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Almeida VN. Somatostatin and the pathophysiology of Alzheimer's disease. Ageing Res Rev 2024; 96:102270. [PMID: 38484981 DOI: 10.1016/j.arr.2024.102270] [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: 07/18/2023] [Revised: 03/09/2024] [Accepted: 03/09/2024] [Indexed: 03/28/2024]
Abstract
Among the central features of Alzheimer's disease (AD) progression are altered levels of the neuropeptide somatostatin (SST), and the colocalisation of SST-positive interneurons (SST-INs) with amyloid-β plaques, leading to cell death. In this theoretical review, I propose a molecular model for the pathogenesis of AD based on SST-IN hypofunction and hyperactivity. Namely, hypofunctional and hyperactive SST-INs struggle to control hyperactivity in medial regions in early stages, leading to axonal Aβ production through excessive presynaptic GABAB inhibition, GABAB1a/APP complex downregulation and internalisation. Concomitantly, excessive SST-14 release accumulates near SST-INs in the form of amyloids, which bind to Aβ to form toxic mixed oligomers. This leads to differential SST-IN death through excitotoxicity, further disinhibition, SST deficits, and increased Aβ release, fibrillation and plaque formation. Aβ plaques, hyperactive networks and SST-IN distributions thereby tightly overlap in the brain. Conversely, chronic stimulation of postsynaptic SST2/4 on gulutamatergic neurons by hyperactive SST-INs promotes intense Mitogen-Activated Protein Kinase (MAPK) p38 activity, leading to somatodendritic p-tau staining and apoptosis/neurodegeneration - in agreement with a near complete overlap between p38 and neurofibrillary tangles. This model is suitable to explain some of the principal risk factors and markers of AD progression, including mitochondrial dysfunction, APOE4 genotype, sex-dependent vulnerability, overactive glial cells, dystrophic neurites, synaptic/spine losses, inter alia. Finally, the model can also shed light on qualitative aspects of AD neuropsychology, especially within the domains of spatial and declarative (episodic, semantic) memory, under an overlying pattern of contextual indiscrimination, ensemble instability, interference and generalisation.
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Affiliation(s)
- Victor N Almeida
- Institute of Psychiatry, Faculty of Medicine, University of São Paulo (USP), Brazil; Faculty of Languages, Federal University of Minas Gerais (UFMG), Brazil.
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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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3
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Presynaptic 5-HT2A-mGlu2/3 Receptor–Receptor Crosstalk in the Prefrontal Cortex: Metamodulation of Glutamate Exocytosis. Cells 2022; 11:cells11193035. [PMID: 36230998 PMCID: PMC9562019 DOI: 10.3390/cells11193035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/19/2022] [Accepted: 09/26/2022] [Indexed: 12/02/2022] Open
Abstract
The glutamatergic nerve endings of a rat prefrontal cortex (PFc) possess presynaptic 5-HT2A heteroreceptors and mGlu2/3 autoreceptors, whose activation inhibits glutamate exocytosis, and is measured as 15 mM KCl-evoked [3H]D-aspartate ([3H]D-asp) release (which mimics glutamate exocytosis). The concomitant activation of the two receptors nulls their inhibitory activities, whereas blockade of the 5-HT2A heteroreceptors with MDL11,939 (1 μM) strengthens the inhibitory effect elicited by the mGlu2/3 receptor agonist LY329268 (1 μM). 5-HT2A receptor antagonists (MDL11,939; ketanserin; trazodone) amplify the impact of low (3 nM) LY379268. Clozapine (0.1–10 μM) mimics the 5-HT2A agonist (±) DOI and inhibits the KCl-evoked [3H]D-asp overflow in a MDL11,939-dependent fashion, but does not modify the (±) DOI-induced effect. mGlu2 and 5-HT2A proteins do not co-immunoprecipitate from synaptosomal lysates, nor does the incubation of PFc synaptosomes with MDL11,939 (1 μM) or clozapine (10 µM) modify the insertion of mGlu2 subunits in synaptosomal plasma membranes. In conclusion, 5-HT2A and mGlu2/3 receptors colocalize, but do not physically associate, in PFc glutamatergic terminals, where they functionally interact in an antagonist-like fashion to control glutamate exocytosis. The mGlu2/3-5-HT2A metamodulation could be relevant to therapy for central neuropsychiatric disorders, including schizophrenia, but also unveil cellular events accounting for their development, which also influence the responsiveness to drugs regimens.
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4
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Chiu KM, Lin TY, Lee MY, Lu CW, Wang SJ. Lappaconitine inhibits glutamate release from rat cerebrocortical nerve terminals by suppressing Ca2+ influx and protein kinase A cascade. Neurotoxicology 2022; 91:218-227. [DOI: 10.1016/j.neuro.2022.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 05/02/2022] [Accepted: 05/20/2022] [Indexed: 10/18/2022]
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Inhibition of Glutamate Release from Rat Cortical Nerve Terminals by Dehydrocorydaline, an Alkaloid from Corydalis yanhusuo. Molecules 2022; 27:molecules27030960. [PMID: 35164225 PMCID: PMC8838318 DOI: 10.3390/molecules27030960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/27/2022] [Accepted: 01/29/2022] [Indexed: 02/01/2023] Open
Abstract
Excessive release of glutamate induces excitotoxicity and causes neuronal damage in several neurodegenerative diseases. Natural products have emerged as potential neuroprotective agents for preventing and treating neurological disorders. Dehydrocorydaline (DHC), an active alkaloid compound isolated from Corydalis yanhusuo, possesses neuroprotective capacity. The present study investigated the effect of DHC on glutamate release using a rat brain cortical synaptosome model. Our results indicate that DHC inhibited 4-aminopyridine (4-AP)-evoked glutamate release and elevated intrasynaptosomal calcium levels. The inhibitory effect of DHC on 4-AP-evoked glutamate release was prevented in the presence of the vesicular transporter inhibitor bafilomycin A1 and the N- and P/Q-type Ca2+ channel blocker ω-conotoxin MVIIC but not the intracellular inhibitor of Ca2+ release dantrolene or the mitochondrial Na+/Ca2+ exchanger inhibitor CGP37157. Moreover, the inhibitory effect of DHC on evoked glutamate release was prevented by the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) inhibitor PD98059. Western blotting data in synaptosomes also showed that DHC significantly decreased the level of ERK1/2 phosphorylation and synaptic vesicle-associated protein synapsin I, the main presynaptic target of ERK. Together, these results suggest that DHC inhibits presynaptic glutamate release from cerebrocortical synaptosomes by suppressing presynaptic voltage-dependent Ca2+ entry and the MAPK/ERK/synapsin I signaling pathway.
