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Cortese K, Gagliani MC, Raiteri L. Interactions between Glycine and Glutamate through Activation of Their Transporters in Hippocampal Nerve Terminals. Biomedicines 2023; 11:3152. [PMID: 38137373 PMCID: PMC10740625 DOI: 10.3390/biomedicines11123152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/14/2023] [Accepted: 11/17/2023] [Indexed: 12/24/2023] Open
Abstract
Evidence supports the pathophysiological relevance of crosstalk between the neurotransmitters Glycine and Glutamate and their close interactions; some reports even support the possibility of Glycine-Glutamate cotransmission in central nervous system (CNS) areas, including the hippocampus. Functional studies with isolated nerve terminals (synaptosomes) permit us to study transporter-mediated interactions between neurotransmitters that lead to the regulation of transmitter release. Our main aims here were: (i) to investigate release-regulating, transporter-mediated interactions between Glycine and Glutamate in hippocampal nerve terminals and (ii) to determine the coexistence of transporters for Glycine and Glutamate in these terminals. Purified synaptosomes, analyzed at the ultrastructural level via electron microscopy, were used as the experimental model. Mouse hippocampal synaptosomes were prelabeled with [3H]D-Aspartate or [3H]Glycine; the release of radiolabeled tracers was monitored with the superfusion technique. The main findings were that (i) exogenous Glycine stimulated [3H]D-Aspartate release, partly by activation of GlyT1 and in part, unusually, through GlyT2 transporters and that (ii) D-Aspartate stimulated [3H]glycine release by a process that was sensitive to Glutamate transporter blockers. Based on the features of the experimental model used, it is suggested that functional transporters for Glutamate and Glycine coexist in a small subset of hippocampal nerve terminals, a condition that may also be compatible with cotransmission; glycinergic and glutamatergic transporters exhibit different functions and mediate interactions between the neurotransmitters. It is hoped that increased information on Glutamate-Glycine interactions in different areas, including the hippocampus, will contribute to a better knowledge of drugs acting at "glycinergic" targets, currently under study in relation with different CNS pathologies.
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Affiliation(s)
- Katia Cortese
- Department of Experimental Medicine (DIMES), Cellular Electron Microscopy Lab, University of Genoa, 16132 Genoa, Italy; (K.C.); (M.C.G.)
| | - Maria Cristina Gagliani
- Department of Experimental Medicine (DIMES), Cellular Electron Microscopy Lab, University of Genoa, 16132 Genoa, Italy; (K.C.); (M.C.G.)
| | - Luca Raiteri
- Department of Pharmacy (DIFAR), Pharmacology and Toxicology Section, University of Genoa, 16148 Genoa, Italy
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2
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Roggeri A, Olivero G, Usai C, Vanmierlo T, Pittaluga A. Presynaptic Release-Regulating Sphingosine 1-Phosphate 1/3 Receptors in Cortical Glutamatergic Terminals: Adaptations in EAE Mice and Impact of Therapeutic FTY720. Cells 2023; 12:2343. [PMID: 37830557 PMCID: PMC10571862 DOI: 10.3390/cells12192343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 09/13/2023] [Accepted: 09/20/2023] [Indexed: 10/14/2023] Open
Abstract
This study provides evidence of the existence of presynaptic inhibitory sphingosine-1-phosphate receptor 1 (S1P1R) and facilitatory S1P3R in cortical nerve endings (synaptosomes) of healthy mice. The conclusion relies on the findings that (i) the S1P1R agonist CS-2100 (0.1-30 nM) inhibits the 12 mM KCl-evoked glutamate exocytosis (quantified as the release of [3H]D-aspartate) while the S1P3R allosteric agonist CYM-5541 potentiates it and (ii) these effects are inhibited by the S1P1R antagonist Ex 26 (30-300 nM) and the S1P3R antagonist TY-52156 (100-1000 nM), respectively. Confocal microscopy and western blot analysis confirmed the presence of S1P1R and S1P3R proteins in cortical glutamatergic synaptosomes, which were scarcely accessible to biotin in a biotinylation study. Then, we demonstrated that S1P1R and S1P3R densities and their release activity are amplified in cortical synaptosomes of mice suffering from experimental autoimmune encephalomyelitis (EAE), despite receptors maintain their preferential internal distribution. Receptor changes recover following chronic oral therapeutic FTY720 (0.03 mg/Kg/day). These results improve our knowledge of the role of presynaptic release-regulating S1P1Rs and S1P3Rs controlling glutamate transmission in the CNS also unravelling functional adaptations during EAE that recover following chronic FTY720. In a whole, these findings provide new information on the central neuroprotectant activities of FTY720.
