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Tao WB, Xiong J, Yuan BF. Site-specific quantification of Adenosine-to-Inosine RNA editing by Endonuclease-Mediated qPCR. Bioorg Med Chem 2024; 110:117837. [PMID: 39013280 DOI: 10.1016/j.bmc.2024.117837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 07/18/2024]
Abstract
RNA molecules contain diverse modified nucleobases that play pivotal roles in numerous biological processes. Adenosine-to-inosine (A-to-I) RNA editing, one of the most prevalent RNA modifications in mammalian cells, is linked to a multitude of human diseases. To unveil the functions of A-to-I RNA editing, accurate quantification of inosine at specific sites is essential. In this study, we developed an endonuclease-mediated cleavage and real-time fluorescence quantitative PCR method for A-to-I RNA editing (EM-qPCR) to quantitatively analyze A-to-I RNA editing at a single site. By employing this method, we successfully quantified the levels of A-to-I RNA editing on various transfer RNA (tRNA) molecules at position 34 (I34) in mammalian cells with precision. Subsequently, this method was applied to tissues from sleep-deprived mice, revealing a notable alteration in the levels of I34 between sleep-deprived and control mice. The proposed method sets a precedent for the quantitative analysis of A-to-I RNA editing at specific sites, facilitating a deeper understanding of the biological implications of A-to-I RNA editing.
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Affiliation(s)
- Wan-Bing Tao
- College of Chemistry and Molecular Sciences, Research Center of Public Health, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430060, PR China
| | - Jun Xiong
- College of Chemistry and Molecular Sciences, Research Center of Public Health, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430060, PR China; Department of Occupational and Environmental Health, School of Public Health, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, PR China
| | - Bi-Feng Yuan
- College of Chemistry and Molecular Sciences, Research Center of Public Health, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430060, PR China; Department of Occupational and Environmental Health, School of Public Health, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, PR China; Hubei Key Laboratory of Biomass Resource Chemistry and Environmental Biotechnology, Wuhan University, Wuhan 430072, PR China; Cancer Precision Diagnosis and Treatment and Translational Medicine Hubei Engineering Research Center, Zhongnan Hospital of Wuhan University, Wuhan Research Center for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan 430071, PR China.
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Juvenal G, Higa GSV, Bonfim Marques L, Tessari Zampieri T, Costa Viana FJ, Britto LR, Tang Y, Illes P, di Virgilio F, Ulrich H, de Pasquale R. Regulation of GABAergic neurotransmission by purinergic receptors in brain physiology and disease. Purinergic Signal 2024:10.1007/s11302-024-10034-x. [PMID: 39046648 DOI: 10.1007/s11302-024-10034-x] [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: 02/28/2024] [Accepted: 06/19/2024] [Indexed: 07/25/2024] Open
Abstract
Purinergic receptors regulate the processing of neural information in the hippocampus and cerebral cortex, structures related to cognitive functions. These receptors are activated when astrocytic and neuronal populations release adenosine triphosphate (ATP) in an autocrine and paracrine manner, following sustained patterns of neuronal activity. The modulation by these receptors of GABAergic transmission has only recently been studied. Through their ramifications, astrocytes and GABAergic interneurons reach large groups of excitatory pyramidal neurons. Their inhibitory effect establishes different synchronization patterns that determine gamma frequency rhythms, which characterize neural activities related to cognitive processes. During early life, GABAergic-mediated synchronization of excitatory signals directs the experience-driven maturation of cognitive development, and dysfunctions concerning this process have been associated with neurological and neuropsychiatric diseases. Purinergic receptors timely modulate GABAergic control over ongoing neural activity and deeply affect neural processing in the hippocampal and neocortical circuitry. Stimulation of A2 receptors increases GABA release from presynaptic terminals, leading to a considerable reduction in neuronal firing of pyramidal neurons. A1 receptors inhibit GABAergic activity but only act in the early postnatal period when GABA produces excitatory signals. P2X and P2Y receptors expressed in pyramidal neurons reduce the inhibitory tone by blocking GABAA receptors. Finally, P2Y receptor activation elicits depolarization of GABAergic neurons and increases GABA release, thus favoring the emergence of gamma oscillations. The present review provides an overall picture of purinergic influence on GABAergic transmission and its consequences on neural processing, extending the discussion to receptor subtypes and their involvement in the onset of brain disorders, including epilepsy and Alzheimer's disease.
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Affiliation(s)
- Guilherme Juvenal
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil
| | - Guilherme Shigueto Vilar Higa
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil
- Department of Biophysics and Physiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Lucas Bonfim Marques
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil
| | - Thais Tessari Zampieri
- Department of Biophysics and Physiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Felipe José Costa Viana
- Department of Biophysics and Physiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Luiz R Britto
- Department of Biophysics and Physiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Yong Tang
- International Joint Research Centre On Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China
| | - Peter Illes
- International Joint Research Centre On Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107, Leipzig, Germany
| | | | - Henning Ulrich
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil.
- International Joint Research Centre On Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China.
| | - Roberto de Pasquale
- Department of Biophysics and Physiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
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Abstract
The endogenous timekeeping system evolved to anticipate the time of the day through the 24 hours cycle of the Earth's rotation. In mammals, the circadian clock governs rhythmic physiological and behavioral processes, including the daily oscillation in glucose metabolism, food intake, energy expenditure, and whole-body insulin sensitivity. The results from a series of studies have demonstrated that environmental or genetic alterations of the circadian cycle in humans and rodents are strongly associated with metabolic diseases such as obesity and type 2 diabetes. Emerging evidence suggests that astrocyte clocks have a crucial role in regulating molecular, physiological, and behavioral circadian rhythms such as glucose metabolism and insulin sensitivity. Given the concurrent high prevalence of type 2 diabetes and circadian disruption, understanding the mechanisms underlying glucose homeostasis regulation by the circadian clock and its dysregulation may improve glycemic control. In this review, we summarize the current knowledge on the tight interconnection between the timekeeping system, glucose homeostasis, and insulin sensitivity. We focus specifically on the involvement of astrocyte clocks, at the organism, cellular, and molecular levels, in the regulation of glucose metabolism.
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Affiliation(s)
- Olga Barca-Mayo
- Circadian and Glial Biology Lab, Physiology Department, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Miguel López
- NeurObesity Lab, Physiology Department, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
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Astrocytes in the Ventrolateral Preoptic Area Promote Sleep. J Neurosci 2020; 40:8994-9011. [PMID: 33067363 DOI: 10.1523/jneurosci.1486-20.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 10/05/2020] [Accepted: 10/13/2020] [Indexed: 11/21/2022] Open
Abstract
Although ventrolateral preoptic (VLPO) nucleus is regarded as a center for sleep promotion, the exact mechanisms underlying the sleep regulation are unknown. Here, we used optogenetic tools to identify the key roles of VLPO astrocytes in sleep promotion. Optogenetic stimulation of VLPO astrocytes increased sleep duration in the active phase in naturally sleep-waking adult male rats (n = 6); it also increased the extracellular ATP concentration (n = 3) and c-Fos expression (n = 3-4) in neurons within the VLPO. In vivo microdialysis analyses revealed an increase in the activity of VLPO astrocytes and ATP levels during sleep states (n = 4). Moreover, metabolic inhibition of VLPO astrocytes reduced ATP levels (n = 4) and diminished sleep duration (n = 4). We further show that tissue-nonspecific alkaline phosphatase (TNAP), an ATP-degrading enzyme, plays a key role in mediating the somnogenic effects of ATP released from astrocytes (n = 5). An appropriate sample size for all experiments was based on statistical power calculations. Our results, taken together, indicate that astrocyte-derived ATP may be hydrolyzed into adenosine by TNAP, which may in turn act on VLPO neurons to promote sleep.SIGNIFICANCE STATEMENT Glia have recently been at the forefront of neuroscience research. Emerging evidence illustrates that astrocytes, the most abundant glial cell type, are the functional determinants for fates of neurons and other glial cells in the central nervous system. In this study, we newly identified the pivotal role of hypothalamic ventrolateral preoptic (VLPO) astrocytes in the sleep regulation, and provide novel insights into the mechanisms underlying the astrocyte-mediated sleep regulation.