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SUGIMOTO A, TSUCHIDA H, NAGAE M, INOUE N, UENOYAMA Y, TSUKAMURA H. Central somatostatin-somatostatin receptor 2 signaling mediates lactational suppression of luteinizing hormone release via the inhibition of glutamatergic interneurons during late lactation in rats. J Reprod Dev 2022; 68:190-197. [PMID: 35249910 PMCID: PMC9184827 DOI: 10.1262/jrd.2022-009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Reproductive function is suppressed during lactation owing to the suckling-induced suppression of the kisspeptin gene (Kiss1) expression in the arcuate nucleus (ARC) and
subsequent suppression of luteinizing hormone (LH) release. Our previous study revealed that somatostatin (SST) neurons mediate suckling-induced suppression of LH release via SST receptor 2
(SSTR2) in ovariectomized lactating rats during early lactation. This study examined whether central SST-SSTR2 signaling mediates the inhibition of ARC Kiss1 expression and
LH release in lactating rats during late lactation and whether the inhibition of glutamatergic neurons, stimulators of LH release, is involved in the suppression of LH release mediated by
central SST-SSTR2 signaling in lactating rats. A central injection of the SSTR2 antagonist CYN154806 (CYN) significantly increased ARC Kiss1 expression in lactating rats on
day 16 of lactation. Dual in situ hybridization revealed that few ARC Kiss1-positive cells co-expressed Sstr2, and some of the ARC
Slc17a6 (a glutamatergic neuronal marker)-positive cells co-expressed Sstr2. Furthermore, almost all ARC Kiss1-positive cells
co-expressed Grin1, a subunit of N-methyl-D-aspartate (NMDA) receptors. The numbers of Slc17a6/Sstr2 double-labeled and
Slc17a6 single-labeled cells were significantly lower in lactating dams than in non-lactating rats whose pups had been removed after parturition. A central injection of an
NMDA antagonist reversed the CYN-induced increase in LH release in lactating rats. Overall, these results suggest that central SST-SSTR2 signaling, at least partly, mediates the suppression
of ARC Kiss1 expression and LH release by inhibiting ARC glutamatergic interneurons in lactating rats.
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Affiliation(s)
- Arisa SUGIMOTO
- Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
| | - Hitomi TSUCHIDA
- Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
| | - Mayuko NAGAE
- Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
| | - Naoko INOUE
- Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
| | - Yoshihisa UENOYAMA
- Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
| | - Hiroko TSUKAMURA
- Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
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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: 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: 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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8
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Somatostatin, a Presynaptic Modulator of Glutamatergic Signal in the Central Nervous System. Int J Mol Sci 2021; 22:ijms22115864. [PMID: 34070785 PMCID: PMC8198526 DOI: 10.3390/ijms22115864] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/19/2021] [Accepted: 05/26/2021] [Indexed: 01/07/2023] Open
Abstract
Somatostatin is widely diffused in the central nervous system, where it participates to control the efficiency of synaptic transmission. This peptide mainly colocalizes with GABA, in inhibitory, GABA-containing interneurons from which it is actively released in a Ca2+ dependent manner upon application of depolarizing stimuli. Once released in the synaptic cleft, somatostatin acts locally, or it diffuses in the extracellular space through "volume diffusion", a mechanism(s) of distribution which mainly operates in the cerebrospinal fluid and that assures the progression of neuronal signalling from signal-secreting sender structures towards receptor-expressing targeted neurons located extrasynaptically, in a non-synaptic, inter-neuronal form of communication. Somatostatin controls the efficiency of central glutamate transmission by either modulating presynaptically the glutamate exocytosis or by metamodulating the activity of glutamate receptors colocalized and functionally coupled with somatostatin receptors in selected subpopulations of nerve terminals. Deciphering the role of somatostatin in the mechanisms of "volume diffusion" and in the "receptor-receptor interaction" unveils new perspectives in the central role of this fine tuner of synaptic strength, paving the road to new therapeutic approaches for the cure of central disorders.
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Chiu KM, Lin TY, Lee MY, Lu CW, Wang MJ, Wang SJ. Typhaneoside Suppresses Glutamate Release Through Inhibition of Voltage-Dependent Calcium Entry in Rat Cerebrocortical Nerve Terminals. Chem Res Toxicol 2021; 34:1286-1295. [PMID: 33621091 DOI: 10.1021/acs.chemrestox.0c00446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Glutamate is the major excitatory neurotransmitter in the brain and is involved in many brain functions. In this study, we investigated whether typhaneoside, a flavonoid from Typhae angustifolia pollen, affects endogenous glutamate release from rat cortical synaptosomes. Using a one-line enzyme-coupled fluorometric assay, glutamate release stimulated by the K+ channel blocker 4-aminopyridine was monitored to explore the possible underlying mechanisms. The vesicular transporter inhibitor bafilomycin A1 and chelation of extracellular Ca2+ ions with EGTA suppressed the effect of typhaneoside on the induced glutamate release. Nevertheless, the typhaneoside activity has not been affected by the glutamate transporter inhibitor dl-threo-beta-benzyloxyaspartate. The synaptosomal plasma membrane potential was assayed using a membrane potential-sensitive dye DiSC3(5), and cytosolic Ca2+ concentrations ([Ca2+]C) was monitored by a Ca2+ indicator Fura-2. Results showed that typhaneoside did not alter the synaptosomal membrane potential but lowered 4-aminopyridine-induced increases in [Ca2+]C. Furthermore, the Cav2.2 (N-type) channel blocker ω-conotoxin GVIA blocked Ca2+ entry and inhibited the effect of typhaneoside on 4-aminopyridine-induced glutamate release. However, the inhibitor of intracellular Ca2+ release dantrolene and the mitochondrial Na+/Ca2+ exchanger blocker 7-chloro-5-(2-chloropheny)-1,5-dihydro-4,1-benzothiazepin-2(3H)-one have no effect on the suppression of glutamate release mediated by typhaneoside. Moreover, inhibition of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) prevented the inhibitory effect of typhaneoside on induced glutamate release. Typhaneoside reduced 4-aminopyridine-induced phosphorylation of ERK1/2 and the major presynaptic ERK target synapsin I, which is a synaptic vesicle-associated protein. In conclusion, these findings suggest a role for typhaneoside in modulating glutamate release by suppressing voltage-dependent Ca2+ channel mediated presynaptic Ca2+ influx and the MAPK/ERK/synapsin I signaling cascade.