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Affiliation(s)
- Alessandra Roggeri
- Department of Pharmacy (DiFar), University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy; (A.R.); (G.O.)
| | - Guendalina Olivero
- Department of Pharmacy (DiFar), University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy; (A.R.); (G.O.)
| | - Cesare Usai
- Institute of Biophysics, National Research Council, Via De Marini 6, 16149 Genoa, Italy;
| | - Tim Vanmierlo
- Department of Neuroscience, Biomedical Research Institute, European Graduate School of Neuroscience, Hasselt University, B-3590 Hasselt, Belgium;
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neurosciences, Division Translational Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands
| | - Anna Pittaluga
- Department of Pharmacy (DiFar), Center of Excellence for Biomedical Research, 3Rs Center, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy
- IRCCS Ospedale Policlinico San Martino, 16145 Genoa, Italy
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Yakovlev AA. Neuronal Exosomes as a New Signaling System. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:457-465. [PMID: 37080932 DOI: 10.1134/s0006297923040028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Number of studies devoted to investigation of neuronal exosomes increases significantly each year. Potential of exosomes as diagnostic markers of neurodegenerative diseases has been examined thoroughly and similar protocols were used to search for the markers of other psychiatric disorders. Biogenesis of exosomes in various types of cells has been studied, physiological role of exosomes has been actively investigated, and many features of their signaling cascades have been clarified. The accumulated data indicate important role of the exosome signaling in interneuronal communication. Do we have enough grounds to recognize exosomes as new non-canonical neurotransmitters in the brain? In this review we discuss this issue and present a concept on the possible role of brain exosomes as a new signaling system to the scientific community.
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Affiliation(s)
- Alexander A Yakovlev
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 117485, Russia.
- Research and Clinical Center for Neuropsychiatry of Moscow Healthcare Department, Moscow, 115419, Russia
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Synaptosomes and Metamodulation of Receptors. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2417:99-111. [PMID: 35099794 DOI: 10.1007/978-1-0716-1916-2_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Synaptosomes are re-sealed pinched off nerve terminals that maintain all the main structural and functional features of the original structures and that are appropriate to study presynaptic events. Because of the discovery of new structural and molecular events that dictate the efficiency of transmitter release and of its receptor-mediated control in the central nervous system, the interest in this tissue preparation is continuously renewing. Most of these events have been already discussed in previous reviews, but few of them were not and deserve some comments since they could suggest new functional and possibly therapeutic considerations. Among them, the "metamodulation" of receptors represents an emerging aspect that dramatically increased the complexity of the presynaptic compartment, adding new insights to the role of presynaptic receptors as modulators of chemical synapses. Deciphering the mechanism of presynaptic metamodulation would permit indirect approaches to control the activity of presynaptic release-regulating receptors that are currently orphans of direct ligands/modulators, paving the road for the proposal of new therapeutic approaches for central neurological diseases.
