK)(SP600125), is essential in the NECA-induced signalling cascade that leads to the increase in IL-6 synthesis in U373 MG cells. Results obtained with protein kinase C (PKC) inhibitors that have different substrate specificities, indicated that the PKC delta and epsilon isoforms are also involved in adenosine receptor A(2b) dependent upregulation of IL-6 expression. This is supported by the fact that NECA induced the activation of PKC delta and epsilon in U373 MG cells.
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Affiliation(s)
- Bernd L Fiebich
- University of Freiburg Medical School, Department of Psychiatry and Psychotherapy, Neurochemistry Research Group, Hauptstrasse 5, D-79104 Freiburg, Germany.
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45
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Gu JW, Hasuo H, Takeya M, Akasu T. Effects of emodin on synaptic transmission in rat hippocampal CA1 pyramidal neurons in vitro. Neuropharmacology 2005; 49:103-11. [PMID: 15992585 DOI: 10.1016/j.neuropharm.2005.02.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2004] [Revised: 02/02/2005] [Accepted: 02/03/2005] [Indexed: 10/25/2022]
Abstract
Rhubarb extracts provide neuroprotection after brain injury, but the mechanism of this protective effect is not known. The present study tests the hypothesis that rhubarb extracts interfere with the release of glutamate by brain neurons and, therefore, reduce glutamate excitotoxicity. To this end, the effects of emodin, an anthraquinone derivative extracted from Rheum tanguticum Maxim. Ex. Balf, on the synaptic transmission of CA1 pyramidal neurons in rat hippocampus were studied in vitro. The excitatory postsynaptic potential (EPSP) was depressed by bath-application of emodin (0.3-30 microM). Paired-pulse facilitation (PPF) of the EPSP was significantly increased by emodin. The monosynaptic inhibitory postsynaptic potential (IPSP) recorded in the presence of glutamate receptor antagonists (DNQX and AP5) was not altered by emodin. Emodin decreased the frequency, but not the amplitude, of the miniature EPSP (mEPSP). The inhibition of the EPSP induced by emodin was blocked by either 8-CPT, an adenosine A1 receptor antagonist, or by adenosine deaminase. These results suggest that emodin inhibits the EPSP by decreasing the release of glutamate from Schaffer collateral/commissural terminals via the activation of adenosine A1 receptors in rat hippocampal CA1 area and that the neuroprotective effects of rhubarb extracts may result from decreased glutamate excitotoxicity.
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Affiliation(s)
- Jian-Wen Gu
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan
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46
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Shinozaki Y, Koizumi S, Ishida S, Sawada JI, Ohno Y, Inoue K. Cytoprotection against oxidative stress-induced damage of astrocytes by extracellular ATP via P2Y1 receptors. Glia 2005; 49:288-300. [PMID: 15494980 DOI: 10.1002/glia.20118] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Oxidative stress is the main cause of neuronal damage in traumatic brain injury, hypoxia/reperfusion injury, and neurodegenerative disorders. Although extracellular nucleosides, especially adenosine, are well known to protect against neuronal damage in such pathological conditions, the effects of these nucleosides or nucleotides on glial cell damage remain largely unknown. We report that ATP but not adenosine protects against the cell death of cultured astrocytes induced by hydrogen peroxide (H2O2). ATP ameliorated the H2O2-induced decrease in cell viability of astrocytes in an incubation time- and concentration-dependent fashion. Protection by ATP was inhibited by P2 receptor antagonists and was mimicked by P2Y1 receptor agonists but not by adenosine. The expressions of P2Y1 mRNAs and functional P2Y1 receptors in astrocytes were confirmed. Thus, ATP, acting on P2Y1 receptors in astrocytes, showed a protective action against H2O2. The astrocytic protection by the P2Y1 receptor agonist 2-methylthio-ADP was inhibited by an intracellular Ca2+ chelator and a blocker of phospholipase C, indicating the involvement of intracellular signals mediated by Gq/11-coupled P2Y1 receptors. The ATP-induced protection was inhibited by cycloheximide, a protein synthesis inhibitor, and it took more than 12 h for the onset of the protective action. In the DNA microarray analysis, ATP induced a dramatic upregulation of various oxidoreductase genes. Taken together, ATP acts on P2Y1 receptors coupled to Gq/11, resulting in the upregulation of oxidoreductase genes, leading to the protection of astrocytes against H2O2.