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Affiliation(s)
- Kuan-Ming Chiu
- Division of Cardiovascular Surgery, Cardiovascular Center, Far-Eastern Memorial Hospital, New Taipei City 22060, Taiwan.,Department of Nursing, Oriental Institute of Technology, New Taipei City 22060, Taiwan.,Department of Photonics Engineering, Yuan Ze University, Taoyuan City 32003, Taiwan
| | - Tzu-Yu Lin
- Department of Anesthesiology, Far-Eastern Memorial Hospital, New Taipei City 22060, Taiwan.,Department of Mechanical Engineering, Yuan Ze University, Taoyuan City 32003, Taiwan
| | - Ming-Yi Lee
- Division of Cardiovascular Surgery, Cardiovascular Center, Far-Eastern Memorial Hospital, New Taipei City 22060, Taiwan
| | - Cheng-Wei Lu
- Department of Anesthesiology, Far-Eastern Memorial Hospital, New Taipei City 22060, Taiwan.,Department of Mechanical Engineering, Yuan Ze University, Taoyuan City 32003, Taiwan
| | - Ming-Jiuh Wang
- Department of Anesthesiology, National Taiwan University Hospital, Taipei City 100225, Taiwan
| | - Su-Jane Wang
- Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan City 33303, Taiwan.,School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan
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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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11
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Song YH, Hwang YS, Kim K, Lee HR, Kim JH, Maclachlan C, Dubois A, Jung MW, Petersen CCH, Knott G, Lee SH, Lee SH. Somatostatin enhances visual processing and perception by suppressing excitatory inputs to parvalbumin-positive interneurons in V1. SCIENCE ADVANCES 2020; 6:eaaz0517. [PMID: 32494634 PMCID: PMC7176413 DOI: 10.1126/sciadv.aaz0517] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 02/03/2020] [Indexed: 06/11/2023]
Abstract
Somatostatin (SST) is a neuropeptide expressed in a major subtype of GABAergic interneurons in the cortex. Despite abundant expression of SST and its receptors, their modulatory function in cortical processing remains unclear. Here, we found that SST application in the primary visual cortex (V1) improves visual discrimination in freely moving mice and enhances orientation selectivity of V1 neurons. We also found that SST reduced excitatory synaptic transmission to parvalbumin-positive (PV+) fast-spiking interneurons but not to regular-spiking neurons. Last, using serial block-face scanning electron microscopy (SBEM), we found that axons of SST+ neurons in V1 often contact other axons that exhibit excitatory synapses onto the soma and proximal dendrites of the PV+ neuron. Collectively, our results demonstrate that the neuropeptide SST improves visual perception by enhancing visual gain of V1 neurons via a reduction in excitatory synaptic transmission to PV+ inhibitory neurons.
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Affiliation(s)
- You-Hyang Song
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Yang-Sun Hwang
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Kwansoo Kim
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Hyoung-Ro Lee
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jae-Hyun Kim
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Catherine Maclachlan
- Biological Electron Microscopy Facility, Centre of Electron Microscopy, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Anaelle Dubois
- Biological Electron Microscopy Facility, Centre of Electron Microscopy, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Min Whan Jung
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science and Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Carl C. H. Petersen
- Brain Mind Institute, Faculty of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Graham Knott
- Biological Electron Microscopy Facility, Centre of Electron Microscopy, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Suk-Ho Lee
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Seung-Hee Lee
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
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12
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Palese F, Bonomi E, Nuzzo T, Benussi A, Mellone M, Zianni E, Cisani F, Casamassa A, Alberici A, Scheggia D, Padovani A, Marcello E, Di Luca M, Pittaluga A, Usiello A, Borroni B, Gardoni F. Anti-GluA3 antibodies in frontotemporal dementia: effects on glutamatergic neurotransmission and synaptic failure. Neurobiol Aging 2019; 86:143-155. [PMID: 31784278 DOI: 10.1016/j.neurobiolaging.2019.10.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/10/2019] [Accepted: 10/26/2019] [Indexed: 11/19/2022]
Abstract
Despite the great effort of the scientific community in the field, the pathogenesis of frontotemporal dementia (FTD) remains elusive. Recently, a role for autoimmunity and altered glutamatergic neurotransmission in triggering disease onset has been put forward. We reported the presence of autoantibodies recognizing the GluA3 subunit of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors in about 25% of FTD cases. In this study, we evaluated the mechanisms involved in anti-GluA3 autoimmunity, through molecular/neurochemical analyses conducted on patients' brain specimens with frontotemporal lobar degeneration-tau neuropathology. We then corroborated these results in vivo in FTD patients with transcranial magnetic stimulation and glutamate, D-serine, and L-serine dosages in the cerebrospinal fluid and serum. We observed that GluA3 autoantibodies affect glutamatergic neurotransmission, decreasing glutamate release and altering GluA3-containing α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor levels. These alterations were accompanied by changes of scaffolding proteins involved in receptor synaptic retention/internalization. The above results were confirmed by transcranial magnetic stimulation, suggesting a significant impairment of indirect measures of glutamatergic neurotransmission in FTD patients compared with controls, with further add-on harmful effect in those FTD patients with anti-GluA3 antibodies. Finally, FTD patients showed a significant increase of glutamate, D-serine, and L-serine levels in the cerebrospinal fluid.