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Presynaptic Release-Regulating Alpha2 Autoreceptors: Potential Molecular Target for Ellagic Acid Nutraceutical Properties. Antioxidants (Basel) 2021; 10:antiox10111759. [PMID: 34829630 PMCID: PMC8614955 DOI: 10.3390/antiox10111759] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 10/26/2021] [Accepted: 11/02/2021] [Indexed: 11/23/2022] Open
Abstract
Polyphenol ellagic acid (EA) possesses antioxidant, anti-inflammatory, anti-carcinogenic, anti-diabetic and cardio protection activities, making it an interesting multi-targeting profile. EA also controls the central nervous system (CNS), since it was proven to reduce the immobility time of mice in both the forced swimming and the tail-suspension tests, with an efficiency comparable to that of classic antidepressants. Interestingly, the anti-depressant-like effect was almost nulled by the concomitant administration of selective antagonists of the noradrenergic receptors, suggesting the involvement of these cellular targets in the central effects elicited by EA and its derivatives. By in silico and in vitro studies, we discuss how EA engages with human α2A-ARs and α2C-AR catalytic pockets, comparing EA behaviour with that of known agonists and antagonists. Structurally, the hydrophobic residues surrounding the α2A-AR pocket confer specificity on the intermolecular interactions and hence lead to favourable binding of EA in the α2A-AR, with respect to α2C-AR. Moreover, EA seems to better accommodate within α2A-ARs into the TM5 area, close to S200 and S204, which play a crucial role for activation of aminergic GPCRs such as the α2-AR, highlighting its promising role as a partial agonist. Consistently, EA mimics clonidine in inhibiting noradrenaline exocytosis from hippocampal nerve endings in a yohimbine-sensitive fashion that confirms the engagement of naïve α2-ARs in the EA-mediated effect.
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Olivero G, Cisani F, Marimpietri D, Di Paolo D, Gagliani MC, Podestà M, Cortese K, Pittaluga A. The Depolarization-Evoked, Ca 2+-Dependent Release of Exosomes From Mouse Cortical Nerve Endings: New Insights Into Synaptic Transmission. Front Pharmacol 2021; 12:670158. [PMID: 34366842 PMCID: PMC8339587 DOI: 10.3389/fphar.2021.670158] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 06/22/2021] [Indexed: 01/08/2023] Open
Abstract
Whether exosomes can be actively released from presynaptic nerve terminals is a matter of debate. To address the point, mouse cortical synaptosomes were incubated under basal and depolarizing (25 mM KCl-enriched medium) conditions, and extracellular vesicles were isolated from the synaptosomal supernatants to be characterized by dynamic light scattering, transmission electron microscopy, Western blot, and flow cytometry analyses. The structural and biochemical analysis unveiled that supernatants contain vesicles that have the size and the shape of exosomes, which were immunopositive for the exosomal markers TSG101, flotillin-1, CD63, and CD9. The marker content increased upon the exposure of nerve terminals to the high-KCl stimulus, consistent with an active release of the exosomes from the depolarized synaptosomes. High KCl-induced depolarization elicits the Ca2+-dependent exocytosis of glutamate. Interestingly, the depolarization-evoked release of exosomes from cortical synaptosomes also occurred in a Ca2+-dependent fashion, since the TSG101, CD63, and CD9 contents in the exosomal fraction isolated from supernatants of depolarized synaptosomes were significantly reduced when omitting external Ca2+ ions. Differently, (±)-baclofen (10 µM), which significantly reduced the glutamate exocytosis, did not affect the amount of exosomal markers, suggesting that the GABAB-mediated mechanism does not control the exosome release. Our findings suggest that the exposure of synaptosomes to a depolarizing stimulus elicits a presynaptic release of exosomes that occurs in a Ca2+-dependent fashion. The insensitivity to the presynaptic GABAB receptors, however, leaves open the question on whether the release of exosomes could be a druggable target for new therapeutic intervention for the cure of synaptopathies.
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Affiliation(s)
- Guendalina Olivero
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy
| | - Francesca Cisani
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy
| | - Danilo Marimpietri
- Stem Cell Laboratory and Cell Therapy Center, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Daniela Di Paolo
- Laboratory of Experimental Therapies in Oncology, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Maria Cristina Gagliani
- Department of Experimental Medicine, DIMES, Human Anatomy Section, University of Genoa, Genoa, Italy
| | - Marina Podestà
- Stem Cell Laboratory and Cell Therapy Center, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Katia Cortese
- Department of Experimental Medicine, DIMES, Human Anatomy Section, University of Genoa, Genoa, Italy
| | - Anna Pittaluga
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, Centre of Excellence for Biomedical Research, 3Rs Center, University of Genoa, Genoa, Italy
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
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Olivero G, Vergassola M, Cisani F, Roggeri A, Pittaluga A. Presynaptic Release-regulating Metabotropic Glutamate Receptors: An Update. Curr Neuropharmacol 2021; 18:655-672. [PMID: 31775600 PMCID: PMC7457419 DOI: 10.2174/1570159x17666191127112339] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/15/2019] [Accepted: 11/22/2019] [Indexed: 12/18/2022] Open
Abstract
Metabotropic glutamate (mGlu) receptors represent the largest family of glutamate receptors in mammals and act as fine tuners of the chemical transmission in central nervous system (CNS). In the last decade, results concerning the expression and the subcellular localization of mGlu receptors further clarified their role in physio-pathological conditions. Concomitantly, their pharmacological characterization largely improved thanks to the identification of new compounds (chemical ligands and antibodies recognizing epitopic sequences of the receptor proteins) that allowed to decipher the protein compositions of the naive receptors. mGlu receptors are expressed at the presynaptic site of chemical synapses. Here, they modulate intraterminal enzymatic pathways controlling the migration and the fusion of vesicles to synaptic membranes as well as the phosphorylation of colocalized receptors. Both the control of transmitter exocytosis and the phosphorylation of colocalized receptors elicited by mGlu receptors are relevant events that dictate the plasticity of nerve terminals, and account for the main role of presynaptic mGlu receptors as modulators of neuronal signalling. The role of the presynaptic mGlu receptors in the CNS has been the matter of several studies and this review aims at briefly summarizing the recent observations obtained with isolated nerve endings (we refer to as synaptosomes). We focus on the pharmacological characterization of these receptors and on their receptor-receptor interaction / oligo-dimerization in nerve endings that could be relevant to the development of new therapeutic approaches for the cure of central pathologies.
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Affiliation(s)
| | | | | | | | - Anna Pittaluga
- Department of Pharmacy, University of Genoa, Genoa, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale Policlinico San Martino, Genoa, Italy
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Cisani F, Olivero G, Usai C, Van Camp G, Maccari S, Morley-Fletcher S, Pittaluga AM. Antibodies Against the NH 2-Terminus of the GluA Subunits Affect the AMPA-Evoked Releasing Activity: The Role of Complement. Front Immunol 2021; 12:586521. [PMID: 33717067 PMCID: PMC7952438 DOI: 10.3389/fimmu.2021.586521] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 01/15/2021] [Indexed: 01/31/2023] Open
Abstract
Antibodies recognizing the amino-terminal domain of receptor subunit proteins modify the receptor efficiency to controlling transmitter release in isolated nerve endings (e.g., synaptosomes) indirectly confirming their presence in these particles but also allowing to speculate on their subunit composition. Western blot analysis and confocal microscopy unveiled the presence of the GluA1, GluA2, GluA3, and GluA4 receptor subunits in cortical synaptosomes. Functional studies confirmed the presence of presynaptic release-regulating AMPA autoreceptors in these terminals, whose activation releases [3H]D-aspartate ([3H]D-Asp, here used as a marker of glutamate) in a NBQX-dependent manner. The AMPA autoreceptors traffic in a constitutive manner, since entrapping synaptosomes with the pep2-SVKI peptide (which interferes with the GluA2-GRIP1/PICK1 interaction) amplified the AMPA-evoked releasing activity, while the inactive pep2-SVKE peptide was devoid of activity. Incubation of synaptosomes with antibodies recognizing the NH2 terminus of the GluA2 and the GluA3 subunits increased, although to a different extent, the GluA2 and 3 densities in synaptosomal membranes, also amplifying the AMPA-evoked glutamate release in a NBQX-dependent fashion. We then analyzed the releasing activity of complement (1:300) from both treated and untreated synaptosomes and found that the complement-induced overflow occurred in a DL-t-BOA-sensitive, NBQX-insensitive fashion. We hypothesized that anti-GluA/GluA complexes in neuronal membranes could trigger the classic pathway of activation of the complement, modifying its releasing activity. Accordingly, the complement-evoked release of [3H]D-Asp from antiGluA2 and anti-GluA3 antibody treated synaptosomes was significantly increased when compared to untreated terminals and facilitation was prevented by omitting the C1q component of the immunocomplex. Antibodies recognizing the NH2 terminus of the GluA1 or the GluA4 subunits failed to affect both the AMPA and the complement-evoked tritium overflow. Our results suggest the presence of GluA2/GluA3-containing release-regulating AMPA autoreceptors in cortical synaptosomes. Incubation of synaptosomes with commercial anti-GluA2 or anti-GluA3 antibodies amplifies the AMPA-evoked exocytosis of glutamate through a complement-independent pathway, involving an excessive insertion of AMPA autoreceptors in plasma membranes but also affects the complement-dependent releasing activity, by promoting the classic pathway of activation of the immunocomplex. Both events could be relevant to the development of autoimmune diseases typified by an overproduction of anti-GluA subunits.