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Contreras-Aguilar MD, Lamy E, Escribano D, Cerón JJ, Tecles F, Quiles AJ, Hevia ML. Changes in Salivary Analytes of Horses Due to Circadian Rhythm and Season: A Pilot Study. Animals (Basel) 2020; 10:ani10091486. [PMID: 32846911 PMCID: PMC7552333 DOI: 10.3390/ani10091486] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/19/2020] [Accepted: 08/22/2020] [Indexed: 12/12/2022] Open
Abstract
Simple Summary The use of salivary biomarkers is gaining interest in the veterinary field, since saliva is usually easy to obtain and its collection from animals causes less stress than blood sampling. However, our knowledge of the possible factors related to daily and seasonal variations in salivary biomarkers is still in its infancy. In our study, the possible circadian or circannual variations in a panel of salivary biomarkers in horse saliva were evaluated. The results showed that daily and/or seasonal variations can be observed in cortisol, salivary alpha-amylase, total esterase, butyrylcholinesterase, adenosine deaminase, and creatine kinase. Therefore, these factors should be considered for the interpretation of these analytes when measured in horse saliva. Abstract This study aims to evaluate the circadian and circannual variations in a panel of analytes in horse saliva that have been previously described as biomarkers related to stress and disease, in order to interpret them correctly when they are measured in this species. This panel of analytes integrated cortisol, salivary alpha-amylase (sAA), lipase (Lip), total esterase (TEA), butyrylcholinesterase (BChE), adenosine deaminase (ADA), γ-glutamyl transferase (gGT), creatine kinase (CK), urea, total bilirubin, total protein (TP), and phosphorus. These analytes were measured in saliva obtained from a population of five clinically healthy mares from 06:30 to 20:30, every 2 h over two consecutive days in two different photoperiod seasons, winter and spring. The temperature and relative humidity did not change between the two consecutive days sampled in each sampled season, and no thermal discomfort was observed. Changes throughout the course of the day were observed for cortisol, sAA, TEA, BChE, ADA, and CK. However, a circadian pattern was only observed for cortisol, TEA, BChE, ADA, and CK. Moreover, the values obtained for sAA, Lip, and BChE were significantly different between seasons, with different daily rhythms for cortisol, TEA, BChE, and ADA depending on the season. In conclusion, this pilot study indicates that the time of the day and the season influence salivary analytes in horses, showing a rhythmic pattern for cortisol, TEA, BChE, ADA, and CK. These factors should thus be taken into consideration for the interpretation of analytes in horse saliva.
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Affiliation(s)
- María D. Contreras-Aguilar
- Interdisciplinary Laboratory of Clinical Analysis of the University of Murcia (Interlab-UMU), Veterinary School, Campus Mare Nostrum, University of Murcia, 30100 Murcia, Spain; (M.D.C.-A.); (D.E.); (J.J.C.); (F.T.)
| | - Elsa Lamy
- Mediterranean Institute for Agriculture, Environment and Development, University of Évora, Núcleo da Mitra, Apartado 94, 7006-554 Évora, Portugal
- Correspondence:
| | - Damián Escribano
- Interdisciplinary Laboratory of Clinical Analysis of the University of Murcia (Interlab-UMU), Veterinary School, Campus Mare Nostrum, University of Murcia, 30100 Murcia, Spain; (M.D.C.-A.); (D.E.); (J.J.C.); (F.T.)
- Department of Animal Production, Veterinary School, Campus Mare Nostrum, University of Murcia, 30100 Murcia, Spain; (A.J.Q.); (M.L.H.)
| | - Jose J. Cerón
- Interdisciplinary Laboratory of Clinical Analysis of the University of Murcia (Interlab-UMU), Veterinary School, Campus Mare Nostrum, University of Murcia, 30100 Murcia, Spain; (M.D.C.-A.); (D.E.); (J.J.C.); (F.T.)
| | - Fernando Tecles
- Interdisciplinary Laboratory of Clinical Analysis of the University of Murcia (Interlab-UMU), Veterinary School, Campus Mare Nostrum, University of Murcia, 30100 Murcia, Spain; (M.D.C.-A.); (D.E.); (J.J.C.); (F.T.)
| | - Alberto J. Quiles
- Department of Animal Production, Veterinary School, Campus Mare Nostrum, University of Murcia, 30100 Murcia, Spain; (A.J.Q.); (M.L.H.)
| | - María L. Hevia
- Department of Animal Production, Veterinary School, Campus Mare Nostrum, University of Murcia, 30100 Murcia, Spain; (A.J.Q.); (M.L.H.)
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Exercise-Induced Adaptations to the Mouse Striatal Adenosine System. Neural Plast 2020; 2020:5859098. [PMID: 32399024 PMCID: PMC7204111 DOI: 10.1155/2020/5859098] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 12/18/2019] [Accepted: 12/27/2019] [Indexed: 12/13/2022] Open
Abstract
Adenosine acts as a key regulator of striatum activity, in part, through the antagonistic modulation of dopamine activity. Exercise can increase adenosine activity in the brain, which may impair dopaminergic functions in the striatum. Therefore, long-term repeated bouts of exercise may subsequently generate plasticity in striatal adenosine systems in a manner that promotes dopaminergic activity. This study investigated the effects of long-term voluntary wheel running on adenosine 1 (A1R), adenosine 2A (A2AR), dopamine 1 (D1R), and dopamine 2 (D2R) receptor protein expression in adult mouse dorsal and ventral striatum structures using immunohistochemistry. In addition, equilibrative nucleoside transporter 1 (ENT1) protein expression was examined after wheel running, as ENT1 regulates the bidirectional flux of adenosine between intra- and extracellular space. The results suggest that eight weeks of running wheel access spared age-related increases of A1R and A2AR protein concentrations across the dorsal and ventral striatal structures. Wheel running mildly reduced ENT1 protein levels in ventral striatum subregions. Moreover, wheel running mildly increased D2R protein density within striatal subregions in the dorsal medial striatum, nucleus accumbens core, and the nucleus accumbens shell. However, D1R protein expression in the striatum was unchanged by wheel running. These data suggest that exercise promotes adaptations to striatal adenosine systems. Exercise-reduced A1R and A2AR and exercise-increased D2R protein levels may contribute to improved dopaminergic signaling in the striatum. These findings may have implications for cognitive and behavioral processes, as well as motor and psychiatric diseases that involve the striatum.
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Chen J, Chaurio RA, Maueröder C, Derer A, Rauh M, Kost A, Liu Y, Mo X, Hueber A, Bilyy R, Herrmann M, Zhao Y, Muñoz LE. Inosine Released from Dying or Dead Cells Stimulates Cell Proliferation via Adenosine Receptors. Front Immunol 2017; 8:504. [PMID: 28496447 PMCID: PMC5406388 DOI: 10.3389/fimmu.2017.00504] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/12/2017] [Indexed: 02/05/2023] Open
Abstract
Introduction Many antitumor therapies induce apoptotic cell death in order to cause tumor regression. Paradoxically, apoptotic cells are also known to promote wound healing, cell proliferation, and tumor cell repopulation in multicellular organisms. We aimed to characterize the nature of the regenerative signals concentrated in the micromilieu of dead and dying cells. Methods Cultures of viable melanoma B16F10 cells, mouse fibroblasts, and primary human fibroblast-like synoviocytes (FLS) in the presence of dead and dying cells, their supernatants (SNs), or purified agonists and antagonists were used to evaluate the stimulation of proliferation. Viable cell quantification was performed by either flow cytometry of harvested cells or by crystal violet staining of adherent cells. High-performance liquid chromatography and liquid chromatography coupled with mass spectrometry of cell SNs were deployed to identify the nature of growth-promoting factors. Coimplantation of living cells in the presence of SNs collected from dead and dying cells and specific agonists was used to evaluate tumor growth in vivo. Results The stimulation of proliferation of few surviving cells by bystander dead cells was confirmed for melanoma cells, mouse fibroblasts, and primary FLS. We found that small soluble molecules present in the protein-free fraction of SNs of dead and dying cells were responsible for the promotion of proliferation. The nucleoside inosine released by dead and dying cells acting via adenosine receptors was identified as putative inducer of proliferation of surviving tumor cells after irradiation and heat treatment. Conclusion Inosine released by dead and dying cells mediates tumor cell proliferation via purinergic receptors. Therapeutic strategies surmounting this pathway may help to reduce the rate of recurrence after radio- and chemotherapy.
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Affiliation(s)
- Jin Chen
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, China.,Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Universitätsklinikum Erlangen, Erlangen, Germany
| | - Ricardo A Chaurio
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Universitätsklinikum Erlangen, Erlangen, Germany
| | - Christian Maueröder
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Universitätsklinikum Erlangen, Erlangen, Germany
| | - Anja Derer
- Department of Radiation Oncology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Universitätsklinikum Erlangen, Erlangen, Germany
| | - Manfred Rauh
- Kinder- und Jugendklinik, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Andriy Kost
- Danylo Halytsky Lviv National Medical University, Lviv, Ukraine
| | - Yi Liu
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, China
| | - Xianming Mo
- Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Axel Hueber
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Universitätsklinikum Erlangen, Erlangen, Germany
| | - Rostyslav Bilyy
- Danylo Halytsky Lviv National Medical University, Lviv, Ukraine
| | - Martin Herrmann
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Universitätsklinikum Erlangen, Erlangen, Germany
| | - Yi Zhao
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, China
| | - Luis E Muñoz
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Universitätsklinikum Erlangen, Erlangen, Germany
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The Role of Adenosine Signaling in Headache: A Review. Brain Sci 2017; 7:brainsci7030030. [PMID: 28335379 PMCID: PMC5366829 DOI: 10.3390/brainsci7030030] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 03/05/2017] [Accepted: 03/07/2017] [Indexed: 12/18/2022] Open
Abstract
Migraine is the third most prevalent disease on the planet, yet our understanding of its mechanisms and pathophysiology is surprisingly incomplete. Recent studies have built upon decades of evidence that adenosine, a purine nucleoside that can act as a neuromodulator, is involved in pain transmission and sensitization. Clinical evidence and rodent studies have suggested that adenosine signaling also plays a critical role in migraine headache. This is further supported by the widespread use of caffeine, an adenosine receptor antagonist, in several headache treatments. In this review, we highlight evidence that supports the involvement of adenosine signaling in different forms of headache, headache triggers, and basic headache physiology. This evidence supports adenosine A2A receptors as a critical adenosine receptor subtype involved in headache pain. Adenosine A2A receptor signaling may contribute to headache via the modulation of intracellular Cyclic adenosine monophosphate (cAMP) production or 5' AMP-activated protein kinase (AMPK) activity in neurons and glia to affect glutamatergic synaptic transmission within the brainstem. This evidence supports the further study of adenosine signaling in headache and potentially illuminates it as a novel therapeutic target for migraine.
