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Masmoudi-Kouki O, Namsi A, Hamdi Y, Bahdoudi S, Ghouili I, Chuquet J, Leprince J, Lefranc B, Ghrairi T, Tonon MC, Lizard G, Vaudry D. Cytoprotective and Neurotrophic Effects of Octadecaneuropeptide (ODN) in in vitro and in vivo Models of Neurodegenerative Diseases. Front Endocrinol (Lausanne) 2020; 11:566026. [PMID: 33250858 PMCID: PMC7672186 DOI: 10.3389/fendo.2020.566026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/28/2020] [Indexed: 11/13/2022] Open
Abstract
Octadecaneuropeptide (ODN) and its precursor diazepam-binding inhibitor (DBI) are peptides belonging to the family of endozepines. Endozepines are exclusively produced by astroglial cells in the central nervous system of mammals, and their release is regulated by stress signals and neuroactive compounds. There is now compelling evidence that the gliopeptide ODN protects cultured neurons and astrocytes from apoptotic cell death induced by various neurotoxic agents. In vivo, ODN causes a very strong neuroprotective action against neuronal degeneration in a mouse model of Parkinson's disease. The neuroprotective activity of ODN is based on its capacity to reduce inflammation, apoptosis, and oxidative stress. The protective effects of ODN are mediated through its metabotropic receptor. This receptor activates a transduction cascade of second messengers to stimulate protein kinase A (PKA), protein kinase C (PKC), and mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase (ERK) signaling pathways, which in turn inhibits the expression of proapoptotic factor Bax and the mitochondrial apoptotic pathway. In N2a cells, ODN also promotes survival and stimulates neurite outgrowth. During the ODN-induced neuronal differentiation process, numerous mitochondria and peroxisomes are identified in the neurites and an increase in the amount of cholesterol and fatty acids is observed. The antiapoptotic and neurotrophic properties of ODN, including its antioxidant, antiapoptotic, and pro-differentiating effects, suggest that this gliopeptide and some of its selective and stable derivatives may have therapeutic value for the treatment of some neurodegenerative diseases.
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Affiliation(s)
- Olfa Masmoudi-Kouki
- Laboratory of Neurophysiology Cellular Physiopathology and Biomolecule Valorisation, LR18ES03, Faculty of Sciences of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - Amira Namsi
- Laboratory of Neurophysiology Cellular Physiopathology and Biomolecule Valorisation, LR18ES03, Faculty of Sciences of Tunis, University Tunis El Manar, Tunis, Tunisia
- Team Bio-PeroxIL, Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism/University Bourgogne Franche-Comté (UBFC)/Inserm, Dijon, France
| | - Yosra Hamdi
- Laboratory of Neurophysiology Cellular Physiopathology and Biomolecule Valorisation, LR18ES03, Faculty of Sciences of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - Seyma Bahdoudi
- Laboratory of Neurophysiology Cellular Physiopathology and Biomolecule Valorisation, LR18ES03, Faculty of Sciences of Tunis, University Tunis El Manar, Tunis, Tunisia
- Normandy University, Neuronal and Neuroendocrine Differentiation and Communication, Inserm U1239, Rouen, France
| | - Ikram Ghouili
- Laboratory of Neurophysiology Cellular Physiopathology and Biomolecule Valorisation, LR18ES03, Faculty of Sciences of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - Julien Chuquet
- Normandy University, Neuronal and Neuroendocrine Differentiation and Communication, Inserm U1239, Rouen, France
| | - Jérôme Leprince
- Normandy University, Neuronal and Neuroendocrine Differentiation and Communication, Inserm U1239, Rouen, France
- Normandy University, Regional Platform for Cell Imaging of Normandy (PRIMACEN), Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
| | - Benjamin Lefranc
- Normandy University, Neuronal and Neuroendocrine Differentiation and Communication, Inserm U1239, Rouen, France
- Normandy University, Regional Platform for Cell Imaging of Normandy (PRIMACEN), Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
| | - Taoufik Ghrairi
- Laboratory of Neurophysiology Cellular Physiopathology and Biomolecule Valorisation, LR18ES03, Faculty of Sciences of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - Marie-Christine Tonon
- Normandy University, Neuronal and Neuroendocrine Differentiation and Communication, Inserm U1239, Rouen, France
| | - Gérard Lizard
- Team Bio-PeroxIL, Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism/University Bourgogne Franche-Comté (UBFC)/Inserm, Dijon, France
| | - David Vaudry
- Normandy University, Neuronal and Neuroendocrine Differentiation and Communication, Inserm U1239, Rouen, France
- Normandy University, Regional Platform for Cell Imaging of Normandy (PRIMACEN), Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
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2
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Solés-Tarrés I, Cabezas-Llobet N, Vaudry D, Xifró X. Protective Effects of Pituitary Adenylate Cyclase-Activating Polypeptide and Vasoactive Intestinal Peptide Against Cognitive Decline in Neurodegenerative Diseases. Front Cell Neurosci 2020; 14:221. [PMID: 32765225 PMCID: PMC7380167 DOI: 10.3389/fncel.2020.00221] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 06/22/2020] [Indexed: 12/23/2022] Open
Abstract
Cognitive impairment is one of the major symptoms in most neurodegenerative disorders such as Alzheimer’s (AD), Parkinson (PD), and Huntington diseases (HD), affecting millions of people worldwide. Unfortunately, there is no treatment to cure or prevent the progression of those diseases. Cognitive impairment has been related to neuronal cell death and/or synaptic plasticity alteration in important brain regions, such as the cerebral cortex, substantia nigra, striatum, and hippocampus. Therefore, compounds that can act to protect the neuronal loss and/or to reestablish the synaptic activity are needed to prevent cognitive decline in neurodegenerative diseases. Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) are two highly related multifunctional neuropeptides widely distributed in the central nervous system (CNS). PACAP and VIP exert their action through two common receptors, VPAC1 and VPAC2, while PACAP has an additional specific receptor, PAC1. In this review article, we first presented evidence showing the therapeutic potential of PACAP and VIP to fight the cognitive decline observed in models of AD, PD, and HD. We also reviewed the main transduction pathways activated by PACAP and VIP receptors to reduce cognitive dysfunction. Furthermore, we identified the therapeutic targets of PACAP and VIP, and finally, we evaluated different novel synthetic PACAP and VIP analogs as promising pharmacological tools.
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Affiliation(s)
- Irene Solés-Tarrés
- New Therapeutic Targets Group (TargetsLab), Department of Medical Science, Faculty of Medicine, Universitat de Girona, Girona, Spain
| | - Núria Cabezas-Llobet
- New Therapeutic Targets Group (TargetsLab), Department of Medical Science, Faculty of Medicine, Universitat de Girona, Girona, Spain
| | - David Vaudry
- Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, Neuropeptides, Neuronal Death and Cell Plasticity Team, Normandie University, UNIROUEN, Inserm, Rouen, France
| | - Xavier Xifró
- New Therapeutic Targets Group (TargetsLab), Department of Medical Science, Faculty of Medicine, Universitat de Girona, Girona, Spain
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Tonon MC, Vaudry H, Chuquet J, Guillebaud F, Fan J, Masmoudi-Kouki O, Vaudry D, Lanfray D, Morin F, Prevot V, Papadopoulos V, Troadec JD, Leprince J. Endozepines and their receptors: Structure, functions and pathophysiological significance. Pharmacol Ther 2020; 208:107386. [DOI: 10.1016/j.pharmthera.2019.06.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 06/20/2019] [Indexed: 02/06/2023]
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4
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Köves K, Szabó E, Kántor O, Heinzlmann A, Szabó F, Csáki Á. Current State of Understanding of the Role of PACAP in the Hypothalamo-Hypophyseal Gonadotropin Functions of Mammals. Front Endocrinol (Lausanne) 2020; 11:88. [PMID: 32210912 PMCID: PMC7067695 DOI: 10.3389/fendo.2020.00088] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 02/11/2020] [Indexed: 01/25/2023] Open
Abstract
PACAP was discovered 30 years ago in Dr. Akira Arimura's laboratory. In the past three decades since then, it has become evident that this peptide plays numerous crucial roles in mammalian organisms. The most important functions of PACAP are the following: 1. neurotransmitter, 2. neuromodulator, 3. hypophysiotropic hormone, 4. neuroprotector. This paper reviews the accumulated data regarding the distribution of PACAP and its receptors in the mammalian hypothalamus and pituitary gland, the role of PACAP in the gonadotropin hormone secretion of females and males. The review also summarizes the interaction between PACAP, GnRH, and sex steroids as well as hypothalamic peptides including kisspeptin. The possible role of PACAP in reproductive functions through the biological clock is also discussed. Finally, the significance of PACAP in the hypothalamo-hypophysial system is considered and the facts missing, that would help better understand the function of PACAP in this system, are also highlighted.