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Affiliation(s)
- Youichi Shinozaki
- Division of Biosignaling, National Institute of Health Sciences, Setagaya, Tokyo, Japan
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Lu CH, Chao PC, Borel CO, Yang CP, Yeh CC, Wong CS, Wu CT. Preincisional intravenous pentoxifylline attenuating perioperative cytokine response, reducing morphine consumption, and improving recovery of bowel function in patients undergoing colorectal cancer surgery. Anesth Analg 2004; 99:1465-1471. [PMID: 15502050 DOI: 10.1213/01.ane.0000132974.32249.c8] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cytokine release during surgery can produce a long-lasting hyperalgesia. Thus, preoperatively-administered cytokine inhibitors might reduce the production of cytokines, decreasing central nervous system sensitization and improving the quality of postoperative pain relief. We investigated the hypothesis that preincisional IV pentoxifylline (PTX) treatment could attenuate the release of proinflammatory (tumor necrosis factor, interleukin (IL)-1beta, IL-6, and IL-8) and antiinflammatory (IL-1 receptor antagonist) cytokines in patients who underwent elective colorectal cancer surgery. Forty patients were randomly assigned to 1 of 2 groups of 20 each: the PTX group received a PTX 5 mg/kg IV infusion before the induction of anesthesia, whereas the control group received an equal volume of normal saline. Venous blood samples were obtained at frequent intervals. After surgery, all patients received patient-controlled analgesia (PCA) morphine for postoperative pain relief. Patients in the PTX group exhibited longer PCA trigger times, less morphine consumption, and a faster return of bowel function compared with patients in the control group. Moreover, the plasma levels of IL-6, IL-8, and IL-1 receptor antagonist were less in the treatment group, and there was no significant difference in wound infections, tumor recurrence, or metastatic rates between groups during a 2-yr follow-up.
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Affiliation(s)
- Chueng-He Lu
- Departments of *Anesthesiology and †Colon and Rectal Surgery, Tri-Service General Hospital and National Defense Medical Center, National Defense University, Taipei, Taiwan; and ‡Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina
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Olsson T, Cronberg T, Rytter A, Asztély F, Fredholm BB, Smith ML, Wieloch T. Deletion of the adenosine A1 receptor gene does not alter neuronal damage following ischaemia in vivo or in vitro. Eur J Neurosci 2004; 20:1197-204. [PMID: 15341591 DOI: 10.1111/j.1460-9568.2004.03564.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Extracellular adenosine is dramatically increased during cerebral ischaemia and is considered to be neuroprotective due to its inhibitory effect on synaptic transmission mediated by the adenosine A1 receptor (A1R). We investigated the importance of the A1R in a mouse model of global ischaemia and in a murine hippocampal slice culture model of in vitro ischaemia, using mice with the A1R gene deleted. In brains from mice lacking the A1R, damage induced by global ischaemia was similar to that in wild-type animals. In contrast, treatment with a selective A1R antagonist [8-cyclo-pentyl theophylline (8-CPT)], administered before the ischaemic insult in naive wild-type mice, exacerbated the neuronal damage following global ischaemia. Although the inhibitory action of adenosine on excitatory neurotransmission in hippocampal slices was lost in A1R knockout mice, there was no difference in damage between slices from wild-type and knockout mice after in vitro ischaemia. The results suggest that some effects of the A1R are compensated for in knockout animals.
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Affiliation(s)
- Tomas Olsson
- Laboratory for Experimental Brain Research, Wallenberg Neuroscience Center, Lund University, BMC A13, SE-221 84, Sweden.