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Sleep-Wake Regulation and Its Impact on Working Memory Performance: The Role of Adenosine. BIOLOGY 2016; 5:biology5010011. [PMID: 26861410 PMCID: PMC4810168 DOI: 10.3390/biology5010011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Revised: 01/15/2016] [Accepted: 01/19/2016] [Indexed: 11/28/2022]
Abstract
The sleep-wake cycle is regulated by a fine-tuned interplay between sleep-homeostatic and circadian mechanisms. Compelling evidence suggests that adenosine plays an important role in mediating the increase of homeostatic sleep pressure during time spent awake and its decrease during sleep. Here, we summarize evidence that adenosinergic mechanisms regulate not only the dynamic of sleep pressure, but are also implicated in the interaction of homeostatic and circadian processes. We review how this interaction becomes evident at several levels, including electrophysiological data, neuroimaging studies and behavioral observations. Regarding complex human behavior, we particularly focus on sleep-wake regulatory influences on working memory performance and underlying brain activity, with a specific emphasis on the role of adenosine in this interplay. We conclude that a change in adenosinergic mechanisms, whether exogenous or endogenous, does not only impact on sleep-homeostatic processes, but also interferes with the circadian timing system.
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Cui SY, Li SJ, Cui XY, Zhang XQ, Yu B, Sheng ZF, Huang YL, Cao Q, Xu YP, Lin ZG, Yang G, Song JZ, Ding H, Wang ZJ, Zhang YH. Phosphorylation of CaMKII in the rat dorsal raphe nucleus plays an important role in sleep-wake regulation. J Neurochem 2015; 136:609-19. [PMID: 26558357 DOI: 10.1111/jnc.13431] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Revised: 10/28/2015] [Accepted: 11/02/2015] [Indexed: 12/19/2022]
Abstract
The Ca(2+) modulation in the dorsal raphe nucleus (DRN) plays an important role in sleep-wake regulation. Calmodulin-dependent kinase II (CaMKII) is an important signal-transducing molecule that is activated by Ca(2+) . This study investigated the effects of intracellular Ca(2+) /CaMKII signaling in the DRN on sleep-wake states in rats. Maximum and minimum CaMKII phosphorylation was detected at Zeitgeber time 21 (ZT 21; wakefulness state) and ZT 3 (sleep state), respectively, across the light-dark rhythm in the DRN in rats. Six-hour sleep deprivation significantly reduced CaMKII phosphorylation in the DRN. Microinjection of the CAMKII activation inhibitor KN-93 (5 or 10 nmol) into the DRN suppressed wakefulness and enhanced rapid-eye-movement sleep (REMS) and non-REM sleep (NREMS). Application of a high dose of KN-93 (10 nmol) increased slow-wave sleep (SWS) time, SWS bouts, the mean duration of SWS, the percentage of SWS relative to total sleep, and delta power density during NREMS. Microinjection of CaCl2 (50 nmol) in the DRN increased CaMKII phosphorylation and decreased NREMS, SWS, and REMS. KN-93 abolished the inhibitory effects of CaCl2 on NREMS, SWS, and REMS. These data indicate a novel wake-promoting and sleep-suppressing role for the Ca(2+) /CaMKII signaling pathway in DRN neurons. We propose that the intracellular Ca(2+) /CaMKII signaling in the dorsal raphe nucleus (DRN) plays wake-promoting and sleep-suppressing role in rats. Intra-DRN application of KN-93 (CaMKII activation inhibitor) suppressed wakefulness and enhanced rapid-eye-movement sleep (REMS) and non-REMS (NREMS). Intra-DRN application of CaCl2 attenuated REMS and NREMS. We think these findings should provide a novel cellular and molecular mechanism of sleep-wake regulation.
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Affiliation(s)
- Su-Ying Cui
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Sheng-Jie Li
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Xiang-Yu Cui
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Xue-Qiong Zhang
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Bin Yu
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Zhao-Fu Sheng
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Yuan-Li Huang
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Qing Cao
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Ya-Ping Xu
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Zhi-Ge Lin
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Guang Yang
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Jin-Zhi Song
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Hui Ding
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Zi-Jun Wang
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
| | - Yong-He Zhang
- Department of pharmacology, Peking University, School of Basic Medical Science, Beijing, China
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Boison D, Aronica E. Comorbidities in Neurology: Is adenosine the common link? Neuropharmacology 2015; 97:18-34. [PMID: 25979489 PMCID: PMC4537378 DOI: 10.1016/j.neuropharm.2015.04.031] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 04/24/2015] [Accepted: 04/27/2015] [Indexed: 12/13/2022]
Abstract
Comorbidities in Neurology represent a major conceptual and therapeutic challenge. For example, temporal lobe epilepsy (TLE) is a syndrome comprised of epileptic seizures and comorbid symptoms including memory and psychiatric impairment, depression, and sleep dysfunction. Similarly, Alzheimer's disease (AD), Parkinson's disease (PD), and Amyotrophic Lateral Sclerosis (ALS) are accompanied by various degrees of memory dysfunction. Patients with AD have an increased likelihood for seizures, whereas all four conditions share certain aspects of psychosis, depression, and sleep dysfunction. This remarkable overlap suggests common pathophysiological mechanisms, which include synaptic dysfunction and synaptotoxicity, as well as glial activation and astrogliosis. Astrogliosis is linked to synapse function via the tripartite synapse, but astrocytes also control the availability of gliotransmitters and adenosine. Here we will specifically focus on the 'adenosine hypothesis of comorbidities' implying that astrocyte activation, via overexpression of adenosine kinase (ADK), induces a deficiency in the homeostatic tone of adenosine. We present evidence from patient-derived samples showing astrogliosis and overexpression of ADK as common pathological hallmark of epilepsy, AD, PD, and ALS. We discuss a transgenic 'comorbidity model', in which brain-wide overexpression of ADK and resulting adenosine deficiency produces a comorbid spectrum of seizures, altered dopaminergic function, attentional impairment, and deficits in cognitive domains and sleep regulation. We conclude that dysfunction of adenosine signaling is common in neurological conditions, that adenosine dysfunction can explain co-morbid phenotypes, and that therapeutic adenosine augmentation might be effective for the treatment of comorbid symptoms in multiple neurological conditions.
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Affiliation(s)
- Detlev Boison
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute, Portland, OR 97232, USA.
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Academic Medical Center and Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, The Netherlands; Stichting Epilepsie Instellingen (SEIN) Nederland, Heemstede, The Netherlands
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12
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Expression of ectonucleotidases in the prosencephalon of melatonin-proficient C3H and melatonin-deficient C57Bl mice: spatial distribution and time-dependent changes. Cell Tissue Res 2015; 362:163-76. [PMID: 25959293 DOI: 10.1007/s00441-015-2179-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 03/20/2015] [Indexed: 12/24/2022]
Abstract
Extracellular purines (ATP, ADP, AMP and adenosine) are important signaling molecules in the CNS. Levels of extracellular purines are regulated by enzymes located at the cell surface referred to as ectonucleotidases. Time-dependent changes in their expression could profoundly influence the availability of extracellular purines and thereby purinergic signaling. Using radioactive in situ hybridization, we analyzed the mRNA distribution of the enzymes NTPDase1, -2 and -3 and ecto-5'-nucleotidase in the prosencephalon of two mouse strains: melatonin-proficient C3H and melatonin-deficient C57Bl. The mRNAs of these enzymes were localized to specific brain regions, such as hippocampus, striatum, medial habenula and ventromedial hypothalamus. NTPDase3 expression was more widely distributed than previously thought. All ectonucleotidases investigated revealed a prominent time-dependent expression pattern. In C3H, the mRNA expression of all four enzymes gradually increased during the day and peaked during the night. In contrast, in C57Bl, ecto-5'-nucleotidase expression peaked at the beginning of the day and gradually decreased to trough levels at night. Recording of locomotor activity revealed higher daytime activity of C57Bl than of C3H. Our results indicate that the expression of ectonucleotidases varies according to time and genotype and suggest that melatonin exerts modulatory effects associated with different regulations of purinergic signaling in the brain. These findings provide an important basis for further examination of the complexity of the purinergic system in the brain.