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Affiliation(s)
- Francesca Cisani
- Pharmacology and Toxicology Section, Department of Pharmacy, DIFAR, Genoa, Italy
| | - Guendalina Olivero
- Pharmacology and Toxicology Section, Department of Pharmacy, DIFAR, Genoa, Italy
| | - Cesare Usai
- Institute of Biophysics, National Research Council, Genoa, Italy
| | - Gilles Van Camp
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
- International Associated Laboratory (LIA), “Prenatal Stress and Neurodegenerative Diseases”, University of Lille – CNRS, UGSF UMR 8576/Sapienza University of Rome and IRCCS Neuromed, Lille, France
| | - Stefania Maccari
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
- International Associated Laboratory (LIA), “Prenatal Stress and Neurodegenerative Diseases”, University of Lille – CNRS, UGSF UMR 8576/Sapienza University of Rome and IRCCS Neuromed, Lille, France
- Department of Science and Medical - Surgical Biotechnology, University Sapienza of Rome, Rome, Italy
| | - Sara Morley-Fletcher
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
- International Associated Laboratory (LIA), “Prenatal Stress and Neurodegenerative Diseases”, University of Lille – CNRS, UGSF UMR 8576/Sapienza University of Rome and IRCCS Neuromed, Lille, France
| | - Anna Maria Pittaluga
- Pharmacology and Toxicology Section, Department of Pharmacy, DIFAR, Genoa, Italy
- IRCCS San Martino Hospital, Genova, Italy
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Pittaluga A. Presynaptic release-regulating NMDA receptors in isolated nerve terminals: A narrative review. Br J Pharmacol 2021; 178:1001-1017. [PMID: 33347605 PMCID: PMC9328659 DOI: 10.1111/bph.15349] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/10/2020] [Accepted: 12/03/2020] [Indexed: 02/02/2023] Open
Abstract
The existence of presynaptic, release‐regulating NMDA receptors in the CNS has been long matter of discussion. Most of the reviews dedicated to support this conclusion have preferentially focussed on the results from electrophysiological studies, paying little or no attention to the data obtained with purified synaptosomes, even though this experimental approach has been recognized as providing reliable information concerning the presence and the role of presynaptic release‐regulating receptors in the CNS. To fill the gap, this review is dedicated to summarising the results from studies with synaptosomes published during the last 40 years, which support the existence of auto and hetero NMDA receptors controlling the release of transmitters such as glutamate, GABA, dopamine, noradrenaline, 5‐HT, acetylcholine and peptides, in the CNS of mammals. The review also deals with the results from immunochemical studies in isolated nerve endings that confirm the functional observations.