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Basheer R, Strecker RE, Thakkar MM, McCarley RW. Adenosine and sleep–wake regulation. Prog Neurobiol 2004; 73:379-96. [PMID: 15313333 DOI: 10.1016/j.pneurobio.2004.06.004] [Citation(s) in RCA: 358] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2003] [Accepted: 06/28/2004] [Indexed: 10/26/2022]
Abstract
This review addresses three principal questions about adenosine and sleep-wake regulation: (1) Is adenosine an endogenous sleep factor? (2) Are there specific brain regions/neuroanatomical targets and receptor subtypes through which adenosine mediates sleepiness? (3) What are the molecular mechanisms by which adenosine may mediate the long-term effects of sleep loss? Data suggest that adenosine is indeed an important endogenous, homeostatic sleep factor, likely mediating the sleepiness that follows prolonged wakefulness. The cholinergic basal forebrain is reviewed in detail as an essential area for mediating the sleep-inducing effects of adenosine by inhibition of wake-promoting neurons via the A1 receptor. The A2A receptor in the subarachnoid space below the rostral forebrain may play a role in the prostaglandin D2-mediated somnogenic effects of adenosine. Recent evidence indicates that a cascade of signal transduction induced by basal forebrain adenosine A1 receptor activation in cholinergic neurons leads to increased transcription of the A1 receptor; this may play a role in mediating the longer-term effects of sleep deprivation, often called sleep debt.
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Affiliation(s)
- Radhika Basheer
- Neuroscience Laboratory, Department of Psychiatry, Harvard Medical School and Boston VA Healthcare System, Brockton, MA 02301, USA
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Leonoudakis D, Braithwaite SP, Beattie MS, Beattie EC. TNFalpha-induced AMPA-receptor trafficking in CNS neurons; relevance to excitotoxicity? NEURON GLIA BIOLOGY 2004; 1:263-73. [PMID: 16520832 PMCID: PMC1389713 DOI: 10.1017/s1740925x05000608] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Injury and disease in the CNS increases the amount of tumor necrosis factor alpha (TNFalpha) that neurons are exposed to. This cytokine is central to the inflammatory response that occurs after injury and during prolonged CNS disease, and contributes to the process of neuronal cell death. Previous studies have addressed how long-term apoptotic-signaling pathways that are initiated by TNFalpha might influence these processes, but the effects of inflammation on neurons and synaptic function in the timescale of minutes after exposure are largely unexplored. Our published studies examining the effect of TNFalpha on trafficking of AMPA-type glutamate receptors (AMPARs) in hippocampal neurons demonstrate that glial-derived TNFalpha causes a rapid (<15 minute) increase in the number of neuronal, surface-localized, synaptic AMPARs leading to an increase in synaptic strength. This indicates that TNFalpha-signal transduction acts to facilitate increased surface localization of AMPARs from internal postsynaptic stores. Importantly, an excess of surface localized AMPARs might predispose the neuron to glutamate-mediated excitotoxicity and excessive intracellular calcium concentrations, leading to cell death. This suggests a new mechanism for excitotoxic TNFalpha-induced neuronal death that is initiated minutes after neurons are exposed to the products of the inflammatory response. Here we review the importance of AMPAR trafficking in normal neuronal function and how abnormalities that are mediated by glial-derived cytokines such as TNFalpha can be central in causing neuronal disorders. We have further investigated the effects of TNFalpha on different neuronal cell types and present new data from cortical and hippocampal neurons in culture. Finally, we have expanded our investigation of the temporal profile of the action of this cytokine relevant to neuronal damage. We conclude that TNFalpha-mediated effects on AMPAR trafficking are common in diverse neuronal cell types and very rapid in their onset. The abnormal AMPAR trafficking elicited by TNFalpha might present a novel target to aid the development of new neuroprotective drugs.
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Affiliation(s)
- Dmitri Leonoudakis
- Department of Neurosciences, California Pacific Medical Center Research Institute, 475 Brannan St Suite 220, San Francisco, CA 94107, USA.
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