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Tempone MH, Borges-Martins VP, César F, Alexandrino-Mattos DP, de Figueiredo CS, Raony Í, dos Santos AA, Duarte-Silva AT, Dias MS, Freitas HR, de Araújo EG, Ribeiro-Resende VT, Cossenza M, P. Silva H, P. de Carvalho R, Ventura ALM, Calaza KC, Silveira MS, Kubrusly RCC, de Melo Reis RA. The Healthy and Diseased Retina Seen through Neuron-Glia Interactions. Int J Mol Sci 2024; 25:1120. [PMID: 38256192 PMCID: PMC10817105 DOI: 10.3390/ijms25021120] [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: 12/21/2023] [Revised: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 01/24/2024] Open
Abstract
The retina is the sensory tissue responsible for the first stages of visual processing, with a conserved anatomy and functional architecture among vertebrates. To date, retinal eye diseases, such as diabetic retinopathy, age-related macular degeneration, retinitis pigmentosa, glaucoma, and others, affect nearly 170 million people worldwide, resulting in vision loss and blindness. To tackle retinal disorders, the developing retina has been explored as a versatile model to study intercellular signaling, as it presents a broad neurochemical repertoire that has been approached in the last decades in terms of signaling and diseases. Retina, dissociated and arranged as typical cultures, as mixed or neuron- and glia-enriched, and/or organized as neurospheres and/or as organoids, are valuable to understand both neuronal and glial compartments, which have contributed to revealing roles and mechanisms between transmitter systems as well as antioxidants, trophic factors, and extracellular matrix proteins. Overall, contributions in understanding neurogenesis, tissue development, differentiation, connectivity, plasticity, and cell death are widely described. A complete access to the genome of several vertebrates, as well as the recent transcriptome at the single cell level at different stages of development, also anticipates future advances in providing cues to target blinding diseases or retinal dysfunctions.
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Affiliation(s)
- Matheus H. Tempone
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| | - Vladimir P. Borges-Martins
- Department of Physiology and Pharmacology, Biomedical Institute and Program of Neurosciences, Federal Fluminense University, Niterói 24020-150, Brazil; (V.P.B.-M.); (A.A.d.S.); (M.C.); (R.C.C.K.)
| | - Felipe César
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| | - Dio Pablo Alexandrino-Mattos
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| | - Camila S. de Figueiredo
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Ícaro Raony
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; (Í.R.); (H.R.F.)
| | - Aline Araujo dos Santos
- Department of Physiology and Pharmacology, Biomedical Institute and Program of Neurosciences, Federal Fluminense University, Niterói 24020-150, Brazil; (V.P.B.-M.); (A.A.d.S.); (M.C.); (R.C.C.K.)
| | - Aline Teixeira Duarte-Silva
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Mariana Santana Dias
- Laboratory of Gene Therapy and Viral Vectors, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.S.D.); (H.P.S.)
| | - Hércules Rezende Freitas
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; (Í.R.); (H.R.F.)
| | - Elisabeth G. de Araújo
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
- National Institute of Science and Technology on Neuroimmunomodulation—INCT-NIM, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro 21040-360, Brazil
| | - Victor Tulio Ribeiro-Resende
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| | - Marcelo Cossenza
- Department of Physiology and Pharmacology, Biomedical Institute and Program of Neurosciences, Federal Fluminense University, Niterói 24020-150, Brazil; (V.P.B.-M.); (A.A.d.S.); (M.C.); (R.C.C.K.)
| | - Hilda P. Silva
- Laboratory of Gene Therapy and Viral Vectors, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.S.D.); (H.P.S.)
| | - Roberto P. de Carvalho
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Ana L. M. Ventura
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Karin C. Calaza
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Mariana S. Silveira
- Laboratory for Investigation in Neuroregeneration and Development, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil;
| | - Regina C. C. Kubrusly
- Department of Physiology and Pharmacology, Biomedical Institute and Program of Neurosciences, Federal Fluminense University, Niterói 24020-150, Brazil; (V.P.B.-M.); (A.A.d.S.); (M.C.); (R.C.C.K.)
| | - Ricardo A. de Melo Reis
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
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Catarzi D, Varano F, Vigiani E, Calenda S, Melani F, Varani K, Vincenzi F, Pasquini S, Mennini N, Nerli G, Dal Ben D, Volpini R, Colotta V. 4-Heteroaryl Substituted Amino-3,5-Dicyanopyridines as New Adenosine Receptor Ligands: Novel Insights on Structure-Activity Relationships and Perspectives. Pharmaceuticals (Basel) 2022; 15:ph15040478. [PMID: 35455475 PMCID: PMC9024521 DOI: 10.3390/ph15040478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 03/31/2022] [Accepted: 04/09/2022] [Indexed: 12/04/2022] Open
Abstract
A new set of amino-3,5-dicyanopyridines was synthesized and biologically evaluated at the adenosine receptors (ARs). This chemical class is particularly versatile, as small structural modifications can influence not only affinity and selectivity, but also the pharmacological profile. Thus, in order to deepen the structure–activity relationships (SARs) of this series, different substituents were evaluated at the diverse positions on the dicyanopyridine scaffold. In general, the herein reported compounds show nanomolar binding affinity and interact better with both the human (h) A1 and A2A ARs than with the other subtypes. Docking studies at hAR structure were performed to rationalize the observed affinity data. Of interest are compounds 1 and 5, which can be considered as pan ligands as binding all the ARs with comparable nanomolar binding affinity (A1AR: 1, Ki = 9.63 nM; 5, Ki = 2.50 nM; A2AAR: 1, Ki = 21 nM; 5, Ki = 24 nM; A3AR: 1, Ki = 52 nM; 5, Ki = 25 nM; A2BAR: 1, EC50 = 1.4 nM; 5, EC50 = 1.12 nM). Moreover, these compounds showed a partial agonist profile at all the ARs. This combined AR partial agonist activity could lead us to hypothesize a potential effect in the repair process of damaged tissue that would be beneficial in both wound healing and remodeling.
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Affiliation(s)
- Daniela Catarzi
- Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Sezione di Farmaceutica e Nutraceutica, Università degli Studi di Firenze, Via Ugo Schiff, 6, 50019 Sesto Fiorentino, Italy; (F.V.); (E.V.); (S.C.); (F.M.); (V.C.)
- Correspondence:
| | - Flavia Varano
- Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Sezione di Farmaceutica e Nutraceutica, Università degli Studi di Firenze, Via Ugo Schiff, 6, 50019 Sesto Fiorentino, Italy; (F.V.); (E.V.); (S.C.); (F.M.); (V.C.)
| | - Erica Vigiani
- Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Sezione di Farmaceutica e Nutraceutica, Università degli Studi di Firenze, Via Ugo Schiff, 6, 50019 Sesto Fiorentino, Italy; (F.V.); (E.V.); (S.C.); (F.M.); (V.C.)
| | - Sara Calenda
- Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Sezione di Farmaceutica e Nutraceutica, Università degli Studi di Firenze, Via Ugo Schiff, 6, 50019 Sesto Fiorentino, Italy; (F.V.); (E.V.); (S.C.); (F.M.); (V.C.)
| | - Fabrizio Melani
- Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Sezione di Farmaceutica e Nutraceutica, Università degli Studi di Firenze, Via Ugo Schiff, 6, 50019 Sesto Fiorentino, Italy; (F.V.); (E.V.); (S.C.); (F.M.); (V.C.)
| | - Katia Varani
- Dipartimento di Medicina Traslazionale, Università degli Studi di Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy; (K.V.); (F.V.); (S.P.)
| | - Fabrizio Vincenzi
- Dipartimento di Medicina Traslazionale, Università degli Studi di Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy; (K.V.); (F.V.); (S.P.)
| | - Silvia Pasquini
- Dipartimento di Medicina Traslazionale, Università degli Studi di Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy; (K.V.); (F.V.); (S.P.)
| | - Natascia Mennini
- Dipartimento di Chimica Ugo Schiff, Università degli Studi di Firenze, Via della Lastruccia, 3, 50019 Sesto Fiorentino, Italy; (N.M.); (G.N.)
| | - Giulia Nerli
- Dipartimento di Chimica Ugo Schiff, Università degli Studi di Firenze, Via della Lastruccia, 3, 50019 Sesto Fiorentino, Italy; (N.M.); (G.N.)
| | - Diego Dal Ben
- Scuola di Scienze del Farmaco e dei Prodotti della Salute, Università degli Studi di Camerino, Via S.Agostino 1, 62032 Camerino, Italy; (D.D.B.); (R.V.)
| | - Rosaria Volpini
- Scuola di Scienze del Farmaco e dei Prodotti della Salute, Università degli Studi di Camerino, Via S.Agostino 1, 62032 Camerino, Italy; (D.D.B.); (R.V.)
| | - Vittoria Colotta
- Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Sezione di Farmaceutica e Nutraceutica, Università degli Studi di Firenze, Via Ugo Schiff, 6, 50019 Sesto Fiorentino, Italy; (F.V.); (E.V.); (S.C.); (F.M.); (V.C.)
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Agarwal P, Agarwal R. Tackling retinal ganglion cell apoptosis in glaucoma: role of adenosine receptors. Expert Opin Ther Targets 2021; 25:585-596. [PMID: 34402357 DOI: 10.1080/14728222.2021.1969362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION The role of adenosine receptors as therapeutic targets for neuroprotection is now widely recognized. Their role, however, in protection against retinal ganglion cell (RGC) apoptosis in glaucoma needs further investigation. Hence, in this review, we look into the possibility of adenosine receptors as potential therapeutic targets by exploring their role in modulating various pathophysiological mechanisms underlying glaucomatous RGC loss. AREAS COVERED This review presents a summary of the adenosine receptor distribution in retina and the cellular functions mediated by them. The major pathophysiological mechanisms such as excitotoxicity, vascular dysregulation, loss of neurotrophic signaling, and inflammatory responses involved in glaucomatous RGC loss are discussed. The literature showing the role of adenosine receptors in modulating these pathophysiological mechanisms is discussed. The literature search was conducted using Pubmed search engine using key words such as 'RGC apoptosis,' 'adenosine,' adenosine receptors' 'retina' 'excitotoxicity,' 'neurotrophins,' 'ischemia', and 'cytokines' individually and in various combinations. EXPERT OPINION Use of adenosine receptor agonists and antagonists, for preservation of the RGCs in glaucomatous eyes independent of the level of intraocular pressure seems a very useful strategy. Future application of this strategy would require appropriate designing of drug formulation for tissue and disease-specific receptor targeting. Furthermore, the modulation of physiological functions and potential adverse effects need further investigations.
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Affiliation(s)
- Puneet Agarwal
- School of Medicine, International Medical University, Kuala Lumpur, Malaysia
| | - Renu Agarwal
- School of Medicine, International Medical University, Kuala Lumpur, Malaysia
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Portugal CC, da Encarnação TG, Sagrillo MA, Pereira MR, Relvas JB, Socodato R, Paes-de-Carvalho R. Activation of adenosine A3 receptors regulates vitamin C transport and redox balance in neurons. Free Radic Biol Med 2021; 163:43-55. [PMID: 33307167 DOI: 10.1016/j.freeradbiomed.2020.11.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 11/01/2020] [Accepted: 11/30/2020] [Indexed: 12/19/2022]
Abstract
Adenosine is an important neuromodulator in the CNS, regulating neuronal survival and synaptic transmission. The antioxidant ascorbate (the reduced form of vitamin C) is concentrated in CNS neurons through a sodium-dependent transporter named SVCT2 and participates in several CNS processes, for instance, the regulation of glutamate receptors functioning and the synthesis of neuromodulators. Here we studied the interplay between the adenosinergic system and ascorbate transport in neurons. We found that selective activation of A3, but not of A1 or A2a, adenosine receptors modulated ascorbate transport, decreasing intracellular ascorbate content. Förster resonance energy transfer (FRET) analyses showed that A3 receptors associate with the ascorbate transporter SVCT2, suggesting tight signaling compartmentalization between A3 receptors and SVCT2. The activation of A3 receptors increased ascorbate release in an SVCT2-dependent manner, which largely altered the neuronal redox status without interfering with cell death, glycolytic metabolism, and bioenergetics. Overall, by regulating vitamin C transport, the adenosinergic system (via activation of A3 receptors) can regulate ascorbate bioavailability and control the redox balance in neurons.
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Affiliation(s)
- Camila C Portugal
- Instituto de Investigação e Inovação em Saúde (i3S) and Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal.
| | | | - Mayara A Sagrillo
- Department of Neurobiology, Biology Institute, Fluminense Federal University, Niterói, Brazil
| | - Mariana R Pereira
- Program of Neurosciences, Fluminense Federal University, Niterói, Brazil; Department of Neurobiology, Biology Institute, Fluminense Federal University, Niterói, Brazil
| | - João B Relvas
- Instituto de Investigação e Inovação em Saúde (i3S) and Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Renato Socodato
- Instituto de Investigação e Inovação em Saúde (i3S) and Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Roberto Paes-de-Carvalho
- Program of Neurosciences, Fluminense Federal University, Niterói, Brazil; Department of Neurobiology, Biology Institute, Fluminense Federal University, Niterói, Brazil.
