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Tasca CI, Zuccarini M, Di Iorio P, Ciruela F. Lessons from the physiological role of guanosine in neurodegeneration and cancer: Toward a multimodal mechanism of action? Purinergic Signal 2024:10.1007/s11302-024-10033-y. [PMID: 39004650 DOI: 10.1007/s11302-024-10033-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 06/18/2024] [Indexed: 07/16/2024] Open
Abstract
Neurodegenerative diseases and brain tumours represent important health challenges due to their severe nature and debilitating consequences that require substantial medical care. Interestingly, these conditions share common physiological characteristics, namely increased glutamate, and adenosine transmission, which are often associated with cellular dysregulation and damage. Guanosine, an endogenous nucleoside, is safe and exerts neuroprotective effects in preclinical models of excitotoxicity, along with cytotoxic effects on tumour cells. However, the lack of well-defined mechanisms of action for guanosine hinders a comprehensive understanding of its physiological effects. In fact, the absence of specific receptors for guanosine impedes the development of structure-activity research programs to develop guanosine derivatives for therapeutic purposes. Alternatively, given its apparent interaction with the adenosinergic system, it is plausible that guanosine exerts its neuroprotective and anti-tumorigenic effects by modulating adenosine transmission through undisclosed mechanisms involving adenosine receptors, transporters, and purinergic metabolism. Here, several potential molecular mechanisms behind the protective actions of guanosine will be discussed. First, we explore its potential interaction with adenosine receptors (A1R and A2AR), including the A1R-A2AR heteromer. In addition, we consider the impact of guanosine on extracellular adenosine levels and the role of guanine-based purine-converting enzymes. Collectively, the diverse cellular functions of guanosine as neuroprotective and antiproliferative agent suggest a multimodal and complementary mechanism of action.
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Affiliation(s)
- Carla Inês Tasca
- Department of Biochemistry, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, SC, Brazil.
- Laboratory of Neurochemistry-4, Neuroscience Program/Biochemistry Program, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, SC, Brazil.
| | - Mariachiara Zuccarini
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, 66100, Chieti, Italy
- Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, 66100, Chieti, Italy
| | - Patrizia Di Iorio
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, 66100, Chieti, Italy
- Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, 66100, Chieti, Italy
| | - Francisco Ciruela
- Pharmacology Unit, Department of Pathology and Experimental Therapeutics, School of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, 08907 L'Hospitalet de Llobregat, Barcelona, Spain
- Neuropharmacology & Pain Group, Neuroscience Program, Bellvitge Institute for Biomedical Research, 08907L'Hospitalet de Llobregat, Bellvitge, Spain
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2
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Dos Santos B, Piermartiri T, Tasca CI. The impact of purine nucleosides on neuroplasticity in the adult brain. Purinergic Signal 2024:10.1007/s11302-024-09988-9. [PMID: 38367178 DOI: 10.1007/s11302-024-09988-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 01/23/2024] [Indexed: 02/19/2024] Open
Abstract
Neuroplasticity refers to the nervous system's ability to adapt and reorganize its cell structures and neuronal networks in response to internal and external stimuli. In adults, this process involves neurogenesis, synaptogenesis, and synaptic and neurochemical plasticity. Several studies have reported the significant impact of the purinergic system on neuroplasticity modulation. And, there is considerable evidence supporting the role of purine nucleosides, such as adenosine, inosine, and guanosine, in this process. This review presents extensive research on how these nucleosides enhance the neuroplasticity of the adult central nervous system, particularly in response to damage. The mechanisms through which these nucleosides exert their effects involve complex interactions with various receptors and signaling pathways. Adenosine's influence on neurogenesis involves interactions with adenosine receptors, specifically A1R and A2AR. A1R activation appears to inhibit neuronal differentiation and promote astrogliogenesis, while A2AR activation supports neurogenesis, neuritogenesis, and synaptic plasticity. Inosine and guanosine positively impact cell proliferation, neurogenesis, and neuritogenesis. Inosine seems to modulate extracellular adenosine levels, and guanosine might act through interactions between purinergic and glutamatergic systems. Additionally, the review discusses the potential therapeutic implications of purinergic signaling in neurodegenerative and neuropsychiatric diseases, emphasizing the importance of these nucleosides in the neuroplasticity of brain function and recovery.
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Affiliation(s)
- Beatriz Dos Santos
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil
- Programa de Pós-Graduação Em Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Tetsade Piermartiri
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
- Programa de Pós-Graduação Em Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
| | - Carla I Tasca
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
- Programa de Pós-Graduação Em Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
- Programa de Pós-Graduação Em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
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3
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Jia Q, Zeng H, Li M, Tang J, Xiao N, Gao S, Li H, Zhang J, Zhang Z, Xie W. Binding asymmetry and conformational studies of the AtGSDA dimer. Comput Struct Biotechnol J 2023; 21:5515-5522. [PMID: 38022696 PMCID: PMC10663702 DOI: 10.1016/j.csbj.2023.11.004] [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: 08/18/2023] [Revised: 11/01/2023] [Accepted: 11/01/2023] [Indexed: 12/01/2023] Open
Abstract
Guanosine deaminase (GSDA) is an important deaminase that converts guanosine to xanthosine, a key intermediate in nitrogen recycling in plants. We previously solved complex structures of Arabidopsis thaliana GSDA bound by various ligands and examined its catalytic mechanism. Here, we report cocrystal structures of AtGSDA bound by inactive guanosine derivatives, which bind relatively weakly to the enzyme and mostly have poor binding geometries. The two protomers display unequal binding performances, and molecular dynamics simulation identified diverse conformations during the enzyme-ligand interactions. Moreover, intersubunit, tripartite salt bridges show conformational differences between the two protomers, possibly acting as "gating" systems for substrate binding and product release. Our structural and biochemical studies provide a comprehensive understanding of the enzymatic behavior of this intriguing enzyme.
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Affiliation(s)
- Qian Jia
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Hui Zeng
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Mingwei Li
- Division of Life Sciences and Medicine, and Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, Anhui 230026, PR China
| | - Jing Tang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Nan Xiao
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Shangfang Gao
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Huanxi Li
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Jinbing Zhang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Zhiyong Zhang
- MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, PR China
| | - Wei Xie
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510006, People's Republic of China
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4
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Weese-Myers ME, Cryan MT, Witt CE, Caldwell KCN, Modi B, Ross AE. Dynamic and Rapid Detection of Guanosine during Ischemia. ACS Chem Neurosci 2023; 14:1646-1658. [PMID: 37040534 PMCID: PMC10265669 DOI: 10.1021/acschemneuro.3c00048] [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] [Indexed: 04/13/2023] Open
Abstract
Guanosine acts in both neuroprotective and neurosignaling pathways in the central nervous system; in this paper, we present the first fast voltammetric measurements of endogenous guanosine release during pre- and post-ischemic conditions. We discuss the metric of our measurements via analysis of event concentration, duration, and interevent time of rapid guanosine release. We observe changes across all three metrics from our normoxic to ischemic conditions. Pharmacological studies were performed to confirm that guanosine release is a calcium-dependent process and that the signaling observed is purinergic. Finally, we show the validity of our ischemic model via staining and fluorescent imaging. Overall, this paper sets the tone for rapid monitoring of guanosine and provides a platform to investigate the extent to which guanosine accumulates at the site of brain injury, i.e., ischemia.
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Affiliation(s)
- Moriah E. Weese-Myers
- University of Cincinnati, Department of Chemistry, 312 College Dr., 404 Crosley Tower, Cincinnati, OH 45221-0172
- Co-first author
| | - Michael T. Cryan
- University of Cincinnati, Department of Chemistry, 312 College Dr., 404 Crosley Tower, Cincinnati, OH 45221-0172
- Co-first author
| | - Colby E. Witt
- University of Cincinnati, Department of Chemistry, 312 College Dr., 404 Crosley Tower, Cincinnati, OH 45221-0172
| | - Kaejaren C. N. Caldwell
- University of Cincinnati, Department of Chemistry, 312 College Dr., 404 Crosley Tower, Cincinnati, OH 45221-0172
| | - Bindu Modi
- University of Cincinnati, Department of Chemistry, 312 College Dr., 404 Crosley Tower, Cincinnati, OH 45221-0172
| | - Ashley E. Ross
- University of Cincinnati, Department of Chemistry, 312 College Dr., 404 Crosley Tower, Cincinnati, OH 45221-0172
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5
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Zuccarini M, Pruccoli L, Balducci M, Giuliani P, Caciagli F, Ciccarelli R, Di Iorio P. Influence of Guanine-Based Purines on the Oxidoreductive Reactions Involved in Normal or Altered Brain Functions. J Clin Med 2023; 12:jcm12031172. [PMID: 36769818 PMCID: PMC9917437 DOI: 10.3390/jcm12031172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/23/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
The production of reactive oxygen species (ROS) in the brain is homeostatically controlled and contributes to normal neural functions. Inefficiency of control mechanisms in brain aging or pathological conditions leads to ROS overproduction with oxidative neural cell damage and degeneration. Among the compounds showing therapeutic potential against neuro-dysfunctions induced by oxidative stress are the guanine-based purines (GBPs), of which the most characterized are the nucleoside guanosine (GUO) and the nucleobase guanine (GUA), which act differently. Indeed, the administration of GUO to in vitro or in vivo models of acute brain injury (ischemia/hypoxia or trauma) or chronic neurological/neurodegenerative disorders, exerts neuroprotective and anti-inflammatory effects, decreasing the production of reactive radicals and improving mitochondrial function via multiple molecular signals. However, GUO administration to rodents also causes an amnesic effect. In contrast, the metabolite, GUA, could be effective in memory-related disorders by transiently increasing ROS production and stimulating the nitric oxide/soluble guanylate cyclase/cGMP/protein kinase G cascade, which has long been recognized as beneficial for cognitive function. Thus, it is worth pursuing further studies to ascertain the therapeutic role of GUO and GUA and to evaluate the pathological brain conditions in which these compounds could be more usefully used.
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Affiliation(s)
- Mariachiara Zuccarini
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Via dei Vestini 29, 66100 Chieti, Italy
- Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, Via L. Polacchi, 66100 Chieti, Italy
| | - Letizia Pruccoli
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, 47921 Rimini, Italy
| | - Martina Balducci
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, 47921 Rimini, Italy
| | - Patricia Giuliani
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Via dei Vestini 29, 66100 Chieti, Italy
- Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, Via L. Polacchi, 66100 Chieti, Italy
| | - Francesco Caciagli
- Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, Via L. Polacchi, 66100 Chieti, Italy
| | - Renata Ciccarelli
- Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, Via L. Polacchi, 66100 Chieti, Italy
| | - Patrizia Di Iorio
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Via dei Vestini 29, 66100 Chieti, Italy
- Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, Via L. Polacchi, 66100 Chieti, Italy
- Correspondence:
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6
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Chojnowski K, Opielka M, Nazar W, Kowianski P, Smolenski RT. Neuroprotective Effects of Guanosine in Ischemic Stroke-Small Steps towards Effective Therapy. Int J Mol Sci 2021; 22:6898. [PMID: 34199004 PMCID: PMC8268871 DOI: 10.3390/ijms22136898] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 12/12/2022] Open
Abstract
Guanosine (Guo) is a nucleotide metabolite that acts as a potent neuromodulator with neurotrophic and regenerative properties in neurological disorders. Under brain ischemia or trauma, Guo is released to the extracellular milieu and its concentration substantially raises. In vitro studies on brain tissue slices or cell lines subjected to ischemic conditions demonstrated that Guo counteracts destructive events that occur during ischemic conditions, e.g., glutaminergic excitotoxicity, reactive oxygen and nitrogen species production. Moreover, Guo mitigates neuroinflammation and regulates post-translational processing. Guo asserts its neuroprotective effects via interplay with adenosine receptors, potassium channels, and excitatory amino acid transporters. Subsequently, guanosine activates several prosurvival molecular pathways including PI3K/Akt (PI3K) and MEK/ERK. Due to systemic degradation, the half-life of exogenous Guo is relatively low, thus creating difficulty regarding adequate exogenous Guo distribution. Nevertheless, in vivo studies performed on ischemic stroke rodent models provide promising results presenting a sustained decrease in infarct volume, improved neurological outcome, decrease in proinflammatory events, and stimulation of neuroregeneration through the release of neurotrophic factors. In this comprehensive review, we discuss molecular signaling related to Guo protection against brain ischemia. We present recent advances, limitations, and prospects in exogenous guanosine therapy in the context of ischemic stroke.
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Affiliation(s)
- Karol Chojnowski
- Faculty of Medicine, Medical University of Gdańsk, Marii Skłodowskiej-Curie 3a, 80-210 Gdańsk, Poland; (K.C.); (W.N.)
| | - Mikolaj Opielka
- Department of Biochemistry, Medical University of Gdansk, 1 Debinki St., 80-211 Gdansk, Poland
- International Research Agenda 3P—Medicine Laboratory, Medical University of Gdańsk, 3A Sklodowskiej-Curie Street, 80-210 Gdansk, Poland
| | - Wojciech Nazar
- Faculty of Medicine, Medical University of Gdańsk, Marii Skłodowskiej-Curie 3a, 80-210 Gdańsk, Poland; (K.C.); (W.N.)
| | - Przemyslaw Kowianski
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Street, 80-211 Gdańsk, Poland;
- Institute of Health Sciences, Pomeranian University of Słupsk, Bohaterów Westerplatte 64, 76-200 Słupsk, Poland
| | - Ryszard T. Smolenski
- Department of Biochemistry, Medical University of Gdansk, 1 Debinki St., 80-211 Gdansk, Poland
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7
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Di Iorio P, Beggiato S, Ronci M, Nedel CB, Tasca CI, Zuccarini M. Unfolding New Roles for Guanine-Based Purines and Their Metabolizing Enzymes in Cancer and Aging Disorders. Front Pharmacol 2021; 12:653549. [PMID: 33935764 PMCID: PMC8085521 DOI: 10.3389/fphar.2021.653549] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/12/2021] [Indexed: 12/22/2022] Open
Affiliation(s)
- P Di Iorio
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Chieti, Italy.,Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, Chieti, Italy
| | - S Beggiato
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Chieti, Italy.,Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, Chieti, Italy
| | - M Ronci
- Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, Chieti, Italy.,Department of Pharmacy, University G. D'Annunzio Chieti, Chieti, Italy
| | - C B Nedel
- Laboratório de Biologia Celular de Gliomas, Programa de Pós-Graduação Em Biologia Celular e Do Desenvolvimento, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - C I Tasca
- Laboratório de Neuroquímica-4, Programa de Pós-Graduação Em Bioquímica, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - M Zuccarini
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Chieti, Italy.,Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, Chieti, Italy
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8
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Almeida RF, Ferreira TP, David CVC, Abreu E Silva PC, Dos Santos SA, Rodrigues ALS, Elisabetsky E. Guanine-Based Purines as an Innovative Target to Treat Major Depressive Disorder. Front Pharmacol 2021; 12:652130. [PMID: 33927625 PMCID: PMC8076783 DOI: 10.3389/fphar.2021.652130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 03/01/2021] [Indexed: 01/18/2023] Open
Affiliation(s)
- Roberto F Almeida
- Departamento de Ciências Biológicas, Programa de Pós-Graduação em Ciências Biológicas, Universidade Federal de Ouro Preto (UFOP), Ouro Preto, Brazil.,Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Tiago P Ferreira
- Departamento de Ciências Biológicas, Programa de Pós-Graduação em Ciências Biológicas, Universidade Federal de Ouro Preto (UFOP), Ouro Preto, Brazil
| | - Camila V C David
- Departamento de Ciências Biológicas, Programa de Pós-Graduação em Ciências Biológicas, Universidade Federal de Ouro Preto (UFOP), Ouro Preto, Brazil
| | - Paulo C Abreu E Silva
- Departamento de Ciências Biológicas, Programa de Pós-Graduação em Ciências Biológicas, Universidade Federal de Ouro Preto (UFOP), Ouro Preto, Brazil
| | - Sulamita A Dos Santos
- Departamento de Ciências Biológicas, Programa de Pós-Graduação em Ciências Biológicas, Universidade Federal de Ouro Preto (UFOP), Ouro Preto, Brazil
| | - Ana L S Rodrigues
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC), Florianópolis, Brazil
| | - Elaine Elisabetsky
- Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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9
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Tasca CI, Lanznaster D, Oliveira KA, Fernández-Dueñas V, Ciruela F. Neuromodulatory Effects of Guanine-Based Purines in Health and Disease. Front Cell Neurosci 2018; 12:376. [PMID: 30459558 PMCID: PMC6232889 DOI: 10.3389/fncel.2018.00376] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 10/02/2018] [Indexed: 12/18/2022] Open
Abstract
The function of guanine-based purines (GBPs) is mostly attributed to the intracellular modulation of heteromeric and monomeric G proteins. However, extracellular effects of guanine derivatives have also been recognized. Thus, in the central nervous system (CNS), a guanine-based purinergic system that exerts neuromodulator effects, has been postulated. The thesis that GBPs are neuromodulators emerged from in vivo and in vitro studies, in which neurotrophic and neuroprotective effects of these kinds of molecules (i.e., guanosine) were demonstrated. GBPs induce several important biological effects in rodent models and have been shown to reduce seizures and pain, stabilize mood disorder behavior and protect against gliomas and diseases related with aging, such as ischemia or Parkinson and Alzheimer diseases. In vitro studies to evaluate the protective and trophic effects of guanosine, and of the nitrogenous base guanine, have been fundamental for understanding the mechanisms of action of GBPs, as well as the signaling pathways involved in their biological roles. Conversely, although selective binding sites for guanosine have been identified in the rat brain, GBP receptors have not been still described. In addition, GBP neuromodulation may depend on the capacity of GBPs to interact with well-known membrane proteins in glutamatergic and adenosinergic systems. Overall, in this review article, we present up-to-date GBP biology, focusing mainly on the mechanisms of action that may lead to the neuromodulator role of GBPs observed in neurological disorders.
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Affiliation(s)
- Carla I Tasca
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil.,Programa de Pós-Graduação em Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Débora Lanznaster
- Programa de Pós-Graduação em Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil.,UMR 1253, Team 2, INSERM/University of Tours, Tours, France
| | - Karen A Oliveira
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil.,Programa de Pós-Graduação em Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Victor Fernández-Dueñas
- Unitat de Farmacologia, Departament de Patologia i Terapèutica Experimental, Facultat de Medicina, IDIBELL, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain.,Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Francisco Ciruela
- Unitat de Farmacologia, Departament de Patologia i Terapèutica Experimental, Facultat de Medicina, IDIBELL, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain.,Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
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10
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Lanznaster D, Dal-Cim T, Piermartiri TCB, Tasca CI. Guanosine: a Neuromodulator with Therapeutic Potential in Brain Disorders. Aging Dis 2016; 7:657-679. [PMID: 27699087 PMCID: PMC5036959 DOI: 10.14336/ad.2016.0208] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 02/08/2016] [Indexed: 12/20/2022] Open
Abstract
Guanosine is a purine nucleoside with important functions in cell metabolism and a protective role in response to degenerative diseases or injury. The past decade has seen major advances in identifying the modulatory role of extracellular action of guanosine in the central nervous system (CNS). Evidence from rodent and cell models show a number of neurotrophic and neuroprotective effects of guanosine preventing deleterious consequences of seizures, spinal cord injury, pain, mood disorders and aging-related diseases, such as ischemia, Parkinson’s and Alzheimer’s diseases. The present review describes the findings of in vivo and in vitro studies and offers an update of guanosine effects in the CNS. We address the protein targets for guanosine action and its interaction with glutamatergic and adenosinergic systems and with calcium-activated potassium channels. We also discuss the intracellular mechanisms modulated by guanosine preventing oxidative damage, mitochondrial dysfunction, inflammatory burden and modulation of glutamate transport. New and exciting avenues for future investigation into the protective effects of guanosine include characterization of a selective guanosine receptor. A better understanding of the neuromodulatory action of guanosine will allow the development of therapeutic approach to brain diseases.
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Affiliation(s)
- Débora Lanznaster
- 2Programa de Pós-graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina-UFSC, Campus Trindade, 88040-900, Florianópolis, SC, Brazil; 3CAPES Foundation, Ministry of Education of Brazil, Brasília - DF 70040-020, Brazil
| | - Tharine Dal-Cim
- 2Programa de Pós-graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina-UFSC, Campus Trindade, 88040-900, Florianópolis, SC, Brazil; 3CAPES Foundation, Ministry of Education of Brazil, Brasília - DF 70040-020, Brazil
| | - Tetsadê C B Piermartiri
- 2Programa de Pós-graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina-UFSC, Campus Trindade, 88040-900, Florianópolis, SC, Brazil; 3CAPES Foundation, Ministry of Education of Brazil, Brasília - DF 70040-020, Brazil
| | - Carla I Tasca
- 1Departamento de Bioquímica,; 2Programa de Pós-graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina-UFSC, Campus Trindade, 88040-900, Florianópolis, SC, Brazil
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Bettio LEB, Gil-Mohapel J, Rodrigues ALS. Guanosine and its role in neuropathologies. Purinergic Signal 2016; 12:411-26. [PMID: 27002712 PMCID: PMC5023624 DOI: 10.1007/s11302-016-9509-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/08/2016] [Indexed: 02/08/2023] Open
Abstract
Guanosine is a purine nucleoside thought to have neuroprotective properties. It is released in the brain under physiological conditions and even more during pathological events, reducing neuroinflammation, oxidative stress, and excitotoxicity, as well as exerting trophic effects in neuronal and glial cells. In agreement, guanosine was shown to be protective in several in vitro and/or in vivo experimental models of central nervous system (CNS) diseases including ischemic stroke, Alzheimer's disease, Parkinson's disease, spinal cord injury, nociception, and depression. The mechanisms underlying the neurobiological properties of guanosine seem to involve the activation of several intracellular signaling pathways and a close interaction with the adenosinergic system, with a consequent stimulation of neuroprotective and regenerative processes in the CNS. Within this context, the present review will provide an overview of the current literature on the effects of guanosine in the CNS. The elucidation of the complex signaling events underlying the biochemical and cellular effects of this nucleoside may further establish guanosine as a potential therapeutic target for the treatment of several neuropathologies.
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Affiliation(s)
- Luis E B Bettio
- Department of Biochemistry, Center of Biological Sciences, Federal University of Santa Catarina, 88040-900, Florianópolis, SC, Brazil
- Division of Medical Sciences and UBC Island Medical Program, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - Joana Gil-Mohapel
- Division of Medical Sciences and UBC Island Medical Program, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - Ana Lúcia S Rodrigues
- Department of Biochemistry, Center of Biological Sciences, Federal University of Santa Catarina, 88040-900, Florianópolis, SC, Brazil.
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12
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Di Liberto V, Mudò G, Garozzo R, Frinchi M, Fernandez-Dueñas V, Di Iorio P, Ciccarelli R, Caciagli F, Condorelli DF, Ciruela F, Belluardo N. The Guanine-Based Purinergic System: The Tale of An Orphan Neuromodulation. Front Pharmacol 2016; 7:158. [PMID: 27378923 PMCID: PMC4911385 DOI: 10.3389/fphar.2016.00158] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 05/30/2016] [Indexed: 11/17/2022] Open
Abstract
Guanine-based purines (GBPs) have been recently proposed to be not only metabolic agents but also extracellular signaling molecules that regulate important functions in the central nervous system. In such way, GBPs-mediated neuroprotection, behavioral responses and neuronal plasticity have been broadly described in the literature. However, while a number of these functions (i.e., GBPs neurothophic effects) have been well-established, the molecular mechanisms behind these GBPs-dependent effects are still unknown. Furthermore, no plasma membrane receptors for GBPs have been described so far, thus GBPs are still considered orphan neuromodulators. Interestingly, an intricate and controversial functional interplay between GBPs effects and adenosine receptors activity has been recently described, thus triggering the hypothesis that GBPs mechanism of action might somehow involve adenosine receptors. Here, we review recent data describing the GBPs role in the brain. We focus on the involvement of GBPs regulating neuronal plasticity, and on the new hypothesis based on putative GBPs receptors. Overall, we expect to shed some light on the GBPs world since although these molecules might represent excellent candidates for certain neurological diseases management, the lack of putative GBPs receptors precludes any high throughput screening intent for the search of effective GBPs-based drugs.
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Affiliation(s)
- Valentina Di Liberto
- Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo Palermo, Italy
| | - Giuseppa Mudò
- Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo Palermo, Italy
| | - Roberta Garozzo
- Department of Biomedical and Biotechnological Sciences, Unit of Medical Biochemistry, University of Catania Catania, Italy
| | - Monica Frinchi
- Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo Palermo, Italy
| | - Víctor Fernandez-Dueñas
- Department of Pathology and Experimental Therapeutics, Faculty of Medicine, Bellvitge Biomedical Research Institute, Institute of Neurosciences, University of Barcelona Barcelona, Spain
| | - Patrizia Di Iorio
- Department of Medical, Oral and Biotecnological Sciences, University of Chieti-Pescara Chieti, Italy
| | - Renata Ciccarelli
- Department of Medical, Oral and Biotecnological Sciences, University of Chieti-Pescara Chieti, Italy
| | - Francesco Caciagli
- Department of Medical, Oral and Biotecnological Sciences, University of Chieti-Pescara Chieti, Italy
| | - Daniele F Condorelli
- Department of Biomedical and Biotechnological Sciences, Unit of Medical Biochemistry, University of Catania Catania, Italy
| | - Francisco Ciruela
- Department of Pathology and Experimental Therapeutics, Faculty of Medicine, Bellvitge Biomedical Research Institute, Institute of Neurosciences, University of Barcelona Barcelona, Spain
| | - Natale Belluardo
- Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo Palermo, Italy
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Ortiz R, Ulrich H, Zarate CA, Machado-Vieira R. Purinergic system dysfunction in mood disorders: a key target for developing improved therapeutics. Prog Neuropsychopharmacol Biol Psychiatry 2015; 57:117-31. [PMID: 25445063 PMCID: PMC4262688 DOI: 10.1016/j.pnpbp.2014.10.016] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/20/2014] [Accepted: 10/28/2014] [Indexed: 02/09/2023]
Abstract
Uric acid and purines (such as adenosine) regulate mood, sleep, activity, appetite, cognition, memory, convulsive threshold, social interaction, drive, and impulsivity. A link between purinergic dysfunction and mood disorders was first proposed a century ago. Interestingly, a recent nationwide population-based study showed elevated risk of gout in subjects with bipolar disorder (BD), and a recent meta-analysis and systematic review of placebo-controlled trials of adjuvant purinergic modulators confirmed their benefits in bipolar mania. Uric acid may modulate energy and activity levels, with higher levels associated with higher energy and BD spectrum. Several recent genetic studies suggest that the purinergic system - particularly the modulation of P1 and P2 receptor subtypes - plays a role in mood disorders, lending credence to this model. Nucleotide concentrations can be measured using brain spectroscopy, and ligands for in vivo positron emission tomography (PET) imaging of adenosine (P1) receptors have been developed, thus allowing potential target engagement studies. This review discusses the key role of the purinergic system in the pathophysiology of mood disorders. Focusing on this promising therapeutic target may lead to the development of therapies with antidepressant, mood stabilization, and cognitive effects.
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Affiliation(s)
- Robin Ortiz
- Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, Division of Intramural Research Programs, National Institutes of Health, Bethesda, MD, USA.
| | - Henning Ulrich
- Departament of Biochemistry, University of Sao Paulo, Sao Paulo, Brazil.
| | - Carlos A Zarate
- Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, Division of Intramural Research Programs, National Institutes of Health, Bethesda, MD, USA.
| | - Rodrigo Machado-Vieira
- Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, Division of Intramural Research Programs, National Institutes of Health, Bethesda, MD, USA; Laboratory of Neuroscience, LIM27, University of Sao Paulo, Sao Paulo, Brazil.
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14
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Melkikh AV, Seleznev VD. Mechanisms and models of the active transport of ions and the transformation of energy in intracellular compartments. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2012; 109:33-57. [DOI: 10.1016/j.pbiomolbio.2012.04.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Revised: 04/23/2012] [Accepted: 04/25/2012] [Indexed: 11/26/2022]
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15
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Molz S, Dal-Cim T, Budni J, Martín-de-Saavedra MD, Egea J, Romero A, del Barrio L, Rodrigues ALS, López MG, Tasca CI. Neuroprotective effect of guanosine against glutamate-induced cell death in rat hippocampal slices is mediated by the phosphatidylinositol-3 kinase/Akt/ glycogen synthase kinase 3β pathway activation and inducible nitric oxide synthase inhibition. J Neurosci Res 2011; 89:1400-8. [PMID: 21671255 DOI: 10.1002/jnr.22681] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Revised: 03/25/2011] [Accepted: 04/01/2011] [Indexed: 01/13/2023]
Abstract
Excitotoxicity and cell death induced by glutamate are involved in many neurodegenerative disorders. We have previously demonstrated that excitotoxicity induced by millimolar concentrations of glutamate in hippocampal slices involves apoptotic features and glutamate-induced glutamate release. Guanosine, an endogenous guanine nucleoside, prevents excitotoxicity by its ability to modulate glutamate transport. In this study, we have evaluated the neuroprotective effect of guanosine against glutamate-induced toxicity in hippocampal slices and the mechanism involved in such an effect. We have found that guanosine (100 μM) was neuroprotective against 1 mM glutamate-induced cell death through the inhibition of glutamate release induced by glutamate. Guanosine also induced the phosphorylation and, thus, activation of protein kinase B (PKB/Akt), a downstream target of phosphatidylinositol-3 kinase (PI3K), as well as phosphorylation of glycogen synthase kinase 3β, which has been reported to be inactivated by Akt after phosphorylation at Ser9. Glutamate treated hippocampal slices showed increased inducible nitric oxide synthase (iNOS) expression that was prevented by guanosine. Slices preincubated with SNAP (an NO donor), inhibited the protective effect of guanosine. LY294002 (30 μM), a PI3K inhibitor, attenuated guanosine-induced neuroprotection, guanosine prevention of glutamate release, and guanosine-induced GSK3β(Ser9) phosphorylation but not guanosine reduction of glutamate-induced iNOS expression. Taken together, the results of this study show that guanosine protects hippocampal slices by a mechanism that involves the PI3K/Akt/GSK3β(Ser9) pathway and prevention of glutamate-induced glutamate release. Furthermore, guanosine also reduces glutamate-induced iNOS by a PI3K/Akt-independent mechanism.
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Affiliation(s)
- Simone Molz
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Trindade, Florianópolis, SC, Brasil. molz.s @hotmail.com
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16
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Rosemberg DB, Kist LW, Etchart RJ, Rico EP, Langoni AS, Dias RD, Bogo MR, Bonan CD, Souza DO. Evidence that acute taurine treatment alters extracellular AMP hydrolysis and adenosine deaminase activity in zebrafish brain membranes. Neurosci Lett 2010; 481:105-9. [PMID: 20600599 DOI: 10.1016/j.neulet.2010.06.062] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 04/30/2010] [Accepted: 06/21/2010] [Indexed: 12/20/2022]
Abstract
Taurine is one of the most abundant free amino acids in excitable tissues. In the brain, extracellular taurine may act as an inhibitory neurotransmitter, neuromodulator, and neuroprotector. Nucleotides are ubiquitous signaling molecules that play crucial roles for brain function. The inactivation of nucleotide-mediated signaling is controlled by ectonucleotidases, which include the nucleoside triphosphate diphosphohydrolase (NTPDase) family and ecto-5'-nucleotidase. These enzymes hydrolyze ATP/GTP to adenosine/guanosine, which exert a modulatory role controlling several neurotransmitter systems. The nucleoside adenosine can be inactivated in extracellular or intracellular milieu by adenosine deaminase (ADA). In this report, we tested whether acute taurine treatment at supra-physiological concentrations alters NTPDase, ecto-5'-nucleotidase, and ADA activities in zebrafish brain. Fish were treated with 42, 150, and 400 mg L(-1) taurine for 1h, the brains were dissected and the enzyme assays were performed. Although the NTPDase activities were not altered, 150 and 400 mg L(-1) taurine increased AMP hydrolysis (128 and 153%, respectively) in zebrafish brain membranes and significantly decreased ecto-ADA activity (29 and 38%, respectively). In vitro assays demonstrated that taurine did not change AMP hydrolysis, whereas it promoted a significant decrease in ecto-ADA activity at 150 and 400 mg L(-1) (24 and 26%, respectively). Altogether, our data provide the first evidence that taurine exposure modulates the ecto-enzymes responsible for controlling extracellular adenosine levels in zebrafish brain. These findings could be relevant to evaluate potential beneficial effects promoted by acute taurine treatment in the central nervous system (CNS) of this species.
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Affiliation(s)
- Denis Broock Rosemberg
- Programa de Pós-graduação em Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul., Rua Ramiro Barcelos 2600-Anexo, 90035-003 Porto Alegre, RS, Brazil.
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17
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Distribution of NTPDase5 and NTPDase6 and the regulation of P2Y receptor signalling in the rat cochlea. Purinergic Signal 2010; 6:249-61. [PMID: 20806016 DOI: 10.1007/s11302-010-9190-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 05/26/2010] [Indexed: 10/19/2022] Open
Abstract
Membrane-bound ectonucleoside triphosphate diphosphohydrolases (E-NTPDases) in the inner ear regulate complex extracellular purinergic type-2 (P2) receptor signalling pathways through hydrolysis of extracellular nucleoside 5'-triphosphates and diphosphates. This study investigated the distribution of NTPDase5 and NTPDase6, two intracellular members of the E-NTPDase family, and linked this to regulation of P2 receptor signalling in the adult rat cochlea. These extracellular ectonucleotidases preferentially hydrolyse nucleoside 5'-diphosphates such as UDP and GDP. Expression of both enzymes at mRNA and protein level was detected in cochlear tissues and there was in vivo release of soluble NTPDase5 and 6 into cochlear fluids. Strong NTPDase5 immunostaining was found in the spiral ganglion neurones and supporting Deiters' cells of the organ of Corti, while NTPDase6 was confined to the inner hair cells. Upregulation of NTPDase5 after exposure to loud sound indicates a dynamic role for NTPDase5 in cochlear response to stress, whereas NTPDase6 may have more limited extracellular roles. Noise-induced upregulation of co-localised UDP-preferring P2Y(6) receptors in the spiral ganglion neurons further supports the involvement of NTPDase5 in regulation of P2Y receptor signalling. Noise stress also induced P2Y(14) (UDP- and UDP-glucose preferring) receptor expression in the root processes of the outer sulcus cells, but this was not associated with localization of the E-NTPDases.
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18
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Lee JS, Cho WJ, Shin L, Jena BP. Involvement of cholesterol in synaptic vesicle swelling. Exp Biol Med (Maywood) 2010; 235:470-7. [PMID: 20407079 DOI: 10.1258/ebm.2010.009259] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Studies demonstrate that cholesterol plays a critical role in the regulation of neurotransmitter release and that secretory vesicle swelling is a requirement for the regulated expulsion of intravesicular contents during cell secretion. In view of this, the involvement of cholesterol in synaptic vesicle swelling was hypothesized and tested in the present study, using isolated synaptic vesicles from rat brain and the determination of their swelling competency in the presence and absence of cholesterol. The involvement of the water channel aquaporin-6 (AQP-6) and proton pump vH(+)-ATPase in GTP-G(alpha o)-mediated synaptic vesicle swelling has been reported previously. Mastoparan, the amphiphilic tetradecapeptide from wasp venom, known to activate the GTPase activity of G(alpha o/i) proteins, stimulates synaptic vesicle swelling in the presence of GTP. In the current study, using nanometer-scale precision measurements of isolated synaptic vesicles, we report for the first time that depletion of cholesterol from synaptic vesicle membrane results in a significant loss of GTP-mastoparan-stimulable synaptic vesicle swelling. In contrast, incorporation of cholesterol into the synaptic vesicle membrane potentiates GTP-mastoparan-stimulable vesicle swelling. Our study further demonstrates that this effect of cholesterol is due, in part, to its involvement in the interactions between AQP-6, vH(+)-ATPase and the GTP-binding G(alpha o) protein at the synaptic vesicle membrane.
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Affiliation(s)
- Jin-Sook Lee
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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19
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Subra C, Grand D, Laulagnier K, Stella A, Lambeau G, Paillasse M, De Medina P, Monsarrat B, Perret B, Silvente-Poirot S, Poirot M, Record M. Exosomes account for vesicle-mediated transcellular transport of activatable phospholipases and prostaglandins. J Lipid Res 2010; 51:2105-20. [PMID: 20424270 DOI: 10.1194/jlr.m003657] [Citation(s) in RCA: 469] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Exosomes are bioactive vesicles released from multivesicular bodies (MVB) by intact cells and participate in intercellular signaling. We investigated the presence of lipid-related proteins and bioactive lipids in RBL-2H3 exosomes. Besides a phospholipid scramblase and a fatty acid binding protein, the exosomes contained the whole set of phospholipases (A2, C, and D) together with interacting proteins such as aldolase A and Hsp 70. They also contained the phospholipase D (PLD) / phosphatidate phosphatase 1 (PAP1) pathway leading to the formation of diglycerides. RBL-2H3 exosomes also carried members of the three phospholipase A2 classes: the calcium-dependent cPLA(2)-IVA, the calcium-independent iPLA(2)-VIA, and the secreted sPLA(2)-IIA and V. Remarkably, almost all members of the Ras GTPase superfamily were present, and incubation of exosomes with GTPgammaS triggered activation of phospholipase A(2) (PLA(2))and PLD(2). A large panel of free fatty acids, including arachidonic acid (AA) and derivatives such as prostaglandin E(2) (PGE(2)) and 15-deoxy-Delta(12,14)-prostaglandinJ(2) (15-d PGJ(2)), were detected. We observed that the exosomes were internalized by resting and activated RBL cells and that they accumulated in an endosomal compartment. Endosomal concentrations were in the micromolar range for prostaglandins; i.e., concentrations able to trigger prostaglandin-dependent biological responses. Therefore exosomes are carriers of GTP-activatable phospholipases and lipid mediators from cell to cell.
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Affiliation(s)
- Caroline Subra
- Metabolism, Oncogenesis and Cell Differentiation Group, INSERM Research Center 563, Pathophysiology Center of Toulouse Purpan, Hôpital Purpan, Toulouse, France
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20
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Jena BP. Functional organization of the porosome complex and associated structures facilitating cellular secretion. Physiology (Bethesda) 2010; 24:367-76. [PMID: 19996367 DOI: 10.1152/physiol.00021.2009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Porosomes, the universal secretory machinery at the cell plasma membrane, are cup-shaped supramolecular lipoprotein structures, where membrane-bound vesicles transiently dock and fuse to release intravesicular contents during cell secretion. In this review, the discovery of the porosome and its structure, dynamics, composition, and functional reconstitution are outlined. Furthermore, the architecture of porosome-like structures such as the "canaliculi system" in human platelets and various associated structures such as the T-bars at the Drosophila synapse or the "beams," "ribs," and "pegs" at the frog neuromuscular junction, each organized to facilitate a certain specialized secretory activity, are briefly discussed.
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Affiliation(s)
- Bhanu P Jena
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, USA.
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21
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Shin L, Basi N, Jeremic A, Lee JS, Cho WJ, Chen Z, Abu-Hamdah R, Oupicky D, Jena BP. Involvement of vH(+)-ATPase in synaptic vesicle swelling. J Neurosci Res 2010; 88:95-101. [PMID: 19610106 DOI: 10.1002/jnr.22180] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Secretory vesicle swelling is central to cell secretion, but the underlying mechanism of vesicle swelling, particularly synaptic vesicles, is not completely understood. The G(alphai3)-PLA2-mediated involvement of water channel AQP-1 in the regulation of secretory vesicle swelling in exocrine pancreas and the G(alphao)-mediated AQP-6 involvement in synaptic vesicle swelling in neurons have previously been reported. Furthermore, the role of vH(+)-ATPase in neurotransmitter transport into synaptic vesicles has also been shown. Using nanometer-scale precision measurements of isolated synaptic vesicles, the present study reports for the first time the involvement of vH(+)-ATPase in GTP-G(alphao)-mediated synaptic vesicle swelling. Results from this study demonstrate that the GTP-G(alphao)-mediated vesicle swelling is vH(+)-ATPase dependent and pH sensitive. Zeta potential measurements of isolated synaptic vesicles further demonstrate a bafilomycin-sensitive vesicle acidification, following the GTP-G(alphao)-induced swelling stimulus. Water channels are bidirectional and the vH(+)-ATPase inhibitor bafilomycin decreases both the volume of isolated synaptic vesicles and GTP-mastoparan stimulated swelling, suggesting that vH(+)-ATPase is upstream of AQP-6, in the pathway leading from G(alphao)-stimulated swelling of synaptic vesicles. Vesicle acidification is therefore a prerequisite for AQP-6-mediated gating of water into synaptic vesicles.
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Affiliation(s)
- Leah Shin
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, USA
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22
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Guanosine-5'-monophosphate induces cell death in rat hippocampal slices via ionotropic glutamate receptors activation and glutamate uptake inhibition. Neurochem Int 2009; 55:703-9. [PMID: 19576258 DOI: 10.1016/j.neuint.2009.06.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 06/19/2009] [Accepted: 06/23/2009] [Indexed: 12/23/2022]
Abstract
Guanine derivatives modulate the glutamatergic system through displacement of binding of glutamate to its receptors acting as antagonist of glutamate receptors in moderate to high micromolar concentrations. Guanosine-5'-monophosphate (GMP) is shown to be neuroprotective against glutamate- or oxygen/glucose deprivation-induced neurotoxicity and also against NMDA-induced apoptosis in hippocampal slices. However, in this study we are showing that high extracellular GMP concentrations (5mM) reduced cell viability in hippocampal brain slices. The toxic effect of GMP was not blocked by dipyridamole, a nucleoside transport inhibitor, nor mimicked by guanosine, suggesting an extracellular mode of action to GMP which does not involve its hydrolysis to guanosine. GMP-dependent cell damage was not blocked by P1 purinergic receptor antagonists, neither altered by adenosine A(1) or A(2A) receptor agonists. The blockage of the ionotropic glutamate receptors AMPA or NMDA, but not KA or metabotropic glutamate receptors, reversed the toxicity induced by GMP. GMP (5mM) induced a decrease in glutamate uptake into hippocampal slices, which was reversed by dl-TBOA. Therefore, GMP-induced hippocampal cell damage involves activation of ionotropic glutamate receptors and inhibition of glutamate transporters activity.
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23
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Guarnieri S, Pilla R, Morabito C, Sacchetti S, Mancinelli R, Fanò G, Mariggiò MA. Extracellular guanosine and GTP promote expression of differentiation markers and induce S-phase cell-cycle arrest in human SH-SY5Y neuroblastoma cells. Int J Dev Neurosci 2008; 27:135-47. [PMID: 19111604 DOI: 10.1016/j.ijdevneu.2008.11.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Revised: 11/04/2008] [Accepted: 11/29/2008] [Indexed: 01/09/2023] Open
Abstract
SH-SY5Y neuroblastoma cells, a model for studying neuronal differentiation, are able to differentiate into either cholinergic or dopaminergic/adrenergic phenotypes depending on media conditions. Using this system, we asked whether guanosine (Guo) or guanosine-5'-triphosphate (GTP) are able to drive differentiation towards one particular phenotype. Differentiation was determined by evaluating the frequency of cells bearing neurites and assessing neurite length after exposure to different concentrations of Guo or GTP for different durations. After 6 days, 0.3 mM Guo or GTP induced a significant increase in the number of cells bearing neurites and increased neurite length. Western blot analyses confirmed that purines induced differentiation; cells exposed to purines showed increases in the levels of GAP43, MAP2, and tyrosine hydroxylase. Proliferation assays and cytofluorimetric analyses indicated a significant anti-proliferative effect of purines, and a concentration-dependent accumulation of cells in S-phase, starting after 24 h of purine exposure and extending for up to 6 days. A transcriptional profile analysis using gene arrays showed that an up-regulation of cyclin E2/cdk2 evident after 24 h was responsible for S-phase entry, and a concurrent down-regulation of cell-cycle progression-promoting cyclin B1/B2 prevented S-phase exit. In addition, patch-clamp recordings revealed that 0.3 mM Guo or GTP, after 6 day incubation, significantly decreased Na(+) currents. In conclusion, we showed Guo- and GTP-induced cell-cycle arrest in neuroblastoma cells and suggest that this makes these cells more responsive to differentiation processes that favor the dopaminergic/adrenergic phenotype.
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Affiliation(s)
- S Guarnieri
- Dipartamento Scienze Mediche di Base ed Applicate Università G. d'Annunzio, Chieti, Italy
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Molz S, Tharine DC, Decker H, Tasca CI. GMP prevents excitotoxicity mediated by NMDA receptor activation but not by reversal activity of glutamate transporters in rat hippocampal slices. Brain Res 2008; 1231:113-20. [PMID: 18655777 DOI: 10.1016/j.brainres.2008.07.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Revised: 07/02/2008] [Accepted: 07/02/2008] [Indexed: 01/11/2023]
Abstract
Glutamate is the main excitatory neurotransmitter in the mammalian nervous system and is essential for its normal functions. However, overstimulation of glutamatergic system due to hyperactivation of NMDA receptors and/or impairment of glutamate reuptake system has been implicated in many acute and chronic neurological diseases. Regulation of extracellular glutamate concentrations relies on the function of glutamate transporters which can be reversed in situations related to excitotoxicity. Guanosine-5'-monophosphate (GMP), a guanine nucleotide which displays important extracellular roles, such as trophic effects to neurons and astrocytes, behaves as antagonist of glutamate receptors and is neuroprotective in hippocampal slices against excitotoxicity or ischemic conditions. Hippocampal slices exposed to 1 or 10 mM glutamate, or 100 microM NMDA with 10 microM glycine for 1 h and evaluated after 6 or 18 h, showed reduced cell viability and DNA fragmentation, respectively. Glutamate- or NMDA-induced cell death was prevented by 50 microM MK-801, but only NMDA-induced cell damage was prevented by GMP (1 mM). Glutamate-induced cell viability impairment and glutamate-induced l-[(3)H]glutamate release were both prevented by adding DL-TBOA (10 microM). Otherwise, NMDA-induced cell viability loss was not prevented by 10 microM of DL-TBOA and NMDA did not induce l-[(3)H]glutamate release. Our results demonstrate that GMP is neuroprotective when acting selectively at NMDA receptors. Glutamate-induced hippocampal slice damage and glutamate release were blocked by glutamate transporter inhibitor, indicating that glutamate-induced toxicity also involves the reversal of glutamate uptake, which cannot be prevented by GMP.
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Affiliation(s)
- Simone Molz
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Trindade, Florianópolis, SC, Brazil
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Decker H, Francisco SS, Mendes-de-Aguiar CBN, Romão LF, Boeck CR, Trentin AG, Moura-Neto V, Tasca CI. Guanine derivatives modulate extracellular matrix proteins organization and improve neuron-astrocyte co-culture. J Neurosci Res 2007; 85:1943-51. [PMID: 17526012 DOI: 10.1002/jnr.21332] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Guanine derivatives (GD) have been shown to exert relevant extracellular effects as intercellular messengers, neuromodulators in the central nervous system, and trophic effects on astrocytes and neurons. Astrocytes have been pointed out as the major source of trophic factors in the nervous system, however, several trophic effects of astrocytic-released soluble factors are mediated through modulation of extracellular matrix (ECM) proteins. In this study, we investigated the effects of guanosine-5'-monophosphate (GMP) and guanosine (GUO) on the expression and organization of ECM proteins in cerebellar astrocytes. Moreover, to evaluate the effects of astrocytes pre-treated with GMP or GUO on cerebellar neurons we used a neuron-astrocyte coculture model. GMP or GUO alters laminin and fibronectin organization from a punctate to a fibrillar pattern, however, the expression levels of the ECM proteins were not altered. Guanine derivatives-induced alteration of ECM proteins organization is mediated by activation of mitogen activated protein kinases (MAPK), CA(2+)-calmodulin-dependent protein kinase II (CaMK-II), protein kinase C (PKC), and protein kinase A (PKA) pathways. Furthermore, astrocytes treated with GMP or GUO promoted an increased number of cerebellar neurons in coculture, without altering the neuritogenesis pattern. No proliferation of neurons or astrocytes was observed due to GMP or GUO treatment. Our results show that guanine derivatives promote a reorganization of the ECM proteins produced by astrocytes, which might be responsible for a better interaction with neurons in cocultures.
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Affiliation(s)
- Helena Decker
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Trindade, Florianópolis, SC, Brasil
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26
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ATP and acetylcholine, equal brethren. Neurochem Int 2007; 52:634-48. [PMID: 18029057 DOI: 10.1016/j.neuint.2007.09.004] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 09/07/2007] [Accepted: 09/10/2007] [Indexed: 12/13/2022]
Abstract
Acetylcholine was the first neurotransmitter identified and ATP is the hitherto final compound added to the list of small molecule neurotransmitters. Despite the wealth of evidence assigning a signaling role to extracellular ATP and other nucleotides in neural and non-neural tissues, the significance of this signaling pathway was accepted very reluctantly. In view of this, this short commentary contrasts the principal molecular and functional components of the cholinergic signaling pathway with those of ATP and other nucleotides. It highlights pathways of their discovery and analyses tissue distribution, synthesis, uptake, vesicular storage, receptors, release, extracellular hydrolysis as well as pathophysiological significance. There are differences but also striking similarities. Comparable to ACh, ATP is taken up and stored in synaptic vesicles, released in a Ca(2+)-dependent manner, acts on nearby ligand-gated or metabotropic receptors and is hydrolyzed extracellularly. ATP and acetylcholine are also costored and coreleased. In addition, ATP is coreleased from biogenic amine storing nerve terminals as well as from at least subpopulations of glutamatergic and GABAergic terminals. Both ACh and ATP fulfill the criteria postulated for neurotransmitters. More recent evidence reveals that the two messengers are not confined to neural functions, exerting a considerable variety of non-neural functions in non-innervated tissues. While it has long been known that a substantial number of pathologies originate from malfunctions of the cholinergic system there is now ample evidence that numerous pathological conditions have a purinergic component.
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Schmidt AP, Lara DR, Souza DO. Proposal of a guanine-based purinergic system in the mammalian central nervous system. Pharmacol Ther 2007; 116:401-16. [PMID: 17884172 DOI: 10.1016/j.pharmthera.2007.07.004] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Accepted: 07/30/2007] [Indexed: 01/06/2023]
Abstract
Guanine-based purines have been traditionally studied as modulators of intracellular processes, mainly G-protein activity. However, they also exert several extracellular effects not related to G proteins, including modulation of glutamatergic activity, trophic effects on neural cells, and behavioral effects. In this article, the putative roles of guanine-based purines on the nervous system are reviewed, and we propose a specific guanine-based purinergic system in addition to the well-characterized adenine-based purinergic system. Current evidence suggest that guanine-based purines modulate glutamatergic parameters, such as glutamate uptake by astrocytes and synaptic vesicles, seizures induced by glutamatergic agents, response to ischemia and excitotoxicity, and are able to affect learning, memory and anxiety. Additionally, guanine-based purines have important trophic functions affecting the development, structure, or maintenance of neural cells. Although studies addressing the mechanism of action (receptors and second messenger systems) of guanine-based purines are still insufficient, these findings point to the guanine-based purines (nucleotides and guanosine) as potential new targets for neuroprotection and neuromodulation.
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Affiliation(s)
- André P Schmidt
- Departamento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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28
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Montgomery K, Suzuki E, Kessler M, Arai AC. Factors affecting guanine nucleotide binding to rat AMPA receptors. Brain Res 2007; 1177:1-8. [PMID: 17884024 PMCID: PMC2078237 DOI: 10.1016/j.brainres.2007.08.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Revised: 07/03/2007] [Accepted: 08/09/2007] [Indexed: 11/24/2022]
Abstract
Glutamate receptors are competitively inhibited by guanine nucleotides. Insight into the physiological function of this inhibition would be greatly advanced if nucleotide binding could be eliminated through mutations without altering other aspects of receptor function, or if compounds were discovered that selectively prevent nucleotide binding. It was previously reported that a lysine in the chick kainate binding protein (cKBP) is specifically involved in guanine nucleotide binding. In the present study we mutated the equivalent lysine in the rat AMPA receptor subunit GluR1 flip to alanine (K445A) and assessed changes in nucleotide affinity from the displacement of [(3)H]fluorowillardiine. As in the cKBP, the affinity for nucleotides was greatly reduced while the binding affinity for agonists remained unchanged. The reduction in affinity was largest for GTP (factor of 5.8) and GDP (4.4) and minor for GMP and guanosine. This suggests that K445 is involved in stabilizing the second phosphate of the nucleotide. Given that bulkier analogs like GDP-fucose are also accommodated at this site, it seems likely that nucleotides bind in such a way that their phosphates project out of the cleft. In excised-patch recordings using short pulses of glutamate, the K445A mutation increased the EC(50) for the peak response 1.8-fold and accelerated desensitization and deactivation. This indicates that the effects of this mutation are not as specific as previously suggested. Efforts to selectively eliminate inhibition by nucleotides may therefore depend on mapping out further the docking site. In a first attempt using point mutations we ruled out several amino acids around the cleft as being involved in nucleotide binding. Also, the AMPA receptor modulator PPNDS which competitively inhibits nucleotide binding to purinergic receptors did not affect nucleotide inhibition, suggesting that there are major differences in the topography between purinergic and glutamate receptors. Thus new approaches, including crystallography, may be called for to identify residues uniquely involved in nucleotide binding.
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Affiliation(s)
- Kyle Montgomery
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL 62702, USA
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29
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Oleskovicz SPB, Martins WC, Leal RB, Tasca CI. Mechanism of guanosine-induced neuroprotection in rat hippocampal slices submitted to oxygen-glucose deprivation. Neurochem Int 2007; 52:411-8. [PMID: 17822807 DOI: 10.1016/j.neuint.2007.07.017] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 07/17/2007] [Accepted: 07/25/2007] [Indexed: 12/23/2022]
Abstract
Guanine derivates have been implicated in many relevant extracellular roles, such as modulation of glutamate transmission, protecting neurons against excitotoxic damage. Guanine derivatives are spontaneously released to the extracellular space from cultured astrocytes during oxygen-glucose deprivation (OGD) and may act as trophic factors, glutamate receptors blockers or glutamate transport modulators, thus promoting neuroprotection. The aim of this study was to evaluate the mechanisms involved in the neuroprotective role of the nucleoside guanosine in rat hippocampal slices submitted to OGD, identifying a putative extracellular binding site and the intracellular signaling pathways related to guanosine-induced neuroprotection. Cell damage to hippocampal slices submitted to 15 min of OGD followed by 2 h of reperfusion was decreased by the addition of guanosine (100 microM) or guanosine-5'-monophosphate (GMP, 100 microM). The neuroprotective effect of guanosine was not altered by the addition of adenosine receptor antagonists, nucleosides transport inhibitor, glutamate receptor antagonists, glutamate transport inhibitors, and a non-selective Na(+) and Ca(2+) channel blocker. However, in a Ca(2+)-free medium (by adding EGTA), guanosine was ineffective. Nifedipine (a Ca(2+) channel blocker) increased the neuroprotective effect of guanosine and 4-aminopyridine, a K(+) channel blocker, reversed the neuroprotective effect of guanosine. Evaluation of the intracellular signaling pathways associated with guanosine-induced neuroprotection showed the involvement of PKA, PKC, MEK and PI-3 K pathways, but not CaMKII. Therefore, this study shows guanosine is acting via K(+) channels activation, depending on extracellular Ca(2+) levels and via modulation of the PKA, PKC, MEK and/or PI-3 K pathways.
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Affiliation(s)
- Scheyla P B Oleskovicz
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Trindade, 88040-900 Florianópolis, SC, Brazil
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30
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Burré J, Zimmermann H, Volknandt W. Identification and characterization of SV31, a novel synaptic vesicle membrane protein and potential transporter. J Neurochem 2007; 103:276-87. [PMID: 17623043 DOI: 10.1111/j.1471-4159.2007.04758.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Synaptic vesicle proteins govern all relevant functions of the synaptic vesicle life cycle, including vesicle biogenesis, vesicle transport, uptake and storage of neurotransmitters, and regulated endocytosis and exocytosis. In spite of impressive progress made in the past years, not all known vesicular functions can be assigned to defined protein components, suggesting that the repertoire of synaptic vesicle proteins is still incomplete. We have identified and characterized a novel synaptic vesicle membrane protein of 31 kDa with six putative transmembrane helices that, according to its membrane topology and phylogenetic relation, may function as a vesicular transporter. The vesicular allocation is demonstrated by subcellular fractionation, heterologous expression, immunocytochemical analysis of brain sections and immunoelectron microscopy. The protein is expressed in select brain regions and contained in subpopulations of nerve terminals that immunostain for the vesicular glutamate transporter 1 and the vesicular GABA transporter VGaT (vesicular amino acid transporter) and may attribute specific and as yet undiscovered functions to subsets of glutamatergic and GABAergic synapses.
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Affiliation(s)
- Jacqueline Burré
- Department of Neurochemistry, Institute of Cell Biology and Neuroscience, Biocenter of JW Goethe University, Frankfurt/Main, Germany.
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31
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Melkikh AV, Seleznev VD. Models of active transport of neurotransmitters in synaptic vesicles. J Theor Biol 2007; 248:350-3. [PMID: 17583751 DOI: 10.1016/j.jtbi.2007.05.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 05/10/2007] [Accepted: 05/17/2007] [Indexed: 10/23/2022]
Abstract
Models of the active transport of neurotransmitters in synaptic vesicles were constructed. The models were used to determine the resting potential at membranes of synaptic vesicles: 40mV (monoamines and acetylcholine) and -40mV (glutamate). The potential at the membrane of a synaptic vesicle was almost absent for the transport of GABA and glycine. The neurotransmitter concentration of a cell was 0.1-18mM at the concentration of neurotransmitters in a vesicle equal to 0.5M. This result is in qualitative agreement with the relevant experimental data.
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Affiliation(s)
- Alexey V Melkikh
- Molecular Physics Chair, Ural State Technical University, 19 Mira Street, 620002 Yekaterinburg, Russia.
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