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Elliott AS, Huber JD, O'Callaghan JP, Rosen CL, Miller DB. A review of sleep deprivation studies evaluating the brain transcriptome. SPRINGERPLUS 2014; 3:728. [PMID: 25932362 PMCID: PMC4409616 DOI: 10.1186/2193-1801-3-728] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 11/25/2014] [Indexed: 12/14/2022]
Abstract
Epidemiological studies show a positive association between adequate sleep and good health. Further, disrupted sleep may increase the risk for CNS diseases, such as stroke and Alzheimer’s disease. However, there has been limited progress in determining how sleep is linked to brain health or how sleep disruption may increase susceptibility to brain insult and disease. Animal studies can aid in understanding these links. In reviewing the animal literature related to the effects of sleep disruption on the brain, we found most of the work was directed toward investigating and characterizing the role of various brain areas or structures in initiating and regulating sleep. In contrast, limited effort has been directed towards understanding how sleep disruption alters the brain’s health or susceptibility to insult. We also note many current studies have determined the changes in the brain following compromised sleep by examining, for example, the brain transcriptome or to a more limited extent the proteome. However, these studies have utilized almost exclusively total sleep deprivation (e.g., 24 out of 24 hours) paradigms or single short periods of limited acute sleep deprivation (e.g., 3 out of 24 hours). While such strategies are beneficial in understanding how sleep is controlled, they may not have much translational value for determining links between sleep and brain health or for determining how sleep disruption may increase brain susceptibility to insult. Surprisingly, few studies have determined how the duration and recurrence of sleep deprivation influence the effects seen after sleep deprivation. Our aim in this review was to identify relevant rodent studies from 1980 through 2012 and analyze those that use varying durations of sleep deprivation or restriction in their effort to evaluate the effects of sleep deprivation on the brain transcriptome and to a more limited extent the proteome. We examined how differences in the duration of sleep deprivation affect gene and protein expression to better understand the full consequences of repeated sleep disruption on the brain. Future research needs to consider and emphasize how the type and extent of the sleep deprivation exposure impacts the conclusions reached concerning the influence of sleep disruption on the brain. We identified relevant studies between 1980 and 2012 by searching the electronic databases of PubMed, Medline (Ovid), Embase (Ovid), and Web of Science using the terms “sleep” AND “disrupt”, “deprivation”, “restrict”, “fragment”, “loss”, “disturb”, “disorder”, “dysfunction”, “brain”, “cortex”, striatum”, hypothalamus”, “hippocampus”, “gene”, “protein”, “genomics”, “proteomics”, “polymerase chain reaction”, “pcr”, “microarray”, “molecular”, “rodent” “rat”, “rats”, “mouse”, “mice”. All searches were limited to rodent studies in English and the reference lists of retrieved articles were searched for additional pertinent studies.
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Affiliation(s)
- Alisa S Elliott
- School of Medicine, West Virginia University, Morgantown, WV USA
| | - Jason D Huber
- School of Pharmacy, West Virginia University, Morgantown, WV USA
| | - James P O'Callaghan
- Toxicology and Molecular Biology Branch, CDC-NIOSH, 1095 Willowdale Rd, Morgantown, WV 26505 USA
| | - Charles L Rosen
- School of Medicine, West Virginia University, Morgantown, WV USA
| | - Diane B Miller
- Toxicology and Molecular Biology Branch, CDC-NIOSH, 1095 Willowdale Rd, Morgantown, WV 26505 USA
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14
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Reichert CF, Maire M, Gabel V, Hofstetter M, Viola AU, Kolodyazhniy V, Strobel W, Goetz T, Bachmann V, Landolt HP, Cajochen C, Schmidt C. The circadian regulation of sleep: impact of a functional ADA-polymorphism and its association to working memory improvements. PLoS One 2014; 9:e113734. [PMID: 25437848 PMCID: PMC4249976 DOI: 10.1371/journal.pone.0113734] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 10/30/2014] [Indexed: 11/18/2022] Open
Abstract
Sleep is regulated in a time-of-day dependent manner and profits working memory. However, the impact of the circadian timing system as well as contributions of specific sleep properties to this beneficial effect remains largely unexplored. Moreover, it is unclear to which extent inter-individual differences in sleep-wake regulation depend on circadian phase and modulate the association between sleep and working memory. Here, sleep electroencephalography (EEG) was recorded during a 40-h multiple nap protocol, and working memory performance was assessed by the n-back task 10 times before and after each scheduled nap sleep episode. Twenty-four participants were genotyped regarding a functional polymorphism in adenosine deaminase (rs73598374, 12 G/A-, 12 G/G-allele carriers), previously associated with differences in sleep-wake regulation. Our results indicate that genotype-driven differences in sleep depend on circadian phase: heterozygous participants were awake longer and slept less at the end of the biological day, while they exhibited longer non rapid eye movement (NREM) sleep and slow wave sleep concomitant with reduced power between 8-16 Hz at the end of the biological night. Slow wave sleep and NREM sleep delta EEG activity covaried positively with overall working memory performance, independent of circadian phase and genotype. Moreover, REM sleep duration benefitted working memory particularly when occurring in the early morning hours and specifically in heterozygous individuals. Even though based on a small sample size and thus requiring replication, our results suggest genotype-dependent differences in circadian sleep regulation. They further indicate that REM sleep, being under strong circadian control, boosts working memory performance according to genotype in a time-of-day dependent manner. Finally, our data provide first evidence that slow wave sleep and NREM sleep delta activity, majorly regulated by sleep homeostatic mechanisms, is linked to working memory independent of the timing of the sleep episode within the 24-h cycle.
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Affiliation(s)
- Carolin F. Reichert
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4012, Basel, Switzerland
| | - Micheline Maire
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4012, Basel, Switzerland
| | - Virginie Gabel
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4012, Basel, Switzerland
| | - Marcel Hofstetter
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4012, Basel, Switzerland
| | - Antoine U. Viola
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4012, Basel, Switzerland
| | - Vitaliy Kolodyazhniy
- Division of Clinical Psychology, Psychotherapy and Health Psychology, Institute for Psychology, University of Salzburg, 5020, Salzburg, Austria
| | - Werner Strobel
- Respiratory Medicine, Department of Internal Medicine, University Hospital Basel, 4031, Basel, Switzerland
| | - Thomas Goetz
- Department of Psychiatry, Public Health Office, 60313, Frankfurt am Main, Germany
| | - Valérie Bachmann
- Institute of Pharmacology and Toxicology, University of Zürich, 8057, Zürich, Switzerland
| | - Hans-Peter Landolt
- Institute of Pharmacology and Toxicology, University of Zürich, 8057, Zürich, Switzerland
| | - Christian Cajochen
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4012, Basel, Switzerland
- * E-mail:
| | - Christina Schmidt
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4012, Basel, Switzerland
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Cortés A, Gracia E, Moreno E, Mallol J, Lluís C, Canela EI, Casadó V. Moonlighting Adenosine Deaminase: A Target Protein for Drug Development. Med Res Rev 2014; 35:85-125. [DOI: 10.1002/med.21324] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Antoni Cortés
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
| | - Eduard Gracia
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
| | - Estefania Moreno
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
| | - Josefa Mallol
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
| | - Carme Lluís
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
| | - Enric I. Canela
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
| | - Vicent Casadó
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Institute of Biomedicine of the University of Barcelona (IBUB); Department of Biochemistry and Molecular Biology; Faculty of Biology; University of Barcelona; Barcelona Spain
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16
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Volgin DV, Lu JW, Stettner GM, Mann GL, Ross RJ, Morrison AR, Kubin L. Time- and behavioral state-dependent changes in posterior hypothalamic GABAA receptors contribute to the regulation of sleep. PLoS One 2014; 9:e86545. [PMID: 24466145 PMCID: PMC3897747 DOI: 10.1371/journal.pone.0086545] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 12/11/2013] [Indexed: 12/17/2022] Open
Abstract
Sleep-wake behavior is regulated by a circadian rhythm, homeostatically and by additional mechanisms that determine the timing of slow-wave sleep and rapid eye movement sleep (REMS) episodes. The posterior hypothalamus coordinates the neural and humoral signals with the rest-activity cycle. It contains wake-active neurons, and is a site where stimulation of inhibitory GABAA receptors promotes sleep, whereas their antagonism enhances wakefulness. We explored whether GABAergic mechanisms present in the posterior hypothalamus contribute to the homeostatic and other aspects of sleep-wake regulation. Using micropunches of tissue extracted from either the perifornical (PF) or dorsomedial (DM) regions of the posterior hypothalamus of rats, we determined that mRNA levels for selected subunits of GABAA receptors (β1, β3 and ε) were higher at the end of the active period or following sleep deprivation, when the need for sleep is high, than after several hours of sleep, when sleep need is partially fulfilled. Such a pattern was present in the PF region only, and was consistent with changes in β1 subunit and GABA synthesizing enzyme (GAD) protein levels. In contrast, in the DM region, the levels of GABAA receptor subunit mRNAs and proteins (α1, α2, β1) and GAD varied with circadian time, but were not responsive to sleep deprivation. Separate experiments with sleep-wake monitoring and local perfusion of the PF region with the GABAA receptor antagonist bicuculline revealed that the antagonist had a weaker sleep-reducing effect when sleep need was enhanced by sleep deprivation and that the increased amount of REMS characteristic of the late sleep period was dependent on endogenous GABAergic inhibition. These results support the concept that a varying magnitude of GABAergic inhibition exerted within the PF region contributes to the homeostatic regulation of sleep and shapes its temporal pattern, whereas GABAergic mechanisms in the DM region contribute to circadian regulation.
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Affiliation(s)
- Denys V. Volgin
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jackie W. Lu
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Georg M. Stettner
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Graziella L. Mann
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Richard J. Ross
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Psychiatry, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Behavioral Health Service, Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania, United States of America
| | - Adrian R. Morrison
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Leszek Kubin
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Abstract
Adenosine kinase (ADK; EC 2.7.1.20) is an evolutionarily conserved phosphotransferase that converts the purine ribonucleoside adenosine into 5'-adenosine-monophosphate. This enzymatic reaction plays a fundamental role in determining the tone of adenosine, which fulfills essential functions as a homeostatic and metabolic regulator in all living systems. Adenosine not only activates specific signaling pathways by activation of four types of adenosine receptors but it is also a primordial metabolite and regulator of biochemical enzyme reactions that couple to bioenergetic and epigenetic functions. By regulating adenosine, ADK can thus be identified as an upstream regulator of complex homeostatic and metabolic networks. Not surprisingly, ADK dysfunction is involved in several pathologies, including diabetes, epilepsy, and cancer. Consequently, ADK emerges as a rational therapeutic target, and adenosine-regulating drugs have been tested extensively. In recent attempts to improve specificity of treatment, localized therapies have been developed to augment adenosine signaling at sites of injury or pathology; those approaches include transplantation of stem cells with deletions of ADK or the use of gene therapy vectors to downregulate ADK expression. More recently, the first human mutations in ADK have been described, and novel findings suggest an unexpected role of ADK in a wider range of pathologies. ADK-regulating strategies thus represent innovative therapeutic opportunities to reconstruct network homeostasis in a multitude of conditions. This review will provide a comprehensive overview of the genetics, biochemistry, and pharmacology of ADK and will then focus on pathologies and therapeutic interventions. Challenges to translate ADK-based therapies into clinical use will be discussed critically.
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Affiliation(s)
- Detlev Boison
- Legacy Research Institute, 1225 NE 16th Ave, Portland, OR 97202, USA.
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18
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Hawryluk JM, Ferrari LL, Keating SA, Arrigoni E. Adenosine inhibits glutamatergic input to basal forebrain cholinergic neurons. J Neurophysiol 2012; 107:2769-81. [PMID: 22357797 PMCID: PMC3362278 DOI: 10.1152/jn.00528.2011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 02/15/2012] [Indexed: 01/03/2023] Open
Abstract
Adenosine has been proposed as an endogenous homeostatic sleep factor that accumulates during waking and inhibits wake-active neurons to promote sleep. It has been specifically hypothesized that adenosine decreases wakefulness and promotes sleep recovery by directly inhibiting wake-active neurons of the basal forebrain (BF), particularly BF cholinergic neurons. We previously showed that adenosine directly inhibits BF cholinergic neurons. Here, we investigated 1) how adenosine modulates glutamatergic input to BF cholinergic neurons and 2) how adenosine uptake and adenosine metabolism are involved in regulating extracellular levels of adenosine. Our experiments were conducted using whole cell patch-clamp recordings in mouse brain slices. We found that in BF cholinergic neurons, adenosine reduced the amplitude of AMPA-mediated evoked glutamatergic excitatory postsynaptic currents (EPSCs) and decreased the frequency of spontaneous and miniature EPSCs through presynaptic A(1) receptors. Thus we have demonstrated that in addition to directly inhibiting BF cholinergic neurons, adenosine depresses excitatory inputs to these neurons. It is therefore possible that both direct and indirect inhibition may synergistically contribute to the sleep-promoting effects of adenosine in the BF. We also found that blocking the influx of adenosine through the equilibrative nucleoside transporters or inhibiting adenosine kinase and adenosine deaminase increased endogenous adenosine inhibitory tone, suggesting a possible mechanism through which adenosine extracellular levels in the basal forebrain are regulated.
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Affiliation(s)
- J M Hawryluk
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
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19
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Abstract
Circadian clocks sustain daily oscillations in gene expression, physiology, and behavior, relying on transcription-translation feedback loops of clock genes for rhythm generation. Cultured astrocytes display daily oscillations of extracellular ATP, suggesting that ATP release is a circadian output. We hypothesized that the circadian clock modulates ATP release via mechanisms that regulate acute ATP release from glia. To test the molecular basis for circadian ATP release, we developed methods to measure in real-time ATP release and Bmal1::dLuc circadian reporter expression in cortical astrocyte cultures from mice of different genotypes. Daily rhythms of gene expression required functional Clock and Bmal1, both Per1 and Per2, and both Cry1 and Cry2 genes. Similarly, high-level, circadian ATP release also required a functional clock mechanism. Whereas blocking IP(3) signaling significantly disrupted ATP rhythms with no effect on Bmal1::dLuc cycling, blocking vesicular release did not alter circadian ATP release or gene expression. We conclude that astrocytes depend on circadian clock genes and IP(3) signaling to express daily rhythms in ATP release.
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20
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Bachmann V, Klaus F, Bodenmann S, Schäfer N, Brugger P, Huber S, Berger W, Landolt HP. Functional ADA polymorphism increases sleep depth and reduces vigilant attention in humans. ACTA ACUST UNITED AC 2011; 22:962-70. [PMID: 21734253 DOI: 10.1093/cercor/bhr173] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Homeostatically regulated slow-wave oscillations in non-rapid eye movement (REM) sleep may reflect synaptic changes across the sleep-wake continuum and the restorative function of sleep. The nonsynonymous c.22G>A polymorphism (rs73598374) of adenosine deaminase (ADA) reduces the conversion of adenosine to inosine and predicts baseline differences in sleep slow-wave oscillations. We hypothesized that this polymorphism affects cognitive functions, and investigated whether it modulates electroencephalogram (EEG), behavioral, subjective, and biochemical responses to sleep deprivation. Attention, learning, memory, and executive functioning were quantified in healthy adults. Right-handed carriers of the variant allele (G/A genotype, n = 29) performed worse on the d2 attention task than G/G homozygotes (n = 191). To test whether this difference reflects elevated homeostatic sleep pressure, sleep and sleep EEG before and after sleep deprivation were studied in 2 prospectively matched groups of G/A and G/G genotype subjects. Deep sleep and EEG 0.75- to 1.5-Hz oscillations in non-REM sleep were significantly higher in G/A than in G/G genotype. Moreover, attention and vigor were reduced, whereas waking EEG alpha activity (8.5-12 Hz), sleepiness, fatigue, and α-amylase in saliva were enhanced. These convergent data demonstrate that genetic reduction of ADA activity elevates sleep pressure and plays a key role in sleep and waking quality in humans.
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Affiliation(s)
- Valérie Bachmann
- Institute of Pharmacology and Toxicology University of Zurich, Zurich, Switzerland
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21
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Detanico BC, de Souza A, Medeiros LF, Rozisky JR, Caumo W, Hidalgo MPL, Battastini AMO, Torres ILDS. 24-hour temporal pattern of NTPDase and 5'-nucleotidase enzymes in rat blood serum. Chronobiol Int 2011; 27:1751-61. [PMID: 20969521 DOI: 10.3109/07420528.2010.512992] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Circadian rhythms represent an important mechanism to prepare the organism for environmental variations. ATP, ADP, AMP, and adenosine can act as extracellular messengers in a range of biological processes and are metabolized by a number of enzymes, including NTPDases and 5'-nucleotidase. In the present study the authors report that ATPase and ADPase activities present 24-h temporal variations that peak during dark (activity) span. These findings suggest that this enzymatic temporal pattern in blood serum might be important for the normal physiology and function of the organism through the maintenance of extracellular nucleotides at physiological levels.
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Affiliation(s)
- Bernardo Carraro Detanico
- Departamento de Farmacologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, Brazil
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22
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Abstract
Sleep and sleep intensity are enhanced by adenosine and its receptor agonists, whereas adenosine receptor antagonists induce wakefulness. Adenosine kinase (ADK) is the primary enzyme metabolizing adenosine in adult brain. To investigate whether adenosine metabolism or clearance affects sleep, we recorded sleep in mice with engineered mutations in Adk. Adk-tg mice overexpress a transgene encoding the cytoplasmic isoform of ADK in the brain but lack the nuclear isoform of the enzyme. Wild-type mice and Adk(+/-) mice that have a 50% reduction of the cytoplasmic and the nuclear isoforms of ADK served as controls. Adk-tg mice showed a remarkable reduction of EEG power in low frequencies in all vigilance states and in theta activity (6.25-11 Hz) in rapid eye movement (REM) sleep and waking. Adk-tg mice were awake 58 min more per day than wild-type mice and spent significantly less time in REM sleep (102 ± 3 vs 128 ± 3 min in wild type). After sleep deprivation, slow-wave activity (0.75-4 Hz), the intensity component of non-rapid eye movement sleep, increased significantly less in Adk-tg mice and their slow-wave energy was reduced. In contrast, the vigilance states and EEG spectra of Adk(+/-) and wild-type mice did not differ. Our data suggest that overexpression of the cytoplasmic isoform of ADK is sufficient to alter sleep physiology. ADK might orchestrate neurotransmitter pathways involved in the generation of EEG oscillations and regulation of sleep.
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Lusardi TA. Adenosine neuromodulation and traumatic brain injury. Curr Neuropharmacol 2010; 7:228-37. [PMID: 20190964 PMCID: PMC2769006 DOI: 10.2174/157015909789152137] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 05/18/2009] [Accepted: 05/20/2009] [Indexed: 12/17/2022] Open
Abstract
Adenosine is a ubiquitous signaling molecule, with widespread activity across all organ systems. There is evidence that adenosine regulation is a significant factor in traumatic brain injury (TBI) onset, recovery, and outcome, and a growing body of experimental work examining the therapeutic potential of adenosine neuromodulation in the treatment of TBI. In the central nervous system (CNS), adenosine (dys)regulation has been demonstrated following TBI, and correlated to several TBI pathologies, including impaired cerebral hemodynamics, anaerobic metabolism, and inflammation. In addition to acute pathologies, adenosine function has been implicated in TBI comorbidities, such as cognitive deficits, psychiatric function, and post-traumatic epilepsy. This review presents studies in TBI as well as adenosine-related mechanisms in co-morbidities of and unfavorable outcomes resulting from TBI. While the exact role of the adenosine system following TBI remains unclear, there is increasing evidence that a thorough understanding of adenosine signaling will be critical to the development of diagnostic and therapeutic tools for the treatment of TBI.
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Affiliation(s)
- T A Lusardi
- R. S. Dow Neurobiology Laboratory, Portland OR, USA.
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24
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Arrigoni E, Lu J, Vetrivelan R, Saper CB. Long-term synaptic plasticity is impaired in rats with lesions of the ventrolateral preoptic nucleus. Eur J Neurosci 2009; 30:2112-20. [PMID: 20128848 DOI: 10.1111/j.1460-9568.2009.07001.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Impairment of memory functions has been frequently reported in models of sleep deprivation. Similarly, hippocampal long-term synaptic plasticity has been shown to be sensitive to sleep loss caused by acute sleep restriction. However, such approaches are limited by the stressful nature of sleep deprivation, and because it is difficult to study long-term sleep restriction in animals. Here, we report the effects of chronic sleep loss on hippocampal long-term potentiation (LTP) in a rodent model of chronic partial sleep deprivation. We studied LTP of the Schaffer collateral-CA1 synapses in hippocampal slices prepared from rats with lesions of the ventrolateral preoptic nucleus (VLPO), which suffered reductions in total sleep time for several weeks after lesions. In slices prepared from VLPO-lesioned rats, LTP was impaired proportionally to the amount of sleep loss, and the decline in LTP followed a single exponential function over the amount of accumulated sleep debt. As compared with sham-lesioned controls, hippocampal slices from VLPO-lesioned rats showed a greater response to adenosine antagonists and greater paired-pulse facilitation (PPF). However, exogenous adenosine depressed evoked synaptic transmission and increased PPF in VLPO-lesioned and sham-lesioned rats by equal amounts, suggesting that the greater endogenous adenosine inhibitory tone in the VLPO-lesioned rats is associated with greater ligand accumulation rather than a change in adenosine receptor sensitivity or adenosine-mediated neurotransmitter release probability. LTP in VLPO-lesioned animals was partially restored by adenosine antagonists, suggesting that adenosine accumulation in VLPO-lesioned animals could account for some of the observed synaptic plasticity deficits.
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Affiliation(s)
- Elda Arrigoni
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
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25
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Vazquez J, Hall SC, Witkowska HE, Greco MA. Rapid alterations in cortical protein profiles underlie spontaneous sleep and wake bouts. J Cell Biochem 2008; 105:1472-84. [DOI: 10.1002/jcb.21970] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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26
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Scharf MT, Naidoo N, Zimmerman JE, Pack AI. The energy hypothesis of sleep revisited. Prog Neurobiol 2008; 86:264-80. [PMID: 18809461 DOI: 10.1016/j.pneurobio.2008.08.003] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Revised: 06/08/2008] [Accepted: 08/27/2008] [Indexed: 01/09/2023]
Abstract
One of the proposed functions of sleep is to replenish energy stores in the brain that have been depleted during wakefulness. Benington and Heller formulated a version of the energy hypothesis of sleep in terms of the metabolites adenosine and glycogen. They postulated that during wakefulness, adenosine increases and astrocytic glycogen decreases reflecting the increased energetic demand of wakefulness. We review recent studies on adenosine and glycogen stimulated by this hypothesis. We also discuss other evidence that wakefulness is an energetic challenge to the brain including the unfolded protein response, the electron transport chain, NPAS2, AMP-activated protein kinase, the astrocyte-neuron lactate shuttle, production of reactive oxygen species and uncoupling proteins. We believe the available evidence supports the notion that wakefulness is an energetic challenge to the brain, and that sleep restores energy balance in the brain, although the mechanisms by which this is accomplished are considerably more complex than envisaged by Benington and Heller.
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Affiliation(s)
- Matthew T Scharf
- Center for Sleep and Respiratory Neurobiology, University of Pennsylvania School of Medicine, Translational Research Building, Suite 2100, 125 S. 31st Street, Philadelphia, PA 19104-3403, USA.
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27
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Sleep homeostasis: A role for adenosine in humans? Biochem Pharmacol 2008; 75:2070-9. [DOI: 10.1016/j.bcp.2008.02.024] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 02/11/2008] [Accepted: 02/11/2008] [Indexed: 11/22/2022]
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Abstract
This paper presents an overview of the current knowledge of the neurophysiology and cellular pharmacology of sleep mechanisms. It is written from the perspective that recent years have seen a remarkable development of knowledge about sleep mechanisms, due to the capability of current cellular neurophysiological, pharmacological and molecular techniques to provide focused, detailed, and replicable studies that have enriched and informed the knowledge of sleep phenomenology and pathology derived from electroencephalographic (EEG) analysis. This chapter has a cellular and neurophysiological/neuropharmacological focus, with an emphasis on rapid eye movement (REM) sleep mechanisms and non-REM (NREM) sleep phenomena attributable to adenosine. The survey of neuronal and neurotransmitter-related brainstem mechanisms of REM includes monoamines, acetylcholine, the reticular formation, a new emphasis on GABAergic mechanisms and a discussion of the role of orexin/hypcretin in diurnal consolidation of REM sleep. The focus of the NREM sleep discussion is on the basal forebrain and adenosine as a mediator of homeostatic control. Control is through basal forebrain extracellular adenosine accumulation during wakefulness and inhibition of wakefulness-active neurons. Over longer periods of sleep loss, there is a second mechanism of homeostatic control through transcriptional modification. Adenosine acting at the A1 receptor produces an up-regulation of A1 receptors, which increases inhibition for a given level of adenosine, effectively increasing the gain of the sleep homeostat. This second mechanism likely occurs in widespread cortical areas as well as in the basal forebrain. Finally, the results of a new series of experimental paradigms in rodents to measure the neurocognitive effects of sleep loss and sleep interruption (modeling sleep apnea) provide animal model data congruent with those in humans.
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Affiliation(s)
- Robert W McCarley
- Neuroscience Laboratory, VA Boston Healthcare System, 940 Belmont St., Brockton, MA 02301, USA.
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Blanco-Centurion C, Xu M, Murillo-Rodriguez E, Gerashchenko D, Shiromani AM, Salin-Pascual RJ, Hof PR, Shiromani PJ. Adenosine and sleep homeostasis in the Basal forebrain. J Neurosci 2006; 26:8092-100. [PMID: 16885223 PMCID: PMC6673779 DOI: 10.1523/jneurosci.2181-06.2006] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
It is currently hypothesized that the drive to sleep is determined by the activity of the basal forebrain (BF) cholinergic neurons, which release adenosine (AD), perhaps because of increased metabolic activity associated with the neuronal discharge during waking, and the accumulating AD begins to inhibit these neurons so that sleep-active neurons can become active. This hypothesis grew from the observation that AD induces sleep and AD levels increase with wake in the basal forebrain, but surprisingly it still remains untested. Here we directly test whether the basal forebrain cholinergic neurons are central to the AD regulation of sleep drive by administering 192-IgG-saporin to lesion the BF cholinergic neurons and then measuring AD levels in the BF. In rats with 95% lesion of the BF cholinergic neurons, AD levels in the BF did not increase with 6 h of prolonged waking. However, the lesioned rats had intact sleep drive after 6 and 12 h of prolonged waking, indicating that the AD accumulation in the BF is not necessary for sleep drive. Next we determined that, in the absence of the BF cholinergic neurons, the selective adenosine A1 receptor agonist N6-cyclohexyladenosine, administered to the BF, continued to be effective in inducing sleep, indicating that the BF cholinergic neurons are not essential to sleep induction. Thus, neither the activity of the BF cholinergic neurons nor the accumulation of AD in the BF during wake is necessary for sleep drive.
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King AE, Ackley MA, Cass CE, Young JD, Baldwin SA. Nucleoside transporters: from scavengers to novel therapeutic targets. Trends Pharmacol Sci 2006; 27:416-25. [PMID: 16820221 DOI: 10.1016/j.tips.2006.06.004] [Citation(s) in RCA: 204] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Revised: 04/18/2006] [Accepted: 06/19/2006] [Indexed: 11/26/2022]
Abstract
Hydrophilic purine and pyrimidine nucleosides rely on specialized carrier proteins for their membrane translocation. The recent identification of two gene families encoding equilibrative and concentrative nucleoside transporters in mammals and other organisms has provided the essential breakthrough to a more complete understanding of the biological significance of nucleoside transport. Although nucleoside salvage is a primary function of these proteins, recent data indicate functions beyond metabolic recycling. In brain and spinal cord, for example, nucleoside transporters have the potential to regulate synaptic levels of neuroactive purines such as adenosine and, thereby, indirectly modulate physiological processes through G-protein-coupled purine P1 receptors. As described in this review, recent research indicates novel putative functions for CNS nucleoside transporters in sleep, arousal, drug and alcohol addiction, nociception and analgesia. The therapeutic use of nucleoside analogue drugs and nucleoside transporter inhibitors in viral, neoplastic, cardiovascular and infectious disease is also described.
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Affiliation(s)
- Anne E King
- Institute of Membrane and Systems Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
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Li XM, Kanekal S, Crépin D, Guettier C, Carrière J, Elliott G, Lévi F. Circadian pharmacology of l-alanosine (SDX-102) in mice. Mol Cancer Ther 2006; 5:337-46. [PMID: 16505107 DOI: 10.1158/1535-7163.mct-05-0332] [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: 11/16/2022]
Abstract
L-alanosine (SDX-102) exerts its cytotoxicity through inhibition of de novo purine biosynthesis, an effect potentiated by methylthioadenosine phosphorylase (MTAP) deficiency. The relevance of circadian dosing time was investigated for chronotherapeutic optimization of SDX-102. Toxicity was assessed in healthy mice following single (1,150, 1,650, or 1,850 mg/kg/d) or multiple doses (250 or 270 mg/kg/d). Efficacy was tested in mice with P388 leukemia receiving multiple doses (225 or 250 mg/kg/d). SDX-102 was administered at six circadian times 4 hours apart in mice synchronized with 12 hours of light alternating with 12 hours of darkness. MTAP expression was determined in liver, bone marrow, small intestinal mucosa, and P388 cells. Dosing at 19 hours after light onset reduced lethality 5-fold after single administration and 3-fold after multiple doses as compared with worst time [P < 0.001 and P < 0.01, respectively (chi2 test)]. Neutropenia, lymphopenia, and bone marrow hemorrhagic lesions were significantly less in mice dosed at 19 hours after light onset as compared with 7 hours after light onset. SDX-102 at 7 hours after light onset transiently ablated the 24-hour patterns in body temperature and activity. A circadian rhythm characterized small intestinal MTAP expression with a maximum at 6:30 hours after light onset (P = 0.04). A minor survival improvement was found in MTAP-deficient P388 mice receiving SDX-102 at 7 or 23 hours after light onset as compared with other times (P = 0.03, log-rank test). In conclusion, the therapeutic index of SDX-102 was improved by the delivery of SDX-102 in the mid to late activity span. These results support the concept of chronomodulated infusion of SDX-102 in cancer patients.
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Affiliation(s)
- Xiao-Mei Li
- Institut National de la Sante et de la Recherche Medicale, U776 "Rythmes biologiques et cancers" (Université Paris Sud), Paul Brousse Hospital, 94800 Villejuif, France
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Rétey JV, Adam M, Honegger E, Khatami R, Luhmann UFO, Jung HH, Berger W, Landolt HP. A functional genetic variation of adenosine deaminase affects the duration and intensity of deep sleep in humans. Proc Natl Acad Sci U S A 2005; 102:15676-81. [PMID: 16221767 PMCID: PMC1266101 DOI: 10.1073/pnas.0505414102] [Citation(s) in RCA: 214] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Slow, rhythmic oscillations (<5 Hz) in the sleep electroencephalogram may be a sign of synaptic plasticity occurring during sleep. The oscillations, referred to as slow-wave activity (SWA), reflect sleep need and sleep intensity. The amount of SWA is homeostatically regulated. It is enhanced after sleep loss and declines during sleep. Animal studies suggested that sleep need is genetically controlled, yet the physiological mechanisms remain unknown. Here we show in humans that a genetic variant of adenosine deaminase, which is associated with the reduced metabolism of adenosine to inosine, specifically enhances deep sleep and SWA during sleep. In contrast, a distinct polymorphism of the adenosine A(2A) receptor gene, which was associated with interindividual differences in anxiety symptoms after caffeine intake in healthy volunteers, affects the electroencephalogram during sleep and wakefulness in a non-state-specific manner. Our findings indicate a direct role of adenosine in human sleep homeostasis. Moreover, our data suggest that genetic variability in the adenosinergic system contributes to the interindividual variability in brain electrical activity during sleep and wakefulness.
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Affiliation(s)
- J V Rétey
- Institute of Pharmacology and Toxicology and Center for Integrative Human Physiology, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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Fredholm BB, Chen JF, Masino SA, Vaugeois JM. ACTIONS OF ADENOSINE AT ITS RECEPTORS IN THE CNS: Insights from Knockouts and Drugs. Annu Rev Pharmacol Toxicol 2005; 45:385-412. [PMID: 15822182 DOI: 10.1146/annurev.pharmtox.45.120403.095731] [Citation(s) in RCA: 265] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Adenosine and its receptors have been the topic of many recent reviews ( 1 – 26 ). These reviews provide a good summary of much of the relevant literature—including the older literature. We have, therefore, chosen to focus the present review on the insights gained from recent studies on genetically modified mice, particularly with respect to the function of adenosine receptors and their potential as therapeutic targets. The information gained from studies of drug effects is discussed in this context, and discrepancies between genetic and pharmacological results are highlighted.
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Affiliation(s)
- Bertil B Fredholm
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden
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Fredholm BB, Chen JF, Cunha RA, Svenningsson P, Vaugeois JM. Adenosine and Brain Function. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2005; 63:191-270. [PMID: 15797469 DOI: 10.1016/s0074-7742(05)63007-3] [Citation(s) in RCA: 500] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Bertil B Fredholm
- Department of Physiology and Pharmacology, Karolinska Institutet Stockholm, Sweden
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Abstract
The function of the pituitary gland is tightly controlled by neuronal and hormonal afferents of the brain. In this review, the role of the neurohormone melatonin and the neuromodulator adenosine for rodent pituitary function will be elucidated. Adenosine is known as an important paracrine modulator for pituitary endocrine and folliculostellate cells, with availability regulated by local metabolic cellular activity. In general, adenosine inhibits the cyclic adenosine monophosphate (AMP) pathway in pituitary cells by binding to A1-, and A3-adenosinergic receptors, and activates it via A2-adenosinergic receptors. The neurohormone melatonin integrates time-of-day and time-of-year into pituitary function via binding to MT1-melatonin receptors. Melatonin impacts at the hypothalamic level neurons that synthesize releasing and release-inhibiting hormones, and at the pituitary level only cells of the hypophyseal pars tuberalis (PT). Thereby, the daily changes in the duration of the nocturnal melatonin surge are decoded and subsequently relayed to the pars distalis to adapt gonadotropin and prolactin release, respectively, to season. An exciting integration of time within the regulation of pituitary function was deciphered by analysing transmembrane signalling events in cells of the hypophyseal PT: a consecutive daily impact of initially the neurohormone melatonin and later the neuromodulator adenosine on rodent PT cells leads to a circadian rhythm in the transcription of cyclic-AMP-sensitive genes.
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Affiliation(s)
- Christian A Kell
- Department of Neurology, Johann Wolfgang Goethe-University, Frankfurt, Germany
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Sahin B, Kansy JW, Nairn AC, Spychala J, Ealick SE, Fienberg AA, Greene RW, Bibb JA. Molecular characterization of recombinant mouse adenosine kinase and evaluation as a target for protein phosphorylation. ACTA ACUST UNITED AC 2004; 271:3547-55. [PMID: 15317590 DOI: 10.1111/j.1432-1033.2004.04291.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The regulation of adenosine kinase (AK) activity has the potential to control intracellular and interstitial adenosine (Ado) concentrations. In an effort to study the role of AK in Ado homeostasis in the central nervous system, two isoforms of the enzyme were cloned from a mouse brain cDNA library. Following overexpression in bacterial cells, the corresponding proteins were purified to homogeneity. Both isoforms were enzymatically active and found to possess K(m) and V(max) values in agreement with kinetic parameters described for other forms of AK. The distribution of AK in discrete brain regions and various peripheral tissues was defined. To investigate the possibility that AK activity is regulated by protein phosphorylation, a panel of protein kinases was screened for ability to phosphorylate recombinant mouse AK. Data from these in vitro phosphorylation studies suggest that AK is most likely not an efficient substrate for PKA, PKG, CaMKII, CK1, CK2, MAPK, Cdk1, or Cdk5. PKC was found to phosphorylate recombinant AK efficiently in vitro. Further analysis revealed, however, that this PKC-dependent phosphorylation occurred at one or more serine residues associated with the N-terminal affinity tag used for protein purification.
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Affiliation(s)
- Bogachan Sahin
- The University of Texas Southwestern Medical Center, Dallas, TX 75390-9070, USA
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Basheer R, Strecker RE, Thakkar MM, McCarley RW. Adenosine and sleep–wake regulation. Prog Neurobiol 2004; 73:379-96. [PMID: 15313333 DOI: 10.1016/j.pneurobio.2004.06.004] [Citation(s) in RCA: 358] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2003] [Accepted: 06/28/2004] [Indexed: 10/26/2022]
Abstract
This review addresses three principal questions about adenosine and sleep-wake regulation: (1) Is adenosine an endogenous sleep factor? (2) Are there specific brain regions/neuroanatomical targets and receptor subtypes through which adenosine mediates sleepiness? (3) What are the molecular mechanisms by which adenosine may mediate the long-term effects of sleep loss? Data suggest that adenosine is indeed an important endogenous, homeostatic sleep factor, likely mediating the sleepiness that follows prolonged wakefulness. The cholinergic basal forebrain is reviewed in detail as an essential area for mediating the sleep-inducing effects of adenosine by inhibition of wake-promoting neurons via the A1 receptor. The A2A receptor in the subarachnoid space below the rostral forebrain may play a role in the prostaglandin D2-mediated somnogenic effects of adenosine. Recent evidence indicates that a cascade of signal transduction induced by basal forebrain adenosine A1 receptor activation in cholinergic neurons leads to increased transcription of the A1 receptor; this may play a role in mediating the longer-term effects of sleep deprivation, often called sleep debt.
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Affiliation(s)
- Radhika Basheer
- Neuroscience Laboratory, Department of Psychiatry, Harvard Medical School and Boston VA Healthcare System, Brockton, MA 02301, USA
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Murillo-Rodriguez E, Blanco-Centurion C, Gerashchenko D, Salin-Pascual RJ, Shiromani PJ. The diurnal rhythm of adenosine levels in the basal forebrain of young and old rats. Neuroscience 2004; 123:361-70. [PMID: 14698744 DOI: 10.1016/j.neuroscience.2003.09.015] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
There are significant decrements in sleep with age. These include fragmentation of sleep, increased wake time, decrease in the length of sleep bouts, decrease in the amplitude of the diurnal rhythm of sleep, decrease in rapid eye movement sleep and a profound decrease in electroencephalogram Delta power (0.3-4 Hz). Old rats also have less sleep in response to 12 h-prolonged wakefulness (W) indicating a reduction in sleep drive with age. The mechanism contributing to the decline in sleep with aging is not known but cannot be attributed to loss of neurons implicated in sleep since the numbers of neurons in the ventral lateral preoptic area, a region implicated in generating sleep, is similar between young (3.5 months) and old (21.5 months) rats. One possibility for the reduced sleep drive with age is that sleep-wake active neurons may be stimulated less as a result of a decline in endogenous sleep factors. Here, we test this hypothesis by focusing on the purine, adenosine (AD), one such sleep factor that increases after prolonged W. In experiment 1, microdialysis measurements of AD in the basal forebrain at 1 h intervals reveal that old (21.5 months) rats have more extracellular levels of AD compared with young rats across the 24 h diurnal cycle. In experiment 2, old rats kept awake for 6 h (first half of lights-on period) accumulated more AD compared with young rats. If old rats have more AD then why do they sleep less? To investigate whether changes in sensitivity of the AD receptor contribute to the decline in sleep, experiments 3 and 4 determined that for the same concentration of AD or the AD receptor 1 agonist, cyclohexyladenosine, old rats have less sleep compared with young rats. We conclude that even though old rats have more AD, a reduction in the sensitivity of the AD receptor to the ligand does not transduce the AD signal at the same strength as in young rats and may be a contributing factor to the decline in sleep drive in the elderly.
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Affiliation(s)
- E Murillo-Rodriguez
- Department of Neurology, West Roxbury VA Medical Center and Harvard Medical School, Building 3, Room 2C109, 1400 VFW Parkway, West Roxbury, MA 02132, USA
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Stenberg D, Litonius E, Halldner L, Johansson B, Fredholm BB, Porkka-Heiskanen T. Sleep and its homeostatic regulation in mice lacking the adenosine A1 receptor. J Sleep Res 2003; 12:283-90. [PMID: 14633239 DOI: 10.1046/j.0962-1105.2003.00367.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Sleep deprivation (SD) increases extracellular adenosine levels in the basal forebrain, and pharmacological manipulations that increase extracellular adenosine in the same area promote sleep. As pharmacological evidence indicates that the effect is mediated through adenosine A1 receptors (A1R), we expected A1R knockout (KO) mice to have reduced rebound sleep after SD. Male homozygous A1R KO mice, wild-type (WT) mice, and heterozygotes (HET) from a mixed 129/C57BL background were implanted during anesthesia with electrodes for electroencephalography (EEG) and electromyography (EMG). After 1 week of recovery, they were allowed to adapt to recording leads for 2 weeks. EEG and EMG were recorded continuously. All genotypes had a pronounced diurnal sleep/wake rhythm after 2 weeks of adaptation. We then analyzed 24 h of baseline recording, 6 h of SD starting at light onset, and 42 h of recovery recording. Neither rapid eye movement sleep (REM sleep) nor non-REM sleep (NREMS) amounts differed significantly between the groups. SD for 6 h induced a strong NREMS rebound in all three groups. NREMS time and accumulated EEG delta power were equal in WT, HET and KO. Systemic administration of the selective A1R antagonist 8-cyclopentyltheophylline (8-CPT) inhibited sleep for 30 min in WT, whereas saline and 8-CPT both inhibited sleep in KO. We conclude that constitutional lack of adenosine A1R does not prevent the homeostatic regulation of sleep.
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Affiliation(s)
- Dag Stenberg
- Institute of Biomedicine/Physiology, University of Helsinki, Helsinki, Finland.
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Alanko L, Stenberg D, Porkka-Heiskanen T. Nitrobenzylthioinosine (NBMPR) binding and nucleoside transporter ENT1 mRNA expression after prolonged wakefulness and recovery sleep in the cortex and basal forebrain of rat. J Sleep Res 2003; 12:299-304. [PMID: 14633241 DOI: 10.1046/j.0962-1105.2003.00372.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have previously shown that extracellular adenosine levels increase locally in the basal forebrain (BF) during prolonged wakefulness, yet the cellular mechanisms of this local accumulation have remained unknown. The extracellular adenosine levels are strictly regulated by adenosine metabolism and its transport through cell membrane by the nucleoside transporters. As we previously showed that the key adenosine metabolizing enzymes were not affected by prolonged wakefulness, we now focussed on potential changes in the nucleoside transporters. In the present study, we measured the binding of nitrobenzylthioinosine (NBMPR), an ENT1 transporter inhibitor, and the ENT1 transporter mRNA after prolonged wakefulness and recovery sleep. Rats were sleep-deprived for 3 or 6 h using gentle handling. After 6 h one group was allowed to sleep for 2 h. NBMPR binding was determined from BF and cortex by incubating tissue extracts with [3H] NBMPR. The in situ hybridization was carried out on 20 microm cryosections using [35S]dATP-labelled oligonucleotide probe for ENT1 mRNA. The NBMPR binding was significantly decreased in the BF, but not in the cortex, after 6 h sleep deprivation when compared with the time-matched controls, suggesting a decline in adenosine transport. The expression of ENT1 mRNA did not change during prolonged wakefulness or recovery sleep in either cortex or the BF, although circadian variations were measured in both areas. We conclude that the regional decrease in adenosine transport could contribute to the gradual accumulation of extracellular adenosine in the basal forebrain during prolonged wakefulness.
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Affiliation(s)
- Lauri Alanko
- Institute of Biomedicine/Physiology, University of Helsinki, Helsinki, Finland.
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