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Affiliation(s)
- Katalin Köves
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Enikő Szabó
- Department of Conservative Dentistry, Faculty of Dentistry, Semmelweis University, Budapest, Hungary
| | - Orsolya Kántor
- Department of Molecular Embryology, Medical Faculty, Institute of Anatomy and Cell Biology, University of Freiburg, Freiburg, Germany
| | - Andrea Heinzlmann
- Department of Anatomy and Histology, University of Veterinary Sciences, Budapest, Hungary
| | - Flóra Szabó
- Department of Pediatrics, Virginia Commonwealth University, Richmond, VA, United States
| | - Ágnes Csáki
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
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5
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Ghouili I, Bahdoudi S, Morin F, Amri F, Hamdi Y, Coly PM, Walet-Balieu ML, Leprince J, Zekri S, Vaudry H, Vaudry D, Castel H, Amri M, Tonon MC, Masmoudi-Kouki O. Endogenous Expression of ODN-Related Peptides in Astrocytes Contributes to Cell Protection Against Oxidative Stress: Astrocyte-Neuron Crosstalk Relevance for Neuronal Survival. Mol Neurobiol 2017; 55:4596-4611. [PMID: 28698967 DOI: 10.1007/s12035-017-0630-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 05/22/2017] [Indexed: 11/29/2022]
Abstract
Astroglial cells are important actors in the defense of brain against oxidative stress injuries. Glial cells synthesize and release the octadecaneuropeptide ODN, a diazepam-binding inhibitor (DBI)-related peptide, which acts through its metabotropic receptor to protect neurons and astrocytes from oxidative stress-induced apoptosis. The purpose of the present study is to examine the contribution of the endogenous ODN in the protection of astrocytes and neurons from moderate oxidative stress. The administration of H2O2 (50 μM, 6 h) induced a moderate oxidative stress in cultured astrocytes, i.e., an increase in reactive oxygen species, malondialdehyde, and carbonyl group levels, but it had no effect on astrocyte death. Mass spectrometry and QPCR analysis revealed that 50 μM H2O2 increased ODN release and DBI mRNA levels. The inhibition of ODN release or pharmacological blockage of the effects of ODN revealed that in these conditions, 50 μM H2O2 induced the death of astrocytes. The transfection of astrocytes with DBI siRNA increased the vulnerability of cells to moderate stress. Finally, the addition of 1 nM ODN to culture media reversed cell death observed in DBI-deficient astrocytes. The treatment of neurons with media from 50 μM H2O2-stressed astrocytes significantly reduced the neuronal death induced by H2O2; this effect is greatly attenuated by the administration of an ODN metabotropic receptor antagonist. Overall, these results indicate that astrocytes produce authentic ODN, notably in a moderate oxidative stress situation, and this glio- and neuro-protective agent may form part of the brain defense mechanisms against oxidative stress injury.
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Affiliation(s)
- Ikram Ghouili
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Research Unit UR/11ES09, Laboratory of Functional Neurophysiology and Pathology, 2092, Tunis, Tunisia
| | - Seyma Bahdoudi
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Research Unit UR/11ES09, Laboratory of Functional Neurophysiology and Pathology, 2092, Tunis, Tunisia.,Inserm U1239, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen Normandie, 76128, Mont-Saint-Aignan, France
| | - Fabrice Morin
- Inserm U1239, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen Normandie, 76128, Mont-Saint-Aignan, France
| | - Fatma Amri
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Research Unit UR/11ES09, Laboratory of Functional Neurophysiology and Pathology, 2092, Tunis, Tunisia
| | - Yosra Hamdi
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Research Unit UR/11ES09, Laboratory of Functional Neurophysiology and Pathology, 2092, Tunis, Tunisia
| | - Pierre Michael Coly
- Inserm U1239, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen Normandie, 76128, Mont-Saint-Aignan, France
| | - Marie-Laure Walet-Balieu
- Regional Proteomic Platform (Pissaro), IRIB, University of Rouen Normandie, Mont-Saint-Aignan, France
| | - Jérôme Leprince
- Inserm U1239, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen Normandie, 76128, Mont-Saint-Aignan, France.,Regional Platform for Cell Imaging of Normandie (PRIMACEN), IRIB, University of Rouen Normandie, Mont-Saint-Aignan, France.,International Associated Laboratory Samuel de Champlain, University of Rouen Normandie, Mont-Saint-Aignan, France
| | - Sami Zekri
- Electron Microscopy Laboratory, Faculty of Medicine of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - Hubert Vaudry
- Regional Platform for Cell Imaging of Normandie (PRIMACEN), IRIB, University of Rouen Normandie, Mont-Saint-Aignan, France.,International Associated Laboratory Samuel de Champlain, University of Rouen Normandie, Mont-Saint-Aignan, France
| | - David Vaudry
- Inserm U1239, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen Normandie, 76128, Mont-Saint-Aignan, France.,Regional Proteomic Platform (Pissaro), IRIB, University of Rouen Normandie, Mont-Saint-Aignan, France.,Regional Platform for Cell Imaging of Normandie (PRIMACEN), IRIB, University of Rouen Normandie, Mont-Saint-Aignan, France.,International Associated Laboratory Samuel de Champlain, University of Rouen Normandie, Mont-Saint-Aignan, France
| | - Hélène Castel
- Inserm U1239, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen Normandie, 76128, Mont-Saint-Aignan, France
| | - Mohamed Amri
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Research Unit UR/11ES09, Laboratory of Functional Neurophysiology and Pathology, 2092, Tunis, Tunisia
| | - Marie-Christine Tonon
- Inserm U1239, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen Normandie, 76128, Mont-Saint-Aignan, France.
| | - Olfa Masmoudi-Kouki
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Research Unit UR/11ES09, Laboratory of Functional Neurophysiology and Pathology, 2092, Tunis, Tunisia.
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Douiri S, Bahdoudi S, Hamdi Y, Cubì R, Basille M, Fournier A, Vaudry H, Tonon MC, Amri M, Vaudry D, Masmoudi-Kouki O. Involvement of endogenous antioxidant systems in the protective activity of pituitary adenylate cyclase-activating polypeptide against hydrogen peroxide-induced oxidative damages in cultured rat astrocytes. J Neurochem 2016; 137:913-30. [DOI: 10.1111/jnc.13614] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 02/09/2016] [Accepted: 02/24/2016] [Indexed: 02/04/2023]
Affiliation(s)
- Salma Douiri
- Laboratory of Functional Neurophysiology and Pathology; Research Unit UR/11ES09; Department of Biological Sciences; Faculty of Science of Tunis; University Tunis El Manar; Tunis Tunisia
| | - Seyma Bahdoudi
- Laboratory of Functional Neurophysiology and Pathology; Research Unit UR/11ES09; Department of Biological Sciences; Faculty of Science of Tunis; University Tunis El Manar; Tunis Tunisia
- Inserm U982; Laboratory of Neuronal and Neuroendocrine Communication and Differentiation; University of Rouen; Mont-Saint-Aignan France
| | - Yosra Hamdi
- Laboratory of Functional Neurophysiology and Pathology; Research Unit UR/11ES09; Department of Biological Sciences; Faculty of Science of Tunis; University Tunis El Manar; Tunis Tunisia
| | - Roger Cubì
- Inserm U982; Laboratory of Neuronal and Neuroendocrine Communication and Differentiation; University of Rouen; Mont-Saint-Aignan France
| | - Magali Basille
- Inserm U982; Laboratory of Neuronal and Neuroendocrine Communication and Differentiation; University of Rouen; Mont-Saint-Aignan France
- Regional Platform for Cell Imaging of Normandie (PRIMACEN); Institute for Biomedical Research and Innovation; University of Rouen; Mont-Saint-Aignan France
| | - Alain Fournier
- INRS - Institut Armand-Frappier; Laval Quebec Canada
- Laboratoire International Associé Samuel de Champlain; Institut Armand-Frappier; Laval Quebec Canada
- International Associated Laboratory Samuel de Champlain; University of Rouen; Mont-Saint-Aignan France
| | - Hubert Vaudry
- Inserm U982; Laboratory of Neuronal and Neuroendocrine Communication and Differentiation; University of Rouen; Mont-Saint-Aignan France
- Regional Platform for Cell Imaging of Normandie (PRIMACEN); Institute for Biomedical Research and Innovation; University of Rouen; Mont-Saint-Aignan France
- International Associated Laboratory Samuel de Champlain; University of Rouen; Mont-Saint-Aignan France
| | - Marie-Christine Tonon
- Inserm U982; Laboratory of Neuronal and Neuroendocrine Communication and Differentiation; University of Rouen; Mont-Saint-Aignan France
- Regional Platform for Cell Imaging of Normandie (PRIMACEN); Institute for Biomedical Research and Innovation; University of Rouen; Mont-Saint-Aignan France
| | - Mohamed Amri
- Laboratory of Functional Neurophysiology and Pathology; Research Unit UR/11ES09; Department of Biological Sciences; Faculty of Science of Tunis; University Tunis El Manar; Tunis Tunisia
| | - David Vaudry
- Inserm U982; Laboratory of Neuronal and Neuroendocrine Communication and Differentiation; University of Rouen; Mont-Saint-Aignan France
- Regional Platform for Cell Imaging of Normandie (PRIMACEN); Institute for Biomedical Research and Innovation; University of Rouen; Mont-Saint-Aignan France
- International Associated Laboratory Samuel de Champlain; University of Rouen; Mont-Saint-Aignan France
| | - Olfa Masmoudi-Kouki
- Laboratory of Functional Neurophysiology and Pathology; Research Unit UR/11ES09; Department of Biological Sciences; Faculty of Science of Tunis; University Tunis El Manar; Tunis Tunisia
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Abstract
Since their introduction in the 1960s, benzodiazepines (BZs) remain one of the most commonly prescribed medications, acting as potent sedatives, hypnotics, anxiolytics, anticonvulsants, and muscle relaxants. The primary neural action of BZs and related compounds is augmentation of inhibitory transmission, which occurs through allosteric modulation of the gamma-aminobutyric acid (GABA)-induced current at the gamma-aminobutyric acid receptor (GABAAR). The discovery of the BZ-binding site on GABAARs encouraged many to speculate that the brain produces its own endogenous ligands to this site (Costa & Guidotti, 1985). The romanticized quest for endozepines, endogenous ligands to the BZ-binding site, has uncovered a variety of ligands that might fulfill this role, including oleamides (Cravatt et al., 1995), nonpeptidic endozepines (Rothstein et al., 1992), and the protein diazepam-binding inhibitor (DBI) (Costa & Guidotti, 1985). Of these ligands, DBI, and affiliated peptide fragments, is the most extensively studied endozepine. The quest for the "brain's Valium" over the decades has been elusive as mainly negative allosteric modulatory effects have been observed (Alfonso, Le Magueresse, Zuccotti, Khodosevich, & Monyer, 2012; Costa & Guidotti, 1985), but recent evidence is accumulating that DBI displays regionally discrete endogenous positive modulation of GABA transmission through activation of the BZ receptor (Christian et al., 2013). Herein, we review the literature on this topic, focusing on identification of the endogenous molecule and its region-specific expression and function.
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8
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Irwin M, Greig A, Tvrdik P, Lucero MT. PACAP modulation of calcium ion activity in developing granule cells of the neonatal mouse olfactory bulb. J Neurophysiol 2014; 113:1234-48. [PMID: 25475351 DOI: 10.1152/jn.00594.2014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ca(2+) activity in the CNS is critical for the establishment of developing neuronal circuitry prior to and during early sensory input. In developing olfactory bulb (OB), the neuromodulators that enhance network activity are largely unknown. Here we provide evidence that pituitary adenylate cyclase-activating peptide (PACAP)-specific PAC1 receptors (PAC1Rs) expressed in postnatal day (P)2-P5 mouse OB are functional and enhance network activity as measured by increases in calcium in genetically identified granule cells (GCs). We used confocal Ca(2+) imaging of OB slices from Dlx2-tdTomato mice to visualize GABAergic GCs. To address whether the PACAP-induced Ca(2+) oscillations were direct or indirect effects of PAC1R activation, we used antagonists for the GABA receptors (GABARs) and/or glutamate receptors (GluRs) in the presence and absence of PACAP. Combined block of GABARs and GluRs yielded a 66% decrease in the numbers of PACAP-responsive cells, suggesting that 34% of OB neurons are directly activated by PACAP. Similarly, immunocytochemistry using anti-PAC1 antibody showed that 34% of OB neurons express PAC1R. Blocking either GluRs or GABARs alone indirectly showed that PACAP stimulates release of both glutamate and GABA, which activate GCs. The appearance of PACAP-induced Ca(2+) activity in immature GCs suggests a role for PACAP in GC maturation. To conclude, we find that PACAP has both direct and indirect effects on neonatal OB GABAergic cells and may enhance network activity by promoting glutamate and GABA release. Furthermore, the numbers of PACAP-responsive GCs significantly increased between P2 and P5, suggesting that PACAP-induced Ca(2+) activity contributes to neonatal OB development.
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Affiliation(s)
- Mavis Irwin
- Department of Physiology, University of Utah School of Medicine, Salt Lake City, Utah
| | - Ann Greig
- Department of Physiology, University of Utah School of Medicine, Salt Lake City, Utah
| | - Petr Tvrdik
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah; Interdepartmental Neuroscience Program, University of Utah School of Medicine, Salt Lake City, Utah; and
| | - Mary T Lucero
- Department of Physiology, University of Utah School of Medicine, Salt Lake City, Utah; Interdepartmental Neuroscience Program, University of Utah School of Medicine, Salt Lake City, Utah; and Department of Neuroscience and Physiology, American University of the Caribbean, Cupecoy, Sint Maarten, Netherlands Antilles
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9
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Astrocytes potentiate GABAergic transmission in the thalamic reticular nucleus via endozepine signaling. Proc Natl Acad Sci U S A 2013; 110:20278-83. [PMID: 24262146 DOI: 10.1073/pnas.1318031110] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Emerging evidence indicates that diazepam-binding inhibitor (DBI) mediates an endogenous benzodiazepine-mimicking (endozepine) effect on synaptic inhibition in the thalamic reticular nucleus (nRT). Here we demonstrate that DBI peptide colocalizes with both astrocytic and neuronal markers in mouse nRT, and investigate the role of astrocytic function in endozepine modulation in this nucleus by testing the effects of the gliotoxin fluorocitrate (FC) on synaptic inhibition and endozepine signaling in the nRT using patch-clamp recordings. FC treatment reduced the effective inhibitory charge of GABAA receptor (GABAAR)-mediated spontaneous inhibitory postsynaptic currents in WT mice, indicating that astrocytes enhance GABAAR responses in the nRT. This effect was abolished by both a point mutation that inhibits classical benzodiazepine binding to GABAARs containing the α3 subunit (predominant in the nRT) and a chromosomal deletion that removes the Dbi gene. Thus, astrocytes are required for positive allosteric modulation via the α3 subunit benzodiazepine-binding site by DBI peptide family endozepines. Outside-out sniffer patches pulled from neurons in the adjacent ventrobasal nucleus, which does not contain endozepines, show a potentiated response to laser photostimulation of caged GABA when placed in the nRT. FC treatment blocked the nRT-dependent potentiation of this response, as did the benzodiazepine site antagonist flumazenil. When sniffer patches were placed in the ventrobasal nucleus, however, subsequent treatment with FC led to potentiation of the uncaged GABA response, suggesting nucleus-specific roles for thalamic astrocytes in regulating inhibition. Taken together, these results suggest that astrocytes are required for endozepine actions in the nRT, and as such can be positive modulators of synaptic inhibition.
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10
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Lanfray D, Arthaud S, Ouellet J, Compère V, Do Rego JL, Leprince J, Lefranc B, Castel H, Bouchard C, Monge-Roffarello B, Richard D, Pelletier G, Vaudry H, Tonon MC, Morin F. Gliotransmission and brain glucose sensing: critical role of endozepines. Diabetes 2013; 62:801-10. [PMID: 23160530 PMCID: PMC3581199 DOI: 10.2337/db11-0785] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Hypothalamic glucose sensing is involved in the control of feeding behavior and peripheral glucose homeostasis, and glial cells are suggested to play an important role in this process. Diazepam-binding inhibitor (DBI) and its processing product the octadecaneuropeptide (ODN), collectively named endozepines, are secreted by astroglia, and ODN is a potent anorexigenic factor. Therefore, we investigated the involvement of endozepines in brain glucose sensing. First, we showed that intracerebroventricular administration of glucose in rats increases DBI expression in hypothalamic glial-like tanycytes. We then demonstrated that glucose stimulates endozepine secretion from hypothalamic explants. Feeding experiments indicate that the anorexigenic effect of central administration of glucose was blunted by coinjection of an ODN antagonist. Conversely, the hyperphagic response elicited by central glucoprivation was suppressed by an ODN agonist. The anorexigenic effects of centrally injected glucose or ODN agonist were suppressed by blockade of the melanocortin-3/4 receptors, suggesting that glucose sensing involves endozepinergic control of the melanocortin pathway. Finally, we found that brain endozepines modulate blood glucose levels, suggesting their involvement in a feedback loop controlling whole-body glucose homeostasis. Collectively, these data indicate that endozepines are a critical relay in brain glucose sensing and potentially new targets in treatment of metabolic disorders.
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Affiliation(s)
- Damien Lanfray
- INSERM U982, DC2N Laboratory of Neuronal and Neuroendocrine Cell Differentiation and Communication, Mont-Saint-Aignan, France
- Institute for Biomedical Research and Innovation, Regional Platform for Cell Imaging (PRIMACEN), Rouen, France
- University of Rouen, Mont-Saint-Aignan, France
| | - Sébastien Arthaud
- Institute for Biomedical Research and Innovation, Regional Platform for Cell Imaging (PRIMACEN), Rouen, France
- University of Rouen, Mont-Saint-Aignan, France
- Centre National de la Recherche Scientifique Unité Mixte de Recherche 5167, University Claude Bernard Lyon 1, Lyon, France
| | - Johanne Ouellet
- Research Center in Molecular Endocrinology, Oncology and Human Genomics, Laval University, Quebec, Quebec, Canada
| | - Vincent Compère
- INSERM U982, DC2N Laboratory of Neuronal and Neuroendocrine Cell Differentiation and Communication, Mont-Saint-Aignan, France
- Institute for Biomedical Research and Innovation, Regional Platform for Cell Imaging (PRIMACEN), Rouen, France
- University of Rouen, Mont-Saint-Aignan, France
- Department of Anaesthesiology and Critical Care, Rouen University Hospital, Rouen, France
| | - Jean-Luc Do Rego
- INSERM U982, DC2N Laboratory of Neuronal and Neuroendocrine Cell Differentiation and Communication, Mont-Saint-Aignan, France
- Institute for Biomedical Research and Innovation, Regional Platform for Cell Imaging (PRIMACEN), Rouen, France
- University of Rouen, Mont-Saint-Aignan, France
| | - Jérôme Leprince
- INSERM U982, DC2N Laboratory of Neuronal and Neuroendocrine Cell Differentiation and Communication, Mont-Saint-Aignan, France
- Institute for Biomedical Research and Innovation, Regional Platform for Cell Imaging (PRIMACEN), Rouen, France
- University of Rouen, Mont-Saint-Aignan, France
| | - Benjamin Lefranc
- Institute for Biomedical Research and Innovation, Regional Platform for Cell Imaging (PRIMACEN), Rouen, France
- University of Rouen, Mont-Saint-Aignan, France
| | - Hélène Castel
- INSERM U982, DC2N Laboratory of Neuronal and Neuroendocrine Cell Differentiation and Communication, Mont-Saint-Aignan, France
- Institute for Biomedical Research and Innovation, Regional Platform for Cell Imaging (PRIMACEN), Rouen, France
- University of Rouen, Mont-Saint-Aignan, France
| | - Cynthia Bouchard
- Centre de Recherche de l’Institut Universitaire de Cardiologie et Pneumologie de Québec, Laval University, Quebec, Quebec, Canada
| | - Boris Monge-Roffarello
- Centre de Recherche de l’Institut Universitaire de Cardiologie et Pneumologie de Québec, Laval University, Quebec, Quebec, Canada
| | - Denis Richard
- Centre de Recherche de l’Institut Universitaire de Cardiologie et Pneumologie de Québec, Laval University, Quebec, Quebec, Canada
| | - Georges Pelletier
- Research Center in Molecular Endocrinology, Oncology and Human Genomics, Laval University, Quebec, Quebec, Canada
| | - Hubert Vaudry
- INSERM U982, DC2N Laboratory of Neuronal and Neuroendocrine Cell Differentiation and Communication, Mont-Saint-Aignan, France
- Institute for Biomedical Research and Innovation, Regional Platform for Cell Imaging (PRIMACEN), Rouen, France
- University of Rouen, Mont-Saint-Aignan, France
- Research Center in Molecular Endocrinology, Oncology and Human Genomics, Laval University, Quebec, Quebec, Canada
| | - Marie-Christine Tonon
- INSERM U982, DC2N Laboratory of Neuronal and Neuroendocrine Cell Differentiation and Communication, Mont-Saint-Aignan, France
- Institute for Biomedical Research and Innovation, Regional Platform for Cell Imaging (PRIMACEN), Rouen, France
- University of Rouen, Mont-Saint-Aignan, France
- Corresponding author: Marie-Christine Tonon, , or Fabrice Morin,
| | - Fabrice Morin
- INSERM U982, DC2N Laboratory of Neuronal and Neuroendocrine Cell Differentiation and Communication, Mont-Saint-Aignan, France
- Institute for Biomedical Research and Innovation, Regional Platform for Cell Imaging (PRIMACEN), Rouen, France
- University of Rouen, Mont-Saint-Aignan, France
- Corresponding author: Marie-Christine Tonon, , or Fabrice Morin,
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11
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Blechman J, Levkowitz G. Alternative Splicing of the Pituitary Adenylate Cyclase-Activating Polypeptide Receptor PAC1: Mechanisms of Fine Tuning of Brain Activity. Front Endocrinol (Lausanne) 2013; 4:55. [PMID: 23734144 PMCID: PMC3659299 DOI: 10.3389/fendo.2013.00055] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Accepted: 04/24/2013] [Indexed: 12/11/2022] Open
Abstract
Alternative splicing of the precursor mRNA encoding for the neuropeptide receptor PAC1/ADCYAP1R1 generates multiple protein products that exhibit pleiotropic activities. Recent studies in mammals and zebrafish have implicated some of these splice isoforms in control of both cellular and body homeostasis. Here, we review the regulation of PAC1 splice variants and their underlying signal transduction and physiological processes in the nervous system.
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Affiliation(s)
- Janna Blechman
- Department of Molecular Cell Biology, Weizmann Institute of ScienceRehovot, Israel
| | - Gil Levkowitz
- Department of Molecular Cell Biology, Weizmann Institute of ScienceRehovot, Israel
- *Correspondence: Gil Levkowitz, Department of Molecular Cell Biology, Weizmann Institute of Science, P. O. Box 26, Rehovot 76100, Israel. e-mail:
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12
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Fang KM, Liu YY, Lin CH, Fan SS, Tsai CH, Tzeng SF. Mps one binder 2 gene upregulation in the stellation of astrocytes induced by cAMP-dependent pathway. J Cell Biochem 2012; 113:3019-28. [PMID: 22566124 DOI: 10.1002/jcb.24180] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Astrocytes, the major glial population in the central nervous system (CNS), play an important role in neuronal homeostasis, neurogenesis, and synaptogenesis. The cells have a stellate shape with elaborated processes in the developing CNS. Cultured astrocytes become stellate when the cells undergo differentiation in response to stimuli. Nevertheless, the molecular mechanism for astrocytic stellation is poorly understood. Here, we showed that the addition of serum induced a flat polygonal shape in cultured astrocytes with a reduced level of Mps one binder 2 (Mob2) that is involved in neurite growth by forming stable complex with a nuclear Ser/Thr kinase Dbf2-related protein kinase 1 (NDR1). Furthermore, exposure to a membrane permeable cAMP analogue, dbcAMP, not only induced astrocytic stellation, but also caused an increase in Mob2 expression. Similarly, the upregulation of Mob2 mRNA expression was induced by exposure of astrocytes to pituitary adenylyl cyclase-activating polypeptide (PACAP). Pretreatment with a cAMP/protein kinase A (PKA) inhibitor, KT-5720, significantly blocked the effect of dbcAMP and PACAP on induced upregulation of Mob2 mRNA expression in astrocytes. In addition, the process withdrawal of dbcAMP-treated astrocytes was caused by the inhibition of Mob2 expression using lentivirus-mediated Mob2 shRNA delivery system. Based on our findings, we suggest that Mob2 is involved in PKA signaling-mediated astrocytic stellation.
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Affiliation(s)
- Kuan-Min Fang
- Institute of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan
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13
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Hamdi Y, Kaddour H, Vaudry D, Bahdoudi S, Douiri S, Leprince J, Castel H, Vaudry H, Tonon MC, Amri M, Masmoudi-Kouki O. The octadecaneuropeptide ODN protects astrocytes against hydrogen peroxide-induced apoptosis via a PKA/MAPK-dependent mechanism. PLoS One 2012; 7:e42498. [PMID: 22927932 PMCID: PMC3424241 DOI: 10.1371/journal.pone.0042498] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 07/06/2012] [Indexed: 12/18/2022] Open
Abstract
Astrocytes synthesize and release endozepines, a family of regulatory peptides, including the octadecaneuropeptide (ODN) an endogenous ligand of both central-type benzodiazepine (CBR) and metabotropic receptors. We have recently shown that ODN exerts a protective effect against hydrogen peroxide (H2O2)-induced oxidative stress in astrocytes. The purpose of the present study was to determine the type of receptor and the transduction pathways involved in the protective effect of ODN in cultured rat astrocytes. We have first observed a protective activity of ODN at very low concentrations that was abrogated by the metabotropic ODN receptor antagonist cyclo1–8[DLeu5]OP, but not by the CBR antagonist flumazenil. We have also found that the metabotropic ODN receptor is positively coupled to adenylyl cyclase in astrocytes and that the glioprotective action of ODN upon H2O2-induced astrocyte death is PKA- and MEK-dependent, but PLC/PKC-independent. Downstream of PKA, ODN induced ERK phosphorylation, which in turn activated the expression of the anti-apoptotic gene Bcl-2 and blocked the stimulation by H2O2 of the pro-apoptotic gene Bax. The effect of ODN on the Bax/Bcl-2 balance contributed to abolish the deleterious action of H2O2 on mitochondrial membrane integrity and caspase-3 activation. Finally, the inhibitory effect of ODN on caspase-3 activity was shown to be PKA and MEK-dependent. In conclusion, the present results demonstrate that the potent glioprotective action of ODN against oxidative stress involves the metabotropic ODN receptor coupled to the PKA/ERK-kinase pathway to inhibit caspase-3 activation.
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Affiliation(s)
- Yosra Hamdi
- Laboratory of Functional Neurophysiology and Pathology, Research Unit UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - Hadhemi Kaddour
- Laboratory of Functional Neurophysiology and Pathology, Research Unit UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - David Vaudry
- Inserm U982, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, University of Rouen, Mont-Saint-Aignan, France
- International Associated Laboratory Samuel de Champlain, Mont-Saint-Aignan, France
- Regional Platform for Cell Imaging of Haute-Normandie (PRIMACEN), Institute for Medical Research and Innovation (IRIB), University of Rouen, Mont-Saint-Aignan, France
| | - Seyma Bahdoudi
- Laboratory of Functional Neurophysiology and Pathology, Research Unit UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - Salma Douiri
- Laboratory of Functional Neurophysiology and Pathology, Research Unit UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - Jérôme Leprince
- Inserm U982, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, University of Rouen, Mont-Saint-Aignan, France
- International Associated Laboratory Samuel de Champlain, Mont-Saint-Aignan, France
- Regional Platform for Cell Imaging of Haute-Normandie (PRIMACEN), Institute for Medical Research and Innovation (IRIB), University of Rouen, Mont-Saint-Aignan, France
| | - Helene Castel
- Inserm U982, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, University of Rouen, Mont-Saint-Aignan, France
| | - Hubert Vaudry
- Inserm U982, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, University of Rouen, Mont-Saint-Aignan, France
- International Associated Laboratory Samuel de Champlain, Mont-Saint-Aignan, France
- Regional Platform for Cell Imaging of Haute-Normandie (PRIMACEN), Institute for Medical Research and Innovation (IRIB), University of Rouen, Mont-Saint-Aignan, France
- * E-mail: (MA), (HV)
| | - Marie-Christine Tonon
- Inserm U982, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, University of Rouen, Mont-Saint-Aignan, France
| | - Mohamed Amri
- Laboratory of Functional Neurophysiology and Pathology, Research Unit UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
- * E-mail: (MA), (HV)
| | - Olfa Masmoudi-Kouki
- Laboratory of Functional Neurophysiology and Pathology, Research Unit UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
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14
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Castorina A, Giunta S, Scuderi S, D'Agata V. Involvement of PACAP/ADNP signaling in the resistance to cell death in malignant peripheral nerve sheath tumor (MPNST) cells. J Mol Neurosci 2012; 48:674-83. [PMID: 22454142 DOI: 10.1007/s12031-012-9755-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 03/16/2012] [Indexed: 11/30/2022]
Abstract
Malignant peripheral nerve sheath tumors (MPNSTs) are sarcomas able to grow under conditions of metabolic stress caused by insufficient nutrients or oxygen. Both pituitary adenylate cyclase-activating polypeptide (PACAP) and activity-dependent neuroprotective protein (ADNP) have glioprotective potential. However, whether PACAP/ADNP signaling is involved in the resistance to cell death in MPNST cells remains to be clarified. Here, we investigated the involvement of this signaling system in the survival response of MPNST cells against hydrogen peroxide (H(2)O(2))-evoked death both in the presence of normal serum (NS) and in serum-starved (SS) cells. Results showed that ADNP levels increased time-dependently (6-48 h) in SS cells. Treatment with PACAP38 (10(-9) to 10(-5) M) dose-dependently increased ADNP levels in NS but not in SS cells. PAC(1)/VPAC receptor antagonists completely suppressed PACAP-stimulated ADNP increase and partially reduced ADNP expression in SS cells. NS-cultured cells exposed to H(2)O(2) showed significantly reduced cell viability (~50 %), increased p53 and caspase-3, and DNA fragmentation, without affecting ADNP expression. Serum starvation significantly reduced H(2)O(2)-induced detrimental effects in MPNST cells, which were not further ameliorated by PACAP38. Altogether, these finding provide evidence for the involvement of an endogenous PACAP-mediated ADNP signaling system that increases MPNST cell resistance to H(2)O(2)-induced death upon serum starvation.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Apoptosis/physiology
- Culture Media, Serum-Free/pharmacology
- DNA Replication
- DNA, Neoplasm/analysis
- Dose-Response Relationship, Drug
- Gene Expression Regulation, Neoplastic/drug effects
- Hydrogen Peroxide/toxicity
- Neoplasm Proteins/physiology
- Nerve Sheath Neoplasms/pathology
- Nerve Tissue Proteins/biosynthesis
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/physiology
- Pituitary Adenylate Cyclase-Activating Polypeptide/pharmacology
- Pituitary Adenylate Cyclase-Activating Polypeptide/physiology
- Rats
- Real-Time Polymerase Chain Reaction
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I/antagonists & inhibitors
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I/physiology
- Receptors, Vasoactive Intestinal Peptide, Type II/antagonists & inhibitors
- Receptors, Vasoactive Intestinal Peptide, Type II/physiology
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Tumor Cells, Cultured/drug effects
- Tumor Cells, Cultured/metabolism
- Tumor Cells, Cultured/pathology
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Affiliation(s)
- Alessandro Castorina
- Department of Bio-Medical Sciences, University of Catania, Via S.Sofia 87, 95123, Catania, Italy
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15
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Masmoudi-Kouki O, Douiri S, Hamdi Y, Kaddour H, Bahdoudi S, Vaudry D, Basille M, Leprince J, Fournier A, Vaudry H, Tonon MC, Amri M. Pituitary adenylate cyclase-activating polypeptide protects astroglial cells against oxidative stress-induced apoptosis. J Neurochem 2011; 117:403-11. [PMID: 21244427 DOI: 10.1111/j.1471-4159.2011.07185.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Oxidative stress, associated with a variety of disorders including neurodegenerative diseases, results from accumulation of reactive oxygen species (ROS). Oxidative stress is not only responsible for neuron apoptosis, but can also provoke astroglial cell death. Numerous studies indicate that pituitary adenylate cyclase-activating polypeptide (PACAP) promotes neuron survival, but nothing is known regarding the action of PACAP on astroglial cell survival. Thus, the purpose of the present study was to investigate the potential glioprotective effect of PACAP on H(2)O(2)-induced astrocyte death. Pre-treatment of cultured rat astrocytes with nanomolar concentrations of PACAP prevented cell death provoked by H(2)O(2) (300 μM), whereas vasoactive intestinal polypeptide was devoid of protective activity. The effect of PACAP on astroglial cell survival was abolished by the type 1 PACAP receptor antagonist, PACAP6-38. The protective action of PACAP was blocked by the protein kinase A inhibitor H89, the protein kinase C inhibitor chelerythrine and the mitogen-activated protein (MAP)-kinase kinase (MEK) inhibitor U0126. PACAP stimulated glutathione formation, and blocked H(2)O(2)-evoked ROS accumulation and glutathione content reduction. In addition, PACAP prevented the decrease of mitochondrial activity and caspase 3 activation induced by H(2)O(2). Taken together, these data indicate for the first time that PACAP, acting through type 1 PACAP receptor, exerts a potent protective effect against oxidative stress-induced astrocyte death. The anti-apoptotic activity of PACAP on astrocytes is mediated through the protein kinase A, protein kinase C and MAPK transduction pathways, and can be accounted for by inhibition of ROS-induced mitochondrial dysfunctions and caspase 3 activation.
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Affiliation(s)
- Olfa Masmoudi-Kouki
- Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
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16
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Loomis WF, Behrens MM, Williams ME, Anjard C. Pregnenolone sulfate and cortisol induce secretion of acyl-CoA-binding protein and its conversion into endozepines from astrocytes. J Biol Chem 2010; 285:21359-65. [PMID: 20452969 PMCID: PMC2898429 DOI: 10.1074/jbc.m110.105858] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 05/05/2010] [Indexed: 01/01/2023] Open
Abstract
Acyl-CoA-binding protein (ACBP) functions both intracellularly as part of fatty acid metabolism and extracellularly as diazepam binding inhibitor, the precursor of endozepine peptides. Two of these peptides, ODN and TTN, bind to the GABA(A) receptor and modulate its sensitivity to gamma-aminobutyric acid (GABA). We have found that depolarization of mouse primary astrocytes induces the rapid release and processing of ACBP to the active peptides. We previously showed that ODN can trigger the rapid sporulation of the social amoeba Dictyostelium. Using this bioassay, we now show that astrocytes release the endozepine peptides within 10 min of exposure to the steroids cortisol, pregnenolone, pregnenolone sulfate, or progesterone. ACBP lacks a signal sequence for secretion through the endoplasmic reticulum/Golgi pathway and its secretion is not affected by addition of brefeldin A, a well known inhibitor of the classical secretion pathway, suggesting that it follows an unconventional pathway for secretion. Moreover, induction of autophagy by addition of rapamycin also resulted in rapid release of ACBP indicating that this protein uses components of the autophagy pathway for secretion. Following secretion, ACBP is proteolytically cleaved to the active neuropeptides by protease activity on the surface of astrocytes. Neurosteroids, such as pregnenolone sulfate, were previously shown to modulate the excitatory/inhibitory balance in brain through increased release of glutamate and decreased release of GABA. These effects of steroids in neurons will be reinforced by the release of endozepines from astrocytes shown here, and suggest an orchestrated astrocyte-neuron cross-talk that can affect a broad spectrum of behavioral functions.
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Affiliation(s)
- William F. Loomis
- From the Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093-0368 and
| | | | - Megan E. Williams
- From the Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093-0368 and
| | - Christophe Anjard
- From the Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093-0368 and
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17
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The vasoactive peptides urotensin II and urotensin II-related peptide regulate astrocyte activity through common and distinct mechanisms: involvement in cell proliferation. Biochem J 2010; 428:113-24. [DOI: 10.1042/bj20090867] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
UII (urotensin II) and its paralogue URP (UII-related peptide) are two vasoactive neuropeptides whose respective central actions are currently unknown. In the present study, we have compared the mechanism of action of URP and UII on cultured astrocytes. Competition experiments performed with [125I]UII showed the presence of very-high- and high-affinity binding sites for UII, and a single high-affinity site for URP. Both UII and URP provoked a membrane depolarization accompanied by a decrease in input resistance, stimulated the release of endozepines, neuropeptides specifically produced by astroglial cells, and generated an increase in [Ca2+]c (cytosolic Ca2+ concentration). The UII/URP-induced [Ca2+]c elevation was PTX (pertussis toxin)-insensitive, and was blocked by the PLC (phospholipase C) inhibitor U73122 or the InsP3 channel blocker 2-APB (2-aminoethoxydiphenylborane). The addition of the Ca2+ chelator EGTA reduced the peak and abolished the plateau phase, whereas the T-type Ca2+ channel blocker mibefradil totally inhibited the Ca2+ response evoked by both peptides. However, URP and UII induced a mono- and bi-phasic dose-dependent increase in [Ca2+]c and provoked short- and long-lasting Ca2+ mobilization respectively. Similar mono- and bi-phasic dose-dependent increases in [3H]inositol incorporation into polyphosphoinositides in astrocytes was obtained, but the effect of UII was significantly reduced by PTX, although BRET (bioluminescence resonance energy transfer) experiments revealed that both UII and URP recruited Gαo-protein. Finally, UII, but not URP, exerted a dose-dependent mitogenic activity on astrocytes. Therefore we described that URP and UII exert not only similar, but also divergent actions on astrocyte activity, with UII exhibiting a broader range of activities at physiological peptide concentrations.
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18
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Differential regulation of vasoactive intestinal peptide (VIP) in the dentate gyrus and hippocampus via the NO-cGMP pathway following kainic acid-induced seizure in the rat. J Mol Neurosci 2010; 42:359-69. [PMID: 20369387 DOI: 10.1007/s12031-010-9353-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Accepted: 03/12/2010] [Indexed: 12/14/2022]
Abstract
We have previously shown that kainic acid (KA) increases nitric oxide (NO) synthase (NOS) production in the rat dentate gyrus (DG) and hippocampus (CA3), and NOS inhibition [(by N(G)-nitro-L-arginine methylester (L-NAME)] modulates the vasoactive intestinal peptide (VIP)-responsive gene, activity-dependent neuroprotective protein, and alters neuro- and astrogliogenesis (Cosgrave et al. in Neurobiol Dis 30(3):281-292 2008, J Mol Neurosci 39(1-2):9-21, 2009, 2010). In the present study, using the same model we demonstrate that VIP synthesis is differentially regulated by the NO-cyclic guanosine monophosphate (cGMP) pathway in the DG and CA3 at 3 h and 3 days post-KA. At 3 h post-KA: In L-NAME+KA/7-nitroindazole (7-NI)+KA, stratum granulosum (SG) and subgranular zone (SGZ) cells were intensely stained for VIP when compared with L-NAME/7-NI/KA alone. Soluble guanylyl cyclase inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, blocks cGMP production), suppressed astrocytic activation (glial fibrillary acidic protein) but other cell types were VIP(+); however, ODQ+KA suppressed overall VIP synthesis in the DG. At 3 days post-KA: In L-NAME+KA/7-NI+KA, SGZ and SG cells continued to express VIP, while in the KA alone, only SGZ cells were VIP(+). ODQ increased VIP(+) cells in the SG, and in contrast to 3 h, VIP-containing nNOS(+) cells increased in ODQ+KA when compared to vehicle+KA. In the hippocampus, 7-NI/ODQ had no effect on VIP at 3 h/3 days, while L-NAME+KA at 3 days increased VIP(+) cells, but reduced VIP-like immunoreactivity in astrocytes. These results suggest that the NO-cGMP pathway differentially regulates VIP in the DG and hippocampus during seizure.
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19
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Vaudry D, Falluel-Morel A, Bourgault S, Basille M, Burel D, Wurtz O, Fournier A, Chow BKC, Hashimoto H, Galas L, Vaudry H. Pituitary Adenylate Cyclase-Activating Polypeptide and Its Receptors: 20 Years after the Discovery. Pharmacol Rev 2009; 61:283-357. [DOI: 10.1124/pr.109.001370] [Citation(s) in RCA: 829] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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20
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Tokay T, Hachem R, Masmoudi-Kouki O, Gandolfo P, Desrues L, Leprince J, Castel H, Diallo M, Amri M, Vaudry H, Tonon MC. Beta-amyloid peptide stimulates endozepine release in cultured rat astrocytes through activation of N-formyl peptide receptors. Glia 2009; 56:1380-9. [PMID: 18512251 DOI: 10.1002/glia.20705] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Astroglial cells synthesize and release endozepines, a family of neuropeptides derived from diazepam-binding inhibitor (DBI). The authors have recently shown that beta-amyloid peptide (Abeta) stimulates DBI gene expression and endozepine release. The purpose of this study was to determine the mechanism of action of Abeta in cultured rat astrocytes. Abeta(25-35) and the N-formyl peptide receptor (FPR) agonist N-formyl-Met-Leu-Phe (fMLF) increased the secretion of endozepines in a dose-dependent manner with EC(50) value of approximately 2 microM. The stimulatory effects of Abeta(25-35) and the FPR agonists fMLF and N-formyl-Met-Met-Met (fMMM) on endozepine release were abrogated by the FPR antagonist N-t-Boc-Phe-Leu-Phe-Leu-Phe. In contrast, Abeta(25-35) increased DBI mRNA expression through a FPR-independent mechanism. Abeta(25-35) induced a transient stimulation of cAMP formation and a sustained activation of polyphosphoinositide turnover. The stimulatory effect of Abeta(25-35) on endozepine release was blocked by the adenylyl cyclase inhibitor somatostatin, the protein kinase A (PKA) inhibitor H89, the phospholipase C inhibitor U73122, the protein kinase C (PKC) inhibitor chelerythrine and the ATP binding cassette transporter blocker glyburide. Taken together, these data demonstrate for the first time that Abeta(25-35) stimulates endozepine release from rat astrocytes through a FPR receptor positively coupled to PKA and PKC.
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Affiliation(s)
- Tursonjan Tokay
- INSERM U413, Laboratory of Cellular and Molecular Neuroendocrinology, University of Rouen, Mont-Saint-Aignan, France
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21
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Qian Z, Bilderback TR, Barmack NH. Acyl coenzyme A-binding protein (ACBP) is phosphorylated and secreted by retinal Müller astrocytes following protein kinase C activation. J Neurochem 2008; 105:1287-99. [DOI: 10.1111/j.1471-4159.2008.05229.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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22
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Nowak JZ, Jozwiak-Bebenista M, Bednarek K. Effects of PACAP and VIP on cyclic AMP formation in rat neuronal and astrocyte cultures under normoxic and hypoxic condition. Peptides 2007; 28:1706-12. [PMID: 17521773 DOI: 10.1016/j.peptides.2007.04.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Revised: 04/10/2007] [Accepted: 04/12/2007] [Indexed: 11/30/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) concentration (0.001-1000 nM)-dependently stimulated cyclic AMP production in rat primary neuronal and glial cell (astrocyte) cultures. The actions of both peptides were much more pronounced in astrocytes than in neuronal cultures. Stimulatory effects of PACAP and VIP on cyclic AMP formation were significantly smaller in cell cultures subjected to 24h lasting hypoxic conditions, induced either chemically (100 microM cobalt chloride) or by low 3% oxygen hypoxia, compared to the normoxic condition (95% air and 5% CO(2)). This picture contrasted with the effects of forskolin that were similar under normoxic and hypoxic conditions. It is suggested that hypoxia leads to changes in PACAP- and VIP-driven cyclic AMP-dependent signaling in the rat brain by influencing molecular processes likely occurring at the level of receptor protein or receptor-Gs protein coupling.
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Affiliation(s)
- Jerzy Z Nowak
- Department of Pharmacology, Medical University, 7/9 Zeligowskiego Street, PL 90-752 Lodz, Poland.
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Masmoudi-Kouki O, Gandolfo P, Castel H, Leprince J, Fournier A, Dejda A, Vaudry H, Tonon MC. Role of PACAP and VIP in astroglial functions. Peptides 2007; 28:1753-60. [PMID: 17655978 DOI: 10.1016/j.peptides.2007.05.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 05/22/2007] [Accepted: 05/24/2007] [Indexed: 11/30/2022]
Abstract
Astrocytes represent at least 50% of the volume of the human brain. Besides their roles in various supportive functions, astrocytes are involved in the regulation of stem cell proliferation, synaptic plasticity and neuroprotection. Astrocytes also influence neuronal physiology by responding to neurotransmitters and neuropeptides and by releasing regulatory factors termed gliotransmitters. In particular, astrocytes express the PACAP-specific receptor PAC1-R and the PACAP/VIP mutual receptors VPAC1-R and VPAC2-R during development and/or in the adult. There is now clear evidence that PACAP and VIP modulate a number of astrocyte activities such as proliferation, plasticity, glycogen production, and biosynthesis of neurotrophic factors and gliotransmitters.
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Affiliation(s)
- Olfa Masmoudi-Kouki
- INSERM U413, Laboratory of Cellular and Molecular Neuroendocrinology, France
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24
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van Landeghem FKH, Weiss T, Oehmichen M, von Deimling A. Cellular localization of pituitary adenylate cyclase-activating peptide (PACAP) following traumatic brain injury in humans. Acta Neuropathol 2007; 113:683-93. [PMID: 17431645 DOI: 10.1007/s00401-007-0208-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 01/16/2007] [Accepted: 02/10/2007] [Indexed: 10/23/2022]
Abstract
The pituitary adenylate cyclase-activating peptide (PACAP) is involved in many processes of the developing and mature central nervous system, such as proliferation, differentiation, apoptosis, neurotransmission, inflammation and neuroprotection. Alternative posttranslational processing of PACAP results in two biologically active, amidated 27- and 38-amino acid peptides termed PACAP27 and PACAP38. In the present study, we examined whether traumatic brain injury (TBI) affects cellular immunopositivity for PACAP27 and PACAP38. Patients (n = 55) were classified into three groups dependent on their survival time (under 24 h, between 24 h and 7 days and between 7 days and 99 days postinjury). PACAP27 and PACAP38 were expressed by neurons and glial cells in normal human neocortex (n = 10). Following TBI, the total number of PACAP27- and PACAP38-positive cells was significantly decreased for a prolonged survival period within the traumatized neocortex. In the pericontusional cortex, the number of cells expressing PACAP27 and PACAP38 was significantly increased at all survival times examined. Triple immunofluorescence examinations revealed a significant increase in the absolute numbers of GFAP-positive reactive astrocytes as well as a decrease in the CNP-positive oligodendrocytes, each coexpressing PACAP27 or PACAP38 in the contusional and pericontusional cortex. We hypothesize that the increase of glial PACAP immunoreactivity may be interpreted as part of a complex endogenous neuroprotective response in the pericontusional regions, but the precise role of PACAP following TBI is yet to be determined.
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Affiliation(s)
- Frank K H van Landeghem
- Institute of Neuropathology, Charité - Universitätsmedizin Berlin, CVK, Charité Campus Virchow Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany.
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25
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Compère V, Ouellet J, Luu-The V, Dureuil B, Tonon MC, Vaudry H, Labrie F, Pelletier G. Role of androgens and glucocorticoids in the regulation of diazepam-binding inhibitor mRNA levels in male mouse hypothalamus. Brain Res 2006; 1119:50-7. [PMID: 16963002 DOI: 10.1016/j.brainres.2006.08.046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Revised: 08/11/2006] [Accepted: 08/12/2006] [Indexed: 10/24/2022]
Abstract
In peripheral organs, gonadal and adrenal steroids regulate diazepam-binding inhibitor (DBI) mRNA expression. In order to further investigate the involvement of peripheral steroid hormones in the modulation of brain DBI mRNA expression, we studied by semiquantitative in situ hybridization the effect of adrenalectomy (ADX) and castration (CX) and short-term replacement therapy on DBI mRNA levels in the male mouse hypothalamus. Cells expressing DBI mRNA were mostly observed in the arcuate nucleus, the median eminence and the ependyma bordering the third ventricle. In the median eminence and the ependyma bordering the third ventricule, the DBI gene expression was decreased in ADX rats and a single injection of corticosterone to ADX rats induced a significant increase in DBI gene expression at 3 and 12 h time intervals without completely restoring the basal DBI mRNA expression observed in intact mice. In the arcuate nucleus, ADX and corticosterone administration did not modify DBI mRNA expression. CX down-regulated DBI gene expression in the ependyma bordering the third ventricle. The administration of dihydrotestosterone (3-24 h) completely reversed the inhibitory effect of CX. In the median eminence and arcuate nucleus, neither CX or dihydrotestosterone administration modified DBI mRNA levels. These results suggest that the effects of glucocorticoids on the hypothalamo-pituitary-adrenocortical axis and androgens on the hypothalamo-pituitary-gonadal axis are mediated by DBI.
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Affiliation(s)
- V Compère
- European Institute for Peptide Research (IFRMP 23), Laboratory of Cellular and Molecular Neuroendocrinology, INSERM U413, UA CNRS, University of Rouen, Mont-Saint-Aignan, France
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26
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Bruzzone F, Lectez B, Tollemer H, Leprince J, Dujardin C, Rachidi W, Chatenet D, Baroncini M, Beauvillain JC, Vallarino M, Vaudry H, Chartrel N. Anatomical distribution and biochemical characterization of the novel RFamide peptide 26RFa in the human hypothalamus and spinal cord. J Neurochem 2006; 99:616-27. [PMID: 16899066 DOI: 10.1111/j.1471-4159.2006.04090.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
26RFa is a novel RFamide peptide originally isolated in the amphibian brain. The 26RFa precursor has been subsequently characterized in various mammalian species but, until now, the anatomical distribution and the molecular forms of 26RFa produced in the CNS of mammals, in particular in human, are unknown. In the present study, we have investigated the localization and the biochemical characteristics of 26RFa-like immunoreactivity (LI) in two regions of the human CNS--the hypothalamus and the spinal cord. Immunohistochemical labeling using specific antibodies against human 26RFa and in situ hybridization histochemistry revealed that in the human hypothalamus 26RFa-expressing neurons are located in the paraventricular and ventromedial nuclei. In the spinal cord, 26RFa-expressing neurons were observed in the dorsal and lateral horns. Characterization of 26RFa-related peptides showed that two distinct molecular forms of 26RFa are present in the human hypothalamus and spinal cord, i.e. 26RFa and an N-terminally elongated form of 43 amino acids designated 43RFa. These data provide the first evidence that 26RFa and 43RFa are actually produced in the human CNS. The distribution of 26RF-LI suggests that 26RFa and/or 43RFa may modulate feeding, sexual behavior and transmission of nociceptive stimuli.
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Affiliation(s)
- Federica Bruzzone
- INSERM U413, Laboratory of Cellular and Molecular Neuroendocrinology, European Institute for Peptide Research, IFRMP 23, University of Rouen, Mont-Saint-Aignan, France
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27
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Nakamachi T, Li M, Shioda S, Arimura A. Signaling involved in pituitary adenylate cyclase-activating polypeptide-stimulated ADNP expression. Peptides 2006; 27:1859-64. [PMID: 16564114 DOI: 10.1016/j.peptides.2006.01.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Revised: 01/20/2006] [Accepted: 01/20/2006] [Indexed: 10/24/2022]
Abstract
Activity-dependent neurotrophic protein (ADNP) was discovered as a novel response gene for VIP and has neuroprotective potential. When the VIP paralog, PACAP38 was added to mouse neuron-glia co-cultures, it induced ADNP mRNA expression in a bimodal fashion at subpico- and nanomolar concentrations with greater response at subpicomolar level. The response was attenuated by a PAC1-R antagonist at both concentrations and by a VPAC1-R antagonist at nanomolar concentration only. An IP3/PLC inhibitor attenuated the response at both concentrations of PACAP38, but a MAPK inhibitor had no effect. A PKA inhibitor suppressed the response at nanomolar concentration only. These findings suggest that ADNP expression is mediated through multiple receptors and signaling pathways that are regulated by different concentrations of PACAP.
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Affiliation(s)
- Tomoya Nakamachi
- U.S.-Japan Biomedical Research Laboratories, Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA
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28
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Abstract
Angiopoietin-1 (Ang1) has powerful vascular protective effects: suppressing plasma leakage, inhibiting vascular inflammation, and preventing endothelial death. Preclinical studies indicate that Ang1 may be therapeutically useful in a number of situations, including treatment of edema, endotoxemia, and transplant arteriosclerosis. However, the ligand has also been implicated in vessel remodeling, induction of angiogenesis and pulmonary hypertension, indicating that strategies to minimize any deleterious effects while optimizing vessel protection are likely to be needed. This review surveys the published data on vascular protective effects of Ang1 and highlights the therapeutic potential of this ligand, as well as possible limitations to its use. We also consider the data on Ang1 receptors and speculate on how to maximize therapeutic benefit by targeting the Tie receptors.
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Affiliation(s)
- Nicholas P J Brindle
- Department of Cardiovascular Sciences, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK.
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29
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Tokay T, Masmoudi O, Gandolfo P, Leprince J, Pelletier G, Vaudry H, Tonon MC. Beta-amyloid peptides stimulate endozepine biosynthesis in cultured rat astrocytes. J Neurochem 2005; 94:607-16. [PMID: 16033417 DOI: 10.1111/j.1471-4159.2005.03102.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Accumulation of beta-amyloid peptide (Abeta), which is a landmark of Alzheimer's disease, may alter astrocyte functions before any visible symptoms of the disease occur. Here, we examined the effects of Abeta on biosynthesis and release of diazepam-binding inhibitor (DBI), a polypeptide primarily expressed by astroglial cells in the CNS. Quantitative RT-PCR and specific radioimmunoassay demonstrated that aggregated Abeta(25-35), at concentrations up to 10(-4) m, induced a dose-dependent increase in DBI mRNA expression and DBI-related peptide release from cultured rat astrocytes. These effects were totally suppressed when aggregation of Abeta(25-35) was prevented by Congo red. Measurement of the number of living cells revealed that Abeta(25-35) induced a trophic rather than a toxic effect on astrocytes. Administration of cycloheximide blocked Abeta(25-35)-induced increase of DBI gene expression and endozepine accumulation in astrocytes, indicating that protein synthesis is required for DBI gene expression. Altogether, the present data suggest that Abeta-induced activation of endozepine biosynthesis and release may contribute to astrocyte proliferation associated with Alzheimer's disease.
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Affiliation(s)
- Tursonjan Tokay
- INSERM U413, European Institute for Peptide Research (IFRMP 23), Laboratory of Cellular and Molecular Neuroendocrinology, UA CNRS, University of Rouen, Mont-Saint-Aignan, France
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30
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Masmoudi O, Gandolfo P, Tokay T, Leprince J, Ravni A, Vaudry H, Tonon MC. Somatostatin down-regulates the expression and release of endozepines from cultured rat astrocytes via distinct receptor subtypes. J Neurochem 2005; 94:561-71. [PMID: 16033415 DOI: 10.1111/j.1471-4159.2005.03076.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Endozepines, a family of regulatory peptides related to diazepam-binding inhibitor (DBI), are synthesized and released by astroglial cells. Because rat astrocytes express various subtypes of somatostatin receptors (sst), we have investigated the effect of somatostatin on DBI mRNA level and endozepine secretion in rat astrocytes in secondary culture. Somatostatin reduced in a concentration-dependent manner the level of DBI mRNA in cultured astrocytes. This inhibitory effect was mimicked by the selective sst4 receptor agonist L803-087 but not by the selective sst1, sst2 and sst3 receptor agonists L779-591, L779-976 and L797-778, respectively. Somatostatin was unable to further reduce DBI mRNA level in the presence of the MEK inhibitor U0126. Somatostatin and the sst1, sst2 and sst4 receptor agonists induced a concentration-dependent inhibition of endozepine release. Somatostatin and the sst1, sst2 and sst4 receptor agonists also inhibited cAMP formation dose-dependently. In addition, somatostatin reduced forskolin-induced endozepine release. H89 mimicked the inhibitory effect of somatostatin on endozepine secretion. In contrast the PLC inhibitor U73122, the PKC activator PMA and the PKC inhibitor calphostin C had no effect on somatostatin-induced inhibition of endozepine release. The present data demonstrate that somatostatin reduces DBI mRNA level mainly through activation of sst4 receptors negatively coupled to the MAPK pathway, and inhibits endozepine release through activation of sst1, sst2 and sst4 receptors negatively coupled to the adenylyl cyclase/PKA pathway.
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Affiliation(s)
- Olfa Masmoudi
- European Institute for Peptide Research (IFRMP 23), Laboratory of Cellular and Molecular Neuroendocrinology, INSERM U413, UA CNRS, University of Rouen, Mont-Saint-Aignan, France
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31
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Ostuni MA, Lacapère JJ. Un nouveau rôle pour le récepteur périphérique des benzodiazépines ? Med Sci (Paris) 2005; 21:240-2. [PMID: 15745695 DOI: 10.1051/medsci/2005213240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Mariano A Ostuni
- Inserm U.683, Faculté de Médecine Xavier Bichat, 16, rue Henri Huchard, 75870 Paris Cedex 18, France
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32
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Joo KM, Chung YH, Kim MK, Nam RH, Lee BL, Lee KH, Cha CI. Distribution of vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide receptors (VPAC1, VPAC2, and PAC1 receptor) in the rat brain. J Comp Neurol 2004; 476:388-413. [PMID: 15282712 DOI: 10.1002/cne.20231] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
To examine the distributions of VIP/PACAP receptors (VPAC1, VPAC2, and PAC1 receptors) in the brain and to identify the cell types that express these receptors, we performed immunohistochemistry and double immunofluorescence in the rat brain with specific antibodies. The immunohistochemistry revealed that the receptors had distinctive, complementary, and overlapping distribution patterns. High levels of the VPAC1 receptor were expressed in the cerebral cortex, hippocampal formation, deep cerebellar nuclei, thalamus, hypothalamus, and brainstem. The VPAC2 receptors were concentrated in the cerebral cortex, hippocampal formation, amygdalar regions, cerebellar cortex, deep cerebellar nuclei, hypothalamus, and brainstem. On the other hand, the PAC1 receptors had a more restricted distribution pattern in the brain, and high levels of the PAC1 receptors were confined to the cerebellar cortex, deep cerebellar nuclei, epithalamus, hypothalamus, brainstem, and white matter of many brain regions. Also, many fibers expressing the PAC1 receptors were observed in various areas, i.e., the thalamus, hypothalamus, and brainstem. The double immunofluorescence showed that the VIP/PACAP receptors were confined to the neuroglia as well as the neurons. All three types of the VIP/PACAP receptors were expressed in the astrocytes, and the PAC1 receptors were also expressed in the oligodendrocytes. These findings indicate that VIP and PACAP exert their functions through their receptors in specific locations in different combinations. We hope that this first demonstration of the distributions of the VIP/PACAP receptors provides data useful in the investigation of the mechanisms of the many functions of VIP and PACAP in the brain, which require further elucidation.
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MESH Headings
- Aging/physiology
- Animals
- Brain/cytology
- Brain/metabolism
- Immunohistochemistry
- Male
- Neuroglia/metabolism
- Neurons/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I
- Receptors, Pituitary Hormone/classification
- Receptors, Pituitary Hormone/metabolism
- Receptors, Vasoactive Intestinal Peptide/metabolism
- Receptors, Vasoactive Intestinal Peptide, Type II
- Receptors, Vasoactive Intestinal Polypeptide, Type I
- Tissue Distribution
- Vasoactive Intestinal Peptide/metabolism
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Affiliation(s)
- Kyeung Min Joo
- Department of Anatomy, Seoul National University College of Medicine, Seoul 110-799, Korea
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33
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Chartrel N, Leprince J, Dujardin C, Chatenet D, Tollemer H, Baroncini M, Balment RJ, Beauvillain JC, Vaudry H. Biochemical characterization and immunohistochemical localization of urotensin II in the human brainstem and spinal cord. J Neurochem 2004; 91:110-8. [PMID: 15379892 DOI: 10.1111/j.1471-4159.2004.02698.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The human urotensin II (UII) precursor encompasses several potential cleavage sites and thus, processing of pro-UII may generate various forms of mature UII including the peptides of 11 (UII11), 16 (UII16) and 19 (UII19) residues. Until now, the native form of human UII had not been characterized. Here, we show that the major UII peptide occurring in the human spinal cord corresponds to UII11. In contrast, neither the UII16 nor the UII19 forms could be detected. In 50% of the brainstem and in all the spinal cord extracts analysed, a second minor UII-immunoreactive peptide was resolved. Immunohistochemical labelling of the cervical segment of the human spinal cord revealed that the UII-immunoreactive material was confined to a subset of ventral horn motoneurones. These data provide the first evidence that in the human, the UII precursor, expressed in motoneurones, is processed at the tribasic KKR93 cleavage site to generate a mature form of UII of 11 amino acids. The absence of N-terminally elongated forms of UII of 16 and 19 residues indicates that pro-UII is not cleaved at the R85 or K88 monobasic sites. Finally, the minor UII-immunoreactive peptide detected in several tissue extracts might correspond to an extended form of UII resulting from the processing of the UII precursor at the basic RK50 or RK66 doublets.
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Affiliation(s)
- Nicolas Chartrel
- Institut Fédératif de Recherches Multidisciplinaires sur les Peptides, Laboratoire de Neuroendocrinologie Cellulaire et Moléculaire, Université de Rouen, Mont-Saint-Aignan, France
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Suzuki R, Arata S, Nakajo S, Ikenaka K, Kikuyama S, Shioda S. Expression of the receptor for pituitary adenylate cyclase-activating polypeptide (PAC1-R) in reactive astrocytes. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2003; 115:10-20. [PMID: 12824050 DOI: 10.1016/s0169-328x(03)00172-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We generated transgenic mice that express an enhanced green fluorescent protein (EGFP) under the control of the mouse glial fibrillary acidic protein (GFAP) promoter. In one of the transgenic lines, the green fluorescence of EGFP was undetectable in almost all of the brain regions, including the neocortex, in untreated animals. However, when reactive astrogliosis was induced by cortical stab wounding, the strong fluorescence of EGFP was observed around the needle track but was not found in the corresponding area of the contralateral hemisphere. The EGFP-expressing cells had the morphological features of reactive astrocytes such as thick processes. The EGFP-expressing cells were found to overlap with the astroglial marker GFAP, but not with the microglial marker CD11b or the neuronal marker NeuN. Furthermore, there were some EGFP-expressing cells that expressed vimentin-like immunoreactivity, the specific marker for reactive astrocytes. These results strongly suggest that the EGFP-expressing cells are reactive astrocytes, but not resting astrocytes. Using these transgenic mice, immunostaining for the PAC1 receptor (PAC1-R) was performed. PAC1-R, which is a pituitary adenylate cyclase-activating polypeptide (PACAP)-specific receptor, binds PACAP, which is known to have a wide variety of functions. An immunohistochemical study revealed the localization of PAC1-R in reactive astrocytes visualized with EGFP around the needle track at 5 days postsurgery.
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Affiliation(s)
- Ryusuke Suzuki
- Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
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