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Affiliation(s)
- Francesca Palese
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Elisa Bonomi
- Department of Clinical and Experimental Sciences, Neurology Unit, Centre for Neurodegenerative Disorders, University of Brescia, Brescia, Italy
| | - Tommaso Nuzzo
- Translational Neuroscience Unit, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Alberto Benussi
- Department of Clinical and Experimental Sciences, Neurology Unit, Centre for Neurodegenerative Disorders, University of Brescia, Brescia, Italy
| | - Manuela Mellone
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Elisa Zianni
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Francesca Cisani
- Department of Pharmacy, DiFAR, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy
| | - Alessia Casamassa
- Translational Neuroscience Unit, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Antonella Alberici
- Department of Clinical and Experimental Sciences, Neurology Unit, Centre for Neurodegenerative Disorders, University of Brescia, Brescia, Italy
| | - Diego Scheggia
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Alessandro Padovani
- Department of Clinical and Experimental Sciences, Neurology Unit, Centre for Neurodegenerative Disorders, University of Brescia, Brescia, Italy
| | - Elena Marcello
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Monica Di Luca
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Anna Pittaluga
- Department of Pharmacy, DiFAR, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy
| | - Alessandro Usiello
- Translational Neuroscience Unit, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy; Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania Luigi Vanvitelli, Caserta, Italy
| | - Barbara Borroni
- Department of Clinical and Experimental Sciences, Neurology Unit, Centre for Neurodegenerative Disorders, University of Brescia, Brescia, Italy
| | - Fabrizio Gardoni
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy.
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13
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Su IC, Hung CF, Lin CN, Huang SK, Wang SJ. Cycloheterophyllin Inhibits the Release of Glutamate from Nerve Terminals of the Rat Hippocampus. Chem Res Toxicol 2019; 32:1591-1598. [PMID: 31264847 DOI: 10.1021/acs.chemrestox.9b00121] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The effect of cycloheterophyllin, a prenylflavone isolated from Artocarpus heteophyllus, on glutamate release was studied in the rat hippocampus using synaptosome and slice preparations. In rat hippocampal synaptosomes, cycloheterophyllin inhibited 4-aminopyridine (4-AP)-evoked glutamate release and elevation of intrasynaptosomal calcium levels. The inhibitory effect of cycloheterophyllin on 4-AP-evoked glutamate release was prevented in the presence of the vesicular transporter inhibitor, the N- and P/Q-type calcium channel blocker, and the protein kinase C (PKC) inhibitor but was insensitive to the intracellular Ca2+ release inhibitors, the protein kinase A inhibitor, and the mitogen-activated/extracellular signal-regulated kinase inhibitor. Western blotting data in synaptosomes also showed that cycloheterophyllin significantly decreased the level of phosphorylation of PKC. In addition, cycloheterophyllin decreased the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) without influencing the amplitude of sEPSCs and glutamate-activated currents in hippocampal slices, supporting a presynaptic action. Together, these results suggest that cycloheterophyllin inhibits presynaptic glutamate release by suppressing N- and P/Q-type calcium channel and PKC activity in the rat hippocampus.
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Affiliation(s)
- I Chang Su
- School of Medicine , Fu Jen Catholic University , No. 510, Chung-Cheng Road , Hsin-Chuang, New Taipei City 24205 , Taiwan.,Division of Neurosurgery, Department of Surgery , Cathay General Hospital , Taipei City , Taiwan 106
| | - Chi Feng Hung
- School of Medicine , Fu Jen Catholic University , No. 510, Chung-Cheng Road , Hsin-Chuang, New Taipei City 24205 , Taiwan
| | - Chun Nan Lin
- College of Pharmacy , Kaoshiung Medical University , Kaohsiung , Taiwan 807
| | - Shu Kuei Huang
- Department of Anesthesiology , Far-Eastern Memorial Hospital , Pan-Chiao District , New Taipei City 22060 , Taiwan
| | - Su Jane Wang
- School of Medicine , Fu Jen Catholic University , No. 510, Chung-Cheng Road , Hsin-Chuang, New Taipei City 24205 , Taiwan.,Research Center for Chinese Herbal Medicine, College of Human Ecology , Chang Gung University of Science and Technology , Taoyuan City , Taiwan 333
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14
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Francis TC, Yano H, Demarest TG, Shen H, Bonci A. High-Frequency Activation of Nucleus Accumbens D1-MSNs Drives Excitatory Potentiation on D2-MSNs. Neuron 2019; 103:432-444.e3. [PMID: 31221559 DOI: 10.1016/j.neuron.2019.05.031] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 04/18/2019] [Accepted: 05/17/2019] [Indexed: 11/19/2022]
Abstract
Subtypes of nucleus accumbens medium spiny neurons (MSNs) promote dichotomous outcomes in motivated behaviors. However, recent reports indicate enhancing activity of either nucleus accumbens (NAc) core MSN subtype augments reward, suggesting coincident MSN activity may underlie this outcome. Here, we report a collateral excitation mechanism in which high-frequency, NAc core dopamine 1 (D1)-MSN activation causes long-lasting potentiation of excitatory transmission (LLP) on dopamine receptor 2 (D2)-MSNs. Our mechanistic investigation demonstrates that this form of plasticity requires release of the excitatory peptide substance P from D1-MSNs and robust cholinergic interneuron activation through neurokinin receptor stimulation. We also reveal that D2-MSN LLP requires muscarinic 1 receptor activation, intracellular calcium signaling, and GluR2-lacking AMPAR insertion. This study uncovers a mechanism for shaping NAc core activity through the transfer of excitatory information from D1-MSNs to D2-MSNs and may provide a means for altering goal-directed behavior through coordinated MSN activity.
