1
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Roh WS, Yoo JH, Dravid SM, Mannaioni G, Krizman EN, Wahl P, Robinson MB, Traynelis SF, Lee CJ, Han KS. Astrocytic PAR1 and mGluR2/3 control synaptic glutamate time course at hippocampal CA1 synapses. Glia 2024. [PMID: 38864289 DOI: 10.1002/glia.24579] [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: 12/20/2023] [Revised: 05/30/2024] [Accepted: 05/31/2024] [Indexed: 06/13/2024]
Abstract
Astrocytes play an essential role in regulating synaptic transmission. This study describes a novel form of modulation of excitatory synaptic transmission in the mouse hippocampus by astrocytic G-protein-coupled receptors (GPCRs). We have previously described astrocytic glutamate release via protease-activated receptor-1 (PAR1) activation, although the regulatory mechanisms for this are complex. Through electrophysiological analysis and modeling, we discovered that PAR1 activation consistently increases the concentration and duration of glutamate in the synaptic cleft. This effect was not due to changes in the presynaptic glutamate release or alteration in glutamate transporter expression. However, blocking group II metabotropic glutamate receptors (mGluR2/3) abolished PAR1-mediated regulation of synaptic glutamate concentration, suggesting a role for this GPCR in mediating the effects of PAR1 activation on glutamate release. Furthermore, activation of mGluR2/3 causes glutamate release through the TREK-1 channel in hippocampal astrocytes. These data show that astrocytic GPCRs engage in a novel regulatory mechanism to shape the time course of synaptically-released glutamate in excitatory synapses of the hippocampus.
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Affiliation(s)
- Woo Suk Roh
- Department of Biological Sciences, Chungnam National University, Daejeon, South Korea
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, South Korea
| | - Jae Hong Yoo
- Department of Biological Sciences, Chungnam National University, Daejeon, South Korea
| | - Shashank M Dravid
- Emory University School of Medicine, Department of Pharmacology and Chemical Biology, Atlanta, Georgia, USA
- Creighton University, Department of Pharmacology, Omaha, Nebraska, USA
| | - Guido Mannaioni
- Emory University School of Medicine, Department of Pharmacology and Chemical Biology, Atlanta, Georgia, USA
- Department of Pharmacology, University of Florence, Florence, GA, Italy
| | - Elizabeth N Krizman
- Departments of Pediatrics and Pharmacology, Children's Hospital of Philadelphia Research Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Philip Wahl
- Emory University School of Medicine, Department of Pharmacology and Chemical Biology, Atlanta, Georgia, USA
| | - Michael B Robinson
- Departments of Pediatrics and Pharmacology, Children's Hospital of Philadelphia Research Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Stephen F Traynelis
- Emory University School of Medicine, Department of Pharmacology and Chemical Biology, Atlanta, Georgia, USA
| | - C Justin Lee
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, South Korea
| | - Kyung-Seok Han
- Department of Biological Sciences, Chungnam National University, Daejeon, South Korea
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2
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Lalo U, Pankratov Y. ATP-mediated signalling in the central synapses. Neuropharmacology 2023; 229:109477. [PMID: 36841527 DOI: 10.1016/j.neuropharm.2023.109477] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 02/13/2023] [Accepted: 02/23/2023] [Indexed: 02/27/2023]
Abstract
ATP released from the synaptic terminals and astrocytes can activate neuronal P2 receptors at a variety of locations across the CNS. Although the postsynaptic ATP-mediated signalling does not bring a major contribution into the excitatory transmission, it is instrumental for slow and diffuse modulation of synaptic dynamics and neuronal firing in many CNS areas. Neuronal P2X and P2Y receptors can be activated by ATP released from the synaptic terminals, astrocytes and microglia and thereby can participate in the regulation of synaptic homeostasis and plasticity. There is growing evidence of importance of purinergic regulation of synaptic transmission in different physiological and pathological contexts. Here, we review the main mechanisms underlying the complexity and diversity of purinergic signalling and purinergic modulation in central neurons.
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Affiliation(s)
- Ulyana Lalo
- School of Life Sciences, University of Warwick, United Kingdom
| | - Yuriy Pankratov
- School of Life Sciences, University of Warwick, United Kingdom.
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3
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Ren WJ, Zhao YF, Li J, Rubini P, Yuan ZQ, Tang Y, Illes P. P2X7 receptor-mediated depression-like reactions arising in the mouse medial prefrontal cortex. Cereb Cortex 2023:7161772. [PMID: 37183178 DOI: 10.1093/cercor/bhad166] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 05/16/2023] Open
Abstract
Major depressive disorder is a frequent and debilitating psychiatric disease. We have shown in some of the acute animal models of major depressive disorder (tail suspension test and forced swim test) that depression-like behavior can be aggravated in mice by the microinjection into the medial prefrontal cortex of the P2X7R agonistic adenosine 5'-triphosphate or its structural analog dibenzoyl-ATP, and these effects can be reversed by the P2X7R antagonistic JNJ-47965567. When measuring tail suspension test, the prolongation of immobility time by the P2YR agonist adenosine 5'-[β-thio]diphosphate and the reduction of the adenosine 5'-(γ-thio)triphosphate effect by P2Y1R (MRS 2179) or P2Y12R (PSB 0739) antagonists, but not by JNJ-47965567, all suggest the involvement of P2YRs. In order to elucidate the localization of the modulatory P2X7Rs in the brain, we recorded current responses to dibenzoyl-ATP in layer V astrocytes and pyramidal neurons of medial prefrontal cortex brain slices by the whole-cell patch-clamp procedure; the current amplitudes were not altered in preparations taken from tail suspension test or foot shock-treated mice. The release of adenosine 5'-triphosphate was decreased by foot shock, although not by tail suspension test both in the hippocampus and PFC. In conclusion, we suggest, that in the medial prefrontal cortex, acute stressful stimuli cause supersensitivity of P2X7Rs facilitating the learned helplessness reaction.
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Affiliation(s)
- Wen-Jing Ren
- International Joint Research Center on Purinergic Signaling of Sichuan Province, Chengdu University of TCM, Chengdu 610075, China
- School of Acupuncture and Tuina, Chengdu University of TCM, Chengdu 610075, China
| | - Ya-Fei Zhao
- International Joint Research Center on Purinergic Signaling of Sichuan Province, Chengdu University of TCM, Chengdu 610075, China
- School of Acupuncture and Tuina, Chengdu University of TCM, Chengdu 610075, China
| | - Jie Li
- International Joint Research Center on Purinergic Signaling of Sichuan Province, Chengdu University of TCM, Chengdu 610075, China
- School of Acupuncture and Tuina, Chengdu University of TCM, Chengdu 610075, China
| | - Patrizia Rubini
- International Joint Research Center on Purinergic Signaling of Sichuan Province, Chengdu University of TCM, Chengdu 610075, China
- School of Acupuncture and Tuina, Chengdu University of TCM, Chengdu 610075, China
| | - Zeng-Qiang Yuan
- The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing 100850, China
- School of Medicine, University of South China, Hengyang 421000, Hunan, China
| | - Yong Tang
- International Joint Research Center on Purinergic Signaling of Sichuan Province, Chengdu University of TCM, Chengdu 610075, China
- School of Acupuncture and Tuina, Chengdu University of TCM, Chengdu 610075, China
- Acupuncture and Chronobiology Key Laboratory of Sichuan Province, Chengdu University of TCM, Chengdu 610075, China
| | - Peter Illes
- International Joint Research Center on Purinergic Signaling of Sichuan Province, Chengdu University of TCM, Chengdu 610075, China
- School of Acupuncture and Tuina, Chengdu University of TCM, Chengdu 610075, China
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, Leipzig 04107, Germany
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4
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Lohr C. Role of P2Y receptors in astrocyte physiology and pathophysiology. Neuropharmacology 2023; 223:109311. [PMID: 36328064 DOI: 10.1016/j.neuropharm.2022.109311] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/24/2022] [Accepted: 10/27/2022] [Indexed: 11/07/2022]
Abstract
Astrocytes are active constituents of the brain that manage ion homeostasis and metabolic support of neurons and directly tune synaptic transmission and plasticity. Astrocytes express all known P2Y receptors. These regulate a multitude of physiological functions such as cell proliferation, Ca2+ signalling, gliotransmitter release and neurovascular coupling. In addition, P2Y receptors are fundamental in the transition of astrocytes into reactive astrocytes, as occurring in many brain disorders such as neurodegenerative diseases, neuroinflammation and epilepsy. This review summarizes the current literature addressing the function of P2Y receptors in astrocytes in the healthy brain as well as in brain diseases.
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Affiliation(s)
- Christian Lohr
- Institute of Cell and Systems Biology of Animals, University of Hamburg, Germany.
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5
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Zhao YF, Verkhratsky A, Tang Y, Illes P. Astrocytes and major depression: The purinergic avenue. Neuropharmacology 2022; 220:109252. [PMID: 36122663 DOI: 10.1016/j.neuropharm.2022.109252] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 08/19/2022] [Accepted: 09/06/2022] [Indexed: 10/14/2022]
Abstract
Major depressive disorder (MDD) is one of the most prevalent psychiatric illnesses worldwide which impairs the social functioning of the afflicted patients. Astrocytes promote homeostasis of the CNS and provide defense against various types of harmful influences. Increasing evidence suggests that the number, morphology and function of astrocytes are deteriorated in the depressed brain and the malfunction of the astrocytic purinergic system appears to participate in the pathophysiology of MDD. Adenosine 5'-triphosphate (ATP) released from astrocytes modulates depressive-like behavior in animal models and probably also clinical depression in patients. Astrocytes possess purinergic receptors, such as adenosine A2A receptors (Rs), and P2X7, P2Y1, and P2Y11Rs, which mediate neuroinflammation, neuro(glio)transmission, and synaptic plasticity in depression-relevant areas of the brain (e.g. medial prefrontal cortex, hippocampus, amygdala nuclei). By contrast, astrocytic A1Rs are neuroprotective and immunosuppressive. In the present review, we shall discuss the release of purines from astrocytes, and the expression/function of astrocytic purinergic receptors. Subsequently, we shall review in more detail novel evidence indicating that the dysregulation of astrocytic purinergic signaling actively contributes to the pathophysiology of depression and shall discuss possible therapeutic options based on knowledge recently acquired in this field.
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Affiliation(s)
- Y F Zhao
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China; International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China
| | - A Verkhratsky
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China; Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PL, UK; Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT, 01102, Vilnius, Lithuania
| | - Y Tang
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China; International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China.
| | - P Illes
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China; International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China; Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107, Leipzig, Germany.
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6
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Ortinski PI, Reissner KJ, Turner J, Anderson TA, Scimemi A. Control of complex behavior by astrocytes and microglia. Neurosci Biobehav Rev 2022; 137:104651. [PMID: 35367512 DOI: 10.1016/j.neubiorev.2022.104651] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/28/2022] [Accepted: 03/21/2022] [Indexed: 02/07/2023]
Abstract
Evidence that glial cells influence behavior has been gaining a steady foothold in scientific literature. Out of the five main subtypes of glial cells in the brain, astrocytes and microglia have received an outsized share of attention with regard to shaping a wide spectrum of behavioral phenomena and there is growing appreciation that the signals intrinsic to these cells as well as their interactions with surrounding neurons reflect behavioral history in a brain region-specific manner. Considerable regional diversity of glial cell phenotypes is beginning to be recognized and may contribute to behavioral outcomes arising from circuit-specific computations within and across discrete brain nuclei. Here, we summarize current knowledge on the impact of astrocyte and microglia activity on behavioral outcomes, with a specific focus on brain areas relevant to higher cognitive control, reward-seeking, and circadian regulation.
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Affiliation(s)
- P I Ortinski
- Department of Neuroscience, University of Kentucky, USA
| | - K J Reissner
- Department of Psychology and Neuroscience, University of North Carolina Chapel Hill, USA
| | - J Turner
- Department of Pharmaceutical Sciences, University of Kentucky, USA
| | - T A Anderson
- Department of Neuroscience, University of Kentucky, USA
| | - A Scimemi
- Department of Biology, State University of New York at Albany, USA
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7
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Reynolds KE, Wong CR, Scott AL. Astrocyte-mediated purinergic signaling is upregulated in a mouse model of Fragile X syndrome. Glia 2021; 69:1816-1832. [PMID: 33754385 DOI: 10.1002/glia.23997] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 03/10/2021] [Accepted: 03/11/2021] [Indexed: 12/12/2022]
Abstract
Fragile X syndrome (FXS) is the leading monogenic cause of intellectual disability and autism spectrum disorders. With increasing investigation into the molecular mechanisms underlying FXS, there is growing evidence that perturbations in glial signaling are widely associated with neurological pathology. Purinergic signaling, which utilizes nucleoside triphosphates as signaling molecules, provides one of the most ubiquitous signaling systems for glial-neuronal and glial-glial crosstalk. Here, we sought to identify whether purinergic signaling is dysregulated within the FXS mouse cortex, and whether this dysregulation contributes to aberrant intercellular communication. In primary astrocyte cultures derived from the Fmr1 knockout (KO) mouse model of FXS, we found that application of exogenous ATP and UTP evoked elevated intracellular calcium responses compared to wildtype levels. Accordingly, purinergic P2Y2 and P2Y6 receptor expression was increased in Fmr1 KO astrocytes both in vitro and in acutely dissociated tissue, while P2Y antagonism via suramin prevented intracellular calcium elevations, suggesting a role for these receptors in aberrant FXS astrocyte activation. To investigate the impact of elevated purinergic signaling on astrocyte-mediated synaptogenesis, we quantified synaptogenic protein TSP-1, known to be regulated by P2Y activation. TSP-1 secretion and expression were both heightened in Fmr1 KO vs wildtype astrocytes following UTP application, while naïve TSP-1 cortical expression was also transiently elevated in vivo, indicating increased potential for excitatory TSP-1-mediated synaptogenesis in the FXS cortex. Together, our results demonstrate novel and significant purinergic signaling elevations in Fmr1 KO astrocytes, which may serve as a potential therapeutic target to mitigate the signaling aberrations observed in FXS.
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Affiliation(s)
- Kathryn E Reynolds
- Neuroscience Graduate Program, McMaster University, Hamilton, Ontario, Canada
| | - Chloe R Wong
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Angela L Scott
- Neuroscience Graduate Program, McMaster University, Hamilton, Ontario, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
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8
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Purinergic signaling orchestrating neuron-glia communication. Pharmacol Res 2020; 162:105253. [PMID: 33080321 DOI: 10.1016/j.phrs.2020.105253] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/29/2020] [Accepted: 10/09/2020] [Indexed: 12/12/2022]
Abstract
This review discusses the evidence supporting a role for ATP signaling (operated by P2X and P2Y receptors) and adenosine signaling (mainly operated by A1 and A2A receptors) in the crosstalk between neurons, astrocytes, microglia and oligodendrocytes. An initial emphasis will be given to the cooperation between adenosine receptors to sharpen information salience encoding across synapses. The interplay between ATP and adenosine signaling in the communication between astrocytes and neurons will then be presented in context of the integrative properties of the astrocytic syncytium, allowing to implement heterosynaptic depression processes in neuronal networks. The process of microglia 'activation' and its control by astrocytes and neurons will then be analyzed under the perspective of an interplay between different P2 receptors and adenosine A2A receptors. In spite of these indications of a prominent role of purinergic signaling in the bidirectional communication between neurons and glia, its therapeutical exploitation still awaits obtaining an integrated view of the spatio-temporal action of ATP signaling and adenosine signaling, clearly distinguishing the involvement of both purinergic signaling systems in the regulation of physiological processes and in the control of pathogenic-like responses upon brain dysfunction or damage.
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9
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Illes P, Burnstock G, Tang Y. Astroglia-Derived ATP Modulates CNS Neuronal Circuits. Trends Neurosci 2019; 42:885-898. [PMID: 31704181 DOI: 10.1016/j.tins.2019.09.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 09/10/2019] [Accepted: 09/23/2019] [Indexed: 02/08/2023]
Abstract
It is broadly recognized that ATP not only supports energy storage within cells but is also a transmitter/signaling molecule that serves intercellular communication. Whereas the fast (co)transmitter function of ATP in the peripheral nervous system has been convincingly documented, in the central nervous system (CNS) ATP appears to be primarily a slow transmitter/modulator. Data discussed in the present review suggest that the slow modulatory effects of ATP arise as a result of its vesicular/nonvesicular release from astrocytes. ATP acts together with other glial signaling molecules such as cytokines, chemokines, and free radicals to modulate neuronal circuits. Hence, astrocytes are positioned at the crossroads of the neuron-glia-neuron communication pathway.
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Affiliation(s)
- Peter Illes
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany; Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine (TCM), 610075 Chengdu, China.
| | - Geoffrey Burnstock
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Yong Tang
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine (TCM), 610075 Chengdu, China
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10
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He Y, Shu G, Yang Y, Xu P, Xia Y, Wang C, Saito K, Hinton A, Yan X, Liu C, Wu Q, Tong Q, Xu Y. A Small Potassium Current in AgRP/NPY Neurons Regulates Feeding Behavior and Energy Metabolism. Cell Rep 2017; 17:1807-1818. [PMID: 27829152 PMCID: PMC6248907 DOI: 10.1016/j.celrep.2016.10.044] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 09/21/2016] [Accepted: 10/13/2016] [Indexed: 01/06/2023] Open
Abstract
Neurons that co-express agouti-related peptide (AgRP) and neuropeptide Y (NPY) are indispensable for normal feeding behavior. Firing activities of AgRP/NPY neurons are dynamically regulated by energy status and coordinate appropriate feeding behavior to meet nutritional demands. However, intrinsic mechanisms that regulate AgRP/NPY neural activities during the fed-to-fasted transition are not fully understood. We found that AgRP/NPY neurons in satiated mice express high levels of the small-conductance calcium-activated potassium channel 3 (SK3) and are inhibited by SK3-mediated potassium currents; on the other hand, food deprivation suppresses SK3 expression in AgRP/NPY neurons, and the decreased SK3-mediated currents contribute to fasting-induced activation of these neurons. Genetic mutation of SK3 specifically in AgRP/NPY neurons leads to increased sensitivity to diet-induced obesity, associated with chronic hyperphagia and decreased energy expenditure. Our results identify SK3 as a key intrinsic mediator that coordinates nutritional status with AgRP/NPY neural activities and animals’ feeding behavior and energy metabolism. Firing activities of AgRP/NPY neurons are essential for energy homeostasis. Heet al. demonstrate that SK3-mediated currents inhibit AgRP/NPY neurons in satiated mice and decreased SK3 expression contributes to fasting-induced activation of these neurons. Thus, dynamic SK3 functions coordinate nutritional status with AgRP/NPY neural activities and animals’ energy balance.
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Affiliation(s)
- Yanlin He
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Gang Shu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; College of Animal Science, South China Agricultural University, Guangzhou 100044, China
| | - Yongjie Yang
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Pingwen Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Yan Xia
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Chunmei Wang
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Kenji Saito
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Antentor Hinton
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Xiaofeng Yan
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Chen Liu
- Division of Hypothalamic Research, Department of Internal Medical, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Qi Wu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Yong Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
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11
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Beamer E, Kovács G, Sperlágh B. ATP released from astrocytes modulates action potential threshold and spontaneous excitatory postsynaptic currents in the neonatal rat prefrontal cortex. Brain Res Bull 2017; 135:129-142. [PMID: 29030320 DOI: 10.1016/j.brainresbull.2017.10.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 10/04/2017] [Accepted: 10/06/2017] [Indexed: 01/12/2023]
Abstract
Maternal immune activation during pregnancy is a risk factor for neurodevelopmental disorders, such as schizophrenia; however, a full mechanistic understanding has yet to be established. The activity of a transient cell population, the subplate neurons, is critical for the development of cortical inhibition and functional thalamocortical connections. Sensitivity of these cells to factors released during inflammation, therefore, may offer a link between maternal immune activation and the aberrant cortical development underlying some neuropsychiatric disorders. An elevated extracellular ATP concentration is associated with inflammation and has been shown to have an effect on neuronal activity. Here, we investigated the effect of ATP on the electrophysiological properties of subplate neurons. Exogenous ATP increased the frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs) at micromolar concentrations. Further, ATP released by astrocytes activated by the PAR-1 agonist, TFLLR-NH2, also increased the amplitude and frequency of sEPSCs in subplate neurons. The electrophysiological properties of subplate neurons recorded from prefrontal cortical (PFC) slices from neonatal rats were also disrupted in a maternal immune activation rat model of schizophrenia, with a suramin-sensitive increase in frequency and amplitude of sEPSCs. An alternative neurodevelopmental rat model of schizophrenia, MAM-E17, which did not rely on maternal immune activation, however, showed no change in subplate neuron activity. Both models were validated with behavioral assays, showing schizophrenia-like endophenotypes in young adulthood. The purinergic modulation of subplate neuron activity offers a potential explanatory link between maternal immune activation and disruptions in cortical development that lead to the emergence of neuropsychiatric disorders.
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Affiliation(s)
- Edward Beamer
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Gergely Kovács
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Beata Sperlágh
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
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12
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Perez EJ, Tapanes SA, Loris ZB, Balu DT, Sick TJ, Coyle JT, Liebl DJ. Enhanced astrocytic d-serine underlies synaptic damage after traumatic brain injury. J Clin Invest 2017; 127:3114-3125. [PMID: 28714867 DOI: 10.1172/jci92300] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 05/26/2017] [Indexed: 01/09/2023] Open
Abstract
After traumatic brain injury (TBI), glial cells have both beneficial and deleterious roles in injury progression and recovery. However, few studies have examined the influence of reactive astrocytes in the tripartite synapse following TBI. Here, we have demonstrated that hippocampal synaptic damage caused by controlled cortical impact (CCI) injury in mice results in a switch from neuronal to astrocytic d-serine release. Under nonpathological conditions, d-serine functions as a neurotransmitter and coagonist for NMDA receptors and is involved in mediating synaptic plasticity. The phasic release of neuronal d-serine is important in maintaining synaptic function, and deficiencies lead to reductions in synaptic function and plasticity. Following CCI injury, hippocampal neurons downregulated d-serine levels, while astrocytes enhanced production and release of d-serine. We further determined that this switch in the cellular source of d-serine, together with the release of basal levels of glutamate, contributes to synaptic damage and dysfunction. Astrocyte-specific elimination of the astrocytic d-serine-synthesizing enzyme serine racemase after CCI injury improved synaptic plasticity, brain oscillations, and learning behavior. We conclude that the enhanced tonic release of d-serine from astrocytes after TBI underlies much of the synaptic damage associated with brain injury.
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Affiliation(s)
- Enmanuel J Perez
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Stephen A Tapanes
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Zachary B Loris
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Darrick T Balu
- Translational Psychiatry Laboratory, McLean Hospital, Belmont, Massachusetts, USA
| | - Thomas J Sick
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Joseph T Coyle
- Laboratory of Psychiatric and Molecular Neuroscience, McLean Hospital, Belmont, Massachusetts, USA
| | - Daniel J Liebl
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, Florida, USA
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13
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P2Y Receptors in Synaptic Transmission and Plasticity: Therapeutic Potential in Cognitive Dysfunction. Neural Plast 2016; 2016:1207393. [PMID: 27069691 PMCID: PMC4812485 DOI: 10.1155/2016/1207393] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 02/10/2016] [Indexed: 01/02/2023] Open
Abstract
ATP released from neurons and astrocytes during neuronal activity or under pathophysiological circumstances is able to influence information flow in neuronal circuits by activation of ionotropic P2X and metabotropic P2Y receptors and subsequent modulation of cellular excitability, synaptic strength, and plasticity. In the present paper we review cellular and network effects of P2Y receptors in the brain. We show that P2Y receptors inhibit the release of neurotransmitters, modulate voltage- and ligand-gated ion channels, and differentially influence the induction of synaptic plasticity in the prefrontal cortex, hippocampus, and cerebellum. The findings discussed here may explain how P2Y1 receptor activation during brain injury, hypoxia, inflammation, schizophrenia, or Alzheimer's disease leads to an impairment of cognitive processes. Hence, it is suggested that the blockade of P2Y1 receptors may have therapeutic potential against cognitive disturbances in these states.
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Köles L, Kató E, Hanuska A, Zádori ZS, Al-Khrasani M, Zelles T, Rubini P, Illes P. Modulation of excitatory neurotransmission by neuronal/glial signalling molecules: interplay between purinergic and glutamatergic systems. Purinergic Signal 2015; 12:1-24. [PMID: 26542977 DOI: 10.1007/s11302-015-9480-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/26/2015] [Indexed: 12/29/2022] Open
Abstract
Glutamate is the main excitatory neurotransmitter of the central nervous system (CNS), released both from neurons and glial cells. Acting via ionotropic (NMDA, AMPA, kainate) and metabotropic glutamate receptors, it is critically involved in essential regulatory functions. Disturbances of glutamatergic neurotransmission can be detected in cognitive and neurodegenerative disorders. This paper summarizes the present knowledge on the modulation of glutamate-mediated responses in the CNS. Emphasis will be put on NMDA receptor channels, which are essential executive and integrative elements of the glutamatergic system. This receptor is crucial for proper functioning of neuronal circuits; its hypofunction or overactivation can result in neuronal disturbances and neurotoxicity. Somewhat surprisingly, NMDA receptors are not widely targeted by pharmacotherapy in clinics; their robust activation or inhibition seems to be desirable only in exceptional cases. However, their fine-tuning might provide a promising manipulation to optimize the activity of the glutamatergic system and to restore proper CNS function. This orchestration utilizes several neuromodulators. Besides the classical ones such as dopamine, novel candidates emerged in the last two decades. The purinergic system is a promising possibility to optimize the activity of the glutamatergic system. It exerts not only direct and indirect influences on NMDA receptors but, by modulating glutamatergic transmission, also plays an important role in glia-neuron communication. These purinergic functions will be illustrated mostly by depicting the modulatory role of the purinergic system on glutamatergic transmission in the prefrontal cortex, a CNS area important for attention, memory and learning.
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Affiliation(s)
- László Köles
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary.
| | - Erzsébet Kató
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Adrienn Hanuska
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Zoltán S Zádori
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Mahmoud Al-Khrasani
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Tibor Zelles
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Patrizia Rubini
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, 04107, Leipzig, Germany
| | - Peter Illes
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, 04107, Leipzig, Germany.
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Ficker C, Rozmer K, Kató E, Andó RD, Schumann L, Krügel U, Franke H, Sperlágh B, Riedel T, Illes P. Astrocyte-neuron interaction in the substantia gelatinosa of the spinal cord dorsal horn via P2X7 receptor-mediated release of glutamate and reactive oxygen species. Glia 2014; 62:1671-86. [PMID: 24895290 DOI: 10.1002/glia.22707] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 05/23/2014] [Accepted: 05/23/2014] [Indexed: 12/14/2022]
Abstract
The substantia gelatinosa (SG) of the spinal cord processes incoming painful information to ascending projection neurons. Whole-cell patch clamp recordings from SG spinal cord slices documented that in a low Ca(2+) /no Mg(2+) (low X(2+) ) external medium adenosine triphosphate (ATP)/dibenzoyl-ATP, Bz-ATP) caused inward current responses, much larger in amplitude than those recorded in a normal X(2+) -containing bath medium. The effect of Bz-ATP was antagonized by the selective P2X7 receptor antagonist A-438079. Neuronal, but not astrocytic Bz-ATP currents were strongly inhibited by a combination of the ionotropic glutamate receptor antagonists AP-5 and CNQX. In fact, all neurons and some astrocytes responded to NMDA, AMPA, and muscimol with inward current, demonstrating the presence of the respective receptors. The reactive oxygen species H2 O2 potentiated the effect of Bz-ATP at neurons but not at astrocytes. Hippocampal CA1 neurons exhibited a behavior similar to, but not identical with SG neurons. Although a combination of AP-5 and CNQX almost abolished the effect of Bz-ATP, H2 O2 was inactive. A Bz-ATP-dependent and A-438079-antagonizable reactive oxygen species production in SG slices was proven by a microelectrode biosensor. Immunohistochemical investigations showed the colocalization of P2X7-immunoreactivity with microglial (Iba1), but not astrocytic (GFAP, S100β) or neuronal (MAP2) markers in the SG. It is concluded that SG astrocytes possess P2X7 receptors; their activation leads to the release of glutamate, which via NMDA- and AMPA receptor stimulation induces cationic current in the neighboring neurons. P2X7 receptors have a very low density under resting conditions but become functionally upregulated under pathological conditions.
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Affiliation(s)
- Christoph Ficker
- Rudolf Boehm Institute for Pharmacology und Toxicology, University of Leipzig, Leipzig, Germany
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Wu HH, Yin JB, Zhang T, Cui YY, Dong YL, Chen GZ, Wang W. Inhibiting spinal neuron-astrocytic activation correlates with synergistic analgesia of dexmedetomidine and ropivacaine. PLoS One 2014; 9:e92374. [PMID: 24658263 PMCID: PMC3962412 DOI: 10.1371/journal.pone.0092374] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 02/21/2014] [Indexed: 02/07/2023] Open
Abstract
Background This study aims to identify that intrathecal (i.t.) injection of dexmedetomidine (Dex) and ropivacaine (Ropi) induces synergistic analgesia on chronic inflammatory pain and is accompanied with corresponding “neuron-astrocytic” alterations. Methods Male, adult Sprague-Dawley rats were randomly divided into sham, control and i.t. medication groups. The analgesia profiles of i.t. Dex, Ropi, and their combination detected by Hargreaves heat test were investigated on the subcutaneous (s.c.) injection of complete Freund adjuvant (CFA) induced chronic pain in rat and their synergistic analgesia was confirmed by using isobolographic analysis. During consecutive daily administration, pain behavior was daily recorded, and immunohistochemical staining was applied to investigate the number of Fos-immunoreactive (Fos-ir) neurons on hour 2 and day 1, 3 and 7, and the expression of glial fibrillary acidic protein (GFAP) within the spinal dorsal horn (SDH) on day 1, 3, 5 and 7 after s.c. injection of CFA, respectively, and then Western blot to examine spinal GFAP and β-actin levels on day 3 and 7. Results i.t. Dex or Ropi displayed a short-term analgesia in a dose-dependent manner, and consecutive daily administrations of their combination showed synergistic analgesia and remarkably down-regulated neuronal and astrocytic activations indicated by decreases in the number of Fos-ir neurons and the GFAP expression within the SDH, respectively. Conclusion i.t. co-delivery of Dex and Ropi shows synergistic analgesia on the chronic inflammatory pain, in which spinal “neuron-astrocytic activation” mechanism may play an important role.
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Affiliation(s)
- Huang-Hui Wu
- Department of Anesthesiology, Fuzhou General Hospital of Nanjing Military Region, Fuzhou, PR China
| | - Jun-Bin Yin
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, Fourth Military Medical University, Xi’an, PR China
| | - Ting Zhang
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, Fourth Military Medical University, Xi’an, PR China
| | - Yuan-Yuan Cui
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, Fourth Military Medical University, Xi’an, PR China
| | - Yu-Lin Dong
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, Fourth Military Medical University, Xi’an, PR China
| | - Guo-Zhong Chen
- Department of Anesthesiology, Fuzhou General Hospital of Nanjing Military Region, Fuzhou, PR China
- * E-mail: (GZC); (WW)
| | - Wen Wang
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, Fourth Military Medical University, Xi’an, PR China
- * E-mail: (GZC); (WW)
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Verkhratsky A, Burnstock G. Purinergic and glutamatergic receptors on astroglia. ADVANCES IN NEUROBIOLOGY 2014; 11:55-79. [PMID: 25236724 DOI: 10.1007/978-3-319-08894-5_4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Astroglial cells express many neurotransmitter receptors; the receptors to glutamate and ATP being the most abundant. Here, we provide a concise overview on the expression and main properties of astroglial glutamate receptors (ionotropic receptors represented by AMPA and NMDA subtypes) and metabotropic (mainly mGluR5 and mGluR3 subtypes) and purinoceptors (adenosine receptors of A1, A2A, A2B, and A3 types, ionotropic P2X1/5 and P2X7 subtypes, and metabotropic P2Y purinoceptors). We also discuss the role of these receptors in glial physiology and pathophysiology.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Sciences, School of Biological Sciences, The University of Manchester, 1.124 Stopford Building, Oxford Road, Manchester, M13 9PT, UK,
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Franke H, Illes P. Nucleotide signaling in astrogliosis. Neurosci Lett 2013; 565:14-22. [PMID: 24103370 DOI: 10.1016/j.neulet.2013.09.056] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 09/05/2013] [Accepted: 09/17/2013] [Indexed: 12/29/2022]
Abstract
Acute and chronic damage to the central nervous system (CNS) releases large quantities of ATP. Whereas the ATP concentration in the extracellular space is normally in the micromolar range, under these conditions it increases to millimolar levels. A number of ligand-gated cationic channels termed P2X receptors (7 mammalian subtypes), and G protein-coupled P2Y receptors (8 mammalian subtypes) are located at astrocytes, as confirmed by the measurement of the respective mRNA and protein. Activation of both the P2X7 and P2Y1,2 subtypes identified at astrocytes initiates astrogliosis isolating damaged brain areas from surrounding healthy cells and synthesizing neurotrophins and pleotrophins that participate in neuronal recovery. Astrocytes are considered as cells of high plasticity which may alter their properties in a culture medium. Therefore, recent work concentrates on investigating nucleotide effects at in situ (acute brain slices) and in vivo astrocytes. A wealth of data relates to the involvement of purinergic mechanisms in astrogliosis induced by acute CNS injury such as mechanical trauma and hypoxia/ischemia. The released ATP may act within minutes as an excitotoxic molecule; at a longer time-scale within days it causes neuroinflammation. These effects sum up as necrosis/apoptosis on the one hand and proliferation on the other. Although the role of nucleotides in chronic neurodegenerative illnesses is not quite clear, it appears that they aggravate the consequences of the primary disease. Epilepsy and neuropathic pain are also associated with the release of ATP and a pathologic glia-neuron interaction leading to astrogliosis and cell death. In view of these considerations, P2 receptor antagonists may open new therapeutic vistas in all forms of acute and chronic CNS damage.
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Affiliation(s)
- Heike Franke
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany
| | - Peter Illes
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany.
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Choi RCY, Chu GKY, Siow NL, Yung AWY, Yung LY, Lee PSC, Lo CCW, Simon J, Dong TTX, Barnard EA, Tsim KWK. Activation of UTP-sensitive P2Y2 receptor induces the expression of cholinergic genes in cultured cortical neurons: a signaling cascade triggered by Ca2+ mobilization and extracellular regulated kinase phosphorylation. Mol Pharmacol 2013; 84:50-61. [PMID: 23592515 DOI: 10.1124/mol.112.084160] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
ATP functions as an extracellular signaling molecule that is costored and coreleased with neurotransmitters at central and peripheral neuronal synapses. Stimulation by ATP upregulates the expression of synaptic genes in muscle-including the genes for nicotine acetylcholine receptor (α-, δ-, and ε-subunits) and acetylcholinesterase (AChE)-via the P2Y receptor (P2YR), but the trophic response of neurons to the activation of P2YRs is less well understood. We reported that cultured cortical neurons and the developing rat brain expressed different types of P2YRs, and among these the UTP-sensitive P2Y2R was the most abundant. P2Y2R was found to exist in membrane rafts and it colocalized with the postsynaptic protein PSD-95 in cortical neurons. Notably, agonist-dependent stimulation of P2Y2R elevated the neuronal expression of cholinergic genes encoding AChE, PRiMA (an anchor for the globular form AChE), and choline acetyltransferase, and this induction was mediated by a signaling cascade that involved Ca(2+) mobilization and extracellular regulated kinases 1/2 activation. The importance of P2Y2R action was further shown by the receptor's synergistic effect with P2Y1R in enhancing cholinergic gene expression via the robust stimulation of Ca(2+) influx. Taken together our results revealed a developmental function of P2Y2R in promoting synaptic gene expression and demonstrated the influence of costimulation of P2Y1R and P2Y2R in neurons.
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Affiliation(s)
- Roy C Y Choi
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.
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Anoxic depolarization of hippocampal astrocytes: possible modulation by P2X7 receptors. Neurochem Int 2012; 62:15-22. [PMID: 23147683 DOI: 10.1016/j.neuint.2012.11.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 10/31/2012] [Accepted: 11/01/2012] [Indexed: 12/30/2022]
Abstract
Current responses from CA1 neurons and stratum oriens astrocytes were recorded from hippocampal brain slices by means of the whole-cell patch-clamp technique. Anoxic depolarization (AD) was induced by an oxygen/glucose-deprived (OGD) medium also containing sodium iodoacetate and antimycin, in order to block glycolysis and oxidative phosphorylation, respectively. Anoxic depolarization has been reported to be due to the sudden increase of the extracellular K(+) concentration and the accompanying explosive rise in glutamate concentration. We asked ourselves whether the release of ATP activating P2X7 receptors is also involved in the AD. Although, the AD was evoked in absolute synchrony in neurons and astrocytes, and the NMDA receptor antagonistic AP-5 depressed these responses, neither the non-selective P2 receptor antagonist PPADS, nor the highly selective P2X7 receptor antagonist A438079 interfered with the AD or its delay time in neurons/astrocytes after inducing chemical hypoxia. However, A438079, but not PPADS increased in astrocytes the slow inward current observed in a hypoxic medium. It is concluded that ATP co-released with glutamate by hypoxic stimulation has only a minor function in the present brain slice system.
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Ormel L, Stensrud MJ, Chaudhry FA, Gundersen V. A distinct set of synaptic-like microvesicles in atroglial cells contain VGLUT3. Glia 2012; 60:1289-300. [DOI: 10.1002/glia.22348] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 04/13/2012] [Indexed: 11/09/2022]
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Ormel L, Stensrud MJ, Bergersen LH, Gundersen V. VGLUT1 is localized in astrocytic processes in several brain regions. Glia 2011; 60:229-38. [DOI: 10.1002/glia.21258] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 09/26/2011] [Indexed: 01/26/2023]
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Bergersen LH, Morland C, Ormel L, Rinholm JE, Larsson M, Wold JFH, Røe AT, Stranna A, Santello M, Bouvier D, Ottersen OP, Volterra A, Gundersen V. Immunogold detection of L-glutamate and D-serine in small synaptic-like microvesicles in adult hippocampal astrocytes. ACTA ACUST UNITED AC 2011; 22:1690-7. [PMID: 21914633 DOI: 10.1093/cercor/bhr254] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Glutamate and the N-methyl-D-aspartate receptor ligand D-serine are putative gliotransmitters. Here, we show by immunogold cytochemistry of the adult hippocampus that glutamate and D-serine accumulate in synaptic-like microvesicles (SLMVs) in the perisynaptic processes of astrocytes. The estimated concentration of fixed glutamate in the astrocytic SLMVs is comparable to that in synaptic vesicles of excitatory nerve terminals (≈ 45 and ≈ 55 mM, respectively), whereas the D-serine level is about 6 mM. The vesicles are organized in small spaced clusters located near the astrocytic plasma membrane. Endoplasmic reticulum is regularly found in close vicinity to SLMVs, suggesting that astrocytes contain functional nanodomains, where a local Ca(2+) increase can trigger release of glutamate and/or D-serine.
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Affiliation(s)
- L H Bergersen
- Department of Anatomy, Centre for Molecular Biology and Neuroscience, Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway
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VEGF modulates NMDA receptors activity in cerebellar granule cells through Src-family kinases before synapse formation. Proc Natl Acad Sci U S A 2011; 108:13782-7. [PMID: 21804034 DOI: 10.1073/pnas.1100341108] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
NMDA type glutamate receptors (NMDARs) are best known for their role in synaptogenesis and synaptic plasticity. Much less is known about their developmental role before neurons form synapses. We report here that VEGF, which promotes migration of granule cells (GCs) during postnatal cerebellar development, enhances NMDAR-mediated currents and Ca(2+) influx in immature GCs before synapse formation. The VEGF receptor Flk1 forms a complex with the NMDAR subunits NR1 and NR2B. In response to VEGF, the number of Flk1/NR2B coclusters on the cell surface increases. Stimulation of Flk1 by VEGF activates Src-family kinases, which increases tyrosine phosphorylation of NR2B. Inhibition of Src-family kinases abolishes the VEGF-dependent NR2B phosphorylation and amplification of NMDAR-mediated currents and Ca(2+) influx in GCs. These findings identify VEGF as a modulator of NMDARs before synapse formation and highlight a link between an activity-independent neurovascular guidance cue (VEGF) and an activity-regulated neurotransmitter receptor (NMDAR).
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Zhang L, Guo F, Su S, Guo H, Xiong C, Yin J, Li W, Wang Y. Na(+)/K(+)-ATPase inhibition upregulates NMDA-evoked currents in rat hippocampal CA1 pyramidal neurons. Fundam Clin Pharmacol 2011; 26:503-12. [PMID: 21521363 DOI: 10.1111/j.1472-8206.2011.00947.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Na(+)/K(+)-ATPase and N-methyl-D-aspartate (NMDA) receptor in hippocampus play very important roles in the regulation of learning and memory. Here, we showed that dihydroouabain (DHO, 10(-5)-10(-3) M), a Na(+)/K(+)-ATPase inhibitor, significantly potentiated NMDA current in rat hippocampal CA1 pyramidal neurons, which was blocked by PP2 (the selective Src tyrosine kinase inhibitor) and PD-98059 [the selective inhibitor of the mitogen-activated protein kinases (MAPK) cascade]. These findings reported here uncover that Src mediates the cross-talk between Na(+)/K(+)-ATPase and NMDA receptor to transduce the signals from Na(+)/K(+)-ATPase to the MAPK cascade and provide new insights into therapeutic target for deeper understanding of the nature of cognitive disorder.
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Affiliation(s)
- Linan Zhang
- Department of Pharmacology, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang, Hebei 050017, China.
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Köles L, Leichsenring A, Rubini P, Illes P. P2 receptor signaling in neurons and glial cells of the central nervous system. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2011; 61:441-93. [PMID: 21586367 DOI: 10.1016/b978-0-12-385526-8.00014-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Purine and pyrimidine nucleotides are extracellular signaling molecules in the central nervous system (CNS) leaving the intracellular space of various CNS cell types via nonexocytotic mechanisms. In addition, ATP is a neuro-and gliotransmitter released by exocytosis from neurons and neuroglia. These nucleotides activate P2 receptors of the P2X (ligand-gated cationic channels) and P2Y (G protein-coupled receptors) types. In mammalians, seven P2X and eight P2Y receptor subunits occur; three P2X subtypes form homomeric or heteromeric P2X receptors. P2Y subtypes may also hetero-oligomerize with each other as well as with other G protein-coupled receptors. P2X receptors are able to physically associate with various types of ligand-gated ion channels and thereby to interact with them. The P2 receptor homomers or heteromers exhibit specific sensitivities against pharmacological ligands and have preferential functional roles. They may be situated at both presynaptic (nerve terminals) and postsynaptic (somatodendritic) sites of neurons, where they modulate either transmitter release or the postsynaptic sensitivity to neurotransmitters. P2 receptors exist at neuroglia (e.g., astrocytes, oligodendrocytes) and microglia in the CNS. The neuroglial P2 receptors subserve the neuron-glia cross talk especially via their end-feets projecting to neighboring synapses. In addition, glial networks are able to communicate through coordinated oscillations of their intracellular Ca(2+) over considerable distances. P2 receptors are involved in the physiological regulation of CNS functions as well as in its pathophysiological dysregulation. Normal (motivation, reward, embryonic and postnatal development, neuroregeneration) and abnormal regulatory mechanisms (pain, neuroinflammation, neurodegeneration, epilepsy) are important examples for the significance of P2 receptor-mediated/modulated processes.
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Affiliation(s)
- Laszlo Köles
- Rudolph-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Germany
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Nörenberg W, Schunk J, Fischer W, Sobottka H, Riedel T, Oliveira JF, Franke H, Illes P. Electrophysiological classification of P2X7 receptors in rat cultured neocortical astroglia. Br J Pharmacol 2010; 160:1941-52. [PMID: 20649592 DOI: 10.1111/j.1476-5381.2010.00736.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND AND PURPOSE P2X7 receptors are ATP-gated cation channels mediating important functions in microglial cells, such as the release of cytokines and phagocytosis. Electrophysiological evidence that these receptors also occur in CNS astroglia is rare and rather incomplete. EXPERIMENTAL APPROACH We used whole-cell patch-clamp recordings to search for P2X7 receptors in astroglial-neuronal co-cultures prepared from the cerebral cortex of rats. KEY RESULTS All the astroglial cells investigated responded to ATP with membrane currents, reversing around 0 mV. These currents could be also detected in isolated outside-out patch vesicles. The results of the experiments with the P2X [alpha,beta-methylene ATP and 2'-3'-O-(4-benzoyl) ATP] and P2Y receptor agonists [adenosine 5'-O-(2-thiodiphosphate), uridine 5'-diphosphate, uridine 5'-triphosphate (UTP) and UDP-glucose] suggested the involvement of P2X receptors in this response. The potentiation of ATP responses in a low divalent cation or alkaline bath, but not by ivermectin, made it likely that a P2X7 receptor is operational. Blockade of the ATP effect by the P2X7 antagonists Brilliant Blue G, calmidazolium and oxidized ATP corroborated this assumption. CONCLUSIONS AND IMPLICATIONS Rat cultured cortical astroglia possesses functional P2X7 receptors. It is suggested that astrocytic P2X7 receptors respond to high local ATP concentrations during neuronal injury.
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Affiliation(s)
- W Nörenberg
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany.
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Mei XP, Wang W, Wang W, Zhu C, Chen L, Zhang T, Xu LX, Wu SX, Li YQ. Combining ketamine with astrocytic inhibitor as a potential analgesic strategy for neuropathic pain ketamine, astrocytic inhibitor and pain. Mol Pain 2010; 6:50. [PMID: 20815929 PMCID: PMC2942826 DOI: 10.1186/1744-8069-6-50] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Accepted: 09/06/2010] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Neuropathic pain is an intractable clinical problem. Intrathecal ketamine, a noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist, is reported to be useful for treating neuropathic pain in clinic by inhibiting the activity of spinal neurons. Nevertheless, emerging studies have disclosed that spinal astrocytes played a critical role in the initiation and maintenance of neuropathic pain. However, the present clinical therapeutics is still just concerning about neuronal participation. Therefore, the present study is to validate the coadministration effects of a neuronal noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist ketamine and astrocytic cytotoxin L-α-aminoadipate (LAA) on spinal nerve ligation (SNL)-induced neuropathic pain. RESULTS Intrathecal ketamine (10, 100, 1000 μg/kg) or LAA (10, 50, 100 nmol) alleviated SNL-induced mechanical allodynia in a dose-dependent manner respectively. Phosphorylated NR1 (pNR1) or glial fibrillary acidic protein (GFAP) expression was down-regulated by intrathecal ketamine (100, 1000 μg/kg) or LAA (50, 100 nmol) respectively. The combination of ketamine (100 μg/kg) with LAA (50 nmol) showed superadditive effects on neuropathic pain compared with that of intrathecal administration of either ketamine or LAA alone. Combined administration obviously relieved mechanical allodynia in a quick and stable manner. Moreover, down-regulation of pNR1 and GFAP expression were also enhanced by drugs coadministration. CONCLUSIONS These results suggest that combining NMDAR antagonist ketamine with an astrocytic inhibitor or cytotoxin, which is suitable for clinical use once synthesized, might be a potential strategy for clinical management of neuropathic pain.
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Affiliation(s)
- Xiao-Peng Mei
- Department of Anesthesiology, School of Stomatology, Fourth Military Medical University, Xi'an, China
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Oliveira JF, Riedel T, Leichsenring A, Heine C, Franke H, Krügel U, Nörenberg W, Illes P. Rodent cortical astroglia express in situ functional P2X7 receptors sensing pathologically high ATP concentrations. ACTA ACUST UNITED AC 2010; 21:806-20. [PMID: 20739479 DOI: 10.1093/cercor/bhq154] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
ATP is an important neuronal and astroglial signaling molecule in the brain. In the present study, brain slices were prepared from the prefrontal cortex (PFC) of Wistar rats and 2 lines of mice. P2X₇ receptor immunoreactivity was colocalized with astro- and microglial but not neuronal markers. Whole-cell patch-clamp recordings showed that, in astroglial cells, dibenzoyl-ATP (BzATP) and ATP caused inward currents, near the resting membrane potential. The inactivity of α,β-methylene ATP, as well as the potency increases of BzATP and ATP in a low divalent cation (X²(+))-containing superfusion medium suggested the involvement of P2X₇ receptors. This idea was corroborated by the inhibition of these current responses by PPADS, Brilliant Blue G, A 438079, and calmidazolium. Ivermectin, trinitrophenyl-adenosine-5'-triphosphate, and cyclopentyl-dipropylxanthine did not alter the agonist effects. The reversal potential of BzATP was near 0 mV, indicating the opening of cationic receptor channels. In a low X²(+) superfusion medium, ATP-induced current responses in PFC astroglial cells of wild-type mice but not of the P2X₇ knockouts. Hence, cortical astroglia of rats and mice possess functional P2X₇ receptors. These receptors may participate in necrotic/apoptotic or proliferative reactions after stimulation by large quantities of ATP released by central nervous system injury.
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Affiliation(s)
- João Filipe Oliveira
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, D-04107 Leipzig, Germany
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Fischer W, Nörenberg W, Franke H, Schaefer M, Illes P. Increase of intracellular Ca2+ by P2Y but not P2X receptors in cultured cortical multipolar neurons of the rat. J Comp Neurol 2009; 516:343-59. [PMID: 19655384 DOI: 10.1002/cne.22079] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The expression and functionality of P2X/P2Y receptor subtypes in multipolar nonpyramidal neurons of mixed cortical cell cultures were investigated by means of immunocytochemistry and fura-2 microfluorimetry. The morphological studies revealed that most of the neurons are immunoreactive for GABA and express a range of P2X/P2Y receptors, predominantly of the P2X(2,4,6) and P2Y(1,2) subtypes. P2X(1) and P2X(7) receptor immunoreactivity (IR) was found on thin axon-like processes and presynaptic structures, respectively. Application of ATP caused a small concentration-dependent increase in intracellular Ca2+ concentration ([Ca2+]i) in most investigated neurons, whereas only about the half of these cells responded to 2',3'-O-(benzoyl-4-benzoyl)-ATP (BzATP), ADPbetaS, 2MeSADP, or 2MeSATP and even fewer cells to UTP. In contrast, alpha,beta-meATP, UDP, and UDP-glucose failed to produce any [Ca2+]i signaling. The response to ATP itself was inhibited by pyridoxal-5'-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS), Reactive Blue 2, 2'-deoxy-N(6)-methyl adenosine 3',5'-diphosphate (MRS2179), and suramin (300 microM) as well as by a cyclopiazonic acid-induced depletion of intracellular Ca2+ stores. A Ca2+-free external medium tended to decrease the ATP-induced [Ca2+]i transients, although this action did not reach statistical significance. Various blockers of voltage-sensitive Ca2+ channels and the gap junction inhibitor carbenoxolone did not interfere with the effect of ATP, whereas a combination of the ionotropic glutamate receptor antagonists D(-)-2-amino-5-phosphonopentanoic acid (AP5) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) decreased it. Cross-desensitization experiments between ADPbetaS or UTP and ATP suggested that ATP acts on the one hand via P2Y(1,2) receptors and on the other hand by additional signaling mechanisms. These mechanisms may involve the release of glutamate (which in consequence activates ionotropic glutamate receptors) and the entry of Ca2+ via store-operated Ca2+ channels. Evidence for the presence of functional P2X receptors, in particular P2X(7), remains elusive.
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Affiliation(s)
- Wolfgang Fischer
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Haertelstrasse 16-18, Leipzig D-04107, Germany.
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31
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van Heerden JH, Conesa A, Stein DJ, Montaner D, Russell V, Illing N. Parallel changes in gene expression in peripheral blood mononuclear cells and the brain after maternal separation in the mouse. BMC Res Notes 2009; 2:195. [PMID: 19781058 PMCID: PMC2759952 DOI: 10.1186/1756-0500-2-195] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Accepted: 09/25/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The functional integration of the neuro-, endocrine- and immune-systems suggests that the transcriptome of white blood cells may reflect neuropsychiatric states, and be used as a non-invasive diagnostic indicator. We used a mouse maternal separation model, a paradigm of early adversity, to test the hypothesis that transcriptional changes in peripheral blood mononuclear cells (PBMCs) are paralleled by specific gene expression changes in prefrontal cortex (PFC), hippocampus (Hic) and hypothalamus (Hyp). Furthermore, we evaluated whether gene expression profiles of PBMCs could be used to predict the separation status of individual animals. FINDINGS Microarray gene expression profiles of all three brain regions provided substantial evidence of stress-related neural differences between maternally separated and control animals. For example, changes in expression of genes involved in the glutamatergic and GABAergic systems were identified in the PFC and Hic, supporting a stress-related hyperglutamatergic state within the separated group. The expression of 50 genes selected from the PBMC microarray data provided sufficient information to predict treatment classes with 95% accuracy. Importantly, stress-related transcriptome differences in PBMC populations were paralleled by stress-related gene expression changes in CNS target tissues. CONCLUSION These results confirm that the transcriptional profiles of peripheral immune tissues occur in parallel to changes in the brain and contain sufficient information for the efficient diagnostic prediction of stress-related neural states in mice. Future studies will need to evaluate the relevance of the predictor set of 50 genes within clinical settings, specifically within a context of stress-related disorders.
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Affiliation(s)
- Johan H van Heerden
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, 7701, South Africa.
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Mei X, Wang W, Wang W, Li Y, Zhang H, Wu S, Li Y, Xu L. Inhibiting astrocytic activation: a novel analgesic mechanism of ketamine at the spinal level? J Neurochem 2009; 109:1691-700. [DOI: 10.1111/j.1471-4159.2009.06087.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Verkhrasky A, Krishtal OA, Burnstock G. Purinoceptors on Neuroglia. Mol Neurobiol 2009; 39:190-208. [DOI: 10.1007/s12035-009-8063-2] [Citation(s) in RCA: 154] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2009] [Accepted: 02/24/2009] [Indexed: 02/06/2023]
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34
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Oliveira JF, Krügel U, Köles L, Illes P, Wirkner K. Blockade of glutamate transporters leads to potentiation of NMDA receptor current in layer V pyramidal neurons of the rat prefrontal cortex via group II metabotropic glutamate receptor activation. Neuropharmacology 2008; 55:447-53. [PMID: 18680754 DOI: 10.1016/j.neuropharm.2008.07.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 07/13/2008] [Accepted: 07/17/2008] [Indexed: 10/21/2022]
Abstract
Membrane currents of layer V pyramidal cells in slices of the rat prefrontal cortex (PFC) were recorded with the patch-clamp technique. In an Mg2+-free superfusion medium l-trans-pyrrolidine-2,4-dicarboxylic acid (PDC), a preferential blocker of astrocytic glutamate transporters, caused inward current due to the activation of NMDA receptors. The blockade of conducted action potentials by tetrodotoxin did not interfere with this effect. ATP was inactive when given alone and potentiated the NMDA-induced current in an Mg2+-containing but not Mg2+-free superfusion medium. Agonists of group I ((S)-3,5-dihydroxyphenylglycine; DHPG) and II ((1R,4R,5S,6R)-4-amino-2-oxabicyclo[3.1.0]hexane-4,6-dicarboxylic acid; LY 379268) metabotropic glutamate receptors (mGluRs) also potentiated responses to NMDA, whereas the group III mGluR agonist L-(+)-2-amino-4-phosphonobutyric acid (L-AP4) did not affect them. In contrast to ATP, PDC evoked inward current in the absence but not in the presence of external Mg2+, when given alone, and facilitated the NMDA effect Mg2+-independently. The PDC-induced facilitation of NMDA responses was blocked by group II ((2S)-2-amino-2-[(1S,2S)-2-carboxycycloprop-1-yl]-3-(xanth-9-yl) propanoic acid; LY 341495), but not group I ((RS)-1-aminoindan-1,5-dicarboxylic acid; AIDA) or III (alpha-methyl-3-methyl-4-phosphonophenylglycine; UBP 1112) mGluR antagonists. In conclusion, the blockade of astrocytic glutamate uptake by PDC may lead to a stimulation of group II mGluRs, while the triggering of exocytotic glutamate release from astrocytes by ATP may cause activation of group I mGluRs, both situated postsynaptically at layer V PFC pyramidal cells. Either group of mGluRs may interact with NMDA receptors in a positive manner.
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Affiliation(s)
- Joao F Oliveira
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Haertelstrasse 16-18, D-04107 Leipzig, Germany
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35
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Selective loss of P2Y2 nucleotide receptor immunoreactivity is associated with Alzheimer's disease neuropathology. J Neural Transm (Vienna) 2008; 115:1165-72. [PMID: 18506388 DOI: 10.1007/s00702-008-0067-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Accepted: 05/05/2008] [Indexed: 10/22/2022]
Abstract
The uridine nucleotide-activated P2Y2, P2Y4 and P2Y6 receptors are widely expressed in the brain and are involved in many CNS processes, including those which malfunction in Alzheimer's disease (AD). However, the status of these receptors in the AD neocortex, as well as their putative roles in the pathogenesis of neuritic plaques and neurofibrillary tangles, remain unclear. In this study, we used immunoblotting to measure P2Y2, P2Y4 and P2Y6 receptors in two regions of the postmortem neocortex of neuropathologically assessed AD patients and aged controls. P2Y2 immunoreactivity was found to be selectively reduced in the AD parietal cortex, while P2Y4 and P2Y6 levels were unchanged. In contrast, all three receptors were preserved in the occipital cortex, which is known to be minimally affected by AD neuropathology. Furthermore, reductions in parietal P2Y2 immunoreactivity correlated both with neuropathologic scores and markers of synapse loss. These results provide a basis for considering P2Y2 receptor changes as a neurochemical substrate of AD, and point towards uridine nucleotide-activated P2Y receptors as novel targets for disease-modifying AD pharmacotherapeutic strategies.
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36
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Nagy J. Alcohol related changes in regulation of NMDA receptor functions. Curr Neuropharmacol 2008; 6:39-54. [PMID: 19305787 PMCID: PMC2645546 DOI: 10.2174/157015908783769662] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Revised: 07/19/2007] [Accepted: 10/20/2007] [Indexed: 12/25/2022] Open
Abstract
Long-term alcohol exposure may lead to development of alcohol dependence in consequence of altered neurotransmitter functions. Accumulating evidence suggests that the N-methyl-D-aspartate (NMDA) type of glutamate receptors is a particularly important site of ethanol's action. Several studies showed that ethanol potently inhibits NMDA receptors (NMDARs) and prolonged ethanol exposition leads to a compensatory "up-regulation" of NMDAR mediated functions. Therefore, alterations in NMDAR function are supposed to contribute to the development of ethanol tolerance, dependence as well as to the acute and late signs of ethanol withdrawal.A number of publications report alterations in the expression and phosphorylation states of NMDAR subunits, in their interaction with scaffolding proteins or other receptors in consequence of chronic ethanol treatment. Our knowledge on the regulatory processes, which modulate NMDAR functions including factors altering transcription, protein expression and post-translational modifications of NMDAR subunits, as well as those influencing their interactions with different regulatory proteins or other downstream signaling elements are incessantly increasing. The aim of this review is to summarize the complex chain of events supposedly playing a role in the up-regulation of NMDAR functions in consequence of chronic ethanol exposure.
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Affiliation(s)
- József Nagy
- Gedeon Richter Plc., Pharmacological and Drug Safety Research, Laboratory for Molecular Cell Biology, Budapest 10. P.O. Box 27, H-1475 Hungary.
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37
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Köles L, Gerevich Z, Oliveira JF, Zadori ZS, Wirkner K, Illes P. Interaction of P2 purinergic receptors with cellular macromolecules. Naunyn Schmiedebergs Arch Pharmacol 2007; 377:1-33. [DOI: 10.1007/s00210-007-0222-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Accepted: 11/12/2007] [Indexed: 02/04/2023]
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38
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Bowser DN, Khakh BS. Vesicular ATP is the predominant cause of intercellular calcium waves in astrocytes. ACTA ACUST UNITED AC 2007; 129:485-91. [PMID: 17504911 PMCID: PMC2151627 DOI: 10.1085/jgp.200709780] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Brain astrocytes signal to each other and neurons. They use changes in their intracellular calcium levels to trigger release of transmitters into the extracellular space. These can then activate receptors on other nearby astrocytes and trigger a propagated calcium wave that can travel several hundred micrometers over a timescale of seconds. A role for endogenous ATP in calcium wave propagation in hippocampal astrocytes has been suggested, but the mechanisms remain incompletely understood. Here we explored how calcium waves arise and directly tested whether endogenously released ATP contributes to astrocyte calcium wave propagation in hippocampal astrocytes. We find that vesicular ATP is the major, if not the sole, determinant of astrocyte calcium wave propagation over distances between ∼100 and 250 μm, and ∼15 s from the point of wave initiation. These actions of ATP are mediated by P2Y1 receptors. In contrast, metabotropic glutamate receptors and gap junctions do not contribute significantly to calcium wave propagation. Our data suggest that endogenous extracellular astrocytic ATP can signal over broad spatiotemporal scales.
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Affiliation(s)
- David N Bowser
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 2QH, UK
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39
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Resende RR, Majumder P, Gomes KN, Britto LRG, Ulrich H. P19 embryonal carcinoma cells as in vitro model for studying purinergic receptor expression and modulation of N-methyl-d-aspartate–glutamate and acetylcholine receptors during neuronal differentiation. Neuroscience 2007; 146:1169-81. [PMID: 17418494 DOI: 10.1016/j.neuroscience.2007.02.041] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2006] [Revised: 02/09/2007] [Accepted: 02/12/2007] [Indexed: 10/23/2022]
Abstract
The in vitro differentiation of P19 murine embryonal carcinoma cells to neurons resembles developmental stages which are encountered during neuronal development. Three days following induction to neuronal differentiation by retinoic acid, most cells of the P19 population lost expression of the stage specific embryonic antigen (SSEA-1) and expressed the neural progenitor cell specific antigen nestin. Beginning from day 4 of differentiation nestin expression was down-regulated, and expression of neuron-specific enolase as marker of differentiated neurons increased. The molecular mechanisms underlying neuronal differentiation are poorly understood. We have characterized the participation of purinergic ionotropic (P2X) and metabotropic (P2Y) receptors at mRNA transcription and protein levels as well as ATP-induced Ca2+ transients during neuronal differentiation of P19 cells. Gene and protein expression of P2X2, P2X6, P2Y2, and P2Y6 receptors increased during the course of differentiation, whereas P2X3, P2X4, P2Y1 and P2Y4 receptor expression was high in embryonic P19 cells and then decreased following induction of P19 cells to differentiation. P2X1 receptor protein expression was only detected on days 2 and 4 of differentiation. Although P2X5 and P2X7 mRNA transcription was present, no protein expression for this receptor subunit could be detected throughout the differentiation process. In undifferentiated cells, mainly ionotropic P2X receptors contributed to the ATP-induced Ca2+-response. In neuronal-differentiated P19 cells, the ATP-induced Ca2+-response was increased and the metabotropic component predominated. Purinergic receptor function is implicated to participate in neuronal maturation, as cholinergic and glutamate-N-methyl-D-aspartate (NMDA) induced calcium responses were affected when cells were differentiated in the presence of purinergic receptor antagonists pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), suramin or reactive blue-2. Our data suggest that inhibition of P2Y1 and possibly P2X2 receptors led to a loss of NMDA receptor activity whereas blockade of possibly P2X2 and P2Y2 purinergic receptors during neuronal differentiation of P19 mouse led to inhibition of cholinergic receptor responses.
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MESH Headings
- Animals
- Blotting, Western
- Cell Differentiation/physiology
- Cell Line
- Embryonal Carcinoma Stem Cells
- Fluorescent Antibody Technique
- Immunohistochemistry
- Mice
- Mice, Inbred BALB C
- Microscopy, Confocal
- Neoplastic Stem Cells/metabolism
- Neurons/metabolism
- Purinergic Antagonists
- Purinergic P1 Receptor Antagonists
- Purinergic P2 Receptor Antagonists
- Pyridoxal Phosphate/analogs & derivatives
- Pyridoxal Phosphate/pharmacology
- Receptors, Cholinergic/metabolism
- Receptors, Muscarinic/biosynthesis
- Receptors, Muscarinic/genetics
- Receptors, N-Methyl-D-Aspartate/metabolism
- Receptors, Nicotinic/biosynthesis
- Receptors, Nicotinic/genetics
- Receptors, Purinergic/biosynthesis
- Receptors, Purinergic/genetics
- Receptors, Purinergic P1/biosynthesis
- Receptors, Purinergic P1/genetics
- Receptors, Purinergic P2/biosynthesis
- Receptors, Purinergic P2/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Suramin/pharmacology
- Triazines/pharmacology
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Affiliation(s)
- R R Resende
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-900 São Paulo, SP, Brazil
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Lee CJ, Mannaioni G, Yuan H, Woo DH, Gingrich MB, Traynelis SF. Astrocytic control of synaptic NMDA receptors. J Physiol 2007; 581:1057-81. [PMID: 17412766 PMCID: PMC2170820 DOI: 10.1113/jphysiol.2007.130377] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Astrocytes express a wide range of G-protein coupled receptors that trigger release of intracellular Ca2+, including P2Y, bradykinin and protease activated receptors (PARs). By using the highly sensitive sniffer-patch technique, we demonstrate that the activation of P2Y receptors, bradykinin receptors and protease activated receptors all stimulate glutamate release from cultured or acutely dissociated astrocytes. Of these receptors, we have utilized PAR1 as a model system because of favourable pharmacological and molecular tools, its prominent expression in astrocytes and its high relevance to neuropathological processes. Astrocytic PAR1-mediated glutamate release in vitro is Ca2+ dependent and activates NMDA receptors on adjacent neurones in culture. Activation of astrocytic PAR1 in hippocampal slices induces an APV-sensitive inward current in CA1 neurones and causes APV-sensitive neuronal depolarization in CA1 neurones, consistent with release of glutamate from astrocytes. PAR1 activation enhances the NMDA receptor-mediated component of synaptic miniature EPSCs, evoked EPSCs and evoked EPSPs in a Mg2+-dependent manner, which may reflect spine head depolarization and consequent reduction of NMDA receptor Mg2+ block during subsequent synaptic currents. The release of glutamate from astrocytes following PAR1 activation may also lead to glutamate occupancy of some perisynaptic NMDA receptors, which pass current following relief of tonic Mg2+ block during synaptic depolarization. These results suggest that astrocytic G-protein coupled receptors that increase intracellular Ca2+ can tune synaptic NMDA receptor responses.
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Affiliation(s)
- C Justin Lee
- Center for Neural Science, Division of Life Sciences, Korea Institute of Science and Technology, Seoul, Korea
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41
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Cabello N, Remelli R, Canela L, Soriguera A, Mallol J, Canela EI, Robbins MJ, Lluis C, Franco R, McIlhinney RAJ, Ciruela F. Actin-binding protein alpha-actinin-1 interacts with the metabotropic glutamate receptor type 5b and modulates the cell surface expression and function of the receptor. J Biol Chem 2007; 282:12143-53. [PMID: 17311919 DOI: 10.1074/jbc.m608880200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Receptors for neurotransmitters require scaffolding proteins for membrane microdomain targeting and for regulating receptor function. Using a yeast two-hybrid screen, alpha-actinin-1, a major F-actin cross-linking protein, was identified as a binding partner for the C-terminal domain of metabotropic glutamate receptor type 5b (mGlu(5b) receptor). Co-expression, co-immunoprecipitation, and pull-down experiments showed a close and specific interaction between mGlu(5b) receptor and alpha-actinin-1 in both transfected HEK-293 cells and rat striatum. The interaction of alpha-actinin-1 with mGlu(5b) receptor modulated the cell surface expression of the receptor. This was dependent on the binding of alpha-actinin-1 to the actin cytoskeleton. In addition, the alpha-actinin-1/mGlu(5b) receptor interaction regulated receptor-mediated activation of the mitogen-activated protein kinase pathway. Together, these findings indicate that there is an alpha-actinin-1-dependent mGlu(5b) receptor association with the actin cytoskeleton modulating receptor cell surface expression and functioning.
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Affiliation(s)
- Nuria Cabello
- Institut d'Investigacions Biomèdiques August Pi i Sunyer and Department of Biochemistry and Molecular Biology, University of Barcelona, Facultat de Biologia, Avda. Diagonal 645, Barcelona 08028, Spain
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