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Hu Q, Xu L, Liu X, Wang Y, Yuan J. Adenosine A 2A receptor antagonist KW6002 protects against A53T mutant alpha-synuclein-induced brain damage and neuronal apoptosis in Parkinson's disease mice by restoring autophagic flux. Neurosci Lett 2024; 826:137610. [PMID: 38157926 DOI: 10.1016/j.neulet.2023.137610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND Protein misfolding and inclusion body aggregation caused by α-Syn mutations in the brain often cause neurodegeneration and cognitive impairment, among which the A53T point mutation is more common. Inhibition of adenosine A2A receptor (A2AR) can alleviate the pathological symptoms of brain dysfunction caused by A53T-α-Syn protofibrils, but the mechanism of action is still unclear. AIM This studies aimed to investigate the potential therapeutic role of the A2AR inhibitor KW6002 in a mouse model of brain synucleinopathy. METHODS A53T-α-Syn fibre precursor cell nuclear protein was injected into the bilateral prefrontal cortex of mice to establish a synucleinopathy animal model, and the A2AR inhibitor KW6002 (5 mg/kg) was injected intraperitoneally to intervene. RESULT The intracerebral injection of A53T-α-Syn protofibrils triggers the formation of inclusion bodies in the brain, leading to astrocyte activation, an increased number of apoptotic cells, and suppression of autophagic flux. The administration of KW6002 significantly reversed these phenomena. In vitro experiments revealed that A53T-α-Syn protofibrils inhibited HT-22 autophagy in mouse hippocampal neuronal cells, whereas KW6002 increased cellular autophagic flux, upregulated the expression of LAMP2A and Hsc70 proteins and inhibited the expression of SQSTM1 protein. The present study suggests that KW6002 reduces the level of α-Syn phosphorylation by inhibiting A2AR protein, at the same time, enhances the autophagic flux of neuronal cells, resulting in the degradation of A53T-α-Syn protofibrils and thus reducing the neuronal toxicity and apoptosis induced by A53T-α-Syn protofibrils. CONCLUSION KW6002 has a significant protective effect on neuronal injury induced by A53T-α-Syn.
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Affiliation(s)
- Qidi Hu
- Department of Ophthalmology, Wenzhou Medical University Ningbo Eye Hospital, Ningbo 315040, China; Ningbo Clinical Medical Research Center for Ophthalmology, Ningbo 315040, China.
| | - Lingli Xu
- Department of Ophthalmology, Wenzhou Medical University Ningbo Eye Hospital, Ningbo 315040, China
| | - Xiaotian Liu
- Department of Ophthalmology, Wenzhou Medical University Ningbo Eye Hospital, Ningbo 315040, China
| | - Yuwen Wang
- Department of Ophthalmology, Wenzhou Medical University Ningbo Eye Hospital, Ningbo 315040, China
| | - Jianshu Yuan
- Department of Ophthalmology, Wenzhou Medical University Ningbo Eye Hospital, Ningbo 315040, China
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Zhao Y, Ning YL, Zhou YG. A 2AR and traumatic brain injury. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 170:225-265. [PMID: 37741693 DOI: 10.1016/bs.irn.2023.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/25/2023]
Abstract
Accumulating evidence has revealed the adenosine 2A receptor is a key tuner for neuropathological and neurobehavioral changes following traumatic brain injury by experimental animal models and a few clinical trials. Here, we highlight recent data involving acute/sub-acute and chronic alterations of adenosine and adenosine 2A receptor-associated signaling in pathological conditions after trauma, with an emphasis of traumatic brain injury, including neuroinflammation, cognitive and psychiatric disorders, and other severe consequences. We expect this would lead to the development of therapeutic strategies for trauma-related disorders with novel mechanisms of action.
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Affiliation(s)
- Yan Zhao
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping Hospital, Army Medical University, P.R. China; Institute of Brain and Intelligence, Army Medical University, Chongqing, P.R. China
| | - Ya-Lei Ning
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping Hospital, Army Medical University, P.R. China; Institute of Brain and Intelligence, Army Medical University, Chongqing, P.R. China
| | - Yuan-Guo Zhou
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping Hospital, Army Medical University, P.R. China; Institute of Brain and Intelligence, Army Medical University, Chongqing, P.R. China.
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Madeira D, Lopes CR, Simões AP, Canas PM, Cunha RA, Agostinho P. Astrocytic A 2A receptors silencing negatively impacts hippocampal synaptic plasticity and memory of adult mice. Glia 2023. [PMID: 37183905 DOI: 10.1002/glia.24384] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/28/2023] [Accepted: 05/02/2023] [Indexed: 05/16/2023]
Abstract
Astrocytes are wired to bidirectionally communicate with neurons namely with synapses, thus shaping synaptic plasticity, which in the hippocampus is considered to underlie learning and memory. Adenosine A2A receptors (A2A R) are a potential candidate to modulate this bidirectional communication, since A2A R regulate synaptic plasticity and memory and also control key astrocytic functions. Nonetheless, little is known about the role of astrocytic A2A R in synaptic plasticity and hippocampal-dependent memory. Here, we investigated the impact of genetic silencing astrocytic A2A R on hippocampal synaptic plasticity and memory of adult mice. The genetic A2A R silencing in astrocytes was accomplished by a bilateral injection into the CA1 hippocampal area of a viral construct (AAV5-GFAP-GFP-Cre) that inactivate A2A R expression in astrocytes of male adult mice carrying "floxed" A2A R gene, as confirmed by A2A R binding assays. Astrocytic A2A R silencing alters astrocytic morphology, typified by an increment of astrocytic arbor complexity, and led to deficits in spatial reference memory and compromised hippocampal synaptic plasticity, typified by a reduction of LTP magnitude and a shift of synaptic long-term depression (LTD) toward LTP. These data indicate that astrocytic A2A R control astrocytic morphology and influence hippocampal synaptic plasticity and memory of adult mice in a manner different from neuronal A2A R.
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Affiliation(s)
- Daniela Madeira
- Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal
- Center for Neuroscience and Cell Biology- University of Coimbra (CNC- UC), Coimbra, Portugal
| | - Cátia R Lopes
- Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal
- Center for Neuroscience and Cell Biology- University of Coimbra (CNC- UC), Coimbra, Portugal
| | - Ana P Simões
- Center for Neuroscience and Cell Biology- University of Coimbra (CNC- UC), Coimbra, Portugal
| | - Paula M Canas
- Center for Neuroscience and Cell Biology- University of Coimbra (CNC- UC), Coimbra, Portugal
| | - Rodrigo A Cunha
- Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal
- Center for Neuroscience and Cell Biology- University of Coimbra (CNC- UC), Coimbra, Portugal
| | - Paula Agostinho
- Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal
- Center for Neuroscience and Cell Biology- University of Coimbra (CNC- UC), Coimbra, Portugal
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4
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Purnell BS, Alves M, Boison D. Astrocyte-neuron circuits in epilepsy. Neurobiol Dis 2023; 179:106058. [PMID: 36868484 DOI: 10.1016/j.nbd.2023.106058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/20/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023] Open
Abstract
The epilepsies are a diverse spectrum of disease states characterized by spontaneous seizures and associated comorbidities. Neuron-focused perspectives have yielded an array of widely used anti-seizure medications and are able to explain some, but not all, of the imbalance of excitation and inhibition which manifests itself as spontaneous seizures. Furthermore, the rate of pharmacoresistant epilepsy remains high despite the regular approval of novel anti-seizure medications. Gaining a more complete understanding of the processes that turn a healthy brain into an epileptic brain (epileptogenesis) as well as the processes which generate individual seizures (ictogenesis) may necessitate broadening our focus to other cell types. As will be detailed in this review, astrocytes augment neuronal activity at the level of individual neurons in the form of gliotransmission and the tripartite synapse. Under normal conditions, astrocytes are essential to the maintenance of blood-brain barrier integrity and remediation of inflammation and oxidative stress, but in epilepsy these functions are impaired. Epilepsy results in disruptions in the way astrocytes relate to each other by gap junctions which has important implications for ion and water homeostasis. In their activated state, astrocytes contribute to imbalances in neuronal excitability due to their decreased capacity to take up and metabolize glutamate and an increased capacity to metabolize adenosine. Furthermore, due to their increased adenosine metabolism, activated astrocytes may contribute to DNA hypermethylation and other epigenetic changes that underly epileptogenesis. Lastly, we will explore the potential explanatory power of these changes in astrocyte function in detail in the specific context of the comorbid occurrence of epilepsy and Alzheimer's disease and the disruption in sleep-wake regulation associated with both conditions.
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Affiliation(s)
- Benton S Purnell
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America
| | - Mariana Alves
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America; Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin D02 YN77, Ireland
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America; Brain Health Institute, Rutgers University, Piscataway, NJ, United States of America.
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Khan H, Kaur P, Singh TG, Grewal AK, Sood S. Adenosine as a Key Mediator of Neuronal Survival in Cerebral Ischemic Injury. Neurochem Res 2022; 47:3543-3555. [PMID: 36042141 DOI: 10.1007/s11064-022-03737-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 08/15/2022] [Accepted: 08/23/2022] [Indexed: 10/14/2022]
Abstract
Several experimental studies have linked adenosine's neuroprotective role in cerebral ischemia. During ischemia, adenosine is formed due to intracellular ATP breakdown into ADP, further when phosphate is released from ADP, the adenosine monophosphate is formed. It acts via A1, A2, and A3 receptors found on neurons, blood vessels, glial cells, platelets, and leukocytes. It is related to various effector systems such as adenyl cyclase and membrane ion channels via G-proteins. Pharmacological manipulation of adenosine receptors by agonists (CCPA, ADAC, IB-MECA) increases ischemic brain damage in various in vivo and in vitro models of cerebral ischemia whereas, agonist can also be neuroprotective. Mainly, receptor antagonists (CGS15943, MRS1706) indicated neuroprotection. Later, various studies also revealed that the downregulation or upregulation of specific adenosine receptors is necessary during the recovery of cerebral ischemia by activating several downstream signaling pathways. In the current review, we elaborate on the dual roles of adenosine and its receptor subtypes A1, A2, and A3 and their involvement in the pathobiology of cerebral ischemic injury. Adenosine-based therapies have the potential to improve the outcomes of cerebral injury patients, thereby providing them with a more optimistic future.
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Affiliation(s)
- Heena Khan
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India
| | - Parneet Kaur
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India
| | - Thakur Gurejet Singh
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India.
| | - Amarjot Kaur Grewal
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India
| | - Shreya Sood
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India
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Wang M, Li Z, Song Y, Sun Q, Deng L, Lin Z, Zeng Y, Qiu C, Lin J, Guo H, Chen J, Guo W. Genetic tagging of the adenosine A2A receptor reveals its heterogeneous expression in brain regions. Front Neuroanat 2022; 16:978641. [PMID: 36059431 PMCID: PMC9434489 DOI: 10.3389/fnana.2022.978641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 07/29/2022] [Indexed: 11/22/2022] Open
Abstract
The adenosine A2A receptor (A2AR), a G protein-coupled receptor, is involved in numerous and varied physiological and pathological processes, including inflammation, immune responses, blood flow, and neurotransmission. Accordingly, it has become an important drug target for the treatment of neuropsychiatric disorders. However, the exact brain distribution of A2AR in regions outside the striatum that display relatively low levels of endogenous A2AR expression has hampered the exploration of A2AR functions under both physiological and pathological conditions. To further study the detailed distribution of the A2AR in low-expression regions, we have generated A2AR knock-in mice in which the 3xHA-2xMyc epitope tag sequence was fused to the C-terminus of A2AR (A2AR-tag mice) via CRISPR/Cas9 technology. Here, using CRISPR/Cas9 technology, we have generated A2AR knock-in mice in which the 3xHA-2xMyc epitope tag sequence was fused to the C-terminus of A2AR (A2AR-tag mice). The A2AR-tag mice exhibited normal locomotor activity and emotional state. Consistent with previous studies, A2AR fluorescence was widely detected in the striatum, nucleus accumbens, and olfactory tubercles, with numerous labeled cells being evident in these regions in the A2AR-tag mouse. Importantly, we also identified the presence of a few but clearly labeled cells in heterogeneous brain regions where A2AR expression has not previously been unambiguously detected, including the lateral septum, hippocampus, amygdala, cerebral cortex, and gigantocellular reticular nucleus. The A2AR-tag mouse represents a novel useful genetic tool for monitoring the expression of A2AR and dissecting its functions in brain regions other than the striatum.
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Affiliation(s)
- Muran Wang
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Zewen Li
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Yue Song
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Qiuqin Sun
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Lu Deng
- Department of Neurology, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
- Key Laboratory of Structural Malformations in Children of Zhejiang Province, Wenzhou, China
| | - Zhiqing Lin
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Yang Zeng
- Shanghai Pregen Biotechnology Co., Ltd., Shanghai, China
| | - Chunhong Qiu
- Shanghai Pregen Biotechnology Co., Ltd., Shanghai, China
| | - Jingjing Lin
- Department of Neurology, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
- Key Laboratory of Structural Malformations in Children of Zhejiang Province, Wenzhou, China
| | - Hui Guo
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Jiangfan Chen
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
- Jiangfan Chen,
| | - Wei Guo
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
- *Correspondence: Wei Guo,
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Brunner B, Ari C, D’Agostino DP, Kovács Z. Adenosine Receptors Modulate the Exogenous Ketogenic Supplement-Evoked Alleviating Effect on Lipopolysaccharide-Generated Increase in Absence Epileptic Activity in WAG/Rij Rats. Nutrients 2021; 13:nu13114082. [PMID: 34836344 PMCID: PMC8623289 DOI: 10.3390/nu13114082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/04/2021] [Accepted: 11/11/2021] [Indexed: 01/23/2023] Open
Abstract
It has been previously demonstrated that KEKS food containing exogenous ketogenic supplement ketone salt (KS) and ketone ester (KE) decreased the lipopolysaccharide (LPS)-generated increase in SWD (spike-wave discharge) number in Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats, likely through ketosis. KEKS-supplemented food-generated ketosis may increase adenosine levels, and may thus modulate both neuroinflammatory processes and epileptic activity through adenosine receptors (such as A1Rs and A2ARs). To determine whether these adenosine receptors are able to modify the KEKS food-generated alleviating effect on LPS-evoked increases in SWD number, an antagonist of A1R DPCPX (1,3-dipropyl-8-cyclopentylxanthine; 0.2 mg/kg) with LPS (50 µg/kg) and an antagonist of A2AR SCH58261 (7-(2-phenylethyl)-5-amino-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine; 0.5 mg/kg) with LPS were co-injected intraperitoneally (i.p.) on the ninth day of KEKS food administration, and their influence not only on the SWD number, but also on blood glucose, R-beta-hydroxybutyrate (R-βHB) levels, and body weight were measured. We showed that inhibition of A1Rs abolished the alleviating effect of KEKS food on LPS-generated increases in the SWD number, whereas blocking A2ARs did not significantly modify the KEKS food-generated beneficial effect. Our results suggest that the neuromodulatory benefits of KEKS-supplemented food on absence epileptic activity are mediated primarily through A1R, not A2AR.
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Affiliation(s)
- Brigitta Brunner
- Faculty of Sciences, Institute of Biology, University of Pécs, Ifjúság Str. 6, 7624 Pécs, Hungary;
- Savaria University Centre, Department of Biology, ELTE Eötvös Loránd University, Károlyi Gáspár tér 4, 9700 Szombathely, Hungary;
| | - Csilla Ari
- Ketone Technologies LLC, Tampa, FL 33612, USA;
- Behavioral Neuroscience Research Laboratory, Department of Psychology, University of South Florida, Tampa, FL 33620, USA
- Correspondence: ; Tel.: +1-(813)-2409925
| | - Dominic P. D’Agostino
- Ketone Technologies LLC, Tampa, FL 33612, USA;
- Laboratory of Metabolic Medicine, Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
- Institute for Human and Machine Cognition, Ocala, FL 34471, USA
| | - Zsolt Kovács
- Savaria University Centre, Department of Biology, ELTE Eötvös Loránd University, Károlyi Gáspár tér 4, 9700 Szombathely, Hungary;
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Neuroinflammation and L-dopa-induced abnormal involuntary movements in 6-hydroxydopamine-lesioned rat model of Parkinson's disease are counteracted by combined administration of a 5-HT 1A/1B receptor agonist and A 2A receptor antagonist. Neuropharmacology 2021; 196:108693. [PMID: 34229013 DOI: 10.1016/j.neuropharm.2021.108693] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 06/24/2021] [Accepted: 06/29/2021] [Indexed: 12/20/2022]
Abstract
Several lines of evidence have strongly implicated neuroinflammation in Parkinson's disease (PD) progression and l-dopa-induced dyskinesia. The present study investigated whether early subchronic pretreatment with the serotonin 5-HT1A/1B receptor agonist eltoprazine plus the adenosine A2A receptor antagonist preladenant counteracted l-dopa-induced abnormal involuntary movements (AIMs, index of dyskinesia), and neuroinflammation, in unilateral 6-hydroxydopamine(6-OHDA)-lesioned rat model of PD. The immunoreactivity of glial fibrillary acidic protein (GFAP), and the colocalization of ionized calcium binding adaptor molecule-1 (IBA-1), with interleukin (IL)-1β, tumor-necrosis-factor-α (TNF-α) and IL-10 were evaluated in the denervated caudate-putamen (CPu) and substantia nigra pars-compacta (SNc). The combined subchronic pretreatment with l-dopa plus eltoprazine and preladenant reduced AIMs induced by acute l-dopa challenge in these rats and decreased GFAP and IBA-1 immunoreactivity induced by the drug in both CPu and SNc, with reduction in IL-1β in IBA-1-positive cells in both CPu and SNc, and in TNF-α in IBA-1-positive cells in SNc. Moreover, a significant increase in IL-10 in IBA-1-positive cells was observed in SNc. Evaluation of immediate early-gene zif-268 (index of neuronal activation) after l-dopa challenge, showed an increase in its expression in denervated CPu of rats pretreated with l-dopa or l-dopa plus preladenant compared with vehicle, whereas rats pretreated with eltoprazine, with or without preladenant, had lower zif-268 expression. Finally, tyrosine hydroxylase and dopamine transporter examined to evaluate neurodegeneration, showed a significant equal decrease in all experimental groups. The present findings suggest that combination of l-dopa with eltoprazine and preladenant may be promising therapeutic strategy for delaying the onset of dyskinesia, preserving l-dopa efficacy and reducing neuroinflammation markers in nigrostriatal system of 6-OHDA-lesioned rats.
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Zarrinmayeh H, Territo PR. Purinergic Receptors of the Central Nervous System: Biology, PET Ligands, and Their Applications. Mol Imaging 2021; 19:1536012120927609. [PMID: 32539522 PMCID: PMC7297484 DOI: 10.1177/1536012120927609] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Purinergic receptors play important roles in central nervous system (CNS). These receptors are involved in cellular neuroinflammatory responses that regulate functions of neurons, microglial and astrocytes. Based on their endogenous ligands, purinergic receptors are classified into P1 or adenosine, P2X and P2Y receptors. During brain injury or under pathological conditions, rapid diffusion of extracellular adenosine triphosphate (ATP) or uridine triphosphate (UTP) from the damaged cells, promote microglial activation that result in the changes in expression of several of these receptors in the brain. Imaging of the purinergic receptors with selective Positron Emission Tomography (PET) radioligands has advanced our understanding of the functional roles of some of these receptors in healthy and diseased brains. In this review, we have accumulated a list of currently available PET radioligands of the purinergic receptors that are used to elucidate the receptor functions and participations in CNS disorders. We have also reviewed receptors lacking radiotracer, laying the foundation for future discoveries of novel PET radioligands to reveal these receptors roles in CNS disorders.
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Affiliation(s)
- Hamideh Zarrinmayeh
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Paul R Territo
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
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Lopes CR, Cunha RA, Agostinho P. Astrocytes and Adenosine A 2A Receptors: Active Players in Alzheimer's Disease. Front Neurosci 2021; 15:666710. [PMID: 34054416 PMCID: PMC8155589 DOI: 10.3389/fnins.2021.666710] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 03/23/2021] [Indexed: 12/17/2022] Open
Abstract
Astrocytes, through their numerous processes, establish a bidirectional communication with neurons that is crucial to regulate synaptic plasticity, the purported neurophysiological basis of memory. This evidence contributed to change the classic “neurocentric” view of Alzheimer’s disease (AD), being astrocytes increasingly considered a key player in this neurodegenerative disease. AD, the most common form of dementia in the elderly, is characterized by a deterioration of memory and of other cognitive functions. Although, early cognitive deficits have been associated with synaptic loss and dysfunction caused by amyloid-β peptides (Aβ), accumulating evidences support a role of astrocytes in AD. Astrocyte atrophy and reactivity occurring at early and later stages of AD, respectively, involve morphological alterations that translate into functional changes. However, the main signals responsible for astrocytic alterations in AD and their impact on synaptic function remain to be defined. One possible candidate is adenosine, which can be formed upon extracellular catabolism of ATP released by astrocytes. Adenosine can act as a homeostatic modulator and also as a neuromodulator at the synaptic level, through the activation of adenosine receptors, mainly of A1R and A2AR subtypes. These receptors are also present in astrocytes, being particularly relevant in pathological conditions, to control the morphofunctional responses of astrocytes. Here, we will focus on the role of A2AR, since they are particularly associated with neurodegeneration and also with memory processes. Furthermore, A2AR levels are increased in the AD brain, namely in astrocytes where they can control key astrocytic functions. Thus, unveiling the role of A2AR in astrocytes function might shed light on novel therapeutic strategies for AD.
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Affiliation(s)
- Cátia R Lopes
- Center for Neuroscience and Cell Biology, Coimbra, Portugal
| | - Rodrigo A Cunha
- Center for Neuroscience and Cell Biology, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Paula Agostinho
- Center for Neuroscience and Cell Biology, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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Jenner P, Mori A, Aradi SD, Hauser RA. Istradefylline - a first generation adenosine A 2A antagonist for the treatment of Parkinson's disease. Expert Rev Neurother 2021; 21:317-333. [PMID: 33507105 DOI: 10.1080/14737175.2021.1880896] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Introduction It is now accepted that Parkinson's disease (PD) is not simply due to dopaminergic dysfunction, and there is interest in developing non-dopaminergic approaches to disease management. Adenosine A2A receptor antagonists represent a new way forward in the symptomatic treatment of PD.Areas covered In this narrative review, we summarize the literature supporting the utility of adenosine A2A antagonists in PD with a specific focus on istradefylline, the most studied and only adenosine A2A antagonist currently in clinical use.Expert opinion: At this time, the use of istradefylline in the treatment of PD is limited to the management of motor fluctuations as supported by the results of randomized clinical trials and evaluation by Japanese and USA regulatory authorities. The relatively complicated clinical development of istradefylline was based on classically designed studies conducted in PD patients with motor fluctuations on an optimized regimen of levodopa plus adjunctive dopaminergic medications. In animal models, there is consensus that a more robust effect of istradefylline in improving motor function is produced when combined with low or threshold doses of levodopa rather than with high doses that produce maximal dopaminergic improvement. Exploration of istradefylline as a 'levodopa sparing' strategy in earlier PD would seem warranted.
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Affiliation(s)
- Peter Jenner
- Institute of Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Akihisa Mori
- Medical Affairs Department, Kyowa Kirin Co Ltd, Otemachi, Chiyoda-ku, Tokyo, Japan
| | - Stephen D Aradi
- Department of Neurology, University of South Florida, Tampa, Florida, USA
| | - Robert A Hauser
- Department of Neurology, University of South Florida, Tampa, Florida, USA
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12
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Do caffeine and more selective adenosine A 2A receptor antagonists protect against dopaminergic neurodegeneration in Parkinson's disease? Parkinsonism Relat Disord 2020; 80 Suppl 1:S45-S53. [PMID: 33349580 PMCID: PMC8102090 DOI: 10.1016/j.parkreldis.2020.10.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 09/26/2020] [Accepted: 10/11/2020] [Indexed: 12/15/2022]
Abstract
The adenosine A2A receptor is a major target of caffeine, the most widely used psychoactive substance worldwide. Large epidemiological studies have long shown caffeine consumption is a strong inverse predictor of Parkinson’s disease (PD). In this review, we first examine the epidemiology of caffeine use vis-à-vis PD and follow this by looking at the evidence for adenosine A2A receptor antagonists as potential neuroprotective agents. There is a wealth of accumulating biological, epidemiological and clinical evidence to support the further investigation of selective adenosine A2A antagonists, as well as caffeine, as promising candidate therapeutics to fill the unmet need for disease modification of PD.
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13
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Ren X, Chen JF. Caffeine and Parkinson's Disease: Multiple Benefits and Emerging Mechanisms. Front Neurosci 2020; 14:602697. [PMID: 33390888 PMCID: PMC7773776 DOI: 10.3389/fnins.2020.602697] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/25/2020] [Indexed: 12/14/2022] Open
Abstract
Parkinson’s disease (PD) is the second most common neurodegenerative disorder, characterized by dopaminergic neurodegeneration, motor impairment and non-motor symptoms. Epidemiological and experimental investigations into potential risk factors have firmly established that dietary factor caffeine, the most-widely consumed psychoactive substance, may exerts not only neuroprotective but a motor and non-motor (cognitive) benefits in PD. These multi-benefits of caffeine in PD are supported by convergence of epidemiological and animal evidence. At least six large prospective epidemiological studies have firmly established a relationship between increased caffeine consumption and decreased risk of developing PD. In addition, animal studies have also demonstrated that caffeine confers neuroprotection against dopaminergic neurodegeneration using PD models of mitochondrial toxins (MPTP, 6-OHDA, and rotenone) and expression of α-synuclein (α-Syn). While caffeine has complex pharmacological profiles, studies with genetic knockout mice have clearly revealed that caffeine’s action is largely mediated by the brain adenosine A2A receptor (A2AR) and confer neuroprotection by modulating neuroinflammation and excitotoxicity and mitochondrial function. Interestingly, recent studies have highlighted emerging new mechanisms including caffeine modulation of α-Syn degradation with enhanced autophagy and caffeine modulation of gut microbiota and gut-brain axis in PD models. Importantly, since the first clinical trial in 2003, United States FDA has finally approved clinical use of the A2AR antagonist istradefylline for the treatment of PD with OFF-time in Sept. 2019. To realize therapeutic potential of caffeine in PD, genetic study of caffeine and risk genes in human population may identify useful pharmacogenetic markers for predicting individual responses to caffeine in PD clinical trials and thus offer a unique opportunity for “personalized medicine” in PD.
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Affiliation(s)
- Xiangpeng Ren
- Molecular Neuropharmacology Lab, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Visual Science, Wenzhou, China.,Department of Biochemistry, Medical College, Jiaxing University, Jiaxing, China
| | - Jiang-Fan Chen
- Molecular Neuropharmacology Lab, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Visual Science, Wenzhou, China
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14
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Purinergic signaling orchestrating neuron-glia communication. Pharmacol Res 2020; 162:105253. [PMID: 33080321 DOI: 10.1016/j.phrs.2020.105253] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/29/2020] [Accepted: 10/09/2020] [Indexed: 12/12/2022]
Abstract
This review discusses the evidence supporting a role for ATP signaling (operated by P2X and P2Y receptors) and adenosine signaling (mainly operated by A1 and A2A receptors) in the crosstalk between neurons, astrocytes, microglia and oligodendrocytes. An initial emphasis will be given to the cooperation between adenosine receptors to sharpen information salience encoding across synapses. The interplay between ATP and adenosine signaling in the communication between astrocytes and neurons will then be presented in context of the integrative properties of the astrocytic syncytium, allowing to implement heterosynaptic depression processes in neuronal networks. The process of microglia 'activation' and its control by astrocytes and neurons will then be analyzed under the perspective of an interplay between different P2 receptors and adenosine A2A receptors. In spite of these indications of a prominent role of purinergic signaling in the bidirectional communication between neurons and glia, its therapeutical exploitation still awaits obtaining an integrated view of the spatio-temporal action of ATP signaling and adenosine signaling, clearly distinguishing the involvement of both purinergic signaling systems in the regulation of physiological processes and in the control of pathogenic-like responses upon brain dysfunction or damage.
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15
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Burnstock G. Introduction to Purinergic Signalling in the Brain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1202:1-12. [PMID: 32034706 DOI: 10.1007/978-3-030-30651-9_1] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
ATP is a cotransmitter with glutamate, noradrenaline, GABA, acetylcholine and dopamine in the brain. There is a widespread presence of both adenosine (P1) and P2 nucleotide receptors in the brain on both neurons and glial cells. Adenosine receptors play a major role in presynaptic neuromodulation, while P2X ionotropic receptors are involved in fast synaptic transmission and synaptic plasticity. P2Y G protein-coupled receptors are largely involved in presynaptic activities, as well as mediating long-term (trophic) signalling in cell proliferation, differentiation and death during development and regeneration. Both P1 and P2 receptors participate in neuron-glial interactions. Purinergic signalling is involved in control of cerebral vascular tone and remodelling and has been implicated in learning and memory, locomotor and feeding behaviour and sleep. There is increasing interest in the involvement of purinergic signalling in the pathophysiology of the CNS, including trauma, ischaemia, epilepsy, neurodegenerative diseases, neuropsychiatric and mood disorders, and cancer, including gliomas.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Royal Free Campus, Rowland Hill Street, NW3 2PF, London, UK.
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16
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Mateus JM, Ribeiro FF, Alonso-Gomes M, Rodrigues RS, Marques JM, Sebastião AM, Rodrigues RJ, Xapelli S. Neurogenesis and Gliogenesis: Relevance of Adenosine for Neuroregeneration in Brain Disorders. J Caffeine Adenosine Res 2019. [DOI: 10.1089/caff.2019.0010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Joana M. Mateus
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Filipa F. Ribeiro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Marta Alonso-Gomes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Rui S. Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Joana M. Marques
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
- Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Ana M. Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Ricardo J. Rodrigues
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
- Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Sara Xapelli
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
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17
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Nedeljkovic N. Complex regulation of ecto-5'-nucleotidase/CD73 and A 2AR-mediated adenosine signaling at neurovascular unit: A link between acute and chronic neuroinflammation. Pharmacol Res 2019; 144:99-115. [PMID: 30954629 DOI: 10.1016/j.phrs.2019.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 04/01/2019] [Accepted: 04/03/2019] [Indexed: 12/20/2022]
Abstract
The review summarizes available data regarding the complex regulation of CD73 at the neurovascular unit (NVU) during neuroinflammation. Based on available data we propose the biphasic pattern of CD73 regulation at NVU, with an early attenuation and a postponed up-regulation of CD73 activity. Transient attenuation of CD73 activity on leukocyte/vascular endothelium and leukocyte/astrocyte surface, required for the initiation of a neuroinflammatory response, may be effectuated either by catalytic inhibition of CD73 and/or by shedding of the CD73 molecule from the cell surface, while postponed induction of CD73 is effectuated by transcriptional up-regulation of Nt5e and posttranslational modifications. Neuroinflammatory conditions are also associated with significant enhancement and gain-of-function of A2AR-mediated adenosine signaling. However, in contrast to the temporary prevalence of A2AR over A1R signaling during an acute inflammatory response, prolonged induction of A2AR and resulting perpetual CD73/A2AR coupling may be a contributing factors in the transition between acute and chronic neuroinflammation. Thus, pharmacological targeting of the CD73/A2AR axis may attenuate inflammatory response and ameliorate neurological deficits in chronic neuroinflammatory conditions.
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Affiliation(s)
- Nadezda Nedeljkovic
- Department of General Physiology and Biophysics, Faculty of Biology University of Belgrade, Studentski trg 3, Belgrade 11001, Serbia.
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18
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Magni G, Ceruti S. The role of adenosine and P2Y receptors expressed by multiple cell types in pain transmission. Brain Res Bull 2019; 151:132-143. [PMID: 30797817 DOI: 10.1016/j.brainresbull.2019.02.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 01/25/2019] [Accepted: 02/15/2019] [Indexed: 02/07/2023]
Abstract
The role of extracellular nucleotides and nucleosides as signaling molecules in cell-to-cell communication has now been clearly established. This is particularly true in the central and peripheral nervous system, where purines and pyrimidines are involved in both physiological and pathological interactions between neurons and surrounding glial cells. It can be thus foreseen that the purinergic system could represent a new potential target for the development of effective analgesics, also through the normalization of neuronal functions and the inhibition of glial cell activation. Research in the last 15 years has progressively confirmed this hypothesis, but no purinergic-based analgesics have reach the market so far; in the present review we have collected the more recent discoveries on the role of G protein-coupled P2Y nucleotide and of adenosine receptors expressed by both neurons and glial cells under painful conditions, and we have highlighted some of the challenges that must be faced to translate basic and preclinical studies to clinics.
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Affiliation(s)
- Giulia Magni
- Laboratory of Molecular and Cellular Pharmacology of Purinergic Transmission, Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Balzaretti, 9, 20133, Milan, Italy
| | - Stefania Ceruti
- Laboratory of Molecular and Cellular Pharmacology of Purinergic Transmission, Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Balzaretti, 9, 20133, Milan, Italy.
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19
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Ogawa Y, Furusawa E, Saitoh T, Sugimoto H, Omori T, Shimizu S, Kondo H, Yamazaki M, Sakuraba H, Oishi K. Inhibition of astrocytic adenosine receptor A 2A attenuates microglial activation in a mouse model of Sandhoff disease. Neurobiol Dis 2018; 118:142-154. [DOI: 10.1016/j.nbd.2018.07.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 07/02/2018] [Accepted: 07/15/2018] [Indexed: 12/18/2022] Open
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20
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Luongo L, Salvemini D. Targeting metabotropic adenosine receptors for neuropathic pain: Focus on A2A. Brain Behav Immun 2018; 69:60-61. [PMID: 29499304 DOI: 10.1016/j.bbi.2018.02.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 02/26/2018] [Indexed: 11/16/2022] Open
Affiliation(s)
- Livio Luongo
- Department of Experimental Medicine, Università della Campania "L. Vanvitelli", Naples, Italy.
| | - Daniela Salvemini
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO, USA
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21
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Franco R, Navarro G. Adenosine A 2A Receptor Antagonists in Neurodegenerative Diseases: Huge Potential and Huge Challenges. Front Psychiatry 2018; 9:68. [PMID: 29593579 PMCID: PMC5857539 DOI: 10.3389/fpsyt.2018.00068] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Accepted: 02/19/2018] [Indexed: 12/11/2022] Open
Affiliation(s)
- Rafael Franco
- Department of Biochemistry and Molecular Biomedicine, School of Biology, Universidad de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Gemma Navarro
- Department of Biochemistry and Molecular Biomedicine, School of Biology, Universidad de Barcelona, Barcelona, Spain.,Department of Biochemistry and Physiology, Faculty of Pharmacy, Universitat de Barcelona, Barcelona, Spain
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22
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In Vivo PET Imaging of Adenosine 2A Receptors in Neuroinflammatory and Neurodegenerative Disease. CONTRAST MEDIA & MOLECULAR IMAGING 2017; 2017:6975841. [PMID: 29348737 PMCID: PMC5733838 DOI: 10.1155/2017/6975841] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 10/18/2017] [Indexed: 01/01/2023]
Abstract
Adenosine receptors are G-protein coupled P1 purinergic receptors that are broadly expressed in the peripheral immune system, vasculature, and the central nervous system (CNS). Within the immune system, adenosine 2A (A2A) receptor-mediated signaling exerts a suppressive effect on ongoing inflammation. In healthy CNS, A2A receptors are expressed mainly within the neurons of the basal ganglia. Alterations in A2A receptor function and expression have been noted in movement disorders, and in Parkinson's disease pharmacological A2A receptor antagonism leads to diminished motor symptoms. Although A2A receptors are expressed only at a low level in the healthy CNS outside striatum, pathological challenge or inflammation has been shown to lead to upregulation of A2A receptors in extrastriatal CNS tissue, and this has been successfully quantitated using in vivo positron emission tomography (PET) imaging and A2A receptor-binding radioligands. Several radioligands for PET imaging of A2A receptors have been developed in recent years, and A2A receptor-targeting PET imaging may thus provide a potential additional tool to evaluate various aspects of neuroinflammation in vivo. This review article provides a brief overview of A2A receptors in healthy brain and in a selection of most important neurological diseases and describes the recent advances in A2A receptor-targeting PET imaging studies.
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23
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Chen JF, Zhang S, Zhou R, Lin Z, Cai X, Lin J, Huo Y, Liu X. Adenosine receptors and caffeine in retinopathy of prematurity. Mol Aspects Med 2017; 55:118-125. [PMID: 28088487 DOI: 10.1016/j.mam.2017.01.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 12/28/2016] [Accepted: 01/10/2017] [Indexed: 01/26/2023]
Abstract
Retinopathy of prematurity (ROP) is a major cause of childhood blindness in the world and is caused by oxygen-induced damage to the developing retinal vasculature, resulting in hyperoxia-induced vaso-obliteration and subsequent delayed retinal vascularization and hypoxia-induced pathological neovascularization driven by vascular endothelial growth factor (VEGF) signaling pathway in retina. Current anti-VEGF therapy has shown some effective in a clinical trial, but is associated with the unintended effects on delayed eye growth and retinal vasculature development of preterm infants. Notably, cellular responses to hypoxia are characterized by robust increases in extracellular adenosine production and the markedly induced adenosine receptors, which provide a novel target for preferential control of pathological angiogenesis without affecting normal vascular development. Here, we review the experimental evidence in support of adenosine receptor-based therapeutic strategy for ROP, including the aberrant adenosine signaling in oxygen-induced retinopathy and the role of three adenosine receptor subtypes (A1R, A2AR, A2BR) in development and treatment of ROP using oxygen-induced retinopathy models. The clinical and initial animal evidence that implicate the therapeutic effect of caffeine (a non-selective adenosine receptor antagonist) in treatment of ROP are highlighted. Lastly, we discussed the translational potential as well therapeutic advantage of adenosine receptor- and caffeine-based therapy for ROR and possibly other proliferative retinopathy.
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Affiliation(s)
- Jiang-Fan Chen
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health of China, Wenzhou, Zhejiang, China.
| | - Shuya Zhang
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health of China, Wenzhou, Zhejiang, China
| | - Rong Zhou
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health of China, Wenzhou, Zhejiang, China
| | - Zhenlang Lin
- Department of Neonatology, Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaohong Cai
- Department of Neonatology, Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jing Lin
- Department of Neonatology, Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yuqing Huo
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912, USA; Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Xiaoling Liu
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health of China, Wenzhou, Zhejiang, China
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24
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Yamashiro K, Morita M. Novel aspects of extracellular adenosine dynamics revealed by adenosine sensor cells. Neural Regen Res 2017; 12:881-885. [PMID: 28761414 PMCID: PMC5514856 DOI: 10.4103/1673-5374.208544] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Adenosine modulates diverse physiological and pathological processes in the brain, including neuronal activities, blood flow, and inflammation. However, the mechanisms underlying the dynamics of extracellular adenosine are not fully understood. We have recently developed a novel biosensor, called an adenosine sensor cell, and we have characterized the neuronal and astrocytic pathways for elevating extracellular adenosine. In this review, the physiological implications and therapeutic potential of the pathways revealed by the adenosine sensor cells are discussed. We propose that the multiple pathways regulating extracellular adenosine allow for the diverse functions of this neuromodulator, and their malfunctions cause various neurological and psychiatric disorders.
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Affiliation(s)
- Kunihiko Yamashiro
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan.,Department of NCNP Brain Physiology and Pathology, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, Tokyo, Japan.,Department of Biology, Kobe University Graduate School of Sciences, Kobe, Japan
| | - Mitsuhiro Morita
- Department of Biology, Kobe University Graduate School of Sciences, Kobe, Japan
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25
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Barros-Barbosa AR, Ferreirinha F, Oliveira Â, Mendes M, Lobo MG, Santos A, Rangel R, Pelletier J, Sévigny J, Cordeiro JM, Correia-de-Sá P. Adenosine A 2A receptor and ecto-5'-nucleotidase/CD73 are upregulated in hippocampal astrocytes of human patients with mesial temporal lobe epilepsy (MTLE). Purinergic Signal 2016; 12:719-734. [PMID: 27650530 PMCID: PMC5124012 DOI: 10.1007/s11302-016-9535-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 09/05/2016] [Indexed: 12/11/2022] Open
Abstract
Refractoriness to existing medications of up to 80 % of the patients with mesial temporal lobe epilepsy (MTLE) prompts for finding new antiepileptic drug targets. The adenosine A2A receptor emerges as an interesting pharmacological target since its excitatory nature partially counteracts the dominant antiepileptic role of endogenous adenosine acting via inhibitory A1 receptors. Gain of function of the excitatory A2A receptor has been implicated in a significant number of brain pathologies commonly characterized by neuronal excitotoxicity. Here, we investigated changes in the expression and cellular localization of the A2A receptor and of the adenosine-generating enzyme, ecto-5'-nucleotidase/CD73, in the hippocampus of control individuals and MTLE human patients. Western blot analysis indicates that the A2A receptor is more abundant in the hippocampus of MTLE patients compared to control individuals. Immunoreactivity against the A2A receptor predominates in astrocytes staining positively for the glial fibrillary acidic protein (GFAP). No co-localization was observed between the A2A receptor and neuronal cell markers, like synaptotagmin 1/2 (nerve terminals) and neurofilament 200 (axon fibers). Hippocampal astrogliosis observed in MTLE patients was accompanied by a proportionate increase in A2A receptor and ecto-5'-nucleotidase/CD73 immunoreactivities. Given our data, we hypothesize that selective blockade of excessive activation of astrocytic A2A receptors and/or inhibition of surplus adenosine formation by membrane-bound ecto-5'-nucleotidase/CD73 may reduce neuronal excitability, thus providing a novel therapeutic target for drug-refractory seizures in MTLE patients.
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Affiliation(s)
- Aurora R Barros-Barbosa
- Laboratório de Farmacologia e Neurobiologia-Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Fátima Ferreirinha
- Laboratório de Farmacologia e Neurobiologia-Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Ângela Oliveira
- Laboratório de Farmacologia e Neurobiologia-Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Marina Mendes
- Laboratório de Farmacologia e Neurobiologia-Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - M Graça Lobo
- Laboratório de Farmacologia e Neurobiologia-Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Agostinho Santos
- Serviço de Patologia Forense, Instituto Nacional de Medicina Legal e Ciências Forenses-Delegação do Norte (INMLCF-DN), Porto, Portugal
| | - Rui Rangel
- Serviço de Neurocirurgia, Centro Hospitalar do Porto-Hospital Geral de Santo António (CHP-HGSA), Porto, Portugal
| | - Julie Pelletier
- Centre de Recherche du CHU de Québec-Université Laval, CHUL, QC, Québec, Canada
| | - Jean Sévigny
- Centre de Recherche du CHU de Québec-Université Laval, CHUL, QC, Québec, Canada
- Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médicine, Université Laval, QC, Québec, Canada
| | - J Miguel Cordeiro
- Laboratório de Farmacologia e Neurobiologia-Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia-Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
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26
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Role of the purinergic signaling in epilepsy. Pharmacol Rep 2016; 69:130-138. [PMID: 27915186 DOI: 10.1016/j.pharep.2016.09.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 09/20/2016] [Accepted: 09/21/2016] [Indexed: 01/19/2023]
Abstract
Adenine nucleotides and adenosine are signaling molecules that activate purinergic receptors P1 and P2. Activation of A1 adenosine receptors has an anticonvulsant action, whereas activation of A2A receptors might initiate seizures. Therefore, a significant limitation to the use of A1 receptor agonists as drugs in the CNS might be their peripheral side effects. The anti-epileptic activity of adenosine is related to its increased concentration outside the cell. This increase might result from the inhibition of the equilibrative nucleoside transporters (ENTs). Moreover, the implantation of implants or stem cells into the brain might cause slow and persistent increases in adenosine concentrations in the extracellular spaces of the brain. The role of adenosine in seizure inhibition has been confirmed by results demonstrating that in patients with epilepsy, the adenosine kinase (ADK) present in astrocytes is the only purine-metabolizing enzyme that exhibits increased expression. Increased ADK activity causes intensified phosphorylation of adenosine to 5'-AMP, which therefore lowers the adenosine level in the extracellular spaces. These changes might initiate astrogliosis and epileptogenesis, which are the manifestations of epilepsy. Seizures might induce inflammatory processes and vice versa. Activation of P2X7 receptors causes intensified release of pro-inflammatory cytokines (IL-1β and TNF-α) and activates metabolic pathways that induce inflammatory processes in the CNS. Therefore, antagonists of P2X7 and the interleukin 1β receptor might be efficient drugs for recurring seizures and prolonged status epilepticus. Inhibitors of ADK would simultaneously inhibit the seizures, prevent the astrogliosis and epileptogenesis processes and prevent the formation of new epileptogenic foci. Therefore, these drugs might become beneficial seizure-suppressing drugs.
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Cunha RA. How does adenosine control neuronal dysfunction and neurodegeneration? J Neurochem 2016; 139:1019-1055. [PMID: 27365148 DOI: 10.1111/jnc.13724] [Citation(s) in RCA: 320] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/23/2016] [Accepted: 06/23/2016] [Indexed: 12/11/2022]
Abstract
The adenosine modulation system mostly operates through inhibitory A1 (A1 R) and facilitatory A2A receptors (A2A R) in the brain. The activity-dependent release of adenosine acts as a brake of excitatory transmission through A1 R, which are enriched in glutamatergic terminals. Adenosine sharpens salience of information encoding in neuronal circuits: high-frequency stimulation triggers ATP release in the 'activated' synapse, which is locally converted by ecto-nucleotidases into adenosine to selectively activate A2A R; A2A R switch off A1 R and CB1 receptors, bolster glutamate release and NMDA receptors to assist increasing synaptic plasticity in the 'activated' synapse; the parallel engagement of the astrocytic syncytium releases adenosine further inhibiting neighboring synapses, thus sharpening the encoded plastic change. Brain insults trigger a large outflow of adenosine and ATP, as a danger signal. A1 R are a hurdle for damage initiation, but they desensitize upon prolonged activation. However, if the insult is near-threshold and/or of short-duration, A1 R trigger preconditioning, which may limit the spread of damage. Brain insults also up-regulate A2A R, probably to bolster adaptive changes, but this heightens brain damage since A2A R blockade affords neuroprotection in models of epilepsy, depression, Alzheimer's, or Parkinson's disease. This initially involves a control of synaptotoxicity by neuronal A2A R, whereas astrocytic and microglia A2A R might control the spread of damage. The A2A R signaling mechanisms are largely unknown since A2A R are pleiotropic, coupling to different G proteins and non-canonical pathways to control the viability of glutamatergic synapses, neuroinflammation, mitochondria function, and cytoskeleton dynamics. Thus, simultaneously bolstering A1 R preconditioning and preventing excessive A2A R function might afford maximal neuroprotection. The main physiological role of the adenosine modulation system is to sharp the salience of information encoding through a combined action of adenosine A2A receptors (A2A R) in the synapse undergoing an alteration of synaptic efficiency with an increased inhibitory action of A1 R in all surrounding synapses. Brain insults trigger an up-regulation of A2A R in an attempt to bolster adaptive plasticity together with adenosine release and A1 R desensitization; this favors synaptotocity (increased A2A R) and decreases the hurdle to undergo degeneration (decreased A1 R). Maximal neuroprotection is expected to result from a combined A2A R blockade and increased A1 R activation. This article is part of a mini review series: "Synaptic Function and Dysfunction in Brain Diseases".
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Affiliation(s)
- Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,FMUC-Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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Hu Q, Ren X, Liu Y, Li Z, Zhang L, Chen X, He C, Chen JF. Aberrant adenosine A2A receptor signaling contributes to neurodegeneration and cognitive impairments in a mouse model of synucleinopathy. Exp Neurol 2016; 283:213-23. [PMID: 27342081 DOI: 10.1016/j.expneurol.2016.05.040] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 05/21/2016] [Accepted: 05/23/2016] [Indexed: 02/08/2023]
Abstract
Synucleinopathy is characterized by abnormal accumulation of misfolded α-synuclein (α-Syn)-positive cytoplasmic inclusions and by neurodegeneration and cognitive impairments, but the pathogenesis mechanism of synucleinopathy remains to be defined. Using a transmission model of synucleinopathy by intracerebral injection of preformed A53T α-Syn fibrils, we investigated whether aberrant adenosine A2A receptor (A2AR) signaling contributed to pathogenesis of synucleinopathy. We demonstrated that intra-hippocampal injection of preformed mutant α-Syn fibrils triggered a striking and selective induction of A2AR expression which was closely co-localized with pSer129 α-Syn-rich inclusions in neurons and glial cells of hippocampus. Importantly, by abolishing aberrant A2AR signaling triggered by mutant α-Syn, genetic deletion of A2ARs blunted a cascade of pathological events leading to synucleinopathy, including pSer129 α-Syn-rich and p62-positive aggregates, NF-κB activation and astrogliosis, apoptotic neuronal cell death and working memory deficits without affecting motor activity. These findings define α-Syn-triggered aberrant A2AR signaling as a critical pathogenesis mechanism of synucleinopathy with dual controls of cognition and neurodegeneration by modulating α-Syn aggregates. Thus, aberrant A2AR signaling represents a useful biomarker as well as a therapeutic target of synucleinopathy.
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Affiliation(s)
- Qidi Hu
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiangpeng Ren
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China.
| | - Ya Liu
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zhihui Li
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China
| | - Liping Zhang
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China
| | - Xingjun Chen
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Chaoxiang He
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jiang-Fan Chen
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China; Department of Neurology, Boston University School of Medicine, Boston, MA, United States.
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29
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Adenosine kinase facilitated astrogliosis-induced cortical neuronal death in traumatic brain injury. J Mol Histol 2016; 47:259-71. [DOI: 10.1007/s10735-016-9670-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 03/11/2016] [Indexed: 12/20/2022]
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Xu K, Di Luca DG, Orrú M, Xu Y, Chen JF, Schwarzschild MA. Neuroprotection by caffeine in the MPTP model of parkinson's disease and its dependence on adenosine A2A receptors. Neuroscience 2016; 322:129-37. [PMID: 26905951 DOI: 10.1016/j.neuroscience.2016.02.035] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 02/16/2016] [Accepted: 02/17/2016] [Indexed: 01/02/2023]
Abstract
Considerable epidemiological and laboratory data have suggested that caffeine, a nonselective adenosine receptor antagonist, may protect against the underlying neurodegeneration of parkinson's disease (PD). Although both caffeine and more specific antagonists of the A2A subtype of adenosine receptor (A2AR) have been found to confer protection in animal models of PD, the dependence of caffeine's neuroprotective effects on the A2AR is not known. To definitively determine its A2AR dependence, the effect of caffeine on 1-methyl-4-phenyl-1,2,3,6 tetra-hydropyridine (MPTP) neurotoxicity was compared in wild-type (WT) and A2AR gene global knockout (A2A KO) mice, as well as in central nervous system (CNS) cell type-specific (conditional) A2AR knockout (cKO) mice that lack the receptor either in postnatal forebrain neurons or in astrocytes. In WT and in heterozygous A2AR KO mice caffeine pretreatment (25mg/kgip) significantly attenuated MPTP-induced depletion of striatal dopamine. By contrast in homozygous A2AR global KO mice caffeine had no effect on MPTP toxicity. In forebrain neuron A2AR cKO mice, caffeine lost its locomotor stimulant effect, whereas its neuroprotective effect was mostly preserved. In astrocytic A2AR cKO mice, both caffeine's locomotor stimulant and protective properties were undiminished. Taken together, these results indicate that neuroprotection by caffeine in the MPTP model of PD relies on the A2AR, although the specific cellular localization of these receptors remains to be determined.
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Affiliation(s)
- K Xu
- Molecular Neurobiology Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, United States.
| | - D G Di Luca
- Molecular Neurobiology Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, United States.
| | - M Orrú
- Molecular Neurobiology Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, United States.
| | - Y Xu
- Molecular Neurobiology Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, United States.
| | - J-F Chen
- Department of Neurology, 715 Albany Street, C314, Boston University School of Medicine, Boston, MA 02118, United States.
| | - M A Schwarzschild
- Molecular Neurobiology Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, United States.
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31
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Beamer E, Gölöncsér F, Horváth G, Bekő K, Otrokocsi L, Koványi B, Sperlágh B. Purinergic mechanisms in neuroinflammation: An update from molecules to behavior. Neuropharmacology 2015; 104:94-104. [PMID: 26384652 DOI: 10.1016/j.neuropharm.2015.09.019] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 09/11/2015] [Accepted: 09/14/2015] [Indexed: 12/21/2022]
Abstract
The principle functions of neuroinflammation are to limit tissue damage and promote tissue repair in response to pathogens or injury. While neuroinflammation has utility, pathophysiological inflammatory responses, to some extent, underlie almost all neuropathology. Understanding the mechanisms that control the three stages of inflammation (initiation, propagation and resolution) is therefore of critical importance for developing treatments for diseases of the central nervous system. The purinergic signaling system, involving adenosine, ATP and other purines, plus a host of P1 and P2 receptor subtypes, controls inflammatory responses in complex ways. Activation of the inflammasome, leading to release of pro-inflammatory cytokines, activation and migration of microglia and altered astroglial function are key regulators of the neuroinflammatory response. Here, we review the role of P1 and P2 receptors in mediating these processes and examine their contribution to disorders of the nervous system. Firstly, we give an overview of the concept of neuroinflammation. We then discuss the contribution of P2X, P2Y and P1 receptors to the underlying processes, including a discussion of cross-talk between these different pathways. Finally, we give an overview of the current understanding of purinergic contributions to neuroinflammation in the context of specific disorders of the central nervous system, with special emphasis on neuropsychiatric disorders, characterized by chronic low grade inflammation or maternal inflammation. An understanding of the important purinergic contribution to neuroinflammation underlying neuropathology is likely to be a necessary step towards the development of effective interventions. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.
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Affiliation(s)
- Edward Beamer
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450 Budapest, Hungary
| | - Flóra Gölöncsér
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450 Budapest, Hungary
| | - Gergely Horváth
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450 Budapest, Hungary
| | - Katinka Bekő
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450 Budapest, Hungary
| | - Lilla Otrokocsi
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450 Budapest, Hungary
| | - Bence Koványi
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450 Budapest, Hungary
| | - Beáta Sperlágh
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450 Budapest, Hungary.
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32
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Boison D. Adenosinergic signaling in epilepsy. Neuropharmacology 2015; 104:131-9. [PMID: 26341819 DOI: 10.1016/j.neuropharm.2015.08.046] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 08/27/2015] [Accepted: 08/28/2015] [Indexed: 12/12/2022]
Abstract
Despite the introduction of at least 20 new antiepileptic drugs (AEDs) into clinical practice over the past decades, about one third of all epilepsies remain refractory to conventional forms of treatment. In addition, currently used AEDs have been developed to suppress neuronal hyperexcitability, but not necessarily to address pathogenic mechanisms involved in epilepsy development or progression (epileptogenesis). For those reasons endogenous seizure control mechanisms of the brain may provide alternative therapeutic opportunities. Adenosine is a well characterized endogenous anticonvulsant and seizure terminator of the brain. Several lines of evidence suggest that endogenous adenosine-mediated seizure control mechanisms fail in chronic epilepsy, whereas therapeutic adenosine augmentation effectively prevents epileptic seizures, even those that are refractory to conventional AEDs. New findings demonstrate that dysregulation of adenosinergic mechanisms are intricately involved in the development of epilepsy and its comorbidities, whereas adenosine-associated epigenetic mechanisms may play a role in epileptogenesis. The first goal of this review is to discuss how maladaptive changes of adenosinergic mechanisms contribute to the expression of seizures (ictogenesis) and the development of epilepsy (epileptogenesis) by focusing on pharmacological (adenosine receptor dependent) and biochemical (adenosine receptor independent) mechanisms as well as on enzymatic and transport based mechanisms that control the availability (homeostasis) of adenosine. The second goal of this review is to highlight innovative adenosine-based opportunities for therapeutic intervention aimed at reconstructing normal adenosine function and signaling for improved seizure control in chronic epilepsy. New findings suggest that transient adenosine augmentation can have lasting epigenetic effects with disease modifying and antiepileptogenic outcome. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.
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Affiliation(s)
- Detlev Boison
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute, Portland, OR 97232, USA.
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33
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Beckerman SR, Jimenez JE, Shi Y, Al-Ali H, Bixby JL, Lemmon VP. Phenotypic assays to identify agents that induce reactive gliosis: a counter-screen to prioritize compounds for preclinical animal studies. Assay Drug Dev Technol 2015; 13:377-88. [PMID: 26230074 DOI: 10.1089/adt.2015.654] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Astrocyte phenotypes change in a process called reactive gliosis after traumatic central nervous system (CNS) injury. Astrogliosis is characterized by expansion of the glial fibrillary acidic protein (GFAP) cytoskeleton, adoption of stellate morphologies, and differential expression of some extracellular matrix molecules. The astrocytic response immediately after injury is beneficial, but in the chronic injury phase, reactive astrocytes produce inhibitory factors (i.e., chondroitin sulfate proteoglycans [CSPGs]) that limit the regrowth of injured axons. There are no drugs that promote axon regeneration or functional recovery after CNS trauma in humans. To develop novel therapeutics for the injured CNS, we screened various libraries in a phenotypic assay to identify compounds that promote neurite outgrowth. However, the effects these compounds have on astrocytes are unknown. Specifically, we were interested in whether compounds could alter astrocytes in a manner that mimics the glial reaction to injury. To test this hypothesis, we developed cell-based phenotypic bioassays to measure changes in (1) GFAP morphology/localization and (2) CSPG expression/immunoreactivity from primary astrocyte cultures. These assays were optimized for six-point dose-response experiments in 96-well plates. The GFAP morphology assay is suitable for counter-screening with a Z-factor of 0.44±0.03 (mean±standard error of the mean; N=3 biological replicates). The CSPG assay is reproducible and informative, but does not satisfy common metrics for a "screenable" assay. As proof of principle, we tested a small set of hit compounds from our neurite outgrowth bioassay and identified one that can enhance axon growth without exacerbating the deleterious characteristics of reactive gliosis.
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Affiliation(s)
- Samuel R Beckerman
- 1 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| | - Joaquin E Jimenez
- 1 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| | - Yan Shi
- 1 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| | - Hassan Al-Ali
- 1 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| | - John L Bixby
- 1 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida.,2 Center for Computational Science, University of Miami, Coral Gables, Florida.,3 Department of Neurological Surgery, University of Miami Miller School of Medicine , Miami, Florida.,4 Department of Molecular & Cellular Pharmacology, University of Miami Miller School of Medicine , Miami, Florida
| | - Vance P Lemmon
- 1 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida.,2 Center for Computational Science, University of Miami, Coral Gables, Florida.,3 Department of Neurological Surgery, University of Miami Miller School of Medicine , Miami, Florida
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34
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Neuroprotective potential of adenosine A2A and cannabinoid CB1 receptor antagonists in an animal model of Parkinson disease. J Neuropathol Exp Neurol 2014; 73:414-24. [PMID: 24709676 DOI: 10.1097/nen.0000000000000064] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The development of nondopaminergic therapeutic strategies that may improve motor and nonmotor deficits, while possibly slowing down the neurodegenerative process and associated neuroinflammation,is a primary goal of Parkinson disease (PD) research. We investigated the neuroprotective and anti-inflammatory potential of combined and single treatment with adenosine A2A and cannabinoid CB1 receptor antagonists MSX-3 and rimonabant, respectively, in a rodent model of PD. Rats bearing a unilateral intrastriatal 6-hydroxydopamine lesion were treated chronically with MSX-3 (0.5or 1 mg/kg/d) and rimonabant (0.1 mg/kg/d) given as monotherapy or combined. The effects of the treatments to counteract dopaminergic cell death and neuroinflammation were assessed by immunohistochemistry for tyrosine hydroxylase and glial cell markers, respectively. Both rimonabant and MSX-3 (1 mg/kg/d) promoted dopaminergic neuron survival in the substantia nigra pars compacta (SNc) when given alone; this effect was weakened when the compounds were combined. Glial activation was not significantly affected by MSX-3 (1 mg/kg/d), whereas rimonabant seemed to increase astrocyte cell density in the SNc. Our findings demonstrate the neuroprotective potential of single treatments and suggest that glial cells might be involved in this protective effect. The results also indicate that the neuroprotective potential of combined therapy may not necessarily reflect or promote single-drug effects and point out that special care should be taken when considering multidrug therapies in PD.
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35
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Niesman IR, Schilling JM, Shapiro LA, Kellerhals SE, Bonds JA, Kleschevnikov AM, Cui W, Voong A, Krajewski S, Ali SS, Roth DM, Patel HH, Patel PM, Head BP. Traumatic brain injury enhances neuroinflammation and lesion volume in caveolin deficient mice. J Neuroinflammation 2014; 11:39. [PMID: 24593993 PMCID: PMC3975903 DOI: 10.1186/1742-2094-11-39] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 02/10/2014] [Indexed: 11/30/2022] Open
Abstract
Background Traumatic brain injury (TBI) enhances pro-inflammatory responses, neuronal loss and long-term behavioral deficits. Caveolins (Cavs) are regulators of neuronal and glial survival signaling. Previously we showed that astrocyte and microglial activation is increased in Cav-1 knock-out (KO) mice and that Cav-1 and Cav-3 modulate microglial morphology. We hypothesized that Cavs may regulate cytokine production after TBI. Methods Controlled cortical impact (CCI) model of TBI (3 m/second; 1.0 mm depth; parietal cortex) was performed on wild-type (WT; C57Bl/6), Cav-1 KO, and Cav-3 KO mice. Histology and immunofluorescence microscopy (lesion volume, glia activation), behavioral tests (open field, balance beam, wire grip, T-maze), electrophysiology, electron paramagnetic resonance, membrane fractionation, and multiplex assays were performed. Data were analyzed by unpaired t tests or analysis of variance (ANOVA) with post-hoc Bonferroni’s multiple comparison. Results CCI increased cortical and hippocampal injury and decreased expression of MLR-localized synaptic proteins (24 hours), enhanced NADPH oxidase (Nox) activity (24 hours and 1 week), enhanced polysynaptic responses (1 week), and caused hippocampal-dependent learning deficits (3 months). CCI increased brain lesion volume in both Cav-3 and Cav-1 KO mice after 24 hours (P < 0.0001, n = 4; one-way ANOVA). Multiplex array revealed a significant increase in expression of IL-1β, IL-9, IL-10, KC (keratinocyte chemoattractant), and monocyte chemoattractant protein 1 (MCP-1) in ipsilateral hemisphere and IL-9, IL-10, IL-17, and macrophage inflammatory protein 1 alpha (MIP-1α) in contralateral hemisphere of WT mice after 4 hours. CCI increased IL-2, IL-6, KC and MCP-1 in ipsilateral and IL-6, IL-9, IL-17 and KC in contralateral hemispheres in Cav-1 KO and increased all 10 cytokines/chemokines in both hemispheres except for IL-17 (ipsilateral) and MIP-1α (contralateral) in Cav-3 KO (versus WT CCI). Cav-3 KO CCI showed increased IL-1β, IL-9, KC, MCP-1, MIP-1α, and granulocyte-macrophage colony-stimulating factor in ipsilateral and IL-1β, IL-2, IL-9, IL-10, and IL-17 in contralateral hemispheres (P = 0.0005, n = 6; two-way ANOVA) compared to Cav-1 KO CCI. Conclusion CCI caused astrocyte and microglial activation and hippocampal neuronal injury. Cav-1 and Cav-3 KO exhibited enhanced lesion volume and cytokine/chemokine production after CCI. These findings suggest that Cav isoforms may regulate neuroinflammatory responses and neuroprotection following TBI.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | - Brian P Head
- Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA.
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36
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Verkhratsky A, Burnstock G. Purinergic and glutamatergic receptors on astroglia. ADVANCES IN NEUROBIOLOGY 2014; 11:55-79. [PMID: 25236724 DOI: 10.1007/978-3-319-08894-5_4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Astroglial cells express many neurotransmitter receptors; the receptors to glutamate and ATP being the most abundant. Here, we provide a concise overview on the expression and main properties of astroglial glutamate receptors (ionotropic receptors represented by AMPA and NMDA subtypes) and metabotropic (mainly mGluR5 and mGluR3 subtypes) and purinoceptors (adenosine receptors of A1, A2A, A2B, and A3 types, ionotropic P2X1/5 and P2X7 subtypes, and metabotropic P2Y purinoceptors). We also discuss the role of these receptors in glial physiology and pathophysiology.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Sciences, School of Biological Sciences, The University of Manchester, 1.124 Stopford Building, Oxford Road, Manchester, M13 9PT, UK,
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Aronica E, Sandau US, Iyer A, Boison D. Glial adenosine kinase--a neuropathological marker of the epileptic brain. Neurochem Int 2013; 63:688-95. [PMID: 23385089 PMCID: PMC3676477 DOI: 10.1016/j.neuint.2013.01.028] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 12/21/2012] [Accepted: 01/27/2013] [Indexed: 12/16/2022]
Abstract
Experimental research over the past decade has supported the critical role of astrocytes activated by different types of injury and the pathophysiological processes that underlie the development of epilepsy. In both experimental and human epileptic tissues astrocytes undergo complex changes in their physiological properties, which can alter glio-neuronal communication, contributing to seizure precipitation and recurrence. In this context, understanding which of the molecular mechanisms are crucially involved in the regulation of glio-neuronal interactions under pathological conditions associated with seizure development is important to get more insight into the role of astrocytes in epilepsy. This article reviews current knowledge regarding the role of glial adenosine kinase as a neuropathological marker of the epileptic brain. Both experimental findings in clinically relevant models, as well as observations in drug-resistant human epilepsies will be discussed, highlighting the link between astrogliosis, dysfunction of adenosine homeostasis and seizure generation and therefore suggesting new strategies for targeting astrocyte-mediated epileptogenesis.
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Affiliation(s)
- Eleonora Aronica
- Department (Neuro) Pathology, Academisch Medisch Centrum, Amsterdam
- Epilepsy Institute in The Netherlands Foundation (Stichting Epilepsie Instellingen Nederland, SEIN), Heemstede, The Netherlands
| | - Ursula S Sandau
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute, Portland, OR 97232, USA
| | - Anand Iyer
- Department (Neuro) Pathology, Academisch Medisch Centrum, Amsterdam
| | - Detlev Boison
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute, Portland, OR 97232, USA
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38
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Adenosine A2A receptor deficiency alleviates blast-induced cognitive dysfunction. J Cereb Blood Flow Metab 2013; 33:1789-98. [PMID: 23921902 PMCID: PMC3824177 DOI: 10.1038/jcbfm.2013.127] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 07/06/2013] [Accepted: 07/09/2013] [Indexed: 11/09/2022]
Abstract
Traumatic brain injury (TBI), particularly explosive blast-induced TBI (bTBI), has become the most prevalent injury among military personnel. The disruption of cognitive function is one of the most serious consequences of bTBI because its long-lasting effects prevent survivors fulfilling their active duty and resuming normal civilian life. However, the mechanisms are poorly understood and there is no treatment available. This study investigated the effects of adenosine A2A receptor (A2AR) on bTBI-induced cognitive deficit, and explored the underlying mechanisms. After being subjected to moderate whole-body blast injury, mice lacking the A2AR (A2AR knockout (KO)) showed less severity and shorter duration of impaired spatial reference memory and working memory than wild-type mice did. In addition, bTBI-induced cortical and hippocampal lesions, as well as proinflammatory cytokine expression, glutamate release, edema, cell loss, and gliosis in both early and prolonged phases of the injury, were significantly attenuated in A2AR KO mice. The results suggest that early injury and chronic neuropathological damages are important mechanisms of bTBI-induced cognitive impairment, and that the impairment can be attenuated by preventing A2AR activation. These findings suggest that A2AR antagonism is a potential therapeutic strategy for mild-to-moderate bTBI and consequent cognitive impairment.
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39
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Fronz U, Deten A, Baumann F, Kranz A, Weidlich S, Härtig W, Nieber K, Boltze J, Wagner DC. Continuous adenosine A2A receptor antagonism after focal cerebral ischemia in spontaneously hypertensive rats. Naunyn Schmiedebergs Arch Pharmacol 2013; 387:165-73. [PMID: 24170241 DOI: 10.1007/s00210-013-0931-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 10/16/2013] [Indexed: 12/12/2022]
Abstract
Antagonism of the adenosine A2A receptor (A2AR) has been shown to elicit substantial neuroprotective properties when given immediately after cerebral ischemia. We asked whether the continuous application of a selective A2AR antagonist within a clinically relevant time window will be a feasible and effective approach to treat focal cerebral ischemia. To answer this question, we subjected 20 male spontaneously hypertensive rats to permanent middle cerebral artery occlusion and randomized them equally to a verum and a control group. Two hours after stroke onset, the animals received a subcutaneous implantation of an osmotic minipump filled with 5 mg kg(-1) day(-1) 8-(3-chlorostyryl) caffeine (CSC) or vehicle solution. The serum level of CSC was measured twice a day for three consecutive days. The infarct volume was determined at days 1 and 3 using magnetic resonance imaging. We found the serum level of CSC showing a bell-shaped curve with its maximum at 36 h. The infarct volume was not affected by continuous CSC treatment. These results suggest that delayed and continuous CSC application was not sufficient to treat acute ischemic stroke, potentially due to unfavorable hepatic elimination and metabolization of the pharmaceutical.
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Affiliation(s)
- Ulrike Fronz
- Translational Centre for Regenerative Medicine, Leipzig, Germany,
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Franke H, Illes P. Nucleotide signaling in astrogliosis. Neurosci Lett 2013; 565:14-22. [PMID: 24103370 DOI: 10.1016/j.neulet.2013.09.056] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 09/05/2013] [Accepted: 09/17/2013] [Indexed: 12/29/2022]
Abstract
Acute and chronic damage to the central nervous system (CNS) releases large quantities of ATP. Whereas the ATP concentration in the extracellular space is normally in the micromolar range, under these conditions it increases to millimolar levels. A number of ligand-gated cationic channels termed P2X receptors (7 mammalian subtypes), and G protein-coupled P2Y receptors (8 mammalian subtypes) are located at astrocytes, as confirmed by the measurement of the respective mRNA and protein. Activation of both the P2X7 and P2Y1,2 subtypes identified at astrocytes initiates astrogliosis isolating damaged brain areas from surrounding healthy cells and synthesizing neurotrophins and pleotrophins that participate in neuronal recovery. Astrocytes are considered as cells of high plasticity which may alter their properties in a culture medium. Therefore, recent work concentrates on investigating nucleotide effects at in situ (acute brain slices) and in vivo astrocytes. A wealth of data relates to the involvement of purinergic mechanisms in astrogliosis induced by acute CNS injury such as mechanical trauma and hypoxia/ischemia. The released ATP may act within minutes as an excitotoxic molecule; at a longer time-scale within days it causes neuroinflammation. These effects sum up as necrosis/apoptosis on the one hand and proliferation on the other. Although the role of nucleotides in chronic neurodegenerative illnesses is not quite clear, it appears that they aggravate the consequences of the primary disease. Epilepsy and neuropathic pain are also associated with the release of ATP and a pathologic glia-neuron interaction leading to astrogliosis and cell death. In view of these considerations, P2 receptor antagonists may open new therapeutic vistas in all forms of acute and chronic CNS damage.
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Affiliation(s)
- Heike Franke
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany
| | - Peter Illes
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany.
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Prozorow-Krol B, Korolczuk A, Czechowska G, Slomka M, Madro A, Celinski K. The effects of the adenosine A3 receptor agonist IB-MECA on sodium taurocholate-induced experimental acute pancreatitis. Arch Pharm Res 2013; 36:1126-32. [PMID: 23625750 PMCID: PMC3766514 DOI: 10.1007/s12272-013-0126-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The role of adenosine A3 receptors and their distribution in the gastrointestinal tract have been widely investigated. Most of the reports discuss their role in intestinal inflammations. However, the role of adenosine A3 receptor agonist in pancreatitis has not been well established. The aim of this study is [corrected] to evaluate the effects of the adenosine A3 receptor agonist on the course of sodium taurocholate-induced experimental acute pancreatitis (EAP). The experiments were performed on 80 male Wistar rats, 58 of which survived, subdivided into 3 groups: C--control rats, I--EAP group, and II--EAP group treated with the adenosine A3 receptor agonist IB-MECA (1-deoxy-1-6[[(3-iodophenyl) methyl]amino]-9H-purin-9-yl)-N-methyl-B-D-ribofuronamide at a dose of 0.75 mg/kg b.w. i.p. at 48, 24, 12 and 1 h before and 1 h after the injection of 5% sodium taurocholate solution into the biliary-pancreatic duct. Serum for α-amylase and lipase determinations and tissue samples for morphological examinations were collected at 2, 6, and 24 h of the experiment. In the IB-MECA group, α-amylase activity was decreased with statistically high significance compared to group I. The activity of lipase was not significantly different among the experimental groups but higher than in the control group. The administration of IB-MECA attenuated the histological parameters of inflammation as compared to untreated animals. The use of A3 receptor agonist IB-MECA attenuates EAP. Our findings suggest that stimulation of adenosine A3 receptors plays a positive role in the sodium taurocholate-induced EAP in rats.
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MESH Headings
- Adenosine/administration & dosage
- Adenosine/analogs & derivatives
- Adenosine/therapeutic use
- Adenosine A3 Receptor Agonists/administration & dosage
- Adenosine A3 Receptor Agonists/therapeutic use
- Animals
- Anti-Inflammatory Agents, Non-Steroidal/administration & dosage
- Anti-Inflammatory Agents, Non-Steroidal/therapeutic use
- Disease Models, Animal
- Edema/etiology
- Edema/prevention & control
- Injections, Intraperitoneal
- Lipase/metabolism
- Male
- Necrosis
- Pancreas/drug effects
- Pancreas/immunology
- Pancreas/metabolism
- Pancreas/pathology
- Pancreatic alpha-Amylases/blood
- Pancreatitis, Acute Necrotizing/immunology
- Pancreatitis, Acute Necrotizing/metabolism
- Pancreatitis, Acute Necrotizing/pathology
- Pancreatitis, Acute Necrotizing/prevention & control
- Rats
- Rats, Wistar
- Receptor, Adenosine A3/chemistry
- Receptor, Adenosine A3/metabolism
- Taurocholic Acid
- Time Factors
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Affiliation(s)
- Beata Prozorow-Krol
- Department of Gastroenterology with Endoscopic Unit, Medical University of Lublin, Jaczewski Street 8, 20-954 Lublin, Poland
| | - Agnieszka Korolczuk
- Department of Clinical Pathomorphology, Medical University of Lublin, Lublin, Poland
| | - Grazyna Czechowska
- Department of Gastroenterology with Endoscopic Unit, Medical University of Lublin, Jaczewski Street 8, 20-954 Lublin, Poland
| | - Maria Slomka
- Department of Gastroenterology with Endoscopic Unit, Medical University of Lublin, Jaczewski Street 8, 20-954 Lublin, Poland
| | - Agnieszka Madro
- Department of Gastroenterology with Endoscopic Unit, Medical University of Lublin, Jaczewski Street 8, 20-954 Lublin, Poland
| | - Krzysztof Celinski
- Department of Gastroenterology with Endoscopic Unit, Medical University of Lublin, Jaczewski Street 8, 20-954 Lublin, Poland
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Boison D, Sandau US, Ruskin DN, Kawamura M, Masino SA. Homeostatic control of brain function - new approaches to understand epileptogenesis. Front Cell Neurosci 2013; 7:109. [PMID: 23882181 PMCID: PMC3712329 DOI: 10.3389/fncel.2013.00109] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 06/22/2013] [Indexed: 12/31/2022] Open
Abstract
Neuronal excitability of the brain and ongoing homeostasis depend not only on intrinsic neuronal properties, but also on external environmental factors; together these determine the functionality of neuronal networks. Homeostatic factors become critically important during epileptogenesis, a process that involves complex disruption of self-regulatory mechanisms. Here we focus on the bioenergetic homeostatic network regulator adenosine, a purine nucleoside whose availability is largely regulated by astrocytes. Endogenous adenosine modulates complex network function through multiple mechanisms including adenosine receptor-mediated pathways, mitochondrial bioenergetics, and adenosine receptor-independent changes to the epigenome. Accumulating evidence from our laboratories shows that disruption of adenosine homeostasis plays a major role in epileptogenesis. Conversely, we have found that reconstruction of adenosine's homeostatic functions provides new hope for the prevention of epileptogenesis. We will discuss how adenosine-based therapeutic approaches may interfere with epileptogenesis on an epigenetic level, and how dietary interventions can be used to restore network homeostasis in the brain. We conclude that reconstruction of homeostatic functions in the brain offers a new conceptual advance for the treatment of neurological conditions which goes far beyond current target-centric treatment approaches.
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Affiliation(s)
- Detlev Boison
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute Portland, OR, USA
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Gonçalves N, Simões AT, Cunha RA, de Almeida LP. Caffeine and adenosine A2Areceptor inactivation decrease striatal neuropathology in a lentiviral-based model of Machado-Joseph disease. Ann Neurol 2013; 73:655-66. [DOI: 10.1002/ana.23866] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 01/21/2013] [Accepted: 02/01/2013] [Indexed: 12/20/2022]
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Introduction to Purinergic Signalling in the Brain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 986:1-12. [DOI: 10.1007/978-94-007-4719-7_1] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Brisevac D, Bjelobaba I, Bajic A, Clarner T, Stojiljkovic M, Beyer C, Andjus P, Kipp M, Nedeljkovic N. Regulation of ecto-5′-nucleotidase (CD73) in cultured cortical astrocytes by different inflammatory factors. Neurochem Int 2012; 61:681-8. [DOI: 10.1016/j.neuint.2012.06.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2011] [Revised: 06/12/2012] [Accepted: 06/21/2012] [Indexed: 12/16/2022]
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Lecca D, Ceruti S, Fumagalli M, Abbracchio MP. Purinergic trophic signalling in glial cells: functional effects and modulation of cell proliferation, differentiation, and death. Purinergic Signal 2012; 8:539-57. [PMID: 22528683 PMCID: PMC3360088 DOI: 10.1007/s11302-012-9310-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 09/09/2011] [Indexed: 12/15/2022] Open
Abstract
In the last decades, the discovery that glial cells do not only fill in the empty space among neurons or furnish them with trophic support but are rather essential participants to the various activities of the central and peripheral nervous system has fostered the search for the signalling pathways controlling their functions. Since the early 1990s, purines were foreseen as some of the most promising candidate molecules. Originally just a hypothesis, this has become a certainty as experimental evidence accumulated over years, as demonstrated by the exponentially growing number of articles related to the role of extracellular nucleotides and nucleosides in controlling glial cell functions. Indeed, as new functions for already known glial cells (for example, the ability of parenchymal astrocytes to behave as stem cells) or new subtypes of glial cells (for example, NG2(+) cells, also called polydendrocytes) are discovered also, new actions and new targets for the purinergic system are identified. Thus, glial purinergic receptors have emerged as new possible pharmacological targets for various acute and chronic pathologies, such as stroke, traumatic brain and spinal cord injury, demyelinating diseases, trigeminal pain and migraine, and retinopathies. In this article, we will summarize the most important and promising actions mediated by extracellular purines and pyrimidines in controlling the functions, survival, and differentiation of the various "classical" types of glial cells (i.e., astrocytes, oligodendrocytes, microglial cells, Müller cells, satellite glial cells, and enteric glial cells) but also of some rather new members of the family (e.g., polydendrocytes) and of other cells somehow related to glial cells (e.g., pericytes and spinal cord ependymal cells).
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Affiliation(s)
- Davide Lecca
- Laboratory of Molecular and Cellular Pharmacology of Purinergic Transmission, Department of Pharmacological Sciences, Università degli Studi di Milano, via Balzaretti, 9-Milan, 20133 Italy
| | - Stefania Ceruti
- Laboratory of Molecular and Cellular Pharmacology of Purinergic Transmission, Department of Pharmacological Sciences, Università degli Studi di Milano, via Balzaretti, 9-Milan, 20133 Italy
| | - Marta Fumagalli
- Laboratory of Molecular and Cellular Pharmacology of Purinergic Transmission, Department of Pharmacological Sciences, Università degli Studi di Milano, via Balzaretti, 9-Milan, 20133 Italy
| | - Maria P. Abbracchio
- Laboratory of Molecular and Cellular Pharmacology of Purinergic Transmission, Department of Pharmacological Sciences, Università degli Studi di Milano, via Balzaretti, 9-Milan, 20133 Italy
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Bogenpohl JW, Ritter SL, Hall RA, Smith Y. Adenosine A2A receptor in the monkey basal ganglia: ultrastructural localization and colocalization with the metabotropic glutamate receptor 5 in the striatum. J Comp Neurol 2012; 520:570-89. [PMID: 21858817 DOI: 10.1002/cne.22751] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The adenosine A(2A) receptor (A(2A) R) is a potential drug target for the treatment of Parkinson's disease and other neurological disorders. In rodents, the therapeutic efficacy of A(2A) R modulation is improved by concomitant modulation of the metabotropic glutamate receptor 5 (mGluR5). To elucidate the anatomical substrate(s) through which these therapeutic benefits could be mediated, pre-embedding electron microscopy immunohistochemistry was used to conduct a detailed, quantitative ultrastructural analysis of A(2A) R localization in the primate basal ganglia and to assess the degree of A(2A) R/mGluR5 colocalization in the striatum. A(2A) R immunoreactivity was found at the highest levels in the striatum and external globus pallidus (GPe). However, the monkey, but not the rat, substantia nigra pars reticulata (SNr) also harbored a significant level of neuropil A(2A) R immunoreactivity. At the electron microscopic level, striatal A(2A) R labeling was most commonly localized in postsynaptic elements (58% ± 3% of labeled elements), whereas, in the GPe and SNr, the labeling was mainly presynaptic (71% ± 5%) or glial (27% ± 6%). In both striatal and pallidal structures, putative inhibitory and excitatory terminals displayed A(2A) R immunoreactivity. Striatal A(2A) R/mGluR5 colocalization was commonly found; 60-70% of A(2A) R-immunoreactive dendrites or spines in the monkey striatum coexpress mGluR5. These findings provide the first detailed account of the ultrastructural localization of A(2A) R in the primate basal ganglia and demonstrate that A(2A) R and mGluR5 are located to interact functionally in dendrites and spines of striatal neurons. Together, these data foster a deeper understanding of the substrates through which A(2A) R could regulate primate basal ganglia function and potentially mediate its therapeutic effects in parkinsonism.
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Affiliation(s)
- James W Bogenpohl
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA
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Mishina M, Kimura Y, Naganawa M, Ishii K, Oda K, Sakata M, Toyohara J, Kobayashi S, Katayama Y, Ishiwata K. Differential effects of age on human striatal adenosine A₁ and A(2A) receptors. Synapse 2012; 66:832-9. [PMID: 22623181 DOI: 10.1002/syn.21573] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 05/01/2012] [Accepted: 05/14/2012] [Indexed: 01/19/2023]
Abstract
The aim of this study was to investigate the effect of age on the distribution of adenosine A₁ receptors (A₁Rs) and adenosine A(2A) receptors (A(2A)Rs) in the striatum of healthy subjects using PET imaging with 8-dicyclopropylmethyl-1-[¹¹C]methyl-3-propylxanthine ([¹¹C]MPDX) and [7-methyl-¹¹C]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthine ([¹¹C]TMSX), respectively. We recruited 8 young (22.0 ± 1.7 years) and 10 elderly (65.4 ± 7.6 years) volunteers to undergo [¹¹C]MPDX PET scanning, and 11 young (22.7 ± 2.7 years) and six elderly (60.7 ± 8.5 years) volunteers to undergo [¹¹C]TMSX PET scanning. A dynamic series of decay-corrected PET scans was performed for 60 min following injection of [¹¹C]MPDX or [¹¹C]TMSX. We calculated the binding potential (BP(ND) ) of [¹¹C]MPDX and distribution volume ratio (DVR) of [¹¹C]TMSX in the striatum. The BP(ND) of [¹¹C]MPDX was significantly lower in elderly than in young subjects, both in the putamen and head of the caudate nucleus. The BP(ND) was negatively correlated with age in both the putamen and the head of the caudate nucleus. However, no difference was found between the DVR of [¹¹C]TMSX in the striata of young and elderly subjects, nor was there a correlation between age and the DVR of [¹¹C]TMSX. The effect of age on the distribution of A₁Rs in the human striatum described herein is similar to previous reports of age-related decreases in dopamine D₁ and D₂ receptors. Unlike A₁Rs, however, this study suggests that the distribution of A(2A) Rs does not change with age.
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Affiliation(s)
- Masahiro Mishina
- The Second Department of Internal Medicine, Nippon Medical School, Bunkyo-Ku, Tokyo, Japan; Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-Ku, Tokyo, Japan.
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Tebano MT, Martire A, Popoli P. Adenosine A(2A)-cannabinoid CB(1) receptor interaction: an integrative mechanism in striatal glutamatergic neurotransmission. Brain Res 2012; 1476:108-18. [PMID: 22565012 DOI: 10.1016/j.brainres.2012.04.051] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 04/26/2012] [Accepted: 04/26/2012] [Indexed: 12/12/2022]
Abstract
The striatum is a subcortical area involved in sensorimotor, cognitive and emotional processes. Adenosine A(2A) receptors (A(2A)Rs) are highly expressed in the striatum, and their ability to establish functional and molecular interactions with many other receptors attributes to a pivotal role in the modulation and integration of striatal neurotransmission. This review will focus on the interaction between A(2A)Rs and cannabinoid CB(1) receptors (CB(1)Rs), taking it as a paradigmatic example of synaptic integration. Indeed, A(2A)Rs can exert an opposite (permissive vs. inhibitory) influence on CB1-dependent synaptic effect. These apparently irreconcilable functions could depend on a different role of pre- vs. postsynaptic A(2A)Rs, on their interaction with other receptors (namely adenosine A(1), metabotropic glutamate 5 and dopamine D2 receptors), and on whether A(2A)Rs form or not heteromers with CB(1)Rs. Besides providing a good example of the intricate pattern of events taking place in striatal synapses, the A(2A)/CB(1)R interaction proves very informative to understand the physiology of the basal ganglia and the mechanisms of related diseases. This article is part of a Special Issue entitled: Brain Integration.
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Affiliation(s)
- Maria Teresa Tebano
- Section of Central Nervous System Pharmacology, Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
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50
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Boison D. Adenosine dysfunction in epilepsy. Glia 2011; 60:1234-43. [PMID: 22700220 DOI: 10.1002/glia.22285] [Citation(s) in RCA: 134] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 11/30/2011] [Indexed: 12/13/2022]
Abstract
Extracellular levels of the brain's endogenous anticonvulsant and neuroprotectant adenosine largely depend on an astrocyte-based adenosine cycle, comprised of ATP release, rapid degradation of ATP into adenosine, and metabolic reuptake of adenosine through equilibrative nucleoside transporters and phosphorylation by adenosine kinase (ADK). Changes in ADK expression and activity therefore rapidly translate into changes of extracellular adenosine, which exerts its potent anticonvulsive and neuroprotective effects by activation of pre- and postsynaptic adenosine A(1) receptors. Increases in ADK increase neuronal excitability, whereas decreases in ADK render the brain resistant to seizures and injury. Importantly, ADK was found to be overexpressed and associated with astrogliosis and spontaneous seizures in rodent models of epilepsy, as well as in human specimen resected from patients with hippocampal sclerosis and temporal lobe epilepsy. Several lines of evidence indicate that overexpression of astroglial ADK and adenosine deficiency are pathological hallmarks of the epileptic brain. Consequently, adenosine augmentation therapies constitute a powerful approach for seizure prevention, which is effective in models of epilepsy that are resistant to conventional antiepileptic drugs. The adenosine kinase hypothesis of epileptogenesis suggests that adenosine dysfunction in epilepsy undergoes a biphasic response: an acute surge of adenosine that can be triggered by any type of injury might contribute to the development of astrogliosis via adenosine receptor-dependent and -independent mechanisms. Astrogliosis in turn is associated with overexpression of ADK, which was shown to be sufficient to trigger spontaneous recurrent electrographic seizures. Thus, ADK emerges as a promising target for the prediction and prevention of epilepsy.
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Affiliation(s)
- Detlev Boison
- R.S. Dow Neurobiology Labs, Legacy Research Institute, Portland, Oregon 97232, USA.
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