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Affiliation(s)
- T Chase Francis
- Intramural Research Program, Synaptic Plasticity Section, National Institute on Drug Abuse, NIH, Baltimore, MD 21224, USA
| | - Hideaki Yano
- Intramural Research Program, Computational Chemistry and Molecular Biophysics Unit, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, NIH, Baltimore, MD 21224, USA
| | - Tyler G Demarest
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD 21224, USA; Laboratory of Neurosciences, National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - Hui Shen
- Intramural Research Program, Synaptic Plasticity Section, National Institute on Drug Abuse, NIH, Baltimore, MD 21224, USA
| | - Antonello Bonci
- Intramural Research Program, Synaptic Plasticity Section, National Institute on Drug Abuse, NIH, Baltimore, MD 21224, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neuroscience, School of Medicine, Georgetown University Medical Center, Washington, DC, USA; Department of Psychiatry, School of Medicine, University of Maryland, Baltimore, MD, USA.
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15
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Olivero G, Vergassola M, Cisani F, Usai C, Pittaluga A. Immuno-Pharmacological Characterization of Presynaptic GluN3A-Containing NMDA Autoreceptors: Relevance to Anti-NMDA Receptor Autoimmune Diseases. Mol Neurobiol 2019; 56:6142-6155. [PMID: 30734226 DOI: 10.1007/s12035-019-1511-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 01/24/2019] [Indexed: 01/22/2023]
Abstract
Mouse hippocampal glutamatergic nerve endings express presynaptic release-regulating NMDA autoreceptors (NMDARs). The presence of GluN1, GluN2A, GluN2B, and GluN3A subunits in hippocampal vesicular glutamate transporter type 1-positive synaptosomes was confirmed with confocal microscopy. GluN2C, GluN2D, and GluN3B immunopositivity was scarcely present. Incubation of synaptosomes with the anti-GluN1, the anti-GluN2A, the anti-GluN2B, or the anti-GluN3A antibody prevented the 30 μM NMDA/1 μM glycine-evoked [3H]D-aspartate ([3H]D-ASP) release. The NMDA/glycine-evoked [3H]D-ASP release was reduced by increasing the external protons, consistent with the participation of GluN1 subunits lacking the N1 cassette to the receptor assembly. The result also excludes the involvement of GluN1/GluN3A dimers into the NMDA-evoked overflow. Complement (1:300) released [3H]D-ASP in a dizocilpine-sensitive manner, suggesting the participation of a NMDAR-mediated component in the releasing activity. Accordingly, the complement-evoked glutamate overflow was reduced in anti-GluN-treated synaptosomes when compared to the control. We speculated that incubation with antibodies had favored the internalization of NMDA receptors. Indeed, a significant reduction of the GluN1 and GluN2B proteins in the plasma membranes of anti-GluN1 or anti-GluN2B antibody-treated synaptosomes emerged in biotinylation studies. Altogether, our findings confirm the existence of presynaptic GluN3A-containing release-regulating NMDARs in mouse hippocampal glutamatergic nerve endings. Furthermore, they unveil presynaptic alteration of the GluN subunit insertion in synaptosomal plasma membranes elicited by anti-GluN antibodies that might be relevant to the central alterations occurring in patients suffering from autoimmune anti-NMDA diseases.
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Affiliation(s)
- Guendalina Olivero
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - Matteo Vergassola
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - Francesca Cisani
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - Cesare Usai
- Institute of Biophysics, National Research Council, via De Marini 6, 16149, Genoa, Italy
| | - Anna Pittaluga
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy. .,IRCCS Ospedale Policlinico San Martino, Genova, Italy.
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16
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Sugimoto A, Tsuchida H, Ieda N, Ikegami K, Inoue N, Uenoyama Y, Tsukamura H. Somatostatin-Somatostatin Receptor 2 Signaling Mediates LH Pulse Suppression in Lactating Rats. Endocrinology 2019; 160:473-483. [PMID: 30544226 DOI: 10.1210/en.2018-00882] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 12/07/2018] [Indexed: 01/09/2023]
Abstract
Follicular development and ovulation are profoundly suppressed during lactation in mammals. This suppression is suggested to be mainly due to the suckling-induced inhibition of kisspeptin gene (Kiss1) expression in the arcuate nucleus (ARC) and consequent inhibition of pulsatile GnRH/LH release. We examined whether central somatostatin (SST) signaling mediates the suckling-induced suppression of pulsatile LH secretion. SST has been reported to be expressed in the posterior intralaminar thalamic nucleus (PIL), where the suckling stimulus is postulated to be relayed to the hypothalamus during lactation. SST inhibitory receptors (SSTRs) are abundantly expressed in the ARC, where kisspeptin/neurokinin B/dynorphin A (KNDy) neurons are located. Histological and quantitative studies revealed that the suckling stimulus increased the number of SST-expressing cells in the PIL, and Sstr2 expression in the ARC. Furthermore, a central injection of an SSTR2 antagonist caused a significant increase in pulsatile LH release in lactating rats. Double labeling of Sstr2 and the neurokinin B gene, as a marker for ARC KNDy neurons, showed Sstr2 expression was abundantly detected in the ARC, but few KNDy neurons coexpressed Sstr2 in lactating rats. Taken together, these findings suggest the suckling-induced activation of SST-SSTR2 signaling mediates, at least in part, the suppression of pulsatile LH secretion during lactation in rats, probably via the indirect effects of SST on KNDy neurons. These results provide a new aspect on the role of central SST-SSTR signaling in understanding the mechanism underlying lactational anestrus.