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Affiliation(s)
- Anna Pittaluga
- Department of Pharmacology (DIFAR), School of Medical and Pharmaceutical Sciences, 3Rs Center, University of Genova, Italy.,San Martino Hospital IRCCS, Genova, Italy
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Cisani F, Roggeri A, Olivero G, Garrone B, Tongiani S, Di Giorgio FP, Pittaluga A. Acute Low Dose of Trazodone Recovers Glutamate Release Efficiency and mGlu2/3 Autoreceptor Impairments in the Spinal Cord of Rats Suffering From Chronic Sciatic Ligation. Front Pharmacol 2020; 11:1108. [PMID: 32765286 PMCID: PMC7379891 DOI: 10.3389/fphar.2020.01108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/08/2020] [Indexed: 11/16/2022] Open
Abstract
We investigated whether chronic sciatic ligation modifies the glutamate release in spinal cord nerve endings (synaptosomes) as well as the expression and the function of presynaptic release-regulating mGlu2/3 autoreceptors and 5-HT2A heteroreceptors in these particles. Synaptosomes were from the spinal cord of animals suffering from the sciatic ligation that developed on day 6 post-surgery a significant decrease of the force inducing paw-withdrawal in the lesioned paw. The exocytosis of glutamate (quantified as release of preloaded [3H]D-aspartate, [3H]D-Asp) elicited by a mild depolarizing stimulus (15 mM KCl) was significantly increased in synaptosomes from injured rats when compared to controls (uninjured rats). The mGlu2/3 agonist LY379268 (1000 pM) significantly inhibited the 15 mM KCl-evoked [3H]D-Asp overflow from control synaptosomes, but not in terminals isolated from injured animals. Differently, a low concentration (10 nM) of (±) DOI, unable to modify the 15 mM KCl-evoked [3H]D-Asp overflow in control spinal cord synaptosomes, significantly reduced the glutamate exocytosis in nerve endings isolated from the injured rats. Acute oral trazodone (TZD, 0.3 mg/kg on day 7 post-surgery) efficiently recovered glutamate exocytosis as well as the efficiency of LY379268 in inhibiting this event in spinal cord synaptosomes from injured animals. The sciatic ligation significantly reduced the expression of mGlu2/3, but not of 5-HT2A, receptor proteins in spinal cord synaptosomal lysates. Acute TZD recovered this parameter. Our results support the use of 5-HT2A antagonists for restoring altered spinal cord glutamate plasticity in rats suffering from sciatic ligation.
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Affiliation(s)
- Francesca Cisani
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Alessandra Roggeri
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Guendalina Olivero
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Beatrice Garrone
- Angelini RR&D (Research, Regulatory & Development), Angelini Pharma S.p.A., Rome, Italy
| | - Serena Tongiani
- Angelini RR&D (Research, Regulatory & Development), Angelini Pharma S.p.A., Rome, Italy
| | | | - Anna Pittaluga
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genova, Italy
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Neuroinflammation in Aged Brain: Impact of the Oral Administration of Ellagic Acid Microdispersion. Int J Mol Sci 2020; 21:ijms21103631. [PMID: 32455600 PMCID: PMC7279224 DOI: 10.3390/ijms21103631] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 05/13/2020] [Accepted: 05/19/2020] [Indexed: 12/12/2022] Open
Abstract
The immune system and the central nervous system message each other to preserving central homeostasis. Both systems undergo changes during aging that determine central age-related defects. Ellagic acid (EA) is a natural product which is beneficial in both peripheral and central diseases, including aging. We analyzed the impact of the oral administration of a new oral ellagic acid micro-dispersion (EAm), that largely increased the EA solubility, in young and old mice. Oral EAm did not modify animal weight and behavioral skills in young and old mice, but significantly recovered changes in "ex-vivo, in vitro" parameters in old animals. Cortical noradrenaline exocytosis decreased in aged mice. EAm administration did not modify noradrenaline overflow in young animals, but recovered it in old mice. Furthermore, GFAP staining was increased in the cortex of aged mice, while IBA-1 and CD45 immunopositivities were unchanged when compared to young ones. EAm treatment significantly reduced CD45 signal in both young and old cortical lysates; it diminished GFAP immunopositivity in young mice, but failed to affect IBA-1 expression in both young and old animals. Finally, EAm treatment significantly reduced IL1beta expression in old mice. These results suggest that EAm is beneficial to aging and represents a nutraceutical ingredient for elders.
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