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Santiago AR, Madeira MH, Boia R, Aires ID, Rodrigues-Neves AC, Santos PF, Ambrósio AF. Keep an eye on adenosine: Its role in retinal inflammation. Pharmacol Ther 2020; 210:107513. [PMID: 32109489 DOI: 10.1016/j.pharmthera.2020.107513] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Adenosine is an endogenous purine nucleoside ubiquitously distributed throughout the body that interacts with G protein-coupled receptors, classified in four subtypes: A1R, A2AR, A2BR and A3R. Among the plethora of functions of adenosine, it has been increasingly recognized as a key mediator of the immune response. Neuroinflammation is a feature of chronic neurodegenerative diseases and contributes to the pathophysiology of several retinal degenerative diseases. Animal models of retinal diseases are helping to elucidate the regulatory roles of adenosine receptors in the development and progression of those diseases. Mounting evidence demonstrates that the adenosinergic system is altered in the retina during pathological conditions, compromising retinal physiology. This review focuses on the roles played by adenosine and the elements of the adenosinergic system (receptors, enzymes, transporters) in the neuroinflammatory processes occurring in the retina. An improved understanding of the molecular and cellular mechanisms of the signalling pathways mediated by adenosine underlying the onset and progression of retinal diseases will pave the way towards the identification of new therapeutic approaches.
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Affiliation(s)
- Ana Raquel Santiago
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548 Coimbra, Portugal.
| | - Maria H Madeira
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548 Coimbra, Portugal
| | - Raquel Boia
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Inês Dinis Aires
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Ana Catarina Rodrigues-Neves
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Paulo Fernando Santos
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - António Francisco Ambrósio
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548 Coimbra, Portugal.
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Caffeine exposure ameliorates acute ischemic cell death in avian developing retina. Purinergic Signal 2020; 16:41-59. [PMID: 32078115 DOI: 10.1007/s11302-020-09687-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 01/15/2020] [Indexed: 12/20/2022] Open
Abstract
In infants, the main cause of blindness is retinopathy of prematurity that stems in a hypoxic-ischemic condition. Caffeine is a psychoactive compound that at low to moderate concentrations, selectively inhibits adenosine A1 and A2A receptors. Caffeine exerts beneficial effects in central nervous system of adult animal models and humans, whereas it seems to have malefic effect on the developing tissue. We observed that 48-h exposure (during synaptogenesis) to a moderate dose of caffeine (30 mg/kg of egg) activated pro-survival signaling pathways, including ERK, CREB, and Akt phosphorylation, alongside BDNF production, and reduced retinal cell death promoted by oxygen glucose deprivation in the chick retina. Blockade of TrkB receptors and inhibition of CREB prevented caffeine protection effect. Similar signaling pathways were described in previously reported data concerning chemical preconditioning mechanism triggered by NMDA receptors activation, with low concentrations of agonist. In agreement to these data, caffeine increased NMDA receptor activity. Caffeine decreased the levels of the chloride co-transporter KCC2 and delayed the developmental shift on GABAA receptor response from depolarizing to hyperpolarizing. These results suggest that the caffeine-induced delaying in depolarizing effect of GABA could be facilitating NMDA receptor activity. DPCPX, an A1 adenosine receptor antagonist, but not A2A receptor inhibitor, mimicked the effect of caffeine, suggesting that the effect of caffeine occurs through A1 receptor blockade. In summary, an in vivo caffeine exposure could increase the resistance of the retina to ischemia-induced cell death, by triggering survival pathways involving CREB phosphorylation and BDNF production/TrkB activation.
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Medrano MP, Pisera-Fuster A, Bernabeu RO, Faillace MP. P2X7 and A 2A receptor endogenous activation protects against neuronal death caused by CoCl 2 -induced photoreceptor toxicity in the zebrafish retina. J Comp Neurol 2020; 528:2000-2020. [PMID: 31997350 DOI: 10.1002/cne.24869] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 01/09/2020] [Accepted: 01/22/2020] [Indexed: 12/20/2022]
Abstract
Injured retinas in mammals do not regenerate and heal with loss of function. The adult retina of zebrafish self-repairs after damage by activating cell-intrinsic mechanisms, which are regulated by extrinsic signal interactions. Among relevant regulatory extrinsic systems, purinergic signaling regulates progenitor proliferation during retinogenesis and regeneration and glia proliferation in proliferative retinopathies. ATP-activated P2X7 (P2RX7) and adenosine (P1R) receptors are involved in the progression of almost all retinopathies leading to blindness. Here, we examined P2RX7 and P1R participation in the retina regenerative response induced by photoreceptor damage caused by a specific dose of CoCl2 . First, we found that treatment of uninjured retinas with a potent agonist of P2RX7 (BzATP) provoked photoreceptor damage and mitotic activation of multipotent progenitors. In CoCl2 -injured retinas, blockade of endogenous extracellular ATP activity on P2RX7 caused further neurodegeneration, Müller cell gliosis, progenitor proliferation, and microglia reactivity. P2RX7 inhibition in injured retinas also increased the expression of lin28a and tnfα genes, which are related to multipotent progenitor proliferation. Levels of hif1α, vegf3r, and vegfaa mRNA were enhanced by blockade of P2RX7 immediately after injury, indicating hypoxic like damage and endothelial cell growth and proliferation. Complete depletion of extracellular nucleotides with an apyrase treatment strongly potentiated cell death and progenitor proliferation induced with CoCl2 . Blockade of adenosine P1 and A2A receptors (A2A R) had deleterious effects and deregulated normal timing for progenitor and precursor cell proliferation following photoreceptor damage. ATP via P2RX7 and adenosine via A2A R are survival extracellular signals key for retina regeneration in zebrafish.
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Affiliation(s)
- Matías P Medrano
- Instituto de Fisiología y Biofísica Prof. Bernardo Houssay (IFIBIO-Houssay) UBA y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Antonella Pisera-Fuster
- Instituto de Fisiología y Biofísica Prof. Bernardo Houssay (IFIBIO-Houssay) UBA y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Ramón O Bernabeu
- Instituto de Fisiología y Biofísica Prof. Bernardo Houssay (IFIBIO-Houssay) UBA y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
| | - María Paula Faillace
- Instituto de Fisiología y Biofísica Prof. Bernardo Houssay (IFIBIO-Houssay) UBA y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
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8
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Cirne-Santos CC, Barros CDS, Nogueira CCR, Azevedo RC, Yamamoto KA, Meira GLS, de Vasconcelos ZFM, Ratcliffe NA, Teixeira VL, Schmidt-Chanasit J, Ferreira DF, Paixão ICNDP. Inhibition by Marine Algae of Chikungunya Virus Isolated From Patients in a Recent Disease Outbreak in Rio de Janeiro. Front Microbiol 2019; 10:2426. [PMID: 31708898 PMCID: PMC6821653 DOI: 10.3389/fmicb.2019.02426] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 10/08/2019] [Indexed: 01/18/2023] Open
Abstract
Chikungunya virus (CHIKV) infection is one of the most challenging re-emergent diseases caused by a virus, and with no specific antiviral treatment it has now become a major public health concern. In this investigation, 25 blood samples were collected from patients with characteristic CHIKV symptoms and submitted to a virus isolation protocol, which detected 3 CHIKV isolates. These samples were evaluated by sequencing for the characterization of the strains and any homology to viruses circulating in Brazil during a recent outbreak. These viruses were used for the development of antiviral assays. Subsequently, the inhibitory effects of seaweed extracts on CHIKV replication were studied. The marine species of algae tested were Bryothamnion triquetrum, Caulerpa racemosa, Laurencia dendroidea, Osmundaria obtusiloba, Ulva fasciata, and Kappaphycus alvarezii, all of which are found in different countries including Brazil. The results revealed high levels of CHIKV inhibition, including extracts of O. obtusiloba with inhibition values of 1.25 μg/mL and a selectivity index of 420. Viral inhibition was dependent on the time of addition of extract of O. obtusiloba to the infected cells, with the optimal inhibition occurring up to 16 h after infection. Neuron evaluations with O. obtusiloba were performed and demonstrated low toxicity, and in infected neurons we observed high inhibitory activity in a dose-dependent manner. These results indicate that the algal extracts may be promising novel candidates for the development of therapeutic agents against CHIKV infections.
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Affiliation(s)
- Claudio Cesar Cirne-Santos
- Laboratório de Virologia Molecular e Biotecnologia Marinha, Programa de Pós-graduação em Ciências e Biotecnologia, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil.,Departamento de Ensino, Curso de Farmácia na Universidade Salgado de Oliveira, Niterói, Brazil
| | - Caroline de Souza Barros
- Laboratório de Virologia Molecular e Biotecnologia Marinha, Programa de Pós-graduação em Ciências e Biotecnologia, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil
| | - Caio Cesar Richter Nogueira
- Laboratório de Virologia Molecular e Biotecnologia Marinha, Programa de Pós-graduação em Ciências e Biotecnologia, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil.,Laboratório de Produtos Naturais de Algas Marinhas (ALGAMAR), Departamento de Biologia Marinha, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil
| | - Renata Campos Azevedo
- Instituto de Microbiologia Paulo de Góes (IMPPG), Departamento de Virologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Kristie Aimi Yamamoto
- Instituto de Microbiologia Paulo de Góes (IMPPG), Departamento de Virologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Guilherme Louzada Silva Meira
- Instituto de Microbiologia Paulo de Góes (IMPPG), Departamento de Virologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Valéria Laneuville Teixeira
- Laboratório de Produtos Naturais de Algas Marinhas (ALGAMAR), Departamento de Biologia Marinha, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil.,Laboratório de Biologia e Taxonomia de Algas (LABIOTAL), Programa de Pós-graduação em Biodiversidade Neotropical, Instituto de Biociencias, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jonas Schmidt-Chanasit
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, Hamburg, Germany
| | - Davis Fernandes Ferreira
- Instituto de Microbiologia Paulo de Góes (IMPPG), Departamento de Virologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC, United States
| | - Izabel Christina Nunes de Palmer Paixão
- Laboratório de Virologia Molecular e Biotecnologia Marinha, Programa de Pós-graduação em Ciências e Biotecnologia, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil
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9
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Borges-Martins VPP, Ferreira DDP, Souto AC, Oliveira Neto JG, Pereira-Figueiredo D, da Costa Calaza K, de Jesus Oliveira K, Manhães AC, de Melo Reis RA, Kubrusly RCC. Caffeine regulates GABA transport via A 1R blockade and cAMP signaling. Neurochem Int 2019; 131:104550. [PMID: 31563462 DOI: 10.1016/j.neuint.2019.104550] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 01/06/2023]
Abstract
Caffeine is the most consumed psychostimulant drug in the world, acting as a non-selective antagonist of adenosine receptors A1R and A2AR, which are widely expressed in retinal layers. We have previously shown that caffeine, when administered acutely, acts on A1R to potentiate the NMDA receptor-induced GABA release. Now we asked if long-term caffeine exposure also modifies GABA uptake in the avian retina and which mechanisms are involved in this process. Chicken embryos aged E11 were injected with a single dose of caffeine (30 mg/kg) in the air chamber. Retinas were dissected on E15 for ex vivo neurochemical assays. Our results showed that [3H]-GABA uptake was dependent on Na+ and blocked at 4 °C or by NO-711 and caffeine. This decrease was observed after 60 min of [3H]-GABA uptake assay at E15, which is accompanied by an increase in [3H]-GABA release. Caffeine increased the protein levels of A1R without altering ADORA1 mRNA and was devoid of effects on A2AR density or ADORA2A mRNA levels. The decrease of GABA uptake promoted by caffeine was reverted by A1R activation with N6-cyclohexyl adenosine (CHA) but not by A2AR activation with CGS 21680. Caffeine exposure increased cAMP levels and GAT-1 protein levels, which was evenly expressed between E11-E15. As expected, we observed an increase of GABA containing amacrine cells and processes in the IPL, also, cAMP pathway blockage by H-89 decreased caffeine mediated [3H]-GABA uptake. Our data support the idea that chronic injection of caffeine alters GABA transport via A1R during retinal development and that the cAMP/PKA pathway plays an important role in the regulation of GAT-1 function.
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Affiliation(s)
| | - Danielle Dias Pinto Ferreira
- Laboratório de Doenças Neurodegenerativas, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Arthur Cardoso Souto
- Laboratório de Neurofarmacologia, Departamento de Fisiologia e Farmacologia, Universidade Federal Fluminense, Niterói, Brazil.
| | - Jessika Geisebel Oliveira Neto
- Laboratório de Fisiologia Endócrina e Metabologia, Departamento de Fisiologia e Farmacologia, Universidade Federal Fluminense, Niterói, Brazil.
| | - Danniel Pereira-Figueiredo
- Laboratório de Neurobiologia da Retina, Departmento de Neurobiologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil.
| | - Karin da Costa Calaza
- Laboratório de Neurobiologia da Retina, Departmento de Neurobiologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil.
| | - Karen de Jesus Oliveira
- Laboratório de Fisiologia Endócrina e Metabologia, Departamento de Fisiologia e Farmacologia, Universidade Federal Fluminense, Niterói, Brazil.
| | - Alex Christian Manhães
- Laboratório de Neurofisiologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Ricardo Augusto de Melo Reis
- Laboratório de Neuroquímica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Regina Célia Cussa Kubrusly
- Laboratório de Neurofarmacologia, Departamento de Fisiologia e Farmacologia, Universidade Federal Fluminense, Niterói, Brazil.
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10
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Li HL, Zaghloul N, Ahmed I, Omelchenko A, Firestein BL, Huang H, Collins L. Caffeine inhibits hypoxia-induced nuclear accumulation in HIF-1α and promotes neonatal neuronal survival. Exp Neurol 2019; 317:66-77. [PMID: 30822423 PMCID: PMC6935249 DOI: 10.1016/j.expneurol.2019.01.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/10/2019] [Accepted: 01/22/2019] [Indexed: 12/13/2022]
Abstract
Apnea of prematurity (AOP) defined as cessation of breathing for 15-20 s, is commonly seen in preterm infants. Caffeine is widely used to treat AOP due to its safety and effectiveness. Caffeine releases respiratory arrest by competing with adenosine for binding to adenosine A1 and A2A receptors (A1R and A2AR). Long before its use in treating AOP, caffeine has been used as a psychostimulant in adult brains. However, the effect of caffeine on developing brains remains unclear. We found that A1R proteins for caffeine binding were expressed in the brains of neonatal rodents and preterm infants (26-27 weeks). Neonatal A1R proteins colocalized with PSD-95, suggesting its synaptic localization. In contrast, our finding on A2R expression in neonatal neurons was restricted to the mRNA level as detected by single cell RT/PCR due to the lack of specific A2AR antibody. Furthermore, caffeine (200 μM) at a dose twice higher than the clinically relevant dose (36-130 μM) had minor or no effects on several basic neuronal functions, such as neurite outgrowth, synapse formation, expression of A1R and transcription of CREB-1 and c-Fos, further supporting the safety of caffeine for clinical use. We found that treatment with CoCl2 (125 μM), a hypoxia mimetic agent, for 24 h triggered neuronal death and nuclear accumulation of HIF-1α in primary neuronal cultures. Subsequent treatment with caffeine at a concentration of 100 μM alleviated CoCl2-induced cell death and prevented nuclear accumulation of HIF-1α. Consistently, caffeine treatment in early postnatal life of neonatal mice (P4-P7) also prevented subsequent hypoxia-induced nuclear increase of HIF-1α. Together, our data support the utility of caffeine in alleviating hypoxia-induced damages in developing neurons.
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Affiliation(s)
- Hsiu-Ling Li
- Department of Physiology and Pharmacology, SUNY-Downstate Medical Center, New York, United States; Department of Biology, Medgar Evers College, City University of New York, United States.
| | - Nahla Zaghloul
- Cohen Children's Medical Center, Northwell Health, New Hyde Park, New York, United States; Feinstein Institute for Medical Research, Northwell Health, Manhasset, New York, United States
| | - Ijaz Ahmed
- Department of Biology, Medgar Evers College, City University of New York, United States
| | - Anton Omelchenko
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States; Neuroscience Graduate Program, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States
| | - Hai Huang
- Department of Biology, Medgar Evers College, City University of New York, United States
| | - Latoya Collins
- Department of Biology, Medgar Evers College, City University of New York, United States
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11
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Cirne-Santos CC, Barros CDS, Nogueira CCR, Azevedo RC, Yamamoto KA, Meira GLS, de Vasconcelos ZFM, Ratcliffe NA, Teixeira VL, Schmidt-Chanasit J, Ferreira DF, Paixão ICNDP. Inhibition by Marine Algae of Chikungunya Virus Isolated From Patients in a Recent Disease Outbreak in Rio de Janeiro. Front Microbiol 2019. [PMID: 31708898 DOI: 10.3389/fmicb201902426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023] Open
Abstract
Chikungunya virus (CHIKV) infection is one of the most challenging re-emergent diseases caused by a virus, and with no specific antiviral treatment it has now become a major public health concern. In this investigation, 25 blood samples were collected from patients with characteristic CHIKV symptoms and submitted to a virus isolation protocol, which detected 3 CHIKV isolates. These samples were evaluated by sequencing for the characterization of the strains and any homology to viruses circulating in Brazil during a recent outbreak. These viruses were used for the development of antiviral assays. Subsequently, the inhibitory effects of seaweed extracts on CHIKV replication were studied. The marine species of algae tested were Bryothamnion triquetrum, Caulerpa racemosa, Laurencia dendroidea, Osmundaria obtusiloba, Ulva fasciata, and Kappaphycus alvarezii, all of which are found in different countries including Brazil. The results revealed high levels of CHIKV inhibition, including extracts of O. obtusiloba with inhibition values of 1.25 μg/mL and a selectivity index of 420. Viral inhibition was dependent on the time of addition of extract of O. obtusiloba to the infected cells, with the optimal inhibition occurring up to 16 h after infection. Neuron evaluations with O. obtusiloba were performed and demonstrated low toxicity, and in infected neurons we observed high inhibitory activity in a dose-dependent manner. These results indicate that the algal extracts may be promising novel candidates for the development of therapeutic agents against CHIKV infections.
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Affiliation(s)
- Claudio Cesar Cirne-Santos
- Laboratório de Virologia Molecular e Biotecnologia Marinha, Programa de Pós-graduação em Ciências e Biotecnologia, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil
- Departamento de Ensino, Curso de Farmácia na Universidade Salgado de Oliveira, Niterói, Brazil
| | - Caroline de Souza Barros
- Laboratório de Virologia Molecular e Biotecnologia Marinha, Programa de Pós-graduação em Ciências e Biotecnologia, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil
| | - Caio Cesar Richter Nogueira
- Laboratório de Virologia Molecular e Biotecnologia Marinha, Programa de Pós-graduação em Ciências e Biotecnologia, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil
- Laboratório de Produtos Naturais de Algas Marinhas (ALGAMAR), Departamento de Biologia Marinha, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil
| | - Renata Campos Azevedo
- Instituto de Microbiologia Paulo de Góes (IMPPG), Departamento de Virologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Kristie Aimi Yamamoto
- Instituto de Microbiologia Paulo de Góes (IMPPG), Departamento de Virologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Guilherme Louzada Silva Meira
- Instituto de Microbiologia Paulo de Góes (IMPPG), Departamento de Virologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Valéria Laneuville Teixeira
- Laboratório de Produtos Naturais de Algas Marinhas (ALGAMAR), Departamento de Biologia Marinha, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil
- Laboratório de Biologia e Taxonomia de Algas (LABIOTAL), Programa de Pós-graduação em Biodiversidade Neotropical, Instituto de Biociencias, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jonas Schmidt-Chanasit
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, Hamburg, Germany
| | - Davis Fernandes Ferreira
- Instituto de Microbiologia Paulo de Góes (IMPPG), Departamento de Virologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC, United States
| | - Izabel Christina Nunes de Palmer Paixão
- Laboratório de Virologia Molecular e Biotecnologia Marinha, Programa de Pós-graduação em Ciências e Biotecnologia, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil
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12
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Ventura ALM, Dos Santos-Rodrigues A, Mitchell CH, Faillace MP. Purinergic signaling in the retina: From development to disease. Brain Res Bull 2018; 151:92-108. [PMID: 30458250 DOI: 10.1016/j.brainresbull.2018.10.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/14/2018] [Accepted: 10/23/2018] [Indexed: 02/07/2023]
Abstract
Retinal injuries and diseases are major causes of human disability involving vision impairment by the progressive and permanent loss of retinal neurons. During development, assembly of this tissue entails a successive and overlapping, signal-regulated engagement of complex events that include proliferation of progenitors, neurogenesis, cell death, neurochemical differentiation and synaptogenesis. During retinal damage, several of these events are re-activated with both protective and detrimental consequences. Purines and pyrimidines, along with their metabolites are emerging as important molecules regulating both retinal development and the tissue's responses to damage. The present review provides an overview of the purinergic signaling in the developing and injured retina. Recent findings on the presence of vesicular and channel-mediated ATP release by retinal and retinal pigment epithelial cells, adenosine synthesis and release, expression of receptors and intracellular signaling pathways activated by purinergic signaling in retinal cells are reported. The pathways by which purinergic receptors modulate retinal cell proliferation, migration and death of retinal cells during development and injury are summarized. The contribution of nucleotides to the self-repair of the injured zebrafish retina is also discussed.
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Affiliation(s)
- Ana Lucia Marques Ventura
- Department of Neurobiology, Neuroscience Program, Fluminense Federal University, Niterói, RJ, Brazil.
| | | | - Claire H Mitchell
- Department of Anatomy and Cell Biology, Ophthalmology, and Physiology, University of Pennsylvania, Philadelphia, PA 19104, United States.
| | - Maria Paula Faillace
- Instituto de Fisiología y Biofísica Prof. Bernardo Houssay (IFIBIO-Houssay), Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina; Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
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13
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Effect of Adenosine and Adenosine Receptor Antagonists on Retinal Müller Cell Inwardly Rectifying Potassium Channels under Exogenous Glutamate Stimulation. BIOMED RESEARCH INTERNATIONAL 2018; 2018:2749257. [PMID: 30228984 PMCID: PMC6136502 DOI: 10.1155/2018/2749257] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 07/25/2018] [Accepted: 08/13/2018] [Indexed: 12/15/2022]
Abstract
The vitreousness of glaucoma subjects contains elevated glutamate, and excessive extracellular glutamate is toxic to retinal neurons. Therefore, glutamate clearance is potentially impaired in the retina of glaucoma subjects. Müller cells play an important role in maintaining low extracellular levels of neurotransmitters, such as glutamate. A better understanding of the cross-talk between adenosine and glutamate may provide a better characterization of the regulatory network in Müller cells. Here, Müller cells were purified from the rat retina on postnatal day 5 using the papain digestion method. Application of increasing concentrations of glutamate (0-20 mmol/L) caused a dose-dependent decrease in the expression levels of Kir4.1, Kir2.1, GLAST, and GS. Exogenous adenosine regulated Kir channels and subsequently promoted GLAST and GS expression levels in Müller cells under exogenous glutamate stimulation. These effects were partly dependent on adenosine receptors.
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14
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Domith I, Duarte-Silva AT, Garcia CG, Calaza KDC, Paes-de-Carvalho R, Cossenza M. Chlorogenic acids inhibit glutamate dehydrogenase and decrease intracellular ATP levels in cultures of chick embryo retina cells. Biochem Pharmacol 2018; 155:393-402. [PMID: 30031809 DOI: 10.1016/j.bcp.2018.07.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 07/18/2018] [Indexed: 11/26/2022]
Abstract
Chlorogenic acids (CGAs) are a group of phenolic compounds found in worldwide consumed beverages such as coffee and green tea. They are synthesized from an esterification reaction between cinnamic acids, including caffeic (CFA), ferulic and p-coumaric acids with quinic acid (QA), forming several mono- and di-esterified isomers. The most prevalent and studied compounds are 3-O-caffeoylquinic acid (3-CQA), 4-O-caffeoylquinic acid (4-CQA) and 5-O-caffeoylquinic acid (5-CQA), widely described as having antioxidant and cell protection effects. CGAs can also modulate glutamate release from microglia by a mechanism involving a decrease of reactive oxygen species (ROS). Increased energy metabolism is highly associated with enhancement of ROS production and cellular damage. Glutamate can also be used as an energy source by glutamate dehydrogenase (GDH) enzyme, providing α-ketoglutarate to the tricarboxylic acid (TCA) cycle for ATP synthesis. High GDH activity is associated with some disorders, such as schizophrenia and hyperinsulinemia/hyperammonemia syndrome. In line with this, our objective was to investigate the effect of CGAs on GDH activity. We show that CGAs and CFA inhibits GDH activity in dose-dependent manner, reaching complete inhibition at high concentration with IC50 of 52 μM for 3-CQA and 158.2 μM for CFA. Using live imaging confocal microscopy and microplate reader, we observed that 3-CQA and CFA can be transported into neuronal cells by an Na+-dependent mechanism. Moreover, neuronal cells treated with CGAs presented lower intracellular ATP levels. Overall, these data suggest that CGAs have therapeutic potential for treatment of disorders associated with high GDH activity.
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Affiliation(s)
- Ivan Domith
- Program of Neurosciences, Fluminense Federal University, Niterói, Brazil
| | | | | | - Karin da Costa Calaza
- Program of Neurosciences, Fluminense Federal University, Niterói, Brazil; Department of Neurobiology, Institute of Biology, Fluminense Federal University, Niterói, Brazil
| | - Roberto Paes-de-Carvalho
- Program of Neurosciences, Fluminense Federal University, Niterói, Brazil; Department of Neurobiology, Institute of Biology, Fluminense Federal University, Niterói, Brazil
| | - Marcelo Cossenza
- Program of Neurosciences, Fluminense Federal University, Niterói, Brazil; Department of Physiology and Pharmacology, Biomedical Institute, Fluminense Federal University, Niterói, Brazil.
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15
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Jackson EK, Kotermanski SE, Menshikova EV, Dubey RK, Jackson TC, Kochanek PM. Adenosine production by brain cells. J Neurochem 2017; 141:676-693. [PMID: 28294336 DOI: 10.1111/jnc.14018] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 03/06/2017] [Accepted: 03/07/2017] [Indexed: 02/06/2023]
Abstract
The early release of adenosine following traumatic brain injury (TBI) suppresses seizures and brain inflammation; thus, it is important to elucidate the cellular sources of adenosine following injurious stimuli triggered by TBI so that therapeutics for enhancing the early adenosine-release response can be optimized. Using mass spectrometry with 13 C-labeled standards, we investigated in cultured rat neurons, astrocytes, and microglia the effects of oxygen-glucose deprivation (OGD; models energy failure), H2 O2 (produces oxidative stress), and glutamate (induces excitotoxicity) on intracellular and extracellular levels of 5'-AMP (adenosine precursor), adenosine, and inosine and hypoxanthine (adenosine metabolites). In neurons, OGD triggered increases in intracellular 5'-AMP (2.8-fold), adenosine (2.6-fold), inosine (2.2-fold), and hypoxanthine (5.3-fold) and extracellular 5'-AMP (2.2-fold), adenosine (2.4-fold), and hypoxanthine (2.5-fold). In neurons, H2 O2 did not affect intracellular or extracellular purines; yet, glutamate increased intracellular adenosine, inosine, and hypoxanthine (1.7-fold, 1.7-fold, and 1.6-fold, respectively) and extracellular adenosine, inosine, and hypoxanthine (2.9-fold, 2.1-fold, and 1.6-fold, respectively). In astrocytes, neither H2 O2 nor glutamate affected intracellular or extracellular purines, and OGD only slightly increased intracellular and extracellular hypoxanthine. Microglia were unresponsive to OGD and glutamate, but were remarkably responsive to H2 O2 , which increased intracellular 5'-AMP (1.6-fold), adenosine (1.6-fold), inosine (2.1-fold), and hypoxanthine (1.6-fold) and extracellular 5'-AMP (5.9-fold), adenosine (4.0-fold), inosine (4.3-fold), and hypoxanthine (1.9-fold). CONCLUSION Under these particular experimental conditions, cultured neurons are the main contributors to adenosine production/release in response to OGD and glutamate, whereas cultured microglia are the main contributors upon oxidative stress. Developing therapeutics that recruit astrocytes to produce/release adenosine could have beneficial effects in TBI.
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Affiliation(s)
- Edwin K Jackson
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Shawn E Kotermanski
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Elizabeth V Menshikova
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Raghvendra K Dubey
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Reproductive Endocrinology, University Hospital Zurich and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Travis C Jackson
- Department of Critical Care Medicine and the Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Patrick M Kochanek
- Department of Critical Care Medicine and the Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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16
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Madeira MH, Elvas F, Boia R, Gonçalves FQ, Cunha RA, Ambrósio AF, Santiago AR. Adenosine A2AR blockade prevents neuroinflammation-induced death of retinal ganglion cells caused by elevated pressure. J Neuroinflammation 2015; 12:115. [PMID: 26054642 PMCID: PMC4465153 DOI: 10.1186/s12974-015-0333-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 05/27/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Elevated intraocular pressure (IOP) is a major risk factor for glaucoma, a degenerative disease characterized by the loss of retinal ganglion cells (RGCs). There is clinical and experimental evidence that neuroinflammation is involved in the pathogenesis of glaucoma. Since the blockade of adenosine A2A receptor (A2AR) confers robust neuroprotection and controls microglia reactivity in the brain, we now investigated the ability of A2AR blockade to control the reactivity of microglia and neuroinflammation as well as RGC loss in retinal organotypic cultures exposed to elevated hydrostatic pressure (EHP) or lipopolysaccharide (LPS). METHODS Retinal organotypic cultures were either incubated with LPS (3 μg/mL), to elicit a pro-inflammatory response, or exposed to EHP (+70 mmHg), to mimic increased IOP, for 4 or 24 h, in the presence or absence of the A2AR antagonist SCH 58261 (50 nM). A2AR expression, microglial reactivity and neuroinflammatory response were evaluated by immunohistochemistry, quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA). RGC loss was assessed by immunohistochemistry. In order to investigate the contribution of pro-inflammatory mediators to RGC loss, the organotypic retinal cultures were incubated with rabbit anti-tumour necrosis factor (TNF) (2 μg/mL) and goat anti-interleukin-1β (IL-1β) (1 μg/mL) antibodies. RESULTS We report that the A2AR antagonist (SCH 58261) prevented microglia reactivity, increase in pro-inflammatory mediators as well as RGC loss upon exposure to either LPS or EHP. Additionally, neutralization of TNF and IL-1β prevented RGC loss induced by LPS or EHP. CONCLUSIONS This work demonstrates that A2AR blockade confers neuroprotection to RGCs by controlling microglia-mediated retinal neuroinflammation and prompts the hypothesis that A2AR antagonists may be a novel therapeutic option to manage glaucomatous disorders.
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Affiliation(s)
- Maria H Madeira
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3004-548, Coimbra, Portugal. .,CNC.IBILI, University of Coimbra, 3004-517, Coimbra, Portugal.
| | - Filipe Elvas
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3004-548, Coimbra, Portugal.
| | - Raquel Boia
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3004-548, Coimbra, Portugal. .,CNC.IBILI, University of Coimbra, 3004-517, Coimbra, Portugal.
| | - Francisco Q Gonçalves
- CNC.IBILI, University of Coimbra, 3004-517, Coimbra, Portugal. .,CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal.
| | - Rodrigo A Cunha
- CNC.IBILI, University of Coimbra, 3004-517, Coimbra, Portugal. .,CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal. .,Faculty of Medicine, University of Coimbra, 3000-548, Coimbra, Portugal.
| | - António Francisco Ambrósio
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3004-548, Coimbra, Portugal. .,CNC.IBILI, University of Coimbra, 3004-517, Coimbra, Portugal. .,Association for Innovation and Biomedical Research on Light (AIBILI), 3000-548, Coimbra, Portugal.
| | - Ana Raquel Santiago
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3004-548, Coimbra, Portugal. .,CNC.IBILI, University of Coimbra, 3004-517, Coimbra, Portugal. .,Association for Innovation and Biomedical Research on Light (AIBILI), 3000-548, Coimbra, Portugal. .,Faculty of Medicine, University of Coimbra, 3000-548, Coimbra, Portugal. .,IBILI, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, 3004-548, Coimbra, Portugal.
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17
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Dos Santos-Rodrigues A, Pereira MR, Brito R, de Oliveira NA, Paes-de-Carvalho R. Adenosine transporters and receptors: key elements for retinal function and neuroprotection. VITAMINS AND HORMONES 2015; 98:487-523. [PMID: 25817878 DOI: 10.1016/bs.vh.2014.12.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Adenosine is an important neuroactive substance in the central nervous system, including in the retina where subclasses of adenosine receptors and transporters are expressed since early stages of development. Here, we review some evidence showing that adenosine plays important functions in the mature as well as in the developing tissue. Adenosine transporters are divided into equilibrative and concentrative, and the major transporter subtype present in the retina is the ENT1. This transporter is responsible for a bidirectional transport of adenosine and the uptake or release of this nucleoside appears to be regulated by different signaling pathways that are also controlled by activation of adenosine receptors. Adenosine receptors are also key players in retina physiology regulating a variety of functions in the mature and developing tissue. Regulation of excitatory neurotransmitter release and neuroprotection are the main functions played be adenosine in the mature tissue, while regulation of cell survival and neurogenesis are some of the functions played by adenosine in developing retina. Since adenosine is neuroprotective against excitotoxic and metabolic dysfunctions observed in neurological and ocular diseases, the search for adenosine-related drugs regulating adenosine transporters and receptors can be important for advancement of therapeutic strategies against these diseases.
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Affiliation(s)
| | - Mariana R Pereira
- Program of Neurosciences, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Rafael Brito
- Program of Neurosciences, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Nádia A de Oliveira
- Program of Neurosciences, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
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18
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Socodato R, Portugal CC, Canedo T, Domith I, Oliveira NA, Paes-de-Carvalho R, Relvas JB, Cossenza M. c-Src deactivation by the polyphenol 3-O-caffeoylquinic acid abrogates reactive oxygen species-mediated glutamate release from microglia and neuronal excitotoxicity. Free Radic Biol Med 2015; 79:45-55. [PMID: 25486178 DOI: 10.1016/j.freeradbiomed.2014.11.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 11/10/2014] [Accepted: 11/26/2014] [Indexed: 12/13/2022]
Abstract
3-O-caffeoylquinic acid (3-CQA) is an isomer of chlorogenic acid, which has been shown to regulate lipopolysaccharide-induced tumor necrosis factor production in microglia. Whereas overactivation of microglia is associated with neuronal loss in brain diseases via reactive oxygen species (ROS) production and glutamate excitotoxicity, naïve (nonactivated) microglia are believed to generate little ROS under basal conditions, contributing to the modulation of synaptic activity and nerve tissue repair. However, the signaling pathways controlling basal ROS homeostasis in microglial cells are still poorly understood. Here we used time-lapse microscopy coupled with highly sensitive FRET biosensors (for detecting c-Src activation, ROS generation, and glutamate release) and lentivirus-mediated shRNA delivery to study the pathways involved in antioxidant-regulated ROS generation and how this associates with microglia-induced neuronal cell death. We report that 3-CQA abrogates the acquisition of an amoeboid morphology in microglia triggered by Aβ oligomers or the HIV Tat peptide. Moreover, 3-CQA deactivates c-Src tyrosine kinase and abrogates c-Src activation during proinflammatory microglia stimulation, which shuts off ROS production in these cells. Moreover, forced increment of c-Src catalytic activity by overexpressing an inducible c-Src heteromerization construct in microglia increases ROS production, abrogating the 3-CQA effects. Whereas oxidant (hydrogen peroxide) stimulation dramatically enhances glutamate release from microglia, such release is diminished by the 3-CQA inhibition of c-Src/ROS generation, significantly alleviating cell death in cultures from embryonic neurons. Overall, we provide further mechanistic insight into the modulation of ROS production in cortical microglia, indicating antioxidant-regulated c-Src function as a pathway for controlling microglia-triggered oxidative damage.
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Affiliation(s)
- Renato Socodato
- Glial Cell Biology Laboratory Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal.
| | - Camila C Portugal
- Glial Cell Biology Laboratory Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal
| | - Teresa Canedo
- Addiction Biology Laboratory, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal
| | - Ivan Domith
- Neurosciences Program, Fluminense Federal University, Niterói 24210-130, Brazil
| | - Nadia A Oliveira
- Neurosciences Program, Fluminense Federal University, Niterói 24210-130, Brazil
| | - Roberto Paes-de-Carvalho
- Neurosciences Program, Fluminense Federal University, Niterói 24210-130, Brazil; Department of Neurobiology, Institute of Biology, Fluminense Federal University, Niterói 24210-130, Brazil
| | - João B Relvas
- Glial Cell Biology Laboratory Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal
| | - Marcelo Cossenza
- Neurosciences Program, Fluminense Federal University, Niterói 24210-130, Brazil; Department of Physiology and Pharmacology, Biomedical Institute, Fluminense Federal University, Niterói 24210-130, Brazil.
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19
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Caffeine potentiates the release of GABA mediated by NMDA receptor activation: Involvement of A1 adenosine receptors. Neuroscience 2014; 281:208-15. [DOI: 10.1016/j.neuroscience.2014.09.060] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/19/2014] [Accepted: 09/26/2014] [Indexed: 11/21/2022]
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20
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Perígolo-Vicente R, Ritt K, Gonçalves-de-Albuquerque CF, Castro-Faria-Neto HC, Paes-de-Carvalho R, Giestal-de-Araujo E. IL-6, A1 and A2aR: a crosstalk that modulates BDNF and induces neuroprotection. Biochem Biophys Res Commun 2014; 449:477-82. [PMID: 24845382 DOI: 10.1016/j.bbrc.2014.05.036] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 05/08/2014] [Indexed: 11/15/2022]
Abstract
Several diseases are related to retinal ganglion cell death, such as glaucoma, diabetes and other retinopathies. Many studies have attempted to identify factors that could increase neuroprotection after axotomy of these cells. Interleukin-6 has been shown to be able to increase the survival and regeneration of retinal ganglion cells (RGC) in mixed culture as well as in vivo. In this work we show that the trophic effect of IL-6 is mediated by adenosine receptor (A2aR) activation and also by the presence of extracellular BDNF. We also show that there is a complex cross-talk between IL-6, BDNF, the Adenosine A1 and A2a receptors that results in neuroprotection of retinal ganglion cells.
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Affiliation(s)
- Rafael Perígolo-Vicente
- Departamento de Neurobiologia, Instituto de Biologia, Universidade Federal Fluminense, Outeiro de São João Batista s/n, Niterói, Rio de Janeiro CEP: 24020-140, Brazil; Blizard Institute - Queen Mary, University of London, 4 Newark St, London, City of London, Greater London E1 2AT, United Kingdom.
| | - Karen Ritt
- Departamento de Neurobiologia, Instituto de Biologia, Universidade Federal Fluminense, Outeiro de São João Batista s/n, Niterói, Rio de Janeiro CEP: 24020-140, Brazil
| | - Cassiano Felippe Gonçalves-de-Albuquerque
- Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Departamento de Fisiologia e Farmacodinâmica, Av. Brasil, n° 4365, Manguinhos, CEP: 21045-900 Rio de Janeiro, RJ, Brazil
| | - Hugo Caire Castro-Faria-Neto
- Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Departamento de Fisiologia e Farmacodinâmica, Av. Brasil, n° 4365, Manguinhos, CEP: 21045-900 Rio de Janeiro, RJ, Brazil
| | - Roberto Paes-de-Carvalho
- Departamento de Neurobiologia, Instituto de Biologia, Universidade Federal Fluminense, Outeiro de São João Batista s/n, Niterói, Rio de Janeiro CEP: 24020-140, Brazil
| | - Elizabeth Giestal-de-Araujo
- Departamento de Neurobiologia, Instituto de Biologia, Universidade Federal Fluminense, Outeiro de São João Batista s/n, Niterói, Rio de Janeiro CEP: 24020-140, Brazil
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Sheth S, Brito R, Mukherjea D, Rybak LP, Ramkumar V. Adenosine receptors: expression, function and regulation. Int J Mol Sci 2014; 15:2024-52. [PMID: 24477263 PMCID: PMC3958836 DOI: 10.3390/ijms15022024] [Citation(s) in RCA: 246] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 01/15/2014] [Accepted: 01/15/2014] [Indexed: 02/06/2023] Open
Abstract
Adenosine receptors (ARs) comprise a group of G protein-coupled receptors (GPCR) which mediate the physiological actions of adenosine. To date, four AR subtypes have been cloned and identified in different tissues. These receptors have distinct localization, signal transduction pathways and different means of regulation upon exposure to agonists. This review will describe the biochemical characteristics and signaling cascade associated with each receptor and provide insight into how these receptors are regulated in response to agonists. A key property of some of these receptors is their ability to serve as sensors of cellular oxidative stress, which is transmitted by transcription factors, such as nuclear factor (NF)-κB, to regulate the expression of ARs. Recent observations of oligomerization of these receptors into homo- and heterodimers will be discussed. In addition, the importance of these receptors in the regulation of normal and pathological processes such as sleep, the development of cancers and in protection against hearing loss will be examined.
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Affiliation(s)
- Sandeep Sheth
- Department of Pharmacology and Neuroscience, Southern Illinois University School of Medicine, Springfield, IL 62702, USA.
| | - Rafael Brito
- Department of Pharmacology and Neuroscience, Southern Illinois University School of Medicine, Springfield, IL 62702, USA.
| | - Debashree Mukherjea
- Department of Surgery (Otolaryngology), Southern Illinois University School of Medicine, Springfield, IL 62702, USA.
| | - Leonard P Rybak
- Department of Pharmacology and Neuroscience, Southern Illinois University School of Medicine, Springfield, IL 62702, USA.
| | - Vickram Ramkumar
- Department of Pharmacology and Neuroscience, Southern Illinois University School of Medicine, Springfield, IL 62702, USA.
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22
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Vindeirinho J, Costa GN, Correia MB, Cavadas C, Santos PF. Effect of diabetes/hyperglycemia on the rat retinal adenosinergic system. PLoS One 2013; 8:e67499. [PMID: 23840723 PMCID: PMC3696088 DOI: 10.1371/journal.pone.0067499] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 05/20/2013] [Indexed: 02/04/2023] Open
Abstract
The early stages of diabetic retinopathy (DR) are characterized by alterations similar to neurodegenerative and inflammatory conditions such as increased neural apoptosis, microglial cell activation and amplified production of pro-inflammatory cytokines. Adenosine regulates several physiological functions by stimulating four subtypes of receptors, A1AR, A2AAR, A2BAR, and A3AR. Although the adenosinergic signaling system is affected by diabetes in several tissues, it is unknown whether diabetic conditions in the retina can also affect it. Adenosine delivers potent suppressive effects on virtually all cells of the immune system, but its potential role in the context of DR has yet to be studied in full. In this study, we used primary mixed cultures of rat retinal cells exposed to high glucose conditions, to mimic hyperglycemia, and a streptozotocin rat model of type 1 diabetes to determine the effect diabetes/hyperglycemia have on the expression and protein levels of adenosine receptors and of the enzymes adenosine deaminase and adenosine kinase. We found elevated mRNA and protein levels of A1AR and A2AAR, in retinal cell cultures under high glucose conditions and a transient increase in the levels of the same receptors in diabetic retinas. Adenosine deaminase and adenosine kinase expression and protein levels showed a significant decrease in diabetic retinas 30 days after diabetes induction. An enzymatic assay performed in retinal cell cultures revealed a marked decrease in the activity of adenosine deaminase under high glucose conditions. We also found an increase in extracellular adenosine levels accompanied by a decrease in intracellular levels when retinal cells were subjected to high glucose conditions. In conclusion, this study shows that several components of the retinal adenosinergic system are affected by diabetes and high glucose conditions, and the modulation observed may uncover a possible mechanism for the alleviation of the inflammatory and excitotoxic conditions observed in diabetic retinas.
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Affiliation(s)
- Joana Vindeirinho
- CNC – Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Gabriel N. Costa
- CNC – Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Mariana B. Correia
- CNC – Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Cláudia Cavadas
- CNC – Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Paulo F. Santos
- CNC – Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
- * E-mail:
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23
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IL-6 treatment increases the survival of retinal ganglion cells in vitro: The role of adenosine A1 receptor. Biochem Biophys Res Commun 2013; 430:512-8. [DOI: 10.1016/j.bbrc.2012.12.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 12/03/2012] [Indexed: 11/23/2022]
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24
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Abreu PA, Castro HC, Paes-de-Carvalho R, Rodrigues CR, Giongo V, Paixão ICNP, Santana MV, Ferreira JM, Caversan OM, Leão RAC, Marins LMS, Henriques AM, Farias FMC, Albuquerque MG, Pinheiro S. Molecular Modeling of a Phenyl-Amidine Class of NMDA Receptor Antagonists and the Rational Design of New Triazolyl-Amidine Derivatives. Chem Biol Drug Des 2012; 81:185-97. [DOI: 10.1111/cbdd.12056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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25
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Brito R, Pereira MR, Paes-de-Carvalho R, Calaza KDC. Expression of A1 adenosine receptors in the developing avian retina: in vivo modulation by A(2A) receptors and endogenous adenosine. J Neurochem 2012; 123:239-49. [PMID: 22862679 DOI: 10.1111/j.1471-4159.2012.07909.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Revised: 07/30/2012] [Accepted: 08/01/2012] [Indexed: 12/13/2022]
Abstract
Little is known about the mechanisms that regulate the expression of adenosine receptors during CNS development. We demonstrate here that retinas from chick embryos injected in ovo with selective adenosine receptor ligands show changes in A1 receptor expression after 48 h. Exposure to A1 agonist N⁶-cyclohexyladenosine (CHA) or antagonist 8-Cyclopentyl-1, 3-dipropylxanthine (DPCPX) reduced or increased, respectively, A1 receptor protein and [³H]DPCPX binding, but together, CHA+DPCPX had no effect. Interestingly, treatment with A(2A) agonist 3-[4-[2-[[6-amino-9-[(2R,3R,4S,5S)-5-(ethylcarbamoyl)-3,4-dihydroxy-oxolan-2-yl]purin-2-yl]amino] ethyl]phenyl] propanoic acid (CGS21680) increased A1 receptor protein and [³H]DPCPX binding, and reduced A(2A) receptors. The A(2A) antagonists 7-(2-phenylethyl)-5-amino-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-trizolo[1,5-c] pyrimidine (SCH58261) and 4-(2-[7-amino-2-[2-furyl][1,2,4]triazolo[2,3-a][1,3,5]triazo-5-yl-amino]ethyl)phenol (ZM241385) had opposite effects on A1 receptor expression. Exposure to CGS21680 + CHA did not change A1 receptor levels, whereas CHA + ZM241385 or CGS21680 + DPCPX had no synergic effect. The blockade of adenosine transporter with S-(4-nitrobenzyl)-6-thioinosine (NBMPR) also reduced [³H]DPCPX binding, an effect blocked by DPCPX, but not enhanced by ZM241385. [³H]DPCPX binding kinetics showed that treatment with CHA reduced and CGS21680 increased the Bmax, but did not affect Kd values. CHA, DPCPX, CGS21680, and ZM241385 had no effect on A1 receptor mRNA. These data demonstrated an in vivo regulation of A1 receptor expression by endogenous adenosine or long-term treatment with A1 and A(2A) receptors modulators.
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Affiliation(s)
- Rafael Brito
- Neurobiology of the Retina Laboratory, Department of Neurobiology and Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niteroi, RJ, Brazil
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26
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Activation of adenosine A2A receptor up-regulates BDNF expression in rat primary cortical neurons. Neurochem Res 2011; 36:2259-69. [PMID: 21792677 DOI: 10.1007/s11064-011-0550-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Revised: 06/18/2011] [Accepted: 07/14/2011] [Indexed: 01/12/2023]
Abstract
As a member of neurotrophin family, brain derived neurotrophic factor (BDNF) plays critical roles in neuronal development, differentiation, synaptogenesis, and neural protection from the harmful stimuli. There have been reported that adenosine A2(A) receptor subtype is widely distributed in the brain regions, such as hippocampus, striatum, and cortex. Adenosine A2(A) receptor is colocalized with BDNF in brain regions and the functional interaction between A2(A) receptor stimulation and BDNF action has been suggested. In this study, we investigated the possibility that the activation of A2(A) receptor modulates BDNF production in rat primary cortical neuron. CGS21680, an adenosine A2(A) receptor agonist, induced BDNF expression and release. An antagonist against A2(A) receptor, ZM241385, prevented CGS21680-induced increase in BDNF production. A2(A) receptor stimulation induced the activation of Akt-GSK-3β signaling pathway and the blockade of the signaling pathway with specific inhibitors abolished the increase in BDNF production, possibly via modulation of ERK1/2-CREB pathway. The physiological roles of A2(A) receptor-induced BDNF production was demonstrated by the protection of neurons from the excitotoxicity and increased neurite extension as well as synapse formation from immature and mature neurons. Taken together, activation of A2(A) receptor regulates BDNF production in rat cortical neuron, which provides neuro-protective action.
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27
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Socodato R, Brito R, Calaza KC, Paes-de-Carvalho R. Developmental regulation of neuronal survival by adenosine in the in vitro and in vivo avian retina depends on a shift of signaling pathways leading to CREB phosphorylation or dephosphorylation. J Neurochem 2010; 116:227-39. [PMID: 21054391 DOI: 10.1111/j.1471-4159.2010.07096.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Previous studies have shown a cAMP/protein kinase A-dependent neuroprotective effect of adenosine on glutamate or re-feeding-induced apoptosis in chick retina neuronal cultures. In the present work, we have studied the effect of adenosine on the survival of retinal progenitor cells. Cultures obtained from 6-day-old (E6) or from 8-day-old (E8) chick embryos were challenged 2 h (C0) or 1 day (C1) after seeding and analyzed after 3-4 days in vitro. Surprisingly, treatment with the selective A2a adenosine receptor agonists N(6) -[2-(3,5-dimethoxyphenyl)-2-(2-methylphenyl)-ethyl]adenosine (DPMA) or 3-[4-[2-[[6-amino-9-[(2R,3R,4S,5S)-5-(ethylcarbamoyl)-3,4-dihydroxy-oxolan-2-yl]purin-2-yl]amino]ethyl]phenyl]propanoic acid (CGS21680) promoted cell death when added at E6C0 but not at E6C1 or E8C0. DPMA-induced cell death involved activation of A2a receptors and the phospholipase C/protein kinase C but not the cAMP/protein kinase A pathway, and was not correlated with early modulation of precursor cells proliferation. Regarding cyclic nucleotide responsive element binding protein (CREB) phosphorylation, cultures from E6 embryos behave in an opposite manner from that from E8 embryos, both in vitro and in vivo. While the phospho-CREB level was high at E6C0 cultures and could be diminished by DPMA, it was lower at E8C0 and could be increased by DPMA. Similar to what was observed in cell survival studies, CREB dephosphorylation induced by DPMA in E6C0 cultures was dependent on the Phospholipase C/protein kinase C pathway. Accordingly, cell death induced by DPMA was inhibited by okadaic acid, a phosphatase blocker. Moreover, DPMA as well as the adenosine uptake blocker nitrobenzyl mercaptopurine riboside (NBMPR) modulate cell survival and CREB phosphorylation in a population of cells in the ganglion cell layer in vivo. These data suggest that A2a adenosine receptors as well as CREB may display a novel and important function by controlling the repertoire of developing retinal neurons.
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Affiliation(s)
- Renato Socodato
- Laboratories of Cellular Neurobiology and Neurobiology of Retina, Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil
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28
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Sebastião AM, Ribeiro JA. Tuning and fine-tuning of synapses with adenosine. Curr Neuropharmacol 2010; 7:180-94. [PMID: 20190960 PMCID: PMC2769002 DOI: 10.2174/157015909789152128] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 04/21/2009] [Accepted: 04/28/2009] [Indexed: 12/03/2022] Open
Abstract
The ‘omnipresence’ of adenosine in all nervous system cells (neurons and glia) together with the intensive release of adenosine following insults, makes adenosine as a sort of ‘maestro’ of synapses leading to the homeostatic coordination of brain function. Besides direct actions of adenosine on the neurosecretory mechanisms, where adenosine operates to tune neurotransmitter release, receptor-receptor interactions as well as interplays between adenosine receptors and transporters occur as part of the adenosine’s attempt to fine tuning synaptic transmission. This review will focus on the different ways adenosine can use to trigger or brake the action of several neurotransmitters and neuromodulators. Adenosine receptors cross talk with other G protein coupled receptors (GPCRs), with ionotropic receptors and with receptor kinases. Most of these interactions occur through A2A receptors, which in spite their low density in some brain areas, such as the hippocampus, may function as metamodulators. Tonic adenosine A2A receptor activity is a required step to allow synaptic actions of neurotrophic factors, namely upon synaptic transmission at both pre- and post-synaptic level as well as upon synaptic plasticity and neuronal survival. The implications of these interactions in normal brain functioning and in neurologic and psychiatric dysfunction will be discussed.
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Affiliation(s)
- A M Sebastião
- Institute of Pharmacology and Neurosciences, Faculty of Medicine and Unit of Neurosciences, Institute of Molecular Medicine, University of Lisbon, Lisboa, Portugal.
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29
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Abstract
The presence of adenosine in all nervous system cells (neurones and glia) together with its intensive release following insults makes adenosine as a sort of 'regulator' of synaptic communication, leading to the homeostatic coordination of brain function. Besides the direct actions of adenosine on the neurosecretory mechanisms, to tune neurotransmitter release, adenosine receptors interact with other receptors as well as with transporters as part of its attempt to fine-tune synaptic transmission. This review will focus on examples of the different ways adenosine can use to modulate or metamodulate synapses, in other words, to trigger or brake the action of some neurotransmitters and neuromodulators, to cross-talk with other G protein-coupled receptors, with ionotropic receptors and with receptor kinases as well as with transporters. Most of these interactions occur through A2A receptors, which in spite of their low density in some brain areas, such as the hippocampus, may function as amplifiers of the signalling of other mediators at synapses.
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Affiliation(s)
- J A Ribeiro
- Institute of Pharmacology and Neurosciences, Faculty of Medicine and Unit of Neurosciences, Institute of Molecular Medicine, University of Lisbon, Lisbon, Portugal.
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30
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Pereira MR, Hang VR, Vardiero E, de Mello FG, Paes-de-Carvalho R. Modulation of A1 adenosine receptor expression by cell aggregation and long-term activation of A2a receptors in cultures of avian retinal cells: involvement of the cyclic AMP/PKA pathway. J Neurochem 2010; 113:661-73. [PMID: 20163523 DOI: 10.1111/j.1471-4159.2010.06641.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The expression of A1 and A2a adenosine receptors is developmentally regulated in the chick retina, but little is known about the factors important for this regulation. Here, we show that cell aggregation and cAMP analogs promote a dramatic increase in A1 receptor expression. Importantly, a long-term stimulation of A2a receptors also promotes an increase of A1 receptor expression accompanied by a down-regulation of A2a receptors. Chick embryo retina cultures grown in the form of aggregates or dispersed cells accumulate cAMP when stimulated with dopamine or the adenosine agonist 2-chloroadenosine. However, inhibition of dopamine-dependent cAMP accumulation by 2-chloroadenosine was observed in aggregate cultures but not in dispersed cell cultures. Accordingly, A1 receptor binding sites were detected in aggregate cultures, but were low or absent from dispersed cell cultures. Interestingly, an increase of A1 binding sites was detected when dispersed cell cultures were treated for 5 days with permeable cAMP analogs, the adenylyl cyclase activator forskolin or A2a receptor agonists. Although a significant amount of A1 receptor protein was detected in dispersed cell cultures by western blot or immunocytochemistry, the long-term stimulation of A2a receptors also promoted an increase of the A1 receptor protein and mRNA, indicating that A2a receptors and cAMP were regulating transcription and/or translation of A1 receptors. We also found an increase of A1 receptors in locations in or near the membrane after treatment with A2a agonist. The long-term stimulation of retinal explants with A2a agonist also promoted an increase of A1 receptor protein. The results indicate that A2a receptors and the cAMP-dependent protein kinase pathway are involved in the regulation of A1 receptor expression during retinal development.
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Affiliation(s)
- Mariana R Pereira
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, Brazil
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Sebastião AM, Ribeiro JA. Triggering neurotrophic factor actions through adenosine A2A receptor activation: implications for neuroprotection. Br J Pharmacol 2009; 158:15-22. [PMID: 19508402 DOI: 10.1111/j.1476-5381.2009.00157.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
G protein coupled receptors and tropomyosin-related kinase (Trk) receptors have distinct structure and transducing mechanisms; therefore, cross-talk among them was unexpected. Evidence has, however, accumulated showing that tonic adenosine A2A receptor activity is a required step to allow synaptic actions of neurotrophic factors, namely upon synaptic transmission at both pre- and post-synaptic level as well as upon synaptic plasticity. An enhancement of A2A receptor tonus upon ageing may partially compensate the loss of TrkB receptors, rescuing to certain degree the facilitatory action of brain derived neurotrophic factor in aged animals, which might prove particularly relevant in the prevention of neurodegeneration upon ageing. A2A receptors also trigger synaptic actions of other neurotrophic factors, such as glial derived neurotrophic factor at dopaminergic striatal nerve endings. The growing evidence that tonic adenosine A2A receptor activity is a crucial step to allow actions of neurotrophic factors in neurones will be reviewed and discussed in the light of therapeutic strategies for neurodegenerative diseases.
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Affiliation(s)
- Ana M Sebastião
- Institute of Pharmacology and Neurosciences, Faculty of Medicine, University of Lisbon, Lisbon, Portugal.
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Portugal CC, Miya VS, Calaza KDC, Santos RAM, Paes-de-Carvalho R. Glutamate receptors modulate sodium-dependent and calcium-independent vitamin C bidirectional transport in cultured avian retinal cells. J Neurochem 2009; 108:507-20. [DOI: 10.1111/j.1471-4159.2008.05786.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Abstract
The adenosine receptors (ARs) in the nervous system act as a kind of "go-between" to regulate the release of neurotransmitters (this includes all known neurotransmitters) and the action of neuromodulators (e.g., neuropeptides, neurotrophic factors). Receptor-receptor interactions and AR-transporter interplay occur as part of the adenosine's attempt to control synaptic transmission. A(2A)ARs are more abundant in the striatum and A(1)ARs in the hippocampus, but both receptors interfere with the efficiency and plasticity-regulated synaptic transmission in most brain areas. The omnipresence of adenosine and A(2A) and A(1) ARs in all nervous system cells (neurons and glia), together with the intensive release of adenosine following insults, makes adenosine a kind of "maestro" of the tripartite synapse in the homeostatic coordination of the brain function. Under physiological conditions, both A(2A) and A(1) ARs play an important role in sleep and arousal, cognition, memory and learning, whereas under pathological conditions (e.g., Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, stroke, epilepsy, drug addiction, pain, schizophrenia, depression), ARs operate a time/circumstance window where in some circumstances A(1)AR agonists may predominate as early neuroprotectors, and in other circumstances A(2A)AR antagonists may alter the outcomes of some of the pathological deficiencies. In some circumstances, and depending on the therapeutic window, the use of A(2A)AR agonists may be initially beneficial; however, at later time points, the use of A(2A)AR antagonists proved beneficial in several pathologies. Since selective ligands for A(1) and A(2A) ARs are now entering clinical trials, the time has come to determine the role of these receptors in neurological and psychiatric diseases and identify therapies that will alter the outcomes of these diseases, therefore providing a hopeful future for the patients who suffer from these diseases.
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Affiliation(s)
- Ana M Sebastião
- Institute of Pharmacology and Neurosciences, Institute of Molecular Medicine, University of Lisbon, 1649-028 Lisbon, Portugal.
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Mejía-García TA, Paes-de-Carvalho R. Nitric oxide regulates cell survival in purified cultures of avian retinal neurons: involvement of multiple transduction pathways. J Neurochem 2006; 100:382-94. [PMID: 17116229 DOI: 10.1111/j.1471-4159.2006.04244.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Nitric oxide (NO) is an important signaling molecule in the CNS, regulating neuronal survival, proliferation and differentiation. Here, we explored the mechanism by which NO, produced from the NO donor S-nitroso-acetyl-d-l-penicillamine (SNAP), exerts its neuroprotective effect in purified cultures of chick retinal neurons. Cultures prepared from 8-day-old chick embryo retinas and incubated for 24 h (1 day in culture, C1) were treated or not with SNAP, incubated for a further 72 h (up to 4 days in culture, C4), fixed, and the number of cells estimated, or processed for cell death estimation, by measuring the reduction of the metabolic dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Experimental cultures were run in parallel but were re-fed with fresh medium in the absence or presence of SNAP at culture day 3 (C3), incubated for a further 24 h up to C4, then fixed or processed for the MTT assay. Previous studies showed that the re-feeding procedure promotes extensive cell death. SNAP prevented this death in a concentration- and time-dependent manner through the activation of soluble guanylate cyclase; this protection was significantly reversed by the enzyme inhibitors 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ) or LY83583, and mimicked by 8-bromo cyclic guanosine 5'-phosphate (8Br-cGMP) (GMP) or 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1), guanylate cyclase activators. The effect was blocked by the NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO). The effect of NO was also suppressed by LY294002, Wortmannin, PD98059, KN93 or H89, indicating the involvement, respectively, of phosphatidylinositol-3 kinase, extracellular-regulated kinases, calmodulin-dependent kinases and protein kinase A signaling pathways. NO also induced a significant increase of neurite outgrowth, indicative of neuronal differentiation, and blocked cell death induced by hydrogen peroxide. Cyclosporin A, an inhibitor of the mitochondrial permeability transition pore considered an important mediator of apoptosis and necrosis, as well as boc-aspartyl (OMe) fluoromethylketone (BAF), a caspase inhibitor, also blocked cell death induced by re-feeding the cultures. These findings demonstrate that NO inhibits apoptosis of retinal neurons in a cGMP/protein kinase G (PKG)-dependent way, and strengthens the notion that NO plays an important role during CNS development.
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Affiliation(s)
- T A Mejía-García
- Department of Neurobiology and Program of Neuroimmunology, Institute of Biology, Federal Fluminense University, Niterói, Brazil
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Donoso MV, Aedo F, Huidobro-Toro JP. The role of adenosine A2A and A3 receptors on the differential modulation of norepinephrine and neuropeptide Y release from peripheral sympathetic nerve terminals. J Neurochem 2006; 96:1680-95. [PMID: 16539684 DOI: 10.1111/j.1471-4159.2006.03671.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The pre-synaptic sympathetic modulator role of adenosine was assessed by studying transmitter release following electrical depolarization of nerve endings from the rat mesenteric artery. Mesentery perfusion with exogenous adenosine exclusively inhibited the release of norepinephrine (NA) but did not affect the overflow of neuropeptide Y (NPY), establishing the basis for a differential pre-synaptic modulator mechanism. Several adenosine structural analogs mimicked adenosine's effect on NA release and their relative order of potency was: 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxamidoadenosine hydrochloride = 1-[2-chloro-6-[[(3-iodophenyl)methyl]amino]-9H-purin-9-yl]-1-deoxy-N-methyl-beta-d-ribofuranuronamide = 5'-(N-ethylcarboxamido)adenosine >> adenosine > N(6)-cyclopentyladenosine. The use of selective receptor subtype antagonists confirmed the involvement of A(2A) and A(3) adenosine receptors. The modulator role of adenosine is probably due to the activation of both receptors; co-application of 1 nM 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxamidoadenosine hydrochloride plus 1 nM 1-[2-chloro-6-[[(3-iodophenyl)methyl]amino]-9H-purin-9-yl]-1-deoxy-N-methyl-beta-D-ribofuranuronamide caused additive reductions in NA released. Furthermore, while 1 nM of an A(2A) or A(3) receptor antagonist only partially reduced the inhibitory action of adenosine, the combined co-application of the two antagonists fully blocked the adenosine-induced inhibition. Only the simultaneous blockade of the adenosine A(2A) plus A(3) receptors with selective antagonists elicited a significant increase in NA overflow. H 89 reduced the release of both NA and NPY. We conclude that pre-synaptic A(2A) and A(3) adenosine receptor activation modulates sympathetic co-transmission by exclusively inhibiting the release of NA without affecting immunoreactive (ir)-NPY and we suggest separate mechanisms for vesicular release modulation.
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Affiliation(s)
- M Verónica Donoso
- Centro de Regulación Celular y Patología Prof J.V. Luco, Departamento de Fisiología, Unidad de Regulación Neurohumoral, P. Universidad Católica de Chile, Santiago, Chile
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Konno T, Sato A, Uchibori T, Nagai A, Kogi K, Nakahata N. Adenosine A2A receptor mediated protective effect of 2-(6-cyano-1-hexyn-1-yl)adenosine on retinal ischaemia/reperfusion damage in rats. Br J Ophthalmol 2006; 90:900-5. [PMID: 16613921 PMCID: PMC1857139 DOI: 10.1136/bjo.2006.091496] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
AIMS To determine the effect of 2-(6-cyano-1-hexyn-1-yl)adenosine (2-CN-Ado), an adenosine A2A receptor agonist, on retinal ischaemia/reperfusion damage in rats. METHODS Retinal ischaemia/reperfusion damage was induced by elevating the intraocular pressure of one eye to 130 mm Hg for 60 minutes and returning it to normal. 7 days later, retinal ischaemia/reperfusion damage was histologically quantified by measuring the thickness of retinal layers. Intraocular pressure was measured by pressure transducer. RESULTS Retinal ischaemia/reperfusion caused cell loss in the ganglion cell layer and thinning of the inner plexiform and nuclear layer. Both ocular topical and intravenous administration of 2-CN-Ado caused a reduction of retinal ischaemia/reperfusion damage. A selective A2A receptor antagonist, 1,3,7-trimethyl-8-(3-chlorostyryl) xanthine (CSC), but not a selective A1 receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), or a selective A2B receptor antagonist, alloxazine, reduced the protective effect of 2-CN-Ado. While ocular topical administration of 2-CN-Ado caused a sustained reduction of intraocular pressure, intravenous administration of 2-CN-Ado showed a transient ocular hypotensive effect. CONCLUSIONS These results suggest that 2-CN-Ado attenuates retinal ischaemia/reperfusion damage, and at least some of this protective effect of 2-CN-Ado might be mediated via activation of the adenosine A2A receptor.
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Affiliation(s)
- T Konno
- Drug Research Section II, Fukushima Research Laboratories, Toa Eiyo Ltd, Yuno, Iizaka, Fukushima 960-0280, Japan.
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Okonkwo DO, Reece TB, Laurent JJ, Hawkins AS, Ellman PI, Linden J, Kron IL, Tribble CG, Stone JR, Kern JA. A comparison of adenosine A2A agonism and methylprednisolone in attenuating neuronal damage and improving functional outcome after experimental traumatic spinal cord injury in rabbits. J Neurosurg Spine 2006; 4:64-70. [PMID: 16506468 DOI: 10.3171/spi.2006.4.1.64] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Steroid agents remain the lone pharmacological treatment in widespread use for acute spinal cord injury (SCI), although their utility remains in dispute in the neurotrauma literature. Adenosine A2A receptor activation with ATL-146e, a selective A2A agonist, has shown potential benefit in treating SCI; however, it has not been compared with the gold standard, methylprednisolone. The authors of this study evaluated ATL-146e and methylprednisolone for their ability to preserve neuronal viability and motor function in experimental SCI.
Methods
New Zealand White rabbits sustained SCI or sham injury via the Allen weight-drop technique. Ten minutes postinjury, animals received ATL-146e (ATL group, 0.06 μg/kg/min intravenously for 3 hours), methylprednisolone (steroid group, 30 mg/kg intravenously), or saline (trauma control group). Hindlimb motor function was recorded every 12 hours using the Tarlov motor grading scale (0, paralysis–5, normal hop). At 48 hours, fixed spinal cord tissue was evaluated for neuronal viability.
Hindlimb motor function in animals treated with ATL-146e was equivalent to that of sham-injured animals and was significantly better than that of trauma control animals at all time points and that of steroid-treated animals at 12 hours (p = 0.05). Motor function in steroid-treated animals was worse than in those given ATL-146e and better than that of trauma control animals at later time points, but was not statistically significant (both p > 0.05). Neuronal viability (measured in neurons/hpf) was significantly higher in both treatment groups compared with the trauma control group (12.1 ± 1.4 neurons/hpf for the ATL and 13.3 ± 1.4 neurons/hpf for the steroid group compared with 7.5 ± 1.5 neurons/hpf for the trauma control group; both p < 0.04). Neuronal viability did not differ among ATL-146e–treated, steroid-treated, and sham-injured groups.
Conclusions
The use of ATL-146e is at least as effective as methylprednisolone in preserving function and is equivalent to methylprednisolone in preserving the structure of spinal cord tissue after blunt SCI. Adenosine A2A receptor activation may be an effective treatment for acute SCI while avoiding the adverse effects of steroid agents.
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Affiliation(s)
- David O Okonkwo
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville 22908-0212, USA.
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Silveira MS, Linden R. Neuroprotection by cAMP: Another brick in the wall. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 557:164-76. [PMID: 16955710 DOI: 10.1007/0-387-30128-3_10] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Programmed cell death occurs in the nervous system both in normal development as well as in pathologic conditions, and is a key issue related to both brain repair and neurodegenerative diseases. Modulation of cell death in the nervous system may involve neurotrophic factors and other peptides, neurotransmitters and neuromodulators, that activate various signal transduction pathways, which in turn interact with the cell death execution machinery. Here we discuss the role of the second messenger cyclic adenosine 3'5'-monophosphate (cAMP) in cell death, and summarize current evidence that cAMP is a nodal point of neuroprotective signaling pathways.
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Affiliation(s)
- Mariana S Silveira
- Laboratório de Neurogênese, Instituto de Biofísca da UFRJ, Rio de Janeiro, Brazil
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Rebola N, Rodrigues RJ, Oliveira CR, Cunha RA. Different roles of adenosine A1, A2A and A3 receptors in controlling kainate-induced toxicity in cortical cultured neurons. Neurochem Int 2005; 47:317-25. [PMID: 16011860 DOI: 10.1016/j.neuint.2005.05.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2005] [Revised: 04/29/2005] [Accepted: 05/13/2005] [Indexed: 02/07/2023]
Abstract
Adenosine is a neuromodulator that can control brain damage through activation of A(1), A(2A) and A(3) receptors, which are located in both neurons and other brain cells. We took advantage of cultured neurons to investigate the role of neuronal adenosine receptors in the control of neurotoxicity caused by kainate and cyclothiazide. Both A(1), A(2A) and A(3) receptors were immunocytochemically identified in cortical neurons. Activation of A(1) receptors with 100 nM CPA did not modify the extent of neuronal death whereas the A(1) receptor antagonist, DPCPX (50 nM), attenuated neurotoxicity by 28 +/- 5%, and effect similar to that resulting from the removal of endogenous adenosine with 2U/ml of adenosine deaminase (27 +/- 3% attenuation of neurotoxicity). In the presence of adenosine deaminase, DPCPX had no further effect and CPA now exacerbated neurotoxicity by 42 +/- 4%. Activation of A(2A) receptor with 30 nM CGS21680 attenuated neurotoxicity by 40 +/- 8%, an effect prevented by the A(2A) receptor antagonists, SCH58261 (50 nM) or ZM241385 (50 nM), which by themselves were devoid of effect. Finally, neither A(3) receptor activation with Cl-IB-MECA (100-500 nM) nor blockade with MRS1191 (5 microM) modified neurotoxicity. These results show that A(1) receptor activation enhances and A(2A) receptor activation attenuates neurotoxicity in cultured cortical neurons, indicating that these two neuronal adenosine receptors directly control neurodegeneration. Interestingly, the control by adenosine of neurotoxicity in cultured neurons is similar to that observed in vivo in newborn animals and is the opposite of what is observed in adult brain preparations where A(1) receptor activation and A(2A) receptor blockade are neuroprotective.
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Affiliation(s)
- Nelson Rebola
- Center for Neurosciences of Coimbra, Institute of Biochemistry, Faculty of Medicine, University of Coimbra, Portugal
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Paes-de-Carvalho R, Dias BV, Martins RA, Pereira MR, Portugal CC, Lanfredi C. Activation of glutamate receptors promotes a calcium-dependent and transporter-mediated release of purines in cultured avian retinal cells: possible involvement of calcium/calmodulin-dependent protein kinase II. Neurochem Int 2005; 46:441-51. [PMID: 15769546 DOI: 10.1016/j.neuint.2004.12.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2004] [Revised: 11/19/2004] [Accepted: 12/22/2004] [Indexed: 10/25/2022]
Abstract
Calcium-dependent release of purines was previously demonstrated in cultures of chick retinal cells stimulated with high potassium concentrations but there is no evidence for an exocytotic mechanism of adenosine release from presynaptic terminals. Here we show that activation of NMDA or alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)/kainate glutamate ionotropic receptors promotes a two- to three-fold increase in the release of purines from these cultures. Approximately 96% of intracellular radioactivity is found as nucleotides after incubation with [(3)H]adenosine, but more than 85% of glutamate-stimulated released material is found as inosine (60%), hypoxanthine (19.9%) and adenosine (7.8%). The release is prevented by removal of extracellular calcium, by the transporter blocker nitrobenzylthioinosine, or inhibitors of calcium/calmodulin-dependent protein kinase II (CAMK II). The uptake of [(3)H]adenosine, but not of [(3)H]GABA or [(3)H]choline, is also blocked by 1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-l-tyrosyl]-4-phenylpiperazine (KN62), N-[2-(N-(4-chlorocinnamyl)-N-methylaminomethyl)phenyl-N-[2-hydroxiethyl]-4-methoxybenzenesulfonamide (KN93) or the myristoylated autocamtide-2-related inhibitory peptide, suggesting that the enzyme modulates the nucleoside transporter. The distribution of intracellular purines was not affected by KN62. These results indicate that activation of glutamate receptors triggers the release of purines from retinal cells by a mechanism involving calcium influx, CAMK II and the nitrobenzylthioinosine-sensitive nucleoside transporter. The regulation of adenosine release by glutamate receptors and CAMK II could have important consequences in the presynaptic control of glutamate release.
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Affiliation(s)
- Roberto Paes-de-Carvalho
- Program of Neuroimmunology and Department of Neurobiology, Institute of Biology, Federal Fluminense University, Caixa Postal 100180, Niterói, Rio de Janeiro 24001-970, Brazil.
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Cunha RA. Neuroprotection by adenosine in the brain: From A(1) receptor activation to A (2A) receptor blockade. Purinergic Signal 2005; 1:111-34. [PMID: 18404497 PMCID: PMC2096528 DOI: 10.1007/s11302-005-0649-1] [Citation(s) in RCA: 396] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2004] [Accepted: 11/10/2004] [Indexed: 12/11/2022] Open
Abstract
Adenosine is a neuromodulator that operates via the most abundant inhibitory adenosine A(1) receptors (A(1)Rs) and the less abundant, but widespread, facilitatory A(2A)Rs. It is commonly assumed that A(1)Rs play a key role in neuroprotection since they decrease glutamate release and hyperpolarize neurons. In fact, A(1)R activation at the onset of neuronal injury attenuates brain damage, whereas its blockade exacerbates damage in adult animals. However, there is a down-regulation of central A(1)Rs in chronic noxious situations. In contrast, A(2A)Rs are up-regulated in noxious brain conditions and their blockade confers robust brain neuroprotection in adult animals. The brain neuroprotective effect of A(2A)R antagonists is maintained in chronic noxious brain conditions without observable peripheral effects, thus justifying the interest of A(2A)R antagonists as novel protective agents in neurodegenerative diseases such as Parkinson's and Alzheimer's disease, ischemic brain damage and epilepsy. The greater interest of A(2A)R blockade compared to A(1)R activation does not mean that A(1)R activation is irrelevant for a neuroprotective strategy. In fact, it is proposed that coupling A(2A)R antagonists with strategies aimed at bursting the levels of extracellular adenosine (by inhibiting adenosine kinase) to activate A(1)Rs might constitute the more robust brain neuroprotective strategy based on the adenosine neuromodulatory system. This strategy should be useful in adult animals and especially in the elderly (where brain pathologies are prevalent) but is not valid for fetus or newborns where the impact of adenosine receptors on brain damage is different.
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Affiliation(s)
- Rodrigo A Cunha
- Center for Neuroscience of Coimbra, Institute of Biochemistry, Faculty of Medicine, University of Coimbra, Coimbra, Portugal,
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Konno T, Murakami A, Uchibori T, Nagai A, Kogi K, Nakahata N. Involvement of adenosine A2a receptor in intraocular pressure decrease induced by 2-(1-octyn-1-yl)adenosine or 2-(6-cyano-1-hexyn-1-yl)adenosine. J Pharmacol Sci 2005; 97:501-9. [PMID: 15821340 DOI: 10.1254/jphs.fp0040730] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The aim of the present study is to clarify the mechanism for the decrease in intraocular pressure by 2-alkynyladenosine derivatives in rabbits. The receptor binding analysis revealed that 2-(1-octyn-1-yl)adenosine (2-O-Ado) and 2-(6-cyano-1-hexyn-1-yl)adenosine (2-CN-Ado) selectively bound to the A(2a) receptor with a high affinity. Ocular hypotensive responses to 2-O-Ado and 2-CN-Ado were inhibited by the adenosine A(2a)-receptor antagonist 1,3,7-trimethyl-8-(3-chlorostyryl)xanthine (CSC), but not by the adenosine A(1)-receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) or the adenosine A(2b)-receptor antagonist alloxazine. In addition, 2-O-Ado and 2-CN-Ado caused an increase in outflow facility, which was inhibited by CSC, but not by DPCPX or alloxazine. Moreover, 2-O-Ado and 2-CN-Ado increased cAMP in the aqueous humor, and the 2-O-Ado-induced an increase in cAMP was inhibited by CSC. These results suggest that 2-O-Ado and 2-CN-Ado reduced intraocular pressure via an increase in outflow facility. The ocular hypotension may be mainly mediated through the activation of adenosine A(2a) receptor, although a possible involvement of adenosine A(1) receptor cannot be completely ruled out. 2-O-Ado and 2-CN-Ado are useful lead compounds for the treatment of glaucoma.
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Affiliation(s)
- Takashi Konno
- Drug Research Section II, Fukushima Research Laboratories, Toa Eiyo Ltd., Iizaka, Fukushima, Japan.
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Boeck CR, Kroth EH, Bronzatto MJ, Vendite D. Adenosine receptors co-operate with NMDA preconditioning to protect cerebellar granule cells against glutamate neurotoxicity. Neuropharmacology 2005; 49:17-24. [PMID: 15992577 DOI: 10.1016/j.neuropharm.2005.01.024] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2004] [Revised: 01/10/2005] [Accepted: 01/26/2005] [Indexed: 10/25/2022]
Abstract
N-Methyl-D-aspartate (NMDA) preconditioning is evoked by subtoxic concentrations of NMDA (50 microM), which has been shown previously to lead to transient resistance to subsequent lethal dose of glutamate or NMDA in cultured neurons. The purpose of this study was to investigate the participation of adenosine A1 and A2A receptors on NMDA preconditioning against glutamate-induced cellular damage in cerebellar granule cells. NMDA preconditioning prevented the stimulatory effect induced by glutamate on AMP hydrolysis, but not on ADP hydrolysis. The neuroprotection evoked by NMDA preconditioning against glutamate-induced cellular damage was prevented by the presence of adenosine A1 receptor antagonist, 8-cyclopentyl-1,3-dimethylxanthine (CPT, 100 nM), but not by the adenosine A2A receptors antagonist, (4-(2[7-amino-2-(2-furyl {1,2,4}-triazolo{2,3-a{1,3,5}triazian-5-yl-aminoethyl)phenol (ZM 241385, 50 nM). Interestingly, a long-term treatment with CPT or ZM 241385 alone protected cells against glutamate-induced neurotoxicity. Moreover, the functionality of adenosine A1 receptor was not affected by NMDA preconditioning, but this treatment promoted adenosine A2A receptor desensitization, measured by cAMP accumulation. Taken together, the results described herein suggest that the neuroprotection evoked by NMDA preconditioning against cellular damage elicited by glutamate occurs through mechanisms involving adenosine A2A receptors desensitization co-operating with adenosine A1 receptors activation in cerebellar granule cells.
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Affiliation(s)
- Carina R Boeck
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 (anexo), 90035-035, Porto Alegre, RS, Brazil
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Oku H, Goto W, Kobayashi T, Okuno T, Hirao M, Sugiyama T, Yoneda S, Hara H, Ikeda T. Adenosine protects cultured retinal neurons against NMDA-induced cell death through A1 receptors. Curr Eye Res 2005; 29:449-55. [PMID: 15764089 DOI: 10.1080/02713680490522443] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To determine whether adenosine can protect cultured retinal neurons, consisting mainly of amacrine cells, from N-methyl-D-aspartate (NMDA)-induced neurotoxicity, and to determine whether agonists and antagonists of adenosine receptors also have a protective effect. METHODS Cultured retinal neurons obtained from fetal Wistar rats (gestational age 18-19 days) were maintained for 10-11 days. Neurons were exposed to NMDA (1.0 mM) for 10 min with or without adenosine or to NMDA with adenosine receptor agonists or antagonists. Neuronal death was assessed by the trypan-blue exclusion method 24 hr after the exposure. RESULTS Adenosine at doses of 0.01 microM and higher significantly protected (p < 0.05, Dunnett) primary cultured fetal rat retinal neurons from apoptotic and/or necrotic death induced by NMDA (1.0 mM). The protective effect of adenosine (10 microM) against NMDA-induced neuronal death was lost by simultaneous exposure to selective A1 receptor antagonist but not to A2a receptor antagonist. Selective A1 receptor agonists had similar effects as adenosine, but A2a receptor agonists and 8-Br-cyclic AMP had no effect on cell viability. CONCLUSIONS Adenosine can protect cultured retinal neurons against NMDA-induced cell death via the A1 receptor.
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Affiliation(s)
- Hidehiro Oku
- Department of Ophthalmology, Osaka Medical, Osaka, Japan.
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Abstract
BACKGROUND AND PURPOSE Purinergic nucleoside inosine elicits protection and regeneration during various injuries. The purpose of this study was to examine the protective effects of inosine against cerebral ischemia. METHODS Adult Sprague-Dawley rats were anesthetized. Inosine, hypoxathine, or vehicle was administered intracerebroventricularly before transient right middle cerebral artery occlusion (MCAo). Animals were placed in behavioral chambers 2 days to 2 weeks after MCAo and then euthanized for tri-phenyl-tetrazolium chloride staining. Glutamate release was measured by microdialysis/high-performance liquid chromatography, and single-unit action potentials were recorded from neurons in the parietal cortex. RESULTS Stroke animals receiving inosine pretreatment demonstrated a higher level of locomotor activity and less cerebral infarction. Intracerebroventricular administration of the same dose of hypoxanthine did not confer protection. Coadministration of selective A3 receptor antagonist 3-ethyl-5-benzyl-2-methyl-4-phenylethynyl-6-phenyl-1, 4-(+/-)-dihydropyridine-3,5-dicarboxylate (MRS1191) significantly reduced inosine-mediated protection. Inosine did not alter basal glutamate release, nor did it reduce ischemia-evoked glutamate overflow from cerebral cortex. However, inosine antagonized glutamate-induced electrophysiological excitation in cerebral cortical neurons. CONCLUSIONS Inosine inhibits glutamate postsynaptic responses and reduces cerebral infarction. Its protective effect against ischemia/reperfusion-related insults may involve activation of adenosine A3 receptors.
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Affiliation(s)
- Hui Shen
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, Md, USA
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Linden R, Martins RAP, Silveira MS. Control of programmed cell death by neurotransmitters and neuropeptides in the developing mammalian retina. Prog Retin Eye Res 2004; 24:457-91. [PMID: 15845345 DOI: 10.1016/j.preteyeres.2004.10.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
It has long been known that a barrage of signals from neighboring and connecting cells, as well as components of the extracellular matrix, control cell survival. Given the extensive repertoire of retinal neurotransmitters, neuromodulators and neurotrophic factors, and the exhuberant interconnectivity of retinal interneurons, it is likely that various classes of released neuroactive substances may be involved in the control of sensitivity to retinal cell death. The aim of this article is to review evidence that neurotransmitters and neuropeptides control the sensitivity to programmed cell death in the developing retina. Whereas the best understood mechanism of execution of cell death is that of caspase-mediated apoptosis, current evidence shows that not only there are many parallel pathways to apoptotic cell death, but non-apoptotic programs of execution of cell death are also available, and may be triggered either in isolation or combined with apoptosis. The experimental data show that many upstream signaling pathways can modulate cell death, including those dependent on the second messengers cAMP-PKA, calcium and nitric oxide. Evidence for anterograde neurotrophic control is provided by a variety of models of the central nervous system, and the data reviewed here indicate that an early function of certain neurotransmitters, such as glutamate and dopamine, as well as neuropeptides such as pituitary adenylyl cyclase-activating polypeptide and vasoactive intestinal peptide is the trophic support of cell populations in the developing retina. This may have implications both regarding the mechanisms of retinal organogenesis, as well as pathological conditions leading to retinal dystrophies and to dysfunctional cellular behavior.
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Affiliation(s)
- Rafael Linden
- Centro de Ciencias da Saude, Instituto de Biofísica da UFRJ, Cidade Universitária, bloco G, Rio de Janeiro 21949-900, Brazil.
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Abstract
Adenosine is thought to participate in the regulation of intraocular pressure since adenosine and several adenosine derivatives increase and/or decrease intraocular pressure. This article reviews the involvement of adenosine receptors in the regulation of intraocular pressure and the possible application of relatively selective adenosine A(2)-receptor agonists, 2-alkynyladenosine derivatives (2-AAs), as novel drugs for treatment of glaucoma. We found that some 2-AAs decreased intraocular pressure in normotensive rabbits. Moreover, these 2-AAs are also effective in the ocular hypertensive models induced by water-loading and alpha-chymotrypsin. In addition, the ocular hypotension induced by 2-(1-octyn-1-yl) derivative was inhibited by an adenosine A(2)-receptor antagonist 3,7-dimethyl-1-propargylxanthine, but not by an adenosine A(1) receptor antagonist 8-cyclopentyl-1,3-dipropyl xanthine. Moreover, the outflow facility was increased by the 2-(1-octyn-1-yl) derivative. These findings suggest that 2-AAs may affect intraocular pressure via adenosine A(2)-receptor, and 2-AAs-induced ocular hypotension is due to the increase in outflow facility. Some 2-AAs may be novel drugs against ocular hypertension and/or glaucoma, although additional studies are required to characterize the effects of 2-AAs on regulation of intraocular pressure in detail.
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Affiliation(s)
- Takashi Konno
- Drug Research Section II, Fukushima Research Laboratories, TOA EIYO LTD., Iizaka, Fukushima, Japan.
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Watanabe S, Yoshimi Y, Ikekita M. Neuroprotective effect of adenine on purkinje cell survival in rat cerebellar primary cultures. J Neurosci Res 2004; 74:754-9. [PMID: 14635226 DOI: 10.1002/jnr.10790] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Although adenosine or ATP is known to control various physiological functions in the brain, including synaptic transmission, neuronal cell death, and neurite outgrowth via P1 or P2 purinergic receptors in the nervous system, little is known about the functions of many other purine derivatives. We examined the effects of various purines on survival in the cerebellar cortex of Purkinje cells with large cell bodies and highly branched dendrites, and it was found that some purine and pyrimidine derivatives influence Purkinje cell survival. Treatment with adenine, guanine, guanosine, guanine nucleotides, and uracil nucleotides protected Purkinje cells from cell death in the cerebellar primary cultures. Among the effective compounds, adenine had the most potent survival activities on Purkinje cells. Other adenine-based purines such as adenosine, AMP, ADP, and ATP did not promote Purkinje cell survival. Furthermore, metabolic inhibitors of adenine had no effect on the protective ability of adenine for Purkinje cells, suggesting that adenine itself, not adenine metabolites, maintains Purkinje cell survival. These results suggest that adenine is involved in the control of Purkinje cell survival in cerebellar primary cultures via a novel adenine-dependent mechanism.
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Affiliation(s)
- Shun Watanabe
- Department of Applied Biology, Faculty of Science and Technology, Tokyo University of Science, Chiba, Japan
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Paes-de-Carvalho R, Maia GA, Ferreira JM. Adenosine regulates the survival of avian retinal neurons and photoreceptors in culture. Neurochem Res 2003; 28:1583-90. [PMID: 14570404 DOI: 10.1023/a:1025686812298] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Adenosine modulates the survival of chick embryo retinal neurons in culture. When cultures were incubated for 3 days and refed with fresh medium, a large proportion of neurons died in the subsequent 3 days of culture. This cell death was prevented by preincubation of cultures for at least 24 h with adenosine plus the adenosine deaminase inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA), an adenosine uptake blocker nitrobenzylthioinosine (NBI), the adenosine A2A receptor agonist 2-[4-(2-carboxyethyl) phenethylamino]-5'-N-ethylcarboxamidoadenosine (CGS21680), or the permeant cyclic AMP analog 8-bromo cyclic AMP, but not the A1 receptor agonist cyclohexyladenosine (CHA). Adenosine deaminase induced cell death when added to culture medium, and this effect was prevented by EHNA. Cell death was not observed when the medium was replaced by a conditioned medium from sister cultures. The data strongly suggest that adenosine regulates the survival of developing retinal neurons by a long-term activation of A2A receptors and the increase of cyclic AMP levels.
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Affiliation(s)
- R Paes-de-Carvalho
- Department of Neurobiology and Program of Neuroimmunology, Institute of Biology, Federal Fluminense University, Niterói, RJ 24001-970, Brazil.
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Lewerenz J, Letz J, Methner A. Activation of stimulatory heterotrimeric G proteins increases glutathione and protects neuronal cells against oxidative stress. J Neurochem 2003; 87:522-31. [PMID: 14511129 DOI: 10.1046/j.1471-4159.2003.02019.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Oxidative glutamate toxicity in the neuronal cell line HT22 is a model for cell death by oxidative stress, where an excess of extracellular glutamate inhibits import of cystine, a building block of the antioxidant glutathione. The subsequent decrease in glutathione then leads to the accumulation of reactive oxygen species (ROS) and programmed cell death. We used pharmacological compounds known to interact with heterotrimeric G-protein signalling and studied their effects on cell survival, morphology, and intracellular events that ultimately lead to cell death. Cholera toxin and phorbol esters were most effective and prevented cell death through independent pathways. Treating HT22 cells with cholera toxin attenuated the glutamate-induced accumulation of ROS and calcium influx. This was, at least in part, caused by an increase in glutathione due to improved uptake of cystine mediated by the induction of the glutamate/cystine-antiporter subunit xCT or, additionally, by the up-regulation of the antiapoptotic protein Bcl-2. Gs activation also protected HT22 cells from hydrogen peroxide or inhibition of glutathione synthesis by buthionine sulfoximine, and immature cortical neurones from oxidative glutamate toxicity. Thus, this pathway might be more generally implicated in protection from neuronal death by oxidative stress.
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Affiliation(s)
- Jan Lewerenz
- Research Group Protective Signalling, Zentrum für Molekulare Neurobiologie and Department of Neurology, University Hospital Hamburg, Hamburg, Germany
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