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Affiliation(s)
- Arisa Sugimoto
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Hitomi Tsuchida
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Nahoko Ieda
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Kana Ikegami
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Naoko Inoue
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Yoshihisa Uenoyama
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Hiroko Tsukamura
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan
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17
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Olivero G, Grilli M, Vergassola M, Bonfiglio T, Padolecchia C, Garrone B, Di Giorgio FP, Tongiani S, Usai C, Marchi M, Pittaluga A. 5-HT 2A-mGlu2/3 receptor complex in rat spinal cord glutamatergic nerve endings: A 5-HT 2A to mGlu2/3 signalling to amplify presynaptic mechanism of auto-control of glutamate exocytosis. Neuropharmacology 2018; 133:429-439. [PMID: 29499271 DOI: 10.1016/j.neuropharm.2018.02.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/23/2018] [Accepted: 02/26/2018] [Indexed: 11/25/2022]
Abstract
Presynaptic mGlu2/3 autoreceptors exist in rat spinal cord nerve terminals as suggested by the finding that LY379268 inhibited the 15 mM KCl-evoked release of [3H]D-aspartate ([3H]D-Asp) in a LY341495-sensitive manner. Spinal cord glutamatergic nerve terminals also possess presynaptic release-regulating 5-HT2A heteroreceptors. Actually, the 15 mM KCl-evoked [3H]D-Asp exocytosis from spinal cord synaptosomes was reduced by the 5-HT2A agonist (±)DOI, an effect reversed by the 5-HT2A antagonists MDL11,939, MDL100907, ketanserin and trazodone (TZD). We investigated whether mGlu2/3 and 5-HT2A receptors colocalize and cross-talk in these terminals and if 5-HT2A ligands modulate the mGlu2/3-mediated control of glutamate exocytosis. Western blot analysis and confocal microscopy highlighted the presence of mGlu2/3 and 5-HT2A receptor proteins in spinal cord VGLUT1 positive synaptosomes, where mGlu2/3 and 5-HT2A receptor immunoreactivities largely colocalize. Furthermore, mGlu2/3 immunoprecipitates from spinal cord synaptosomes were also 5-HT2A immunopositive. Interestingly, the 100 pM LY379268-induced reduction of the 15 mM KCl-evoked [3H]D-Asp overflow as well as its inhibition by 100 nM (±)DOI became undetectable when the two agonists were concomitantly added. Conversely, 5-HT2A antagonists (MDL11,939, MDL100907, ketanserin and TZD) reinforced the release-regulating activity of mGlu2/3 autoreceptors. Increased expression of mGlu2/3 receptor proteins in synaptosomal plasmamembranes paralleled the gain of function of the mGlu2/3 autoreceptors elicited by 5-HT2A antagonists. Based on these results, we propose that in spinal cord glutamatergic terminals i) mGlu2/3 and 5-HT2A receptors colocalize and interact one each other in an antagonist-like manner, ii) 5-HT2A antagonists are indirect positive allosteric modulator of mGlu2/3 autoreceptors controlling glutamate exocytosis.
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Affiliation(s)
- Guendalina Olivero
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, Viale Cembrano 4, 16148, Genoa, Italy
| | - Massimo Grilli
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, Viale Cembrano 4, 16148, Genoa, Italy; Center of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy
| | - Matteo Vergassola
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, Viale Cembrano 4, 16148, Genoa, Italy
| | - Tommaso Bonfiglio
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, Viale Cembrano 4, 16148, Genoa, Italy
| | - Cristina Padolecchia
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, Viale Cembrano 4, 16148, Genoa, Italy
| | - Beatrice Garrone
- Angelini RR&D (Research, Regulatory & Development) - Angelini S.p.A., Piazzale della Stazione Snc, 00071, S. Palomba-Pomezia (Rome), Italy
| | - Francesco Paolo Di Giorgio
- Angelini RR&D (Research, Regulatory & Development) - Angelini S.p.A., Piazzale della Stazione Snc, 00071, S. Palomba-Pomezia (Rome), Italy
| | - Serena Tongiani
- Angelini RR&D (Research, Regulatory & Development) - Angelini S.p.A., Piazzale della Stazione Snc, 00071, S. Palomba-Pomezia (Rome), Italy
| | - Cesare Usai
- Institute of Biophysics, National Research Council, Via De Marini 6, 16149, Genoa, Italy
| | - Mario Marchi
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, Viale Cembrano 4, 16148, Genoa, Italy; Center of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy
| | - Anna Pittaluga
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, Viale Cembrano 4, 16148, Genoa, Italy; Center of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy.
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18
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Bonfiglio T, Olivero G, Vergassola M, Di Cesare Mannelli L, Pacini A, Iannuzzi F, Summa M, Bertorelli R, Feligioni M, Ghelardini C, Pittaluga A. Environmental training is beneficial to clinical symptoms and cortical presynaptic defects in mice suffering from experimental autoimmune encephalomyelitis. Neuropharmacology 2018; 145:75-86. [PMID: 29402503 DOI: 10.1016/j.neuropharm.2018.01.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 01/19/2018] [Accepted: 01/20/2018] [Indexed: 01/08/2023]
Abstract
The effect of "prophylactic" environmental stimulation on clinical symptoms and presynaptic defects in mice suffering from the experimental autoimmune encephalomyelitis (EAE) at the acute stage of disease (21 ± 1 days post immunization, d.p.i.) was investigated. In EAE mice raised in an enriched environment (EE), the clinical score was reduced when compared to EAE mice raised in standard environment (SE).Concomitantly, gain of weight and increased spontaneous motor activity and curiosity were observed, suggesting increased well-being in mice. Impaired glutamate exocytosis and cyclic adenosine monophosphate (cAMP) production in cortical terminals of SE-EAE mice were evident at 21 ± 1 d.p.i.. Differently, the 12 mM KCl-evoked glutamate exocytosis from cortical synaptosomes of EE-EAE mice was comparable to that observed in SE and EE-control mice, but significantly higher than that in SE-EAE mice. Similarly, the 12 mM KCl-evoked cAMP production in EE-EAE mice cortical synaptosomes recovered to the level observed in SE and EE-control mice. MUNC-18 and SNAP25 contents, but not Syntaxin-1a and Synaptotagmin 1 levels, were increased in cortical synaptosomes from EE-EAE mice when compared to SE-EAE mice. Circulating IL-1β was increased in the spinal cord, but not in the cortex, of SE-EAE mice, and it did not recover in EE-EAE mice. Inflammatory infiltrates were reduced in the cortex but not in the spinal cord of EE-EAE mice. Demyelination was observed in the spinal cord; EE significantly diminished it. We conclude that "prophylactic" EE is beneficial to synaptic derangements and preserves glutamate transmission in the cortex of EAE mice. This article is part of the Special Issue entitled "Neurobiology of Environmental Enrichment".
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Affiliation(s)
- T Bonfiglio
- Department of Pharmacy, School of Medical and Pharmaceutical Sciences, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - G Olivero
- Department of Pharmacy, School of Medical and Pharmaceutical Sciences, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - M Vergassola
- Department of Pharmacy, School of Medical and Pharmaceutical Sciences, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - L Di Cesare Mannelli
- Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, Italy
| | - A Pacini
- Department of Experimental and Clinical Medicine, DMSC, Section of Anatomy and Histology, University of Florence, Italy
| | - F Iannuzzi
- EBRI-European Brain Research Institute, Rome, Italy
| | - M Summa
- D3. PharmaChemistry Line, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa, Italy
| | - R Bertorelli
- D3. PharmaChemistry Line, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa, Italy
| | - M Feligioni
- EBRI-European Brain Research Institute, Rome, Italy; Department of Neurorehabilitation Sciences, Casa Cura Policlinico, Milan, Italy
| | - C Ghelardini
- Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, Italy
| | - A Pittaluga
- Department of Pharmacy, School of Medical and Pharmaceutical Sciences, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy; Centre of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy.
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19
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Olivero G, Bonfiglio T, Vergassola M, Usai C, Riozzi B, Battaglia G, Nicoletti F, Pittaluga A. Immuno-pharmacological characterization of group II metabotropic glutamate receptors controlling glutamate exocytosis in mouse cortex and spinal cord. Br J Pharmacol 2017; 174:4785-4796. [PMID: 28967122 PMCID: PMC5727332 DOI: 10.1111/bph.14061] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 09/12/2017] [Accepted: 09/13/2017] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND AND PURPOSE We recently proposed the existence of mGlu3 -preferring autoreceptors in spinal cord terminals and of mGlu2 -preferring autoreceptors in cortical terminals. This study aims to verify our previous conclusions and to extend their pharmacological characterization. EXPERIMENTAL APPROACH We studied the effect of LY566332, an mGlu2 receptor positive allosteric modulator (PAM), and of LY2389575, a selective mGlu3 receptor negative allosteric (NAM) modulator, on the mGlu2/3 agonist LY379268-mediated inhibition of glutamate exocytosis [measured as KCl-evoked release of preloaded [3 H]-D-aspartate]. The mGlu2 PAM BINA and the mGlu3 NAM ML337, as well as selective antibodies recognizing the N-terminal of the receptor proteins, were used to confirm the pharmacological characterization of the native receptors. KEY RESULTS Cortical synaptosomes possess LY566332-sensitive autoreceptors that are slightly, although significantly, susceptible to LY2389575. In contrast, LY566332-insensitive and LY2389575-sensitive autoreceptors are present in spinal cord terminals. BINA and ML337 mimicked LY566332 and LY2389575, respectively, in controlling LY379268-mediated inhibition of glutamate exocytosis from both cortical and spinal cord synaptosomes. Incubation of cortical synaptosomes with anti-mGlu2 antibody prevented the LY379268-induced inhibition of glutamate exocytosis, and this response was partially reduced by the anti-mGlu3 antibody. Incubation of spinal cord synaptosomes with the anti-mGlu3 antibody abolished LY379268-mediated reduction of glutamate exocytosis from these terminals, while the anti-mGlu2 antibody was inactive. Western blot analysis and confocal microscopy data were largely consistent with these functional observations. CONCLUSIONS AND IMPLICATIONS We confirmed that mGlu3 -preferring autoreceptors exist in spinal cord terminals. Differently, cortical glutamatergic terminals possess mGlu2 /mGlu3 heterodimers, whose inhibitory effect is largely mediated by mGlu2 receptors.
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Affiliation(s)
| | | | | | - Cesare Usai
- National Research CouncilInstitute of BiophysicsGenoaItaly
| | | | | | - Ferdinando Nicoletti
- I.R.C.C.S. Neuromed, Località CamerellePozzilliItaly
- Department of Physiology and PharmacologySapienza UniversityRomeItaly
| | - Anna Pittaluga
- Department of Pharmacy, DiFARUniversity of GenoaGenoaItaly
- Centre of Excellence for Biomedical ResearchUniversity of GenoaGenoaItaly
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20
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Pittaluga A. CCL5-Glutamate Cross-Talk in Astrocyte-Neuron Communication in Multiple Sclerosis. Front Immunol 2017; 8:1079. [PMID: 28928746 PMCID: PMC5591427 DOI: 10.3389/fimmu.2017.01079] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 08/18/2017] [Indexed: 12/17/2022] Open
Abstract
The immune system (IS) and the central nervous system (CNS) are functionally coupled, and a large number of endogenous molecules (i.e., the chemokines for the IS and the classic neurotransmitters for the CNS) are shared in common between the two systems. These interactions are key elements for the elucidation of the pathogenesis of central inflammatory diseases. In recent years, evidence has been provided supporting the role of chemokines as modulators of central neurotransmission. It is the case of the chemokines CCL2 and CXCL12 that control pre- and/or post-synaptically the chemical transmission. This article aims to review the functional cross-talk linking another endogenous pro-inflammatory factor released by glial cells, i.e., the chemokine Regulated upon Activation Normal T-cell Expressed and Secreted (CCL5) and the principal neurotransmitter in CNS (i.e., glutamate) in physiological and pathological conditions. In particular, the review discusses preclinical data concerning the role of CCL5 as a modulator of central glutamatergic transmission in healthy and demyelinating disorders. The CCL5-mediated control of glutamate release at chemical synapses could be relevant either to the onset of psychiatric symptoms that often accompany the development of multiple sclerosis (MS), but also it might indirectly give a rationale for the progression of inflammation and demyelination. The impact of disease-modifying therapies for the cure of MS on the endogenous availability of CCL5 in CNS will be also summarized. We apologize in advance for omission in our coverage of the existing literature.
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Affiliation(s)
- Anna Pittaluga
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy
- Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
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Liguz-Lecznar M, Urban-Ciecko J, Kossut M. Somatostatin and Somatostatin-Containing Neurons in Shaping Neuronal Activity and Plasticity. Front Neural Circuits 2016; 10:48. [PMID: 27445703 PMCID: PMC4927943 DOI: 10.3389/fncir.2016.00048] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/20/2016] [Indexed: 01/27/2023] Open
Abstract
Since its discovery over four decades ago, somatostatin (SOM) receives growing scientific and clinical interest. Being localized in the nervous system in a subset of interneurons somatostatin acts as a neurotransmitter or neuromodulator and its role in the fine-tuning of neuronal activity and involvement in synaptic plasticity and memory formation are widely recognized in the recent literature. Combining transgenic animals with electrophysiological, anatomical and molecular methods allowed to characterize several subpopulations of somatostatin-containing interneurons possessing specific anatomical and physiological features engaged in controlling the output of cortical excitatory neurons. Special characteristic and connectivity of somatostatin-containing neurons set them up as significant players in shaping activity and plasticity of the nervous system. However, somatostatin is not just a marker of particular interneuronal subpopulation. Somatostatin itself acts pre- and postsynaptically, modulating excitability and neuronal responses. In the present review, we combine the knowledge regarding somatostatin and somatostatin-containing interneurons, trying to incorporate it into the current view concerning the role of the somatostatinergic system in cortical plasticity.
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Affiliation(s)
- Monika Liguz-Lecznar
- Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology Warsaw, Poland
| | - Joanna Urban-Ciecko
- Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental BiologyWarsaw, Poland; Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon UniversityPittsburgh, PA, USA
| | - Malgorzata Kossut
- Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental BiologyWarsaw, Poland; Department of Psychology, University of Social Sciences and Humanities (SWPS)Warsaw, Poland
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22
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Di Prisco S, Olivero G, Merega E, Bonfiglio T, Marchi M, Pittaluga A. CXCR4 and NMDA Receptors Are Functionally Coupled in Rat Hippocampal Noradrenergic and Glutamatergic Nerve Endings. J Neuroimmune Pharmacol 2016; 11:645-656. [PMID: 27147258 DOI: 10.1007/s11481-016-9677-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 04/25/2016] [Indexed: 01/31/2023]
Abstract
Previous studies had shown that the HIV-1 capsidic glycoprotein gp120 (strain IIIB) modulates presynaptic release-regulating NMDA receptors on noradrenergic and glutamatergic terminals. This study aims to assess whether the chemokine CXC4 receptors (CXCR4s) has a role in the gp120-mediated effects. The effect of CXCL12, the endogenous ligand at CXCR4, on the NMDA-mediated releasing activity was therefore investigated. Rat hippocampal synaptosomes were preloaded with [3H]noradrenaline ([3H]NA) or [3H]D-aspartate ([3H]D-Asp) and acutely exposed to CXCL12, to NMDA or to both agonists. CXCL12, inactive on its own, facilitated the NMDA-evoked tritium release. The NMDA antagonist MK-801 abolished the NMDA/CXCL12-evoked tritium release of both radiolabelled tracers, while the CXCR4 antagonist AMD 3100 halved it, suggesting that rat hippocampal nerve endings possess presynaptic release-regulating CXCR4 receptors colocalized with NMDA receptors. Accordingly, Western blot analysis confirmed the presence of CXCR4 proteins in synaptosomal plasmamembranes. In both synaptosomal preparations, CXCL12-induced facilitation of NMDA-mediated release was dependent upon PLC-mediated src-induced events leading to mobilization of Ca2+ from intraterminal IP3-sensitive stores Finally, the gp120-induced facilitation of NMDA-mediated release of [3H]NA and [3H]D-Asp was prevented by AMD 3100. We propose that CXCR4s are functionally coupled to NMDA receptors in rat hippocampal noradrenergic and glutamatergic terminals and account for the gp120-induced modulation of the NMDA-mediated central effects. The NMDA/CXCR4 cross-talk could have a role in the neuropsychiatric symptoms often observed in HIV-1 positive patients.
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Affiliation(s)
- Silvia Di Prisco
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - Guendalina Olivero
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - Elisa Merega
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - Tommaso Bonfiglio
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy
| | - Mario Marchi
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy.,Center of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy
| | - Anna Pittaluga
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy. .,Center of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy.
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23
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Di Prisco S, Merega E, Bonfiglio T, Olivero G, Cervetto C, Grilli M, Usai C, Marchi M, Pittaluga A. Presynaptic, release-regulating mGlu2 -preferring and mGlu3 -preferring autoreceptors in CNS: pharmacological profiles and functional roles in demyelinating disease. Br J Pharmacol 2016; 173:1465-77. [PMID: 26791341 DOI: 10.1111/bph.13442] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 01/08/2016] [Accepted: 01/17/2016] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND AND PURPOSE Presynaptic, release-regulating metabotropic glutamate 2 and 3 (mGlu2/3) autoreceptors exist in the CNS. They represent suitable targets for therapeutic approaches to central diseases that are typified by hyperglutamatergicity. The availability of specific ligands able to differentiate between mGlu2 and mGlu3 subunits allows us to further characterize these autoreceptors. In this study we investigated the pharmacological profile of mGlu2/3 receptors in selected CNS regions and evaluated their functions in mice with experimental autoimmune encephalomyelitis (EAE). EXPERIMENTAL APPROACH The comparative analysis of presynaptic mGlu2/3 autoreceptors was performed by determining the effect of selective mGlu2/3 receptor agonist(s) and antagonist(s) on the release of [(3)H]-D-aspartate from cortical and spinal cord synaptosomes in superfusion. In EAE mice, mGlu2/3 autoreceptor-mediated release functions were investigated and effects of in vivo LY379268 administration on impaired glutamate release examined ex vivo. KEY RESULTS Western blot analysis and confocal microscopy confirmed the presence of presynaptic mGlu2/3 receptor proteins. Cortical synaptosomes possessed LY541850-sensitive, NAAG-insensitive autoreceptors having low affinity for LY379268, while LY541850-insensitive, NAAG-sