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Du H, Li C, Gao R, Tan Y, Wang B, Peng Y, Yang N, Ning Y, Li P, Zhao Y, Zhou Y. Inhibition of the interaction between microglial adenosine 2A receptor and NLRP3 inflammasome attenuates neuroinflammation posttraumatic brain injury. CNS Neurosci Ther 2024; 30:e14408. [PMID: 37564004 PMCID: PMC10805470 DOI: 10.1111/cns.14408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/24/2023] [Accepted: 07/27/2023] [Indexed: 08/12/2023] Open
Abstract
AIMS Adenosine 2A receptor (A2A R) is widely expressed in the brain and plays important roles in neuroinflammation, and the nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome is a crucial component of the innate immune system while the regulation of A2A R on it in the central nervous system (CNS) has not been clarified. METHODS The effects of microglial A2A R on NLRP3 inflammasome assembly and activation were investigated in wild-type, A2A R- or NLRP3-knockout primary microglia with pharmacological treatment. Microglial A2A R or NLRP3 conditional knockout mice were used to interrogate the effects of this regulation on neuroinflammation posttraumatic brain injury (TBI). RESULTS We found that A2A R directly interacted with NLRP3 and facilitated NLRP3 inflammasome assembly and activation in primary microglia while having no effects on mRNA levels of inflammasome components. Inhibition of the interaction via A2A R agonist or knockout attenuated inflammasome assembly and activation in vitro. In the TBI model, microglial A2A R and NLRP3 were co-expressed at high levels in microglia next to the peri-injured cortex, and abrogating of this interaction by microglial NLRP3 or A2A R conditional knockout attenuated the neurological deficits and neuropathology post-TBI via reducing the NLRP3 inflammasome activation. CONCLUSION Our results demonstrated that inhibition of the interaction between A2A R and NLRP3 in microglia could mitigate the NLRP3 inflammasome assembly and activation and ameliorate the neuroinflammation post-TBI. It provides new insights into the effects of A2A R on neuroinflammation regulation post-TBI and offers a potential target for the treatment of NLRP3 inflammasome-related CNS diseases.
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Affiliation(s)
- Hao Du
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping HospitalArmy Medical UniversityChongqingChina
- The General Hospital of Tibet Military CommandTibetChina
| | - Chang‐Hong Li
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping HospitalArmy Medical UniversityChongqingChina
| | - Ruo‐Bing Gao
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping HospitalArmy Medical UniversityChongqingChina
| | - Yan Tan
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping HospitalArmy Medical UniversityChongqingChina
- Department of Pathophysiology, College of High‐Altitude Military MedicineArmy Medical UniversityChongqingChina
| | - Bo Wang
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping HospitalArmy Medical UniversityChongqingChina
| | - Yan Peng
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping HospitalArmy Medical UniversityChongqingChina
| | - Nan Yang
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping HospitalArmy Medical UniversityChongqingChina
| | - Ya‐Lei Ning
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping HospitalArmy Medical UniversityChongqingChina
- Institute of Brain and IntelligenceArmy Medical UniversityChongqingChina
| | - Ping Li
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping HospitalArmy Medical UniversityChongqingChina
- Institute of Brain and IntelligenceArmy Medical UniversityChongqingChina
| | - Yan Zhao
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping HospitalArmy Medical UniversityChongqingChina
- Institute of Brain and IntelligenceArmy Medical UniversityChongqingChina
| | - Yuan‐Guo Zhou
- Department of Army Occupational Disease, State Key Laboratory of Trauma and Chemical Poisoning, Research Institute of Surgery and Daping HospitalArmy Medical UniversityChongqingChina
- Institute of Brain and IntelligenceArmy Medical UniversityChongqingChina
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2
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Abstract
The adenosine A2A receptor (A2AR) is abundantly expressed in the brain, including both neurons and glial cells. While the expression of A2AR is relative low in glia, its levels elevate robustly in astrocytes and microglia under pathological conditions. Elevated A2AR appears to play a detrimental role in a number of disease states, by promoting neuroinflammation and astrocytic reaction to contribute to the progression of neurodegenerative and psychiatric diseases.
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Affiliation(s)
- Zhihua Gao
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China; Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, West Wenyi Road, Hangzhou, P.R. China; NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, P.R. China.
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3
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Timmerman R, Zuiderwijk-Sick EA, Bajramovic JJ. P2Y6 receptor-mediated signaling amplifies TLR-induced pro-inflammatory responses in microglia. Front Immunol 2022; 13:967951. [PMID: 36203578 PMCID: PMC9531012 DOI: 10.3389/fimmu.2022.967951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/25/2022] [Indexed: 11/22/2022] Open
Abstract
TLR-induced signaling initiates inflammatory responses in cells of the innate immune system. These responses are amongst others characterized by the secretion of high levels of pro-inflammatory cytokines, which are tightly regulated and adapted to the microenvironment. Purinergic receptors are powerful modulators of TLR-induced responses, and we here characterized the effects of P2Y6 receptor (P2RY6)-mediated signaling on TLR responses of rhesus macaque primary bone marrow-derived macrophages (BMDM) and microglia, using the selective P2RY6 antagonist MRS2578. We demonstrate that P2RY6-mediated signaling enhances the levels of TLR-induced pro-inflammatory cytokines in microglia in particular. TLR1, 2, 4, 5 and 8-induced responses were all enhanced in microglia, whereas such effects were much less pronounced in BMDM from the same donors. Transcriptome analysis revealed that the overall contribution of P2RY6-mediated signaling to TLR-induced responses in microglia leads to an amplification of pro-inflammatory responses. Detailed target gene analysis predicts that P2RY6-mediated signaling regulates the expression of these genes via modulation of the activity of transcription factors NFAT, IRF and NF-κB. Interestingly, we found that the expression levels of heat shock proteins were strongly induced by inhibition of P2RY6-mediated signaling, both under homeostatic conditions as well as after TLR engagement. Together, our results shed new lights on the specific pro-inflammatory contribution of P2RY6-mediated signaling in neuroinflammation, which might open novel avenues to control brain inflammatory responses.
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Tozaki-Saitoh H, Takeda H, Inoue K. The Role of Microglial Purinergic Receptors in Pain Signaling. Molecules 2022; 27:molecules27061919. [PMID: 35335282 PMCID: PMC8949888 DOI: 10.3390/molecules27061919] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/10/2022] [Accepted: 03/14/2022] [Indexed: 12/25/2022] Open
Abstract
Pain is an essential modality of sensation in the body. Purinergic signaling plays an important role in nociceptive pain transmission, under both physiological and pathophysiological conditions, and is important for communication between both neuronal and non-neuronal cells. Microglia and astrocytes express a variety of purinergic effectors, and a variety of receptors play critical roles in the pathogenesis of neuropathic pain. In this review, we discuss our current knowledge of purinergic signaling and of the compounds that modulate purinergic transmission, with the aim of highlighting the importance of purinergic pathways as targets for the treatment of persistent pain.
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Affiliation(s)
- Hidetoshi Tozaki-Saitoh
- Department of Pharmacology, School of Pharmacy at Fukuoka, International University of Health and Welfare, 137-1 Enokizu, Okawa 831-8501, Japan;
- Correspondence: ; Tel.: +81-944-32-6137
| | - Hiroshi Takeda
- Department of Pharmacology, School of Pharmacy at Fukuoka, International University of Health and Welfare, 137-1 Enokizu, Okawa 831-8501, Japan;
| | - Kazuhide Inoue
- Institute for Advanced Study, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan;
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5
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Expression of the Adenosine A2A-A3 Receptor Heteromer in Different Brain Regions and Marked Upregulation in the Microglia of the Transgenic APPSw,Ind Alzheimer’s Disease Model. Biomedicines 2022; 10:biomedicines10020214. [PMID: 35203424 PMCID: PMC8869194 DOI: 10.3390/biomedicines10020214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/07/2022] [Accepted: 01/12/2022] [Indexed: 02/01/2023] Open
Abstract
Adenosine (Ado) receptors have been instrumental in the detection of heteromers and other higher-order receptor structures, mainly via interactions with other cell surface G-protein-coupled receptors. Apart from the first report of the A1 Ado receptor interacting with the A2A Ado receptor, there has been more recent data on the possibility that every Ado receptor type, A1, A2A, A2B, and A3, may interact with each other. The aim of this paper was to look for the expression and function of the A2A/A3 receptor heteromer (A2AA3Het) in neurons and microglia. In situ proximity ligation assays (PLA), performed in primary cells, showed that A2AA3Het expression was markedly higher in striatal than in cortical and hippocampal neurons, whereas it was similar in resting and activated microglia. Signaling assays demonstrated that the effect of the A2AR agonist, PSB 777, was reduced in the presence of the A3R agonist, 2-Cl-IB-MECA, whereas the effect of the A3R agonist was potentiated by the A2AR antagonist, SCH 58261. Interestingly, the expression of the heteromer was markedly enhanced in microglia from the APPSw,Ind model of Alzheimer’s disease. The functionality of the heteromer in primary microglia from APPSw,Ind mice was more similar to that found in resting microglia from control mice.
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Timmerman R, Zuiderwijk-Sick EA, Oosterhof N, 't Jong AEJ, Veth J, Burm SM, van Ham TJ, Bajramovic JJ. Transcriptome analysis reveals the contribution of oligodendrocyte and radial glia-derived cues for maintenance of microglia identity. Glia 2021; 70:728-747. [PMID: 34961968 DOI: 10.1002/glia.24136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 11/26/2021] [Accepted: 12/17/2021] [Indexed: 12/13/2022]
Abstract
Microglia are increasingly being recognized as druggable targets in neurodegenerative disorders, and good in vitro models are crucial to address cell biological questions. Major challenges are to recapitulate the complex microglial morphology and their in vivo transcriptome. We have therefore exposed primary microglia from adult rhesus macaques to a variety of different culture conditions including exposure to soluble factors as M-CSF, IL-34, and TGF-β as well as serum replacement approaches, and compared their morphologies and transcriptomes to those of mature, homeostatic in vivo microglia. This enabled us to develop a new, partially serum-free, monoculture protocol, that yields high numbers of ramified cells. We also demonstrate that exposure of adult microglia to M-CSF or IL-34 induces similar transcriptomes, and that exposure to TGF-β has much less pronounced effects than it does on rodent microglia. However, regardless of culture conditions, the transcriptomes of in vitro and in vivo microglia remained substantially different. Analysis of differentially expressed genes inspired us to perform 3D-spherical coculture experiments of microglia with oligodendrocytes and radial glia. In such spheres, microglia signature genes were strongly induced, even in the absence of neurons and astrocytes. These data reveal a novel role for oligodendrocyte and radial glia-derived cues in the maintenance of microglial identity, providing new anchor points to study microglia in health and disease.
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Affiliation(s)
- Raissa Timmerman
- Alternatives Unit, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | | | - Nynke Oosterhof
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.,European Research Institute for the Biology of Ageing, University Medical Center Groningen, Groningen, The Netherlands
| | - Anke E J 't Jong
- Alternatives Unit, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Jennifer Veth
- Alternatives Unit, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Saskia M Burm
- Alternatives Unit, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Tjakko J van Ham
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Jeffrey J Bajramovic
- Alternatives Unit, Biomedical Primate Research Centre, Rijswijk, The Netherlands
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7
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Liston TE, Hama A, Boltze J, Poe RB, Natsume T, Hayashi I, Takamatsu H, Korinek WS, Lechleiter JD. Adenosine A1R/A3R (Adenosine A1 and A3 Receptor) Agonist AST-004 Reduces Brain Infarction in a Nonhuman Primate Model of Stroke. Stroke 2021; 53:238-248. [PMID: 34802248 DOI: 10.1161/strokeaha.121.036396] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND PURPOSE Treatment with A1R/A3R (adenosine A1 and A3 receptor) agonists in rodent models of acute ischemic stroke results in significantly reduced lesion volume, indicating activation of adenosine A1R or A3R is cerebroprotective. However, dosing and timing required for cerebroprotection has yet to be established, and whether adenosine A1R/A3R activation will lead to cerebroprotection in a gyrencephalic species has yet to be determined. METHODS The current study used clinical study intervention timelines in a nonhuman primate model of transient, 4-hour middle cerebral artery occlusion to investigate a potential cerebroprotective effect of the dual adenosine A1R/A3R agonist AST-004. Bolus and then 22 hours intravenous infusion of AST-004 was initiated 2 hours after transient middle cerebral artery occlusion. Primary outcome measures included lesion volume, lesion growth kinetics, penumbra volume as well as initial pharmacokinetic-pharmacodynamic relationships measured up to 5 days after transient middle cerebral artery occlusion. Secondary outcome measures included physiological parameters and neurological function. RESULTS Administration of AST-004 resulted in rapid and statistically significant decreases in lesion growth rate and total lesion volume. In addition, penumbra volume decline over time was significantly less under AST-004 treatment compared with vehicle treatment. These changes correlated with unbound AST-004 concentrations in the plasma and cerebrospinal fluid as well as estimated brain A1R and A3R occupancy. No relevant changes in physiological parameters were observed during AST-004 treatment. CONCLUSIONS These findings suggest that administration of AST-004 and combined A1R/A3R agonism in the brain are efficacious pharmacological interventions in acute ischemic stroke and warrant further clinical evaluation.
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Affiliation(s)
- Theodore E Liston
- Astrocyte Pharmaceuticals Inc, Cambridge, MA (T.E.L., R.B.P., W.S.K.)
| | - Aldric Hama
- Hamamatsu Pharma Research Inc, Japan (A.H., I.H., T.N., H.T.)
| | - Johannes Boltze
- Department of Neuroscience, University of Warwick, United Kingdom (J.B.)
| | - Russell B Poe
- Astrocyte Pharmaceuticals Inc, Cambridge, MA (T.E.L., R.B.P., W.S.K.)
| | | | - Ikuo Hayashi
- Hamamatsu Pharma Research Inc, Japan (A.H., I.H., T.N., H.T.)
| | | | - William S Korinek
- Astrocyte Pharmaceuticals Inc, Cambridge, MA (T.E.L., R.B.P., W.S.K.)
| | - James D Lechleiter
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio (J.D.L.)
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8
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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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9
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Emerging roles of dysregulated adenosine homeostasis in brain disorders with a specific focus on neurodegenerative diseases. J Biomed Sci 2021; 28:70. [PMID: 34635103 PMCID: PMC8507231 DOI: 10.1186/s12929-021-00766-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/04/2021] [Indexed: 02/07/2023] Open
Abstract
In modern societies, with an increase in the older population, age-related neurodegenerative diseases have progressively become greater socioeconomic burdens. To date, despite the tremendous effort devoted to understanding neurodegenerative diseases in recent decades, treatment to delay disease progression is largely ineffective and is in urgent demand. The development of new strategies targeting these pathological features is a timely topic. It is important to note that most degenerative diseases are associated with the accumulation of specific misfolded proteins, which is facilitated by several common features of neurodegenerative diseases (including poor energy homeostasis and mitochondrial dysfunction). Adenosine is a purine nucleoside and neuromodulator in the brain. It is also an essential component of energy production pathways, cellular metabolism, and gene regulation in brain cells. The levels of intracellular and extracellular adenosine are thus tightly controlled by a handful of proteins (including adenosine metabolic enzymes and transporters) to maintain proper adenosine homeostasis. Notably, disruption of adenosine homeostasis in the brain under various pathophysiological conditions has been documented. In the past two decades, adenosine receptors (particularly A1 and A2A adenosine receptors) have been actively investigated as important drug targets in major degenerative diseases. Unfortunately, except for an A2A antagonist (istradefylline) administered as an adjuvant treatment with levodopa for Parkinson's disease, no effective drug based on adenosine receptors has been developed for neurodegenerative diseases. In this review, we summarize the emerging findings on proteins involved in the control of adenosine homeostasis in the brain and discuss the challenges and future prospects for the development of new therapeutic treatments for neurodegenerative diseases and their associated disorders based on the understanding of adenosine homeostasis.
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10
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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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11
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Maas SLN, Abels ER, Van De Haar LL, Zhang X, Morsett L, Sil S, Guedes J, Sen P, Prabhakar S, Hickman SE, Lai CP, Ting DT, Breakefield XO, Broekman MLD, El Khoury J. Glioblastoma hijacks microglial gene expression to support tumor growth. J Neuroinflammation 2020; 17:120. [PMID: 32299465 PMCID: PMC7164149 DOI: 10.1186/s12974-020-01797-2] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 03/31/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Glioblastomas are the most common and lethal primary brain tumors. Microglia, the resident immune cells of the brain, survey their environment and respond to pathogens, toxins, and tumors. Glioblastoma cells communicate with microglia, in part by releasing extracellular vesicles (EVs). Despite the presence of large numbers of microglia in glioblastoma, the tumors continue to grow, and these neuroimmune cells appear incapable of keeping the tumor in check. To understand this process, we analyzed gene expression in microglia interacting with glioblastoma cells. METHODS We used RNASeq of isolated microglia to analyze the expression patterns of genes involved in key microglial functions in mice with glioblastoma. We focused on microglia that had taken up tumor-derived EVs and therefore were within and immediately adjacent to the tumor. RESULTS We show that these microglia have downregulated expression of genes involved in sensing tumor cells and tumor-derived danger signals, as well as genes used for tumor killing. In contrast, expression of genes involved in facilitating tumor spread was upregulated. These changes appear to be in part EV-mediated, since intracranial injection of EVs in normal mice led to similar transcriptional changes in microglia. We observed a similar microglial transcriptomic signature when we analyzed datasets from human patients with glioblastoma. CONCLUSION Our data define a microgliaGlioblastoma specific phenotype, whereby glioblastomas have hijacked gene expression in the neuroimmune system to favor avoiding tumor sensing, suppressing the immune response, clearing a path for invasion, and enhancing tumor propagation. For further exploration, we developed an interactive online tool at http://www.glioma-microglia.com with all expression data and additional functional and pathway information for each gene.
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Affiliation(s)
- Sybren L N Maas
- Departments of Neurology and Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA.,Department of Neurosurgery, UMC Utrecht Brain Center, University Medical Center, Utrecht University, 3584 CX, Utrecht, The Netherlands
| | - Erik R Abels
- Departments of Neurology and Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Lieke L Van De Haar
- Departments of Neurology and Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Xuan Zhang
- Departments of Neurology and Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Liza Morsett
- Center for Immunology & Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Srinjoy Sil
- Cancer Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Joana Guedes
- Center for Immunology & Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA.,Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal
| | - Pritha Sen
- Center for Immunology & Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Shilpa Prabhakar
- Departments of Neurology and Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Suzanne E Hickman
- Center for Immunology & Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA.,Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Charles P Lai
- Departments of Neurology and Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA.,Institute of Atomic and Molecular Sciences/Academia Sinica, 10617, Taipei, Taiwan
| | - David T Ting
- Cancer Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Xandra O Breakefield
- Departments of Neurology and Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Marike L D Broekman
- Departments of Neurology and Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA.,Department of Neurosurgery, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands.,Department of Neurosurgery, Haaglanden Medical Center, 2512 VA, The Hague, The Netherlands
| | - Joseph El Khoury
- Center for Immunology & Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA. .,Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA.
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12
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Wu KC, Lee CY, Chou FY, Chern Y, Lin CJ. Deletion of equilibrative nucleoside transporter-2 protects against lipopolysaccharide-induced neuroinflammation and blood-brain barrier dysfunction in mice. Brain Behav Immun 2020; 84:59-71. [PMID: 31751618 DOI: 10.1016/j.bbi.2019.11.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 11/05/2019] [Accepted: 11/17/2019] [Indexed: 01/22/2023] Open
Abstract
Neuroinflammation is a common pathological feature of many brain diseases and is a key mediator of blood-brain barrier (BBB) breakdown and neuropathogenesis. Adenosine is an endogenous immunomodulator, whose brain extracellular level is tightly controlled by equilibrative nucleoside transporters-1 (ENT1) and ENT2. This study was aimed to investigate the role of ENTs in the modulation of neuroinflammation and BBB function. The results showed that mRNA level of Ent2 was significantly more abundant than that of Ent1 in the brain (hippocampus, cerebral cortex, striatum, midbrain, and cerebellum) of wild-type (WT) mice. Ent2-/- mice displayed higher extracellular adenosine level in the hippocampus than their littermate controls. Repeated lipopolysaccharide (LPS) treatment induced microglia activation, astrogliosis and upregulation of proinflammatory cytokines, along with aberrant BBB phenotypes (including reduced tight junction protein expression, pericyte loss, and immunoglobulin G extravasation) and neuronal apoptosis in the hippocampus of WT mice. Notably, Ent2-/- mice displayed significant resistance to LPS-induced neuroinflammation, BBB breakdown, and neurotoxicity. These findings suggest that Ent2 is critical for the modulation of brain adenosine tone and deletion of Ent2 confers protection against LPS-induced neuroinflammation and neurovascular-associated injury.
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Affiliation(s)
- Kuo-Chen Wu
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chih-Yu Lee
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Fang-Yi Chou
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yijuang Chern
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan; Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chun-Jung Lin
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan.
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13
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Meng F, Guo Z, Hu Y, Mai W, Zhang Z, Zhang B, Ge Q, Lou H, Guo F, Chen J, Duan S, Gao Z. CD73-derived adenosine controls inflammation and neurodegeneration by modulating dopamine signalling. Brain 2020; 142:700-718. [PMID: 30689733 DOI: 10.1093/brain/awy351] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 11/09/2018] [Accepted: 11/22/2018] [Indexed: 12/21/2022] Open
Abstract
Ectonucleotidase-mediated ATP catabolism provides a powerful mechanism to control the levels of extracellular adenosine. While increased adenosine A2A receptor (A2AR) signaling has been well-documented in both Parkinson's disease models and patients, the source of this enhanced adenosine signalling remains unclear. Here, we show that the ecto-5'-nucleotidase (CD73)-mediated adenosine formation provides an important input to activate A2AR, and upregulated CD73 and A2AR in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease models coordinatively contribute to the elevated adenosine signalling. Importantly, we demonstrate that CD73-derived adenosine-A2AR signalling modulates microglial immunoresponses and morphological dynamics. CD73 inactivation significantly attenuated lipopolysaccharide-induced pro-inflammatory responses in microglia, but enhanced microglia process extension, movement and morphological transformation in the laser injury and acute MPTP-induced Parkinson's disease models. Limiting CD73-derived adenosine substantially suppressed microglia-mediated neuroinflammation and improved the viability of dopaminergic neurons and motor behaviours in Parkinson's disease models. Moreover, CD73 inactivation suppressed A2AR induction and A2AR-mediated pro-inflammatory responses, whereas replenishment of adenosine analogues restored these effects, suggesting that CD73 produces a self-regulating feed-forward adenosine formation to activate A2AR and promote neuroinflammation. We further provide the first evidence that A2A enhanced inflammation by antagonizing dopamine-mediated anti-inflammation, suggesting that the homeostatic balance between adenosine and dopamine signalling is key to microglia immunoresponses. Our study thus reveals a novel role for CD73-mediated nucleotide metabolism in regulating neuroinflammation and provides the proof-of-principle that targeting nucleotide metabolic pathways to limit adenosine production and neuroinflammation in Parkinson's disease might be a promising therapeutic strategy.
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Affiliation(s)
- Fan Meng
- Department of Neurobiology and Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhige Guo
- Department of Neurobiology and Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Yaling Hu
- Department of Neurobiology and Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Weihao Mai
- Department of Neurobiology and Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhenjie Zhang
- Department of Neurobiology and Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Bin Zhang
- Department of Neurobiology and Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Qianqian Ge
- Department of Neurobiology and Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Huifang Lou
- Department of Neurobiology and Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Fang Guo
- Department of Neurobiology and Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Jiangfan Chen
- Molecular Neuropharmacology Laboratory and State Key Laboratory of Optometry, Ophthalmology and Vision Science, School of Optometry and Ophthalmology, Wenzhou, Zhejiang, China
| | - Shumin Duan
- Department of Neurobiology and Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhihua Gao
- Department of Neurobiology and Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
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14
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Franco R, Reyes-Resina I, Aguinaga D, Lillo A, Jiménez J, Raïch I, Borroto-Escuela DO, Ferreiro-Vera C, Canela EI, Sánchez de Medina V, Del Ser-Badia A, Fuxe K, Saura CA, Navarro G. Potentiation of cannabinoid signaling in microglia by adenosine A 2A receptor antagonists. Glia 2019; 67:2410-2423. [PMID: 31429130 DOI: 10.1002/glia.23694] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 07/18/2019] [Accepted: 07/22/2019] [Indexed: 12/15/2022]
Abstract
Neuroprotective M2-skewed microglia appear as promising to alter the course of neurodegenerative diseases and G protein-coupled receptors (GPCRs) are potential targets to achieve such microglial polarization. A common feature of adenosine A2A (A2A R) and cannabinoid CB2 (CB2 R) GPCRs in microglia is that their expression is upregulated in Alzheimer's disease (AD). On the one hand, CB2 R seems a target for neuroprotection, delaying neurodegenerative processes like those associated to AD or Parkinson's diseases. A2A R antagonists reduce amyloid burden and improve cognitive performance and memory in AD animal models. We here show a close interrelationship between these two receptors in microglia; they are able to physically interact and affect the signaling of each other, likely due to conformational changes within the A2A -CB2 receptor heteromer (A2A -CB2 Het). Particularly relevant is the upregulation of A2A -CB2 Het expression in samples from the APPSw ,Ind AD transgenic mice model. The most relevant finding, confirmed in both heterologous cells and in primary cultures of microglia, was that blockade of A2A receptors results in increased CB2 R-mediated signaling. This heteromer-specific feature suggests that A2A R antagonists would potentiate, via microglia, the neuroprotective action of endocannabinoids with implications for AD therapy.
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Affiliation(s)
- Rafael Franco
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain
| | - Irene Reyes-Resina
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain
| | - David Aguinaga
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain
| | - Alejandro Lillo
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain
| | - Jasmina Jiménez
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain
| | - Iu Raïch
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain
| | | | | | - Enric I Canela
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain
| | | | - Anna Del Ser-Badia
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain.,Department de Bioquímica i Biologia Molecular, Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Carlos A Saura
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain.,Department de Bioquímica i Biologia Molecular, Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Gemma Navarro
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain.,Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain
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15
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Bobermin LD, Roppa RHA, Quincozes-Santos A. Adenosine receptors as a new target for resveratrol-mediated glioprotection. Biochim Biophys Acta Mol Basis Dis 2019; 1865:634-647. [PMID: 30611861 DOI: 10.1016/j.bbadis.2019.01.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/16/2018] [Accepted: 01/02/2019] [Indexed: 12/11/2022]
Abstract
Resveratrol, a natural polyphenolic compound, has been studied as a neuroprotective molecule. Our group has demonstrated that such effect is closely associated with modulation of glial functionality, but the underlying mechanisms are not fully understood. Because astrocytes actively participate in the brain inflammatory response, and activation of adenosine receptors can attenuate inflammatory processes, the aim of this study was to investigate the role of adenosine receptors as a mechanism for resveratrol glioprotection, particularly regarding to neuroinflammation. Therefore, primary astrocyte cultures were co-incubated with resveratrol and selective antagonists of A1, A2A, and A3 adenosine receptors, as well as with caffeine (a non-selective adenosine receptor antagonist), and then challenged with bacterial inflammogen lipopolysaccharide (LPS). Caffeine and selective adenosine receptor antagonists abolished the anti-inflammatory effect of resveratrol. In accordance with these effects, resveratrol prevented LPS-induced decrease in mRNA levels of adenosine receptors. Resveratrol could also prevent the activation of pro-inflammatory signaling pathways, such as nuclear factor κB (NFκB) and p38 mitogen-activated protein kinase (p38 MAPK) in a mechanism dependent on adenosine receptors. Conversely, trophic factors and protective signaling pathways, including sirtuin 1 (SIRT1), nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and phosphoinositide 3-kinase (PI3K)/Akt were positively modulated by resveratrol in both LPS-stimulated and unstimulated astrocytes, but adenosine receptor antagonism did not abrogate all effects of resveratrol. To our knowledge, our data provide the first evidence that adenosine receptors are involved in the anti-inflammatory activity of resveratrol in astrocytes, thus exerting an important role for resveratrol-mediated glioprotection.
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Affiliation(s)
- Larissa Daniele Bobermin
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
| | - Ricardo Haack Amaral Roppa
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - André Quincozes-Santos
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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16
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Kovács Z, D'Agostino DP, Diamond DM, Ari C. Exogenous Ketone Supplementation Decreased the Lipopolysaccharide-Induced Increase in Absence Epileptic Activity in Wistar Albino Glaxo Rijswijk Rats. Front Mol Neurosci 2019; 12:45. [PMID: 30930744 PMCID: PMC6427924 DOI: 10.3389/fnmol.2019.00045] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 02/05/2019] [Indexed: 12/02/2022] Open
Abstract
It has been demonstrated previously that exogenous ketone supplements such as ketone ester (KE) decreased absence epileptic activity in a well-studied animal model of human absence epilepsy, Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats. It is known that lipopolysaccharide (LPS)-generated changes in inflammatory processes increase absence epileptic activity, while previous studies show that ketone supplement-evoked ketosis can modulate inflammatory processes. Thus, we investigated in the present study whether administration of exogenous ketone supplements, which were mixed with standard rodent chow (containing 10% KE + 10% ketone salt/KS, % by weight, KEKS) for 10 days, can modulate the LPS-evoked changes in absence epileptic activity in WAG/Rij rats. At first, KEKS food alone was administered and changes in spike-wave discharge (SWD) number, SWD time, discharge frequency within SWDs, blood glucose, and beta-hydroxybutyrate (βHB) levels, as well as body weight and sleep-waking stages were measured. In a separate experiment, intraperitoneal (i.p.) injection of LPS (50 μg/kg) alone and a cyclooxygenase 1 and 2 (COX-1 and COX-2) inhibitor indomethacin (10 mg/kg) alone, as well as combined IP injection of indomethacin with LPS (indomethacin + LPS) were applied in WAG/Rij rats to elucidate their influences on SWD number. In order to determine whether KEKS food can modify the LPS-evoked changes in SWD number, KEKS food in combination with IP LPS (50 μg/kg) (KEKS + LPS), as well as KEKS food with IP indomethacin (10 mg/kg) and LPS (50 μg/kg) (KEKS + indomethacin + LPS) were also administered. We demonstrated that KEKS food significantly increased blood βHB levels and decreased not only the spontaneously generated absence epileptic activity (SWD number), but also the LPS-evoked increase in SWD number in WAG/Rij rats. Our results suggest that administration of exogenous ketone supplements (ketogenic foods) may be a promising therapeutic tool in the treatment of epilepsy.
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Affiliation(s)
- Zsolt Kovács
- Department of Biology, ELTE Eötvös Loránd University, Savaria University Centre, Szombathely, Hungary
| | - Dominic P D'Agostino
- Laboratory of Metabolic Medicine, Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States.,Institute for Human and Machine Cognition, Ocala, FL, United States
| | - David M Diamond
- Laboratory of Metabolic Medicine, Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States.,Comparative Neuroscience Research Laboratory, Department of Psychology, University of South Florida, Tampa, FL, United States
| | - Csilla Ari
- Comparative Neuroscience Research Laboratory, Department of Psychology, University of South Florida, Tampa, FL, United States
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17
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van der Putten C, Veth J, Sukurova L, Zuiderwijk-Sick EA, Simonetti E, Koenen HJPM, Burm SM, van Noort JM, IJzerman AP, van Hijum SAFT, Diavatopoulos D, Bajramovic JJ. TLR-Induced IL-12 and CCL2 Production by Myeloid Cells Is Dependent on Adenosine A 3 Receptor-Mediated Signaling. THE JOURNAL OF IMMUNOLOGY 2019; 202:2421-2430. [PMID: 30804043 DOI: 10.4049/jimmunol.1800618] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 01/16/2019] [Indexed: 11/19/2022]
Abstract
TLR-induced signaling potently activates cells of the innate immune system and is subject to regulation at different levels. Inflammatory conditions are associated with increased levels of extracellular adenosine, which can modulate TLR-induced production of cytokines through adenosine receptor-mediated signaling. There are four adenosine receptor subtypes that induce different signaling cascades. In this study, we demonstrate a pivotal contribution of adenosine A3 receptor (A3R)-mediated signaling to the TLR4-induced expression of IL-12 in different types of human myeloid APC. In dendritic cells, IL-12 and CCL2 responses as evoked by TLR2, 3, 4, 5, and 8, as well as IL-12 responses evoked by whole pathogens, were all reduced when A3R-mediated signaling was blocked. As a result, concomitant production of IFN-γ and IL-17 by T cells was significantly inhibited. We further show that selective inhibition of A3R-mediated signaling reduced TLR-induced phosphorylation of the transcription factor STAT1 at tyrosine 701. Next-generation sequencing revealed that A3R-mediated signaling controls the expression of metallothioneins, known inhibitors of STAT1 phosphorylation. Together our results reveal a novel regulatory layer of innate immune responses, with a central role for metallothioneins and autocrine/paracrine signaling via A3Rs.
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Affiliation(s)
- Céline van der Putten
- Alternatives Unit, Biomedical Primate Research Centre, 2288 GJ Rijswijk, the Netherlands
| | - Jennifer Veth
- Alternatives Unit, Biomedical Primate Research Centre, 2288 GJ Rijswijk, the Netherlands
| | - Lejla Sukurova
- Alternatives Unit, Biomedical Primate Research Centre, 2288 GJ Rijswijk, the Netherlands
| | - Ella A Zuiderwijk-Sick
- Alternatives Unit, Biomedical Primate Research Centre, 2288 GJ Rijswijk, the Netherlands
| | - Elles Simonetti
- Laboratory of Pediatric Infectious Diseases, Radboud Centre for Infectious Diseases, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Hans J P M Koenen
- Laboratory of Pediatric Infectious Diseases, Radboud Centre for Infectious Diseases, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Saskia M Burm
- Alternatives Unit, Biomedical Primate Research Centre, 2288 GJ Rijswijk, the Netherlands
| | | | - Ad P IJzerman
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, 2333 CC Leiden, the Netherlands
| | - Sacha A F T van Hijum
- Bacterial (Meta)genomics, Centre for Molecular and Biomolecular Informatics, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands; and.,NIZO, 6718 ZB Ede, the Netherlands
| | - Dimitri Diavatopoulos
- Laboratory of Pediatric Infectious Diseases, Radboud Centre for Infectious Diseases, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Jeffrey J Bajramovic
- Alternatives Unit, Biomedical Primate Research Centre, 2288 GJ Rijswijk, the Netherlands;
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18
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Inhibitors of NF-κB and P2X7/NLRP3/Caspase 1 pathway in microglia: Novel therapeutic opportunities in neuroinflammation induced early-stage Alzheimer’s disease. J Neuroimmunol 2019; 326:62-74. [DOI: 10.1016/j.jneuroim.2018.11.010] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 11/16/2018] [Accepted: 11/18/2018] [Indexed: 12/21/2022]
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19
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Kovács Z, D'Agostino DP, Diamond D, Kindy MS, Rogers C, Ari C. Therapeutic Potential of Exogenous Ketone Supplement Induced Ketosis in the Treatment of Psychiatric Disorders: Review of Current Literature. Front Psychiatry 2019; 10:363. [PMID: 31178772 PMCID: PMC6543248 DOI: 10.3389/fpsyt.2019.00363] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 05/10/2019] [Indexed: 12/16/2022] Open
Abstract
Globally, psychiatric disorders, such as anxiety disorder, bipolar disorder, schizophrenia, depression, autism spectrum disorder, and attention-deficit/hyperactivity disorder (ADHD) are becoming more prevalent. Although the exact pathological alterations are not yet clear, recent studies have demonstrated that widespread changes of very complex metabolic pathways may partially underlie the pathophysiology of many psychiatric diseases. Thus, more attention should be directed to metabolic-based therapeutic interventions in the treatment of psychiatric disorders. Emerging evidence from numerous studies suggests that administration of exogenous ketone supplements, such as ketone salts or ketone esters, generates rapid and sustained nutritional ketosis and metabolic changes, which may evoke potential therapeutic effects in cases of central nervous system (CNS) disorders, including psychiatric diseases. Therefore, the aim of this review is to summarize the current information on ketone supplementation as a potential therapeutic tool for psychiatric disorders. Ketone supplementation elevates blood levels of the ketone bodies: D-β-hydroxybutyrate (βHB), acetoacetate (AcAc), and acetone. These compounds, either directly or indirectly, beneficially affect the mitochondria, glycolysis, neurotransmitter levels, activity of free fatty acid receptor 3 (FFAR3), hydroxycarboxylic acid receptor 2 (HCAR2), and histone deacetylase, as well as functioning of NOD-like receptor pyrin domain 3 (NLRP3) inflammasome and mitochondrial uncoupling protein (UCP) expression. The result of downstream cellular and molecular changes is a reduction in the pathophysiology associated with various psychiatric disorders. We conclude that supplement-induced nutritional ketosis leads to metabolic changes and improvements, for example, in mitochondrial function and inflammatory processes, and suggest that development of specific adjunctive ketogenic protocols for psychiatric diseases should be actively pursued.
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Affiliation(s)
- Zsolt Kovács
- Savaria Department of Biology, ELTE Eötvös Loránd University, Savaria University Centre, Szombathely, Hungary
| | - Dominic P D'Agostino
- Department of Molecular Pharmacology and Physiology, Laboratory of Metabolic Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States.,Institute for Human and Machine Cognition, Ocala, FL, United States
| | - David Diamond
- Department of Molecular Pharmacology and Physiology, Laboratory of Metabolic Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States.,Department of Psychology, Hyperbaric Neuroscience Research Laboratory, University of South Florida, Tampa, FL, United States
| | - Mark S Kindy
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, United States.,James A. Haley VA Medical Center, Tampa, FL, United States.,Shriners Hospital for Children, Tampa, FL, United States
| | - Christopher Rogers
- Department of Molecular Pharmacology and Physiology, Laboratory of Metabolic Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Csilla Ari
- Department of Psychology, Hyperbaric Neuroscience Research Laboratory, University of South Florida, Tampa, FL, United States
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20
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Colella M, Zinni M, Pansiot J, Cassanello M, Mairesse J, Ramenghi L, Baud O. Modulation of Microglial Activation by Adenosine A2a Receptor in Animal Models of Perinatal Brain Injury. Front Neurol 2018; 9:605. [PMID: 30254599 PMCID: PMC6141747 DOI: 10.3389/fneur.2018.00605] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 07/06/2018] [Indexed: 12/19/2022] Open
Abstract
Neuroinflammation has a key role in the pathogenesis of perinatal brain injury. Caffeine, a nonspecific antagonist of adenosine receptors (ARs), is widely used to treat apnea of prematurity and has been linked to a decrease in the incidence of cerebral palsy in premature infants. The mechanisms explaining its neuroprotective effect have not yet been elucidated. The objective of this study was to characterize the expression of adenosine and ARs in two neonatal rat models of neuroinflammation and to determine the effect of A2aR blockade on microglial activation assessed through inflammatory cytokine gene expression. We have used two rat models of microglial activation: the gestational low protein diet (LPD) model, associated with chronic brain injury, and postnatal ibotenate intracerebral injections, responsible for acute excitotoxicity injury. Adenosine blood levels have been measured by Tandem Mass Spectrometry. The expression of ARs in vivo was assessed using qPCR and immunohistochemistry. In vivo models have been replicated in vitro on primary microglial cell cultures exposed to A2aR agonist CGS-21680 or antagonist SCH-58261. The effects of these treatments have been assessed on the M1/M2 cytokine expressions measured by RT-qPCR. LPD during pregnancy was associated with higher adenosine levels in pups at postnatal day 1 and 4. A2aR mRNA expression was significantly increased in both cortex and magnetically sorted microglial cells from LPD animals compared to controls. CD73 expression, responsible for extracellular production of brain adenosine, was significantly increased in LPD cortex and sorted microglia cells. Moreover, CD73 protein level was increased in ibotenate treated animals. In vitro experiments confirmed that LPD or control microglial cells exposed to ibotenate display an increased expression, at both protein and molecular levels, of A2aR and M1 markers (IL-1β, IL-6, iNOS, TNFα). This pro-inflammatory profile was significantly reduced by SCH-58261, which reduces M1 markers in both LPD and ibotenate-exposed cells, with no effect on control cells. In the same experimental conditions, a partial increased of M1 cytokines was observed in response to A2aR agonist CGS-21680. These results support the involvement of adenosine and particularly of its receptor A2aR in the regulation of microglia in two different animal models of neuroinflammation.
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Affiliation(s)
- Marina Colella
- Robert Debré Hospital, PROTECT, Inserm U1141, Paris, France.,Istituto G. Gaslini, Università di Genova, Genoa, Italy
| | - Manuela Zinni
- Robert Debré Hospital, PROTECT, Inserm U1141, Paris, France
| | - Julien Pansiot
- Robert Debré Hospital, PROTECT, Inserm U1141, Paris, France
| | - Michela Cassanello
- Laboratory for the Study of Inborn Errors of Metabolism, Istituto Giannina Gaslini, Genoa, Italy
| | - Jérôme Mairesse
- Robert Debré Hospital, PROTECT, Inserm U1141, Paris, France.,Division of Neonatology and Pediatric Intensive Care, Children's University Hospital of Geneva, University of Geneva, Geneva, Switzerland
| | - Luca Ramenghi
- Neonatal Intensive Care Unit, Istituto Giannina Gaslini, Genoa, Italy
| | - Olivier Baud
- Robert Debré Hospital, PROTECT, Inserm U1141, Paris, France.,Division of Neonatology and Pediatric Intensive Care, Children's University Hospital of Geneva, University of Geneva, Geneva, Switzerland
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21
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Xu S, Zhu W, Shao M, Zhang F, Guo J, Xu H, Jiang J, Ma X, Xia X, Zhi X, Zhou P, Lu F. Ecto-5'-nucleotidase (CD73) attenuates inflammation after spinal cord injury by promoting macrophages/microglia M2 polarization in mice. J Neuroinflammation 2018; 15:155. [PMID: 29788960 PMCID: PMC5964922 DOI: 10.1186/s12974-018-1183-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 04/29/2018] [Indexed: 12/15/2022] Open
Abstract
Background Immune activation, specifically activation of macrophages and resident microglia, leading to inflammation is a key component in the progression of spinal cord injury (SCI). Macrophages/microglia exist in two states—the classically activated M1 phenotype that confers pro-inflammatory effects or the alternatively activated M2 phenotype that confers anti-inflammatory effects. Ecto-5′-nucleotidase (CD73) is an immunosuppressive molecule intricately involved in adaptive and innate immune responses and is able to dephosphorylate AMP to adenosine. However, it is not known if CD73 is able to modulate the macrophages/microglia transformation between the M1 and M2 phenotypes. Methods We used gene-deficient mice to determine the role of CD73 in macrophages/microglia polarization post-SCI in vivo. We used small interference RNA (siRNA) or pcDNA3.1 to inhibit or overexpress CD73 in BV2 cells to verify anterior discovery in vitro. A combination of molecular and histological methods was used to detect the macrophages/microglia polarization and explore the mechanism both in vivo and in vitro. Results We found that SCI induced the upregulation of CD73 expression. CD73 deficient mice were noted to demonstrate overwhelming immune responses, few anti-inflammatory phenotype macrophages/microglia, and had a poorer locomotor recovery in comparison to wild-type mice that were also inflicted with SCI. In vitro studies found that CD73 suppression inhibited the expression of characteristic microglial anti-inflammatory polarization markers in BV2 cells, while the converse was noted in CD73 overexpression. Subsequent experiments confirmed that CD73 promoted microglia alternative activation by stimulating p38 MAPK. Conclusion We were able to conclude that CD73 imparts neuroprotective effects by mediating macrophages/microglia polarization. These findings allow for better understanding of the modulatory factors involved in triggering the change in macrophages/microglia phenotypes, therefore uncovering additional molecules and pathways that may be targeted in the innovation of novel SCI therapies. Electronic supplementary material The online version of this article (10.1186/s12974-018-1183-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shun Xu
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Wulumuqi middle Road, Jingan District, Shanghai, 200040, China
| | - Wei Zhu
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Wulumuqi middle Road, Jingan District, Shanghai, 200040, China
| | - Minghao Shao
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Wulumuqi middle Road, Jingan District, Shanghai, 200040, China
| | - Fan Zhang
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Wulumuqi middle Road, Jingan District, Shanghai, 200040, China
| | - Ji Guo
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Wulumuqi middle Road, Jingan District, Shanghai, 200040, China
| | - Haocheng Xu
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Wulumuqi middle Road, Jingan District, Shanghai, 200040, China
| | - Jianyuan Jiang
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Wulumuqi middle Road, Jingan District, Shanghai, 200040, China
| | - Xiaosheng Ma
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Wulumuqi middle Road, Jingan District, Shanghai, 200040, China
| | - Xinlei Xia
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Wulumuqi middle Road, Jingan District, Shanghai, 200040, China
| | - Xiuling Zhi
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, No.138, Yixueyuan Road, Shanghai, 200032, China
| | - Ping Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, No.138, Yixueyuan Road, Shanghai, 200032, China.
| | - Feizhou Lu
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Wulumuqi middle Road, Jingan District, Shanghai, 200040, China. .,The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China.
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22
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Palani CD, Ramanathapuram L, Lam-ubol A, Kurago ZB. Toll-like receptor 2 induces adenosine receptor A2a and promotes human squamous carcinoma cell growth via extracellular signal regulated kinases ½. Oncotarget 2018; 9:6814-6829. [PMID: 29467931 PMCID: PMC5805517 DOI: 10.18632/oncotarget.23784] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 12/27/2017] [Indexed: 01/26/2023] Open
Abstract
Patient treatment for oral squamous cell carcinoma (OSCC) not associated with Human papillomavirus remains problematic. OSCC microenvironment is typically inflamed and colonized by microorganisms, providing ligands for toll-like receptors (TLR). In immune cells TLR2 and TLR4 activate NF-kB and extracellular signal regulated kinase (ERK)1/2 pathways, leading to upregulation of inhibitory adenosine receptors A2a and A2b, and reduction in stimulatory A1 and A3. How TLR and adenosine receptors function in SCC cells is not understood. To address this gap, we evaluated TLR and adenosine receptor expression and function in human OSCC cells and keratinocytes. TLR2 and A2a were co-expressed in pre-cancer and SCC cells of 17 oral specimens. In vitro, 5/6 OSCC lines expressed more TLR2 than TLR1, 4 or 6 mRNA. TLR2 ligands stimulated A2a expression in TLR2-high cell lines, but no A1 or A3 was detected with or without stimuli. In TLR2-high OSCC, TLR2/1, 2/6 and adenosine receptor agonists activated ERK1/2. TLR2-mediated ERK1/2 phosphorylation resulted in accumulation of c-FOS, ERK-dependent cell proliferation and reduced caspase-3 activity. Similar ERK1/2-dependent proliferation and decreased caspase-3 activity were caused by combined TLR2 and adenosine receptor stimuli. We conclude that TLR2 and adenosine receptor agonists, known to be present in the tumor microenvironment, may contribute to OSCC progression in part via direct effects on the ERK1/2 pathway in squamous carcinoma cells.
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Affiliation(s)
| | | | - Aroonwan Lam-ubol
- Faculty of Dentistry Srinakharinwirot University, Wattana, Bangkok, Thailand
| | - Zoya B. Kurago
- Dental College of Georgia, Augusta University, Augusta, GA, USA
- Medical College of Georgia, Augusta University, Augusta, GA, USA
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23
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Burm SM, Zuiderwijk-Sick EA, Weert PM, Bajramovic JJ. ATP-induced IL-1β secretion is selectively impaired in microglia as compared to hematopoietic macrophages. Glia 2016; 64:2231-2246. [PMID: 27641912 DOI: 10.1002/glia.23059] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 08/30/2016] [Accepted: 09/05/2016] [Indexed: 12/13/2022]
Abstract
Under stressful conditions nucleotides are released from dying cells into the extracellular space, where they can bind to purinergic P2X and P2Y receptors. High concentrations of extracellular ATP in particular induce P2X7-mediated signaling, which leads to inflammasome activation. This in turn leads to the processing and secretion of pro-inflammatory cytokines, like interleukin (IL)-1β. During neurodegenerative diseases, innate immune responses are shaped by microglia and we have previously identified microglia-specific features of inflammasome-mediated responses. Here, we compared ATP-induced IL-1β secretion in primary rhesus macaque microglia and bone marrow-derived macrophages (BMDM). We assessed the full expression profile of P2 receptors and characterized the induction and modulation of IL-1β secretion by extracellular nucleotides. Microglia secreted significantly lower levels of IL-1β in response to ATP when compared to BMDM. We demonstrate that this is not due to differences in sensitivity, kinetics or expression of ATP-processing enzymes, but rather to differences in purinergic receptor expression levels and usage. Using a combined approach of purinergic receptor agonists and antagonists, we demonstrate that ATP-induced IL-1β secretion in BMDM was fully dependent on P2X7 signaling, whereas in microglia multiple purinergic receptors were involved, including P2X7 and P2X4. These cell type-specific features of conserved innate immune responses may reflect adaptations to the vulnerable CNS microenvironment. GLIA 2016;64:2231-2246.
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Affiliation(s)
- Saskia Maria Burm
- Alternatives Unit, Biomedical Primate Research Centre, Lange Kleiweg 161, 2288 GJ Rijswijk, The Netherlands
| | | | - Paola Massiel Weert
- Alternatives Unit, Biomedical Primate Research Centre, Lange Kleiweg 161, 2288 GJ Rijswijk, The Netherlands
| | - Jeffrey John Bajramovic
- Alternatives Unit, Biomedical Primate Research Centre, Lange Kleiweg 161, 2288 GJ Rijswijk, The Netherlands.
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24
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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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25
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Turčin A, Dolžan V, Porcelli S, Serretti A, Plesničar BK. Adenosine Hypothesis of Antipsychotic Drugs Revisited: Pharmacogenomics Variation in Nonacute Schizophrenia. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2016; 20:283-9. [DOI: 10.1089/omi.2016.0003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Arijana Turčin
- University Psychiatric Clinic Ljubljana, Ljubljana, Slovenia
| | - Vita Dolžan
- Pharmacogenetics Laboratory, Faculty of Medicine, Institute of Biochemistry, University of Ljubljana, Ljubljana, Slovenia
| | - Stefano Porcelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Alessandro Serretti
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
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26
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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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27
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Modulatory effects of inosine, guanosine and uridine on lipopolysaccharide-evoked increase in spike-wave discharge activity in Wistar Albino Glaxo/Rijswijk rats. Brain Res Bull 2015; 118:46-57. [DOI: 10.1016/j.brainresbull.2015.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 09/05/2015] [Accepted: 09/07/2015] [Indexed: 12/20/2022]
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28
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Borea PA, Varani K, Vincenzi F, Baraldi PG, Tabrizi MA, Merighi S, Gessi S. The A3 adenosine receptor: history and perspectives. Pharmacol Rev 2015; 67:74-102. [PMID: 25387804 DOI: 10.1124/pr.113.008540] [Citation(s) in RCA: 188] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
By general consensus, the omnipresent purine nucleoside adenosine is considered a major regulator of local tissue function, especially when energy supply fails to meet cellular energy demand. Adenosine mediation involves activation of a family of four G protein-coupled adenosine receptors (ARs): A(1), A(2)A, A(2)B, and A(3). The A(3) adenosine receptor (A(3)AR) is the only adenosine subtype to be overexpressed in inflammatory and cancer cells, thus making it a potential target for therapy. Originally isolated as an orphan receptor, A(3)AR presented a twofold nature under different pathophysiologic conditions: it appeared to be protective/harmful under ischemic conditions, pro/anti-inflammatory, and pro/antitumoral depending on the systems investigated. Until recently, the greatest and most intriguing challenge has been to understand whether, and in which cases, selective A(3) agonists or antagonists would be the best choice. Today, the choice has been made and A(3)AR agonists are now under clinical development for some disorders including rheumatoid arthritis, psoriasis, glaucoma, and hepatocellular carcinoma. More specifically, the interest and relevance of these new agents derives from clinical data demonstrating that A(3)AR agonists are both effective and safe. Thus, it will become apparent in the present review that purine scientists do seem to be getting closer to their goal: the incorporation of adenosine ligands into drugs with the ability to save lives and improve human health.
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Affiliation(s)
- Pier Andrea Borea
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
| | - Katia Varani
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
| | - Fabrizio Vincenzi
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
| | - Pier Giovanni Baraldi
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
| | - Mojgan Aghazadeh Tabrizi
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
| | - Stefania Merighi
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
| | - Stefania Gessi
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
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29
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Merighi S, Borea PA, Stefanelli A, Bencivenni S, Castillo CA, Varani K, Gessi S. A2aand a2badenosine receptors affect HIF-1α signaling in activated primary microglial cells. Glia 2015; 63:1933-1952. [DOI: 10.1002/glia.22861] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 04/30/2015] [Accepted: 05/04/2015] [Indexed: 01/31/2023]
Affiliation(s)
- Stefania Merighi
- Department of Medical Sciences; Pharmacology Section, University of Ferrara; via Fossato Di Mortara 17/19 Ferrara 44121 Italy
| | - Pier Andrea Borea
- Department of Medical Sciences; Pharmacology Section, University of Ferrara; via Fossato Di Mortara 17/19 Ferrara 44121 Italy
| | - Angela Stefanelli
- Department of Medical Sciences; Pharmacology Section, University of Ferrara; via Fossato Di Mortara 17/19 Ferrara 44121 Italy
| | - Serena Bencivenni
- Department of Medical Sciences; Pharmacology Section, University of Ferrara; via Fossato Di Mortara 17/19 Ferrara 44121 Italy
| | - Carlos Alberto Castillo
- Department of Nursing; Faculty of Nursing; Occupational and Speech Therapies, University of Castilla-La Mancha; Talavera De La Reina Spain
| | - Katia Varani
- Department of Medical Sciences; Pharmacology Section, University of Ferrara; via Fossato Di Mortara 17/19 Ferrara 44121 Italy
| | - Stefania Gessi
- Department of Medical Sciences; Pharmacology Section, University of Ferrara; via Fossato Di Mortara 17/19 Ferrara 44121 Italy
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30
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Stoddart LA, Vernall AJ, Briddon SJ, Kellam B, Hill SJ. Direct visualisation of internalization of the adenosine A3 receptor and localization with arrestin3 using a fluorescent agonist. Neuropharmacology 2015; 98:68-77. [PMID: 25937210 DOI: 10.1016/j.neuropharm.2015.04.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/19/2015] [Accepted: 04/14/2015] [Indexed: 11/25/2022]
Abstract
Fluorescence based probes provide a novel way to study the dynamic internalization process of G protein-coupled receptors (GPCRs). Recent advances in the rational design of fluorescent ligands for GPCRs have been used here to generate new fluorescent agonists containing tripeptide linkers for the adenosine A3 receptor. The fluorescent agonist BY630-X-(D)-A-(D)-A-G-ABEA was found to be a highly potent agonist at the adenosine A3 receptor in both reporter gene (pEC50 = 8.48 ± 0.09) and internalization assays (pEC50 = 7.47 ± 0.11). Confocal imaging studies showed that BY630-X-(D)-A-(D)-A-G-ABEA was internalized with A3 linked to yellow fluorescent protein, which was blocked by the competitive antagonist MRS1220. Internalization of untagged adenosine A3 could also be visualized with BY630-X-(D)-A-(D)-A-G-ABEA treatment. Further, BY630-X-(D)-A-(D)-A-G-ABEA stimulated the formation of receptor-arrestin3 complexes and was found to localize with these intracellular complexes. This highly potent agonist with excellent imaging properties should be a valuable tool to study receptor internalization. This article is part of the Special Issue entitled 'Fluorescent Tools in Neuropharmacology'.
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Affiliation(s)
- Leigh A Stoddart
- Cell Signalling Research Group, School of Life Sciences, Queen's Medical Centre, University of Nottingham, NG7 2UH, UK
| | - Andrea J Vernall
- School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Stephen J Briddon
- Cell Signalling Research Group, School of Life Sciences, Queen's Medical Centre, University of Nottingham, NG7 2UH, UK
| | - Barrie Kellam
- School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Stephen J Hill
- Cell Signalling Research Group, School of Life Sciences, Queen's Medical Centre, University of Nottingham, NG7 2UH, UK.
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31
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Inflammasome-induced IL-1β secretion in microglia is characterized by delayed kinetics and is only partially dependent on inflammatory caspases. J Neurosci 2015; 35:678-87. [PMID: 25589762 DOI: 10.1523/jneurosci.2510-14.2015] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Inflammasomes are multiprotein complexes that link pathogen recognition and cellular stress to the processing of the proinflammatory cytokine interleukin-1β (IL-1β). Whereas inflammasome-mediated activation is heavily studied in hematopoietic macrophages and dendritic cells, much less is known about microglia, resident tissue macrophages of the brain that originate from a distinct progenitor. To directly compare inflammasome-mediated activation in different types of macrophages, we isolated primary microglia and hematopoietic macrophages from adult, healthy rhesus macaques. We analyzed the expression profile of NOD (nucleotide-binding oligomerization domain)-like receptors, adaptor proteins, and caspases and characterized inflammasome activation and regulation in detail. We here demonstrate that primary microglia can respond to the same innate stimuli as hematopoietic macrophages. However, microglial responses are more persistent due to lack of negative regulation on pro-IL-1β expression. In addition, we show that while caspase 1, 4, and 5 activation is pivotal for inflammasome-induced IL-1β secretion by hematopoietic macrophages, microglial secretion of IL-1β is only partially dependent on these inflammatory caspases. These results identify key cell type-specific differences that may aid the development of strategies to modulate innate immune responses in the brain.
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32
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George J, Gonçalves FQ, Cristóvão G, Rodrigues L, Meyer Fernandes JR, Gonçalves T, Cunha RA, Gomes CA. Different danger signals differently impact on microglial proliferation through alterations of ATP release and extracellular metabolism. Glia 2015; 63:1636-45. [PMID: 25847308 DOI: 10.1002/glia.22833] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 03/17/2015] [Indexed: 12/20/2022]
Abstract
Microglia rely on their ability to proliferate in the brain parenchyma to sustain brain innate immunity and participate in the reaction to brain damage. We now studied the influence of different danger signals activating microglia, both internal (typified by glutamate, associated with brain damage) and external (using a bacterial lipopolysaccharide, LPS), on the proliferation of microglia cells. We found that LPS (100 ng/mL) increased, whereas glutamate (0.5 mM) decreased proliferation. Notably, LPS decreased whereas glutamate increased the extracellular levels of ATP. In contrast, LPS increased whereas glutamate decreased the extracellular catabolism of ATP into adenosine through ecto-nucleotidases and ecto-5'-nucleotidase. Finally, apyrase (degrades extracellular ATP) abrogated glutamate-induced inhibition of microglia proliferation; conversely, inhibitors of ecto-nucleotidases (ARL67156 or α,β-methylene ADP) and adenosine deaminase (degrades extracellular adenosine) abrogated the LPS-induced increase of microglia proliferation, which was blocked by a selective A2A receptor antagonist, SCH58261 (50 nM). Overall, these results highlight the importance of the extracellular purinergic metabolism to format microglia proliferation and influence the spatio-temporal profile of neuroinflammation in different conditions of brain damage.
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Affiliation(s)
- Jimmy George
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Portugal
| | | | - Gonçalo Cristóvão
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Portugal
| | - Lisa Rodrigues
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Portugal.,FMUC-Faculty of Medicine, University of Coimbra, Portugal
| | | | - Teresa Gonçalves
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Portugal.,FMUC-Faculty of Medicine, University of Coimbra, Portugal
| | - Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Portugal.,FMUC-Faculty of Medicine, University of Coimbra, Portugal
| | - Catarina A Gomes
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Portugal.,FMUC-Faculty of Medicine, University of Coimbra, Portugal
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33
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't Hart BA, Bogers WM, Haanstra KG, Verreck FA, Kocken CH. The translational value of non-human primates in preclinical research on infection and immunopathology. Eur J Pharmacol 2015; 759:69-83. [PMID: 25814254 DOI: 10.1016/j.ejphar.2015.03.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 02/09/2015] [Accepted: 03/12/2015] [Indexed: 01/01/2023]
Abstract
The immune system plays a central role in the defense against environmental threats - such as infection with viruses, parasites or bacteria - but can also be a cause of disease, such as in the case of allergic or autoimmune disorders. In the past decades the impressive development of biotechnology has provided scientists with biological tools for the development of highly selective treatments for the different types of disorders. However, despite some clear successes the translation of scientific discoveries into effective treatments has remained challenging. The often-disappointing predictive validity of the preclinical animal models that are used in the selection of the most promising vaccine or drug candidates is the Achilles heel in the therapy development process. This publication summarizes the relevance and usage of non-human primates as pre-clinical model in infectious and autoimmune diseases, in particular for biologicals, which due to their high species-specificity are inactive in lower species.
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Affiliation(s)
- Bert A 't Hart
- Department Immunobiology, Biomedical Primate Research Centre, Rijswijk, The Netherlands; University of Groningen, University Medical Center, Department Neuroscience, Groningen, The Netherlands.
| | - Willy M Bogers
- Department Virology, Biomedical Primate Research Centre, Rijswijk, The Netherlands.
| | - Krista G Haanstra
- Department Immunobiology, Biomedical Primate Research Centre, Rijswijk, The Netherlands.
| | - Frank A Verreck
- Department Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands.
| | - Clemens H Kocken
- Department Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands.
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The infarct-sparing effect of IB-MECA against myocardial ischemia/reperfusion injury in mice is mediated by sequential activation of adenosine A3 and A 2A receptors. Basic Res Cardiol 2015; 110:16. [PMID: 25711314 DOI: 10.1007/s00395-015-0473-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 01/26/2015] [Accepted: 02/18/2015] [Indexed: 01/30/2023]
Abstract
Conflicting results exist regarding the role of A3 adenosine receptors (A3ARs) in mediating cardioprotection during reperfusion following myocardial infarction. We hypothesized that the effects of the A3AR agonist IB-MECA to produce cardioprotection might involve activation of other adenosine receptor subtypes. C57Bl/6 (B6), A3AR KO, A2AAR KO, and A2AAR KO/WT bone marrow chimeric mice were assigned to 12 groups undergoing either hemodynamic studies or 45 min of LAD occlusion and 60 min of reperfusion. IB-MECA (100 μg/kg) or vehicle was administered by iv bolus 5 min before reperfusion. Radioligand binding assays showed that IB-MECA has high affinity for the mouse A3AR (K i = 0.17 ± 0.05 nM), but also can bind with lower affinity to the A1AR (9.0 ± 2.4 nM) or the A2AAR (56.5 ± 10.2 nM). IB-MECA caused bi-phasic hemodynamic changes, which were completely absent in A3AR KO mice and were modified by A2AAR blockade or deletion. IB-MECA stimulated histamine release, increased heart rate, and significantly reduced IF size in B6 mice from 61.5 ± 1.4 to 48.6 ± 2.4% of risk region (RR; 21% reduction, p < 0.05) but not in A3AR KO mice. Compared to B6, A3AR KO mice had significantly reduced IF size (p < 0.05). In B6/B6 bone marrow chimeras, IB-MECA caused a 47% reduction of IF size (from 47.3 ± 3.9 to 24.7 ± 4.5, p < 0.05). However, no significant cardioprotective effect of IB-MECA was observed in A2AARKO/B6 mice, which lacked A2AARs only on their bone marrow-derived cells. Activation of A3ARs induces a bi-phasic hemodynamic response, which is partially mediated by activation of A2AARs. The cardioprotective effect of IB-MECA is due to the initial activation of A3AR followed by activation of A2AARs in bone marrow-derived cells.
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Newell EA, Exo JL, Verrier JD, Jackson TC, Gillespie DG, Janesko-Feldman K, Kochanek PM, Jackson EK. 2',3'-cAMP, 3'-AMP, 2'-AMP and adenosine inhibit TNF-α and CXCL10 production from activated primary murine microglia via A2A receptors. Brain Res 2014; 1594:27-35. [PMID: 25451117 DOI: 10.1016/j.brainres.2014.10.059] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 10/22/2014] [Accepted: 10/27/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Some cells, tissues and organs release 2',3'-cAMP (a positional isomer of 3',5'-cAMP) and convert extracellular 2',3'-cAMP to 2'-AMP plus 3'-AMP and convert these AMPs to adenosine (called the extracellular 2',3'-cAMP-adenosine pathway). Recent studies show that microglia have an extracellular 2',3'-cAMP-adenosine pathway. The goal of the present study was to investigate whether the extracellular 2',3'-cAMP-adenosine pathway could have functional consequences on the production of cytokines/chemokines by activated microglia. METHODS Experiments were conducted in cultures of primary murine microglia. In the first experiment, the effect of 2',3'-cAMP, 3'-AMP, 2'-AMP and adenosine on LPS-induced TNF-α and CXCL10 production was determined. In the next experiment, the first protocol was replicated but with the addition of 1,3-dipropyl-8-p-sulfophenylxanthine (DPSPX) (0.1 μM; antagonist of adenosine receptors). The last experiment compared the ability of 2-chloro-N(6)-cyclopentyladenosine (CCPA) (10 μM; selective A1 agonist), 5'-N-ethylcarboxamide adenosine (NECA) (10 μM; agonist for all adenosine receptor subtypes) and CGS21680 (10 μM; selective A2A agonist) to inhibit LPS-induced TNF-α and CXCL10 production. RESULTS (1) 2',3'-cAMP, 3'-AMP, 2'-AMP and adenosine similarly inhibited LPS-induced TNF-α and CXCL10 production; (2) DPSPX nearly eliminated the inhibitory effects of 2',3'-cAMP, 3'-AMP, 2'-AMP and adenosine on LPS-induced TNF-α and CXCL10 production; (3) CCPA did not affect LPS-induced TNF-α and CXCL10; (4) NECA and CGS21680 similarly inhibited LPS-induced TNF-α and CXCL10 production. CONCLUSIONS 2',3'-cAMP and its metabolites (3'-AMP, 2'-AMP and adenosine) inhibit LPS-induced TNF-α and CXCL10 production via A2A-receptor activation. Adenosine and its precursors, via A2A receptors, likely suppress TNF-α and CXCL10 production by activated microglia in brain diseases.
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Affiliation(s)
- Elizabeth A Newell
- Department of Critical Care Medicine, Children's Hospital of Pittsburgh, Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Jennifer L Exo
- Department of Critical Care Medicine, Children's Hospital of Pittsburgh, Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Jonathan D Verrier
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Travis C Jackson
- Department of Critical Care Medicine, Children's Hospital of Pittsburgh, Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Delbert G Gillespie
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Keri Janesko-Feldman
- Department of Critical Care Medicine, Children's Hospital of Pittsburgh, Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Patrick M Kochanek
- Department of Critical Care Medicine, Children's Hospital of Pittsburgh, Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Edwin K Jackson
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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Hu X, Liou AKF, Leak RK, Xu M, An C, Suenaga J, Shi Y, Gao Y, Zheng P, Chen J. Neurobiology of microglial action in CNS injuries: receptor-mediated signaling mechanisms and functional roles. Prog Neurobiol 2014; 119-120:60-84. [PMID: 24923657 PMCID: PMC4121732 DOI: 10.1016/j.pneurobio.2014.06.002] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/31/2014] [Accepted: 06/03/2014] [Indexed: 12/28/2022]
Abstract
Microglia are the first line of immune defense against central nervous system (CNS) injuries and disorders. These highly plastic cells play dualistic roles in neuronal injury and recovery and are known for their ability to assume diverse phenotypes. A broad range of surface receptors are expressed on microglia and mediate microglial 'On' or 'Off' responses to signals from other host cells as well as invading microorganisms. The integrated actions of these receptors result in tightly regulated biological functions, including cell mobility, phagocytosis, the induction of acquired immunity, and trophic factor/inflammatory mediator release. Over the last few years, significant advances have been made toward deciphering the signaling mechanisms related to these receptors and their specific cellular functions. In this review, we describe the current state of knowledge of the surface receptors involved in microglial activation, with an emphasis on their engagement of distinct functional programs and their roles in CNS injuries. It will become evident from this review that microglial homeostasis is carefully maintained by multiple counterbalanced strategies, including, but not limited to, 'On' and 'Off' receptor signaling. Specific regulation of theses microglial receptors may be a promising therapeutic strategy against CNS injuries.
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Affiliation(s)
- Xiaoming Hu
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai, China; Geriatric Research, Educational and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15240, USA.
| | - Anthony K F Liou
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Rehana K Leak
- Division of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA 15282, USA
| | - Mingyue Xu
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai, China
| | - Chengrui An
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai, China
| | - Jun Suenaga
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Yejie Shi
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Yanqin Gao
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai, China
| | - Ping Zheng
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai, China
| | - Jun Chen
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai, China; Geriatric Research, Educational and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15240, USA.
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Potent and multiple regulatory actions of microglial glucocorticoid receptors during CNS inflammation. Cell Death Differ 2013; 20:1546-57. [PMID: 24013726 DOI: 10.1038/cdd.2013.108] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 05/18/2013] [Accepted: 06/21/2013] [Indexed: 01/11/2023] Open
Abstract
In CNS, glucocorticoids (GCs) activate both GC receptor (GR) and mineralocorticoid receptor (MR), whereas GR is widely expressed, the expression of MR is restricted. However, both are present in the microglia, the resident macrophages of the brain and their activation can lead to pro- or anti-inflammatory effects. We have therefore addressed the specific functions of GR in microglia. In mice lacking GR in macrophages/microglia and in the absence of modifications in MR expression, intraparenchymal injection of lipopolysaccharide (LPS) activating Toll-like receptor 4 signaling pathway resulted in exacerbated cellular lesion, neuronal and axonal damage. Global inhibition of GR by RU486 pre-treatment revealed that microglial GR is the principal mediator preventing neuronal degeneration triggered by lipopolysaccharide (LPS) and contributes with GRs of other cell types to the protection of non-neuronal cells. In vivo and in vitro data show GR functions in microglial differentiation, proliferation and motility. Interestingly, microglial GR also abolishes the LPS-induced delayed outward rectifier currents by downregulating Kv1.3 expression known to control microglia proliferation and oxygen radical production. Analysis of GR transcriptional function revealed its powerful negative control of pro-inflammatory effectors as well as upstream inflammatory activators. Finally, we analyzed the role of GR in chronic unpredictable mild stress and aging, both known to prime or sensitize microglia in vivo. We found that microglial GR suppresses rather than mediates the deleterious effects of stress or aging on neuronal survival. Overall, the results show that microglial GR acts on several key processes limiting pro-inflammatory actions of activated microglia.
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Li Z, Li W, Li Q, Tang M. Extracellular nucleotides and adenosine regulate microglial motility and their role in cerebral ischemia. Acta Pharm Sin B 2013. [DOI: 10.1016/j.apsb.2013.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Kannan V, Brouwer N, Hanisch UK, Regen T, Eggen BJL, Boddeke HWGM. Histone deacetylase inhibitors suppress immune activation in primary mouse microglia. J Neurosci Res 2013; 91:1133-42. [PMID: 23686642 DOI: 10.1002/jnr.23221] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 02/18/2013] [Accepted: 02/19/2013] [Indexed: 01/17/2023]
Abstract
Neuroinflammation is required for tissue clearance and repair after infections or insults. To prevent excessive damage, it is crucial to limit the extent of neuroinflammation and thereby the activation of its principal effector cell, microglia. The two main major innate immune cell types in the CNS are astrocytes and microglia. Histone deacetylases (HDACs) have been implicated in regulating the innate inflammatory response, and here we addressed their role in pure astrocyte and microglia cultures. Endogenous HDAC expression levels were determined in microglia and astrocytes and after treatment with lipopolysaccharide (LPS) or LPS and interferon γ (IFNγ). The relative expression level of HDACs was reduced in LPS- or LPS/IFNγ (with the exception of HDAC1 and -7)-stimulated astrocytes and increased in microglia after LPS treatment both in primary cultures and in microglia acutely isolated from LPS-treated mice, so we focused on the inflammatory response in microglia. Primary microglia cultures were treated with LPS in the presence or absence of HDAC inhibitors (HDACi). Expression and release of inflammatory cytokines was determined by quantitative RT-PCR, flow cytometry, and ELISA. HDACi strongly suppressed LPS-induced cytokine expression and release by microglia. Furthermore, expression of M1- and M2-associated activation markers was suppressed, and the migratory behavior of microglia was attenuated. Our findings strongly suggest that HDACi suppress innate immune activation in microglia.
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Affiliation(s)
- Vishnu Kannan
- Department of Neuroscience, Section of Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Gomes C, Ferreira R, George J, Sanches R, Rodrigues DI, Gonçalves N, Cunha RA. Activation of microglial cells triggers a release of brain-derived neurotrophic factor (BDNF) inducing their proliferation in an adenosine A2A receptor-dependent manner: A2A receptor blockade prevents BDNF release and proliferation of microglia. J Neuroinflammation 2013; 10:16. [PMID: 23363775 PMCID: PMC3567964 DOI: 10.1186/1742-2094-10-16] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 01/18/2013] [Indexed: 01/12/2023] Open
Abstract
Background Brain-derived neurotrophic factor (BDNF) has been shown to control microglial responses in neuropathic pain. Since adenosine A2A receptors (A2ARs) control neuroinflammation, as well as the production and function of BDNF, we tested to see if A2AR controls the microglia-dependent secretion of BDNF and the proliferation of microglial cells, a crucial event in neuroinflammation. Methods Murine N9 microglial cells were challenged with lipopolysaccharide (LPS, 100 ng/mL) in the absence or in the presence of the A2AR antagonist, SCH58261 (50 nM), as well as other modulators of A2AR signaling. The BDNF cellular content and secretion were quantified by Western blotting and ELISA, A2AR density was probed by Western blotting and immunocytochemistry and cell proliferation was assessed by BrdU incorporation. Additionally, the A2AR modulation of LPS-driven cell proliferation was also tested in primary cultures of mouse microglia. Results LPS induced time-dependent changes of the intra- and extracellular levels of BDNF and increased microglial proliferation. The maximal LPS-induced BDNF release was time-coincident with an LPS-induced increase of the A2AR density. Notably, removing endogenous extracellular adenosine or blocking A2AR prevented the LPS-mediated increase of both BDNF secretion and proliferation, as well as exogenous BDNF-induced proliferation. Conclusions We conclude that A2AR activation plays a mandatory role controlling the release of BDNF from activated microglia, as well as the autocrine/paracrine proliferative role of BDNF.
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Affiliation(s)
- Catarina Gomes
- Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, Coimbra 3004-517, Portugal.
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Corriden R, Insel PA. New insights regarding the regulation of chemotaxis by nucleotides, adenosine, and their receptors. Purinergic Signal 2012; 8:587-98. [PMID: 22528684 PMCID: PMC3360098 DOI: 10.1007/s11302-012-9311-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 01/05/2012] [Indexed: 12/23/2022] Open
Abstract
The directional movement of cells can be regulated by ATP, certain other nucleotides (e.g., ADP, UTP), and adenosine. Such regulation occurs for cells that are "professional phagocytes" (e.g., neutrophils, macrophages, certain lymphocytes, and microglia) and that undergo directional migration and subsequent phagocytosis. Numerous other cell types (e.g., fibroblasts, endothelial cells, neurons, and keratinocytes) also change motility and migration in response to ATP, other nucleotides, and adenosine. In this article, we review how nucleotides and adenosine modulate chemotaxis and motility and highlight the importance of nucleotide- and adenosine-regulated cell migration in several cell types: neutrophils, microglia, endothelial cells, and cancer cells. We also discuss difficulties in conducting experiments and drawing conclusions regarding the ability of nucleotides and adenosine to modulate the migration of professional and non-professional phagocytes.
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Affiliation(s)
- Ross Corriden
- Institute of Cell Signalling, University of Nottingham, Nottingham, UK
| | - Paul A. Insel
- Departments of Pharmacology and Medicine, University of California, San Diego, CA USA
- Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, Mail code 0636, La Jolla, CA 92093 USA
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Koscsó B, Csóka B, Selmeczy Z, Himer L, Pacher P, Virág L, Haskó G. Adenosine augments IL-10 production by microglial cells through an A2B adenosine receptor-mediated process. THE JOURNAL OF IMMUNOLOGY 2011; 188:445-53. [PMID: 22116830 DOI: 10.4049/jimmunol.1101224] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Microglia are activated by pathogen-associated molecular patterns and produce proinflammatory cytokines, such as TNF-α, IL-6, and IL-12, and the anti-inflammatory cytokine IL-10. Adenosine is an endogenous purine nucleoside and a ligand of four G protein-coupled adenosine receptors (ARs), which are the A(1)AR, A(2A)AR, A(2B)AR, and A(3)AR. ARs have been shown to suppress TNF-α production by microglia, but their role in regulating IL-10 production has not been studied. In this study, we demonstrate that adenosine augments IL-10 production by activated murine microglia while suppressing the production of proinflammatory cytokines. Because the order of potency of selective AR agonists in inducing IL-10 production was NECA > IB-MECA > CCPA ≥ CGS21680, and the A(2B)AR antagonist MRS1754 prevented the effect of NECA, we conclude that the stimulatory effect of adenosine on IL-10 production is mediated by the A(2B)AR. Mechanistically, adenosine augmented IL-10 mRNA accumulation by a transcriptional process. Using mutant IL-10 promoter constructs we showed that a CREB-binding region in the promoter mediated the augmenting effect of adenosine on IL-10 transcription. Chromatin immunoprecipitation analysis demonstrated that adenosine induced CREB phosphorylation at the IL-10 promoter. Silencing CREB using lentivirally delivered short hairpin RNA blocked the enhancing effect of adenosine on IL-10 production, confirming a role for CREB in mediating the stimulatory effect of adenosine on IL-10 production. In addition, adenosine augmented IL-10 production by stimulating p38 MAPK. Collectively, our results establish that A(2B)ARs augment IL-10 production by activated murine microglia.
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Affiliation(s)
- Balázs Koscsó
- Department of Surgery, University of Medicine and Dentistry of New Jersey, Newark, NJ 07103, USA
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Choi IY, Lee JC, Ju C, Hwang S, Cho GS, Lee HW, Choi WJ, Jeong LS, Kim WK. A3 adenosine receptor agonist reduces brain ischemic injury and inhibits inflammatory cell migration in rats. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:2042-52. [PMID: 21854743 PMCID: PMC3181366 DOI: 10.1016/j.ajpath.2011.07.006] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 06/23/2011] [Accepted: 07/01/2011] [Indexed: 12/27/2022]
Abstract
A3 adenosine receptor (A3AR) is recognized as a novel therapeutic target for ischemic injury; however, the mechanism underlying anti-ischemic protection by the A3AR agonist remains unclear. Here, we report that 2-chloro-N(6)-(3-iodobenzyl)-5'-N-methylcarbamoyl-4'-thioadenosine (LJ529), a selective A3AR agonist, reduces inflammatory responses that may contribute to ischemic cerebral injury. Postischemic treatment with LJ529 markedly reduced cerebral ischemic injury caused by 1.5-hour middle cerebral artery occlusion, followed by 24-hour reperfusion in rats. This effect was abolished by the simultaneous administration of the A3AR antagonist MRS1523, but not the A2AAR antagonist SCH58261. LJ529 prevented the infiltration/migration of microglia and monocytes occurring after middle cerebral artery occlusion and reperfusion, and also after injection of lipopolysaccharides into the corpus callosum. The reduced migration of microglia by LJ529 could be related with direct inhibition of chemotaxis and down-regulation of spatiotemporal expression of Rho GTPases (including Rac, Cdc42, and Rho), rather than by biologically relevant inhibition of inflammatory cytokine/chemokine release (eg, IL-1β, TNF-α, and MCP-1) or by direct inhibition of excitotoxicity/oxidative stress (not affected by LJ529). The present findings indicate that postischemic activation of A3AR and the resultant reduction of inflammatory response should provide a promising therapeutic strategy for the treatment of ischemic stroke.
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Affiliation(s)
- In-Young Choi
- Department of Neuroscience, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Jae-Chul Lee
- Clinical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Chung Ju
- Department of Neuroscience, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Sunyoung Hwang
- Department of Neuroscience, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Geum-Sil Cho
- Department of Neuroscience, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Hyuk Woo Lee
- Department of Bioinspired Science and College of Pharmacy, Ewha Womans University, Seoul, Republic of Korea
| | - Won Jun Choi
- College of Pharmacy, Dongguk University, Goyang-si, Republic of Korea
| | - Lak Shin Jeong
- Department of Bioinspired Science and College of Pharmacy, Ewha Womans University, Seoul, Republic of Korea
| | - Won-Ki Kim
- Department of Neuroscience, College of Medicine, Korea University, Seoul, Republic of Korea
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Van Der Putten C, Kuipers HF, Zuiderwijk-Sick EA, Van Straalen L, Kondova I, Van Den Elsen PJ, Bajramovic JJ. Statins amplify TLR-induced responses in microglia via inhibition of cholesterol biosynthesis. Glia 2011; 60:43-52. [PMID: 21964955 DOI: 10.1002/glia.21245] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 08/29/2011] [Indexed: 02/06/2023]
Abstract
Statins inhibit the endogenous intracellular mevalonate pathway and exposure to statins affects innate and adaptive immune responses. Different statins are currently under evaluation as (co)therapy in neuro-inflammatory diseases like multiple sclerosis. However, there are important discrepancies in the reported effects of statins on innate immune responses in different cell types. Studies to characterize such responses in clinically relevant primary cells are currently lacking. In this study, we investigated the effect of statins on Toll-like receptor (TLR)-induced responses of microglia, the resident macrophages of the central nervous system (CNS). Exposure of primary microglia from adult rhesus monkeys to different statins strongly amplified pro-inflammatory cytokine protein and mRNA levels in response to myeloid differentiation primary response gene 88-dependent TLR activation in particular. Rather than affecting nuclear facor-κB activation levels, statin exposure affected stress-activated protein/Jun-amino-terminal and p38 kinase signaling pathways. Mechanistic studies using specific pathway inhibitors and rescue experiments show that statin-induced inhibition of cholesterol biosynthesis, rather than inhibition of isoprenylation, was mainly responsible for the amplified TLR responses. Additionally, microglia were more sensitive to statin-mediated effects than bone marrow-derived macrophages of the same donor. This correlated to lower intrinsic microglial expression levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase, the enzyme targeted by statins. Amplification of TLR-induced responses in microglia by statin exposure might contribute to the generation of a more pro-inflammatory CNS microenvironment which can be of relevance for the pathogenesis of neuroinflammatory disorders.
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Ohsawa K, Kohsaka S. Dynamic motility of microglia: Purinergic modulation of microglial movement in the normal and pathological brain. Glia 2011; 59:1793-9. [DOI: 10.1002/glia.21238] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 08/02/2011] [Indexed: 01/23/2023]
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Abstract
Microglial cells are the resident macrophages in the central nervous system. These cells of mesodermal/mesenchymal origin migrate into all regions of the central nervous system, disseminate through the brain parenchyma, and acquire a specific ramified morphological phenotype termed "resting microglia." Recent studies indicate that even in the normal brain, microglia have highly motile processes by which they scan their territorial domains. By a large number of signaling pathways they can communicate with macroglial cells and neurons and with cells of the immune system. Likewise, microglial cells express receptors classically described for brain-specific communication such as neurotransmitter receptors and those first discovered as immune cell-specific such as for cytokines. Microglial cells are considered the most susceptible sensors of brain pathology. Upon any detection of signs for brain lesions or nervous system dysfunction, microglial cells undergo a complex, multistage activation process that converts them into the "activated microglial cell." This cell form has the capacity to release a large number of substances that can act detrimental or beneficial for the surrounding cells. Activated microglial cells can migrate to the site of injury, proliferate, and phagocytose cells and cellular compartments.
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Abstract
Inflammation plays an important role in the pathogenesis of early brain injury after subarachnoid haemorrhage. Adenosine A3 receptor (A3R) activation produces anti-inflammatory effects. In this study, the effects of a selective A3R agonist, 2-chloro-N⁶-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (CL-IB-MECA), on early brain injury and inflammatory response after subarachnoid haemorrhage were studied. Our results showed that mortality, neurological impairment and brain oedema were significantly attenuated after the administration of CL-IB-MECA. Moreover, treatment with CL-IB-MECA inhibited microglial activation and reduced the expression of proinflammatory cytokines including tumour necrosis factor-α and interleukin-1β. These data suggest that activation of A3R provides a neuroprotective effect against brain injury after subarachnoid haemorrhage, and that these effects may be associated with the anti-inflammatory properties of A3R.
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Rebola N, Simões AP, Canas PM, Tomé AR, Andrade GM, Barry CE, Agostinho PM, Lynch MA, Cunha RA. Adenosine A2A receptors control neuroinflammation and consequent hippocampal neuronal dysfunction. J Neurochem 2011; 117:100-11. [PMID: 21235574 DOI: 10.1111/j.1471-4159.2011.07178.x] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The blockade of adenosine A(2A) receptors (A2AR) affords a robust neuroprotection in different noxious brain conditions. However, the mechanisms underlying this general neuroprotection are unknown. One possible mechanism could be the control of neuroinflammation that is associated with brain damage, especially because A2AR efficiently control peripheral inflammation. Thus, we tested if the intracerebroventricular injection of a selective A2AR antagonist (SCH58261) would attenuate the changes in the hippocampus triggered by intraperitoneal administration of lipopolysaccharide (LPS) that induces neuroinflammation through microglia activation. LPS administration triggers an increase in inflammatory mediators like interleukin-1β that causes biochemical changes (p38 and c-jun N-terminal kinase phosphorylation and caspase 3 activation) contributing to neuronal dysfunction typified by decreased long-term potentiation, a form of synaptic plasticity. Long-term potentiation, measured 30 min after the tetanus, was significantly lower in LPS-treated rats compared with control-treated rats, while SCH58261 attenuated the LPS-induced change. The LPS-induced increases in phosphorylation of c-jun N-terminal kinase and p38 and activation of caspase 3 were also prevented by SCH58261. Significantly, SCH58261 also prevented the LPS-induced recruitment of activated microglial cells and the increase in interleukin-1β concentration in the hippocampus, indicating that A2AR activation is a pivotal step in mediating the neuroinflammation triggered by LPS. These results indicate that A2AR antagonists prevent neuroinflammation and support the hypothesis that this mechanism might contribute for the ability of A2AR antagonists to control different neurodegenerative diseases known to involve neuroinflammation.
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Affiliation(s)
- Nelson Rebola
- Center for Neuroscience of Coimbra, Institute of Biochemistry, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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Henn A, Kirner S, Leist M. TLR2 hypersensitivity of astrocytes as functional consequence of previous inflammatory episodes. THE JOURNAL OF IMMUNOLOGY 2011; 186:3237-47. [PMID: 21282508 DOI: 10.4049/jimmunol.1002787] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Precedent inflammatory episodes may drastically modify the function and reactivity of cells. We investigated whether priming of astrocytes by microglia-derived cytokines alters their subsequent reaction to pathogen-associated danger signals not recognized in the quiescent state. Resting primary murine astrocytes expressed little TLR2, and neither the TLR2/6 ligand fibroblast-stimulating lipopeptide-1 (FSL1) nor the TLR1/2 ligand Pam(3)CysSK(4) (P3C) triggered NF-κB translocation or IL-6 release. We made use of single-cell detection of NF-κB translocation as easily detectable and sharply regulated upstream indicator of an inflammatory response or of c-Jun phosphorylation to measure restimulation events in astrocytes under varying conditions. Cells prestimulated with IL-1β, with a TLR3 ligand, with a complete cytokine mix consisting of TNF-α, IL-1β, and IFN-γ, or with media conditioned by activated microglia responded strongly to FSL1 or P3C stimulation, whereas the sensitivity of the NF-κB response to other pattern recognition receptors was unchanged. This sensitization to TLR2 ligands was associated with an initial upregulation of TLR2, displayed a "memory" window of several days, and was largely independent of the length of prestimulation. The altered signaling led to altered function, as FSL1 or P3C triggered the release of IL-6, CCL-20, and CXCL-2 in primed cells, but not in resting astrocytes. These data confirmed the hypothesis that astrocytes exposed to activated microglia assume a different functional phenotype involving longer term TLR2 responsiveness, even after the initial stimulation by inflammatory mediators has ended.
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Affiliation(s)
- Anja Henn
- Doerenkamp-Zbinden Chair of in vitro Toxicology and Biomedicine, University of Konstanz, D-78457 Konstanz, Germany
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Tozaki-Saitoh H, Tsuda M, Inoue K. Role of purinergic receptors in CNS function and neuroprotection. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2011; 61:495-528. [PMID: 21586368 DOI: 10.1016/b978-0-12-385526-8.00015-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The purinergic receptor family contains some of the most abundant receptors in living organisms. A growing body of evidence indicates that extracellular nucleotides play important roles in the regulation of neuronal and glial functions in the nervous system through purinergic receptors. Nucleotides are released from or leaked through nonexcitable cells and neurons during normal physiological and pathophysiological conditions. Ionotropic P2X and metabotropic P2Y purinergic receptors are expressed in the central nervous system (CNS), participate in the synaptic processes, and mediate intercellular communications between neuron and gila and between glia and other glia. Glial cells in the CNS are classified into astrocytes, oligodendrocytes, and microglia. Astrocytes express many types of purinergic receptors, which are integral to their activation. Astrocytes release adenosine triphosphate (ATP) as a "gliotransmitter" that allows communication with neurons, the vascular walls of capillaries, oligodendrocytes, and microglia. Oligodendrocytes are myelin-forming cells that construct insulating layers of myelin sheets around axons, and using purinergic receptor signaling for their development and for myelination. Microglia also express many types of purinergic receptors and are known to function as immunocompetent cells in the CNS. ATP and other nucleotides work as "warning molecules" especially by activating microglia in pathophysiological conditions. Studies on purinergic signaling could facilitate the development of novel therapeutic strategies for disorder of the CNS.
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Affiliation(s)
- Hidetoshi Tozaki-Saitoh
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi, Fukuoka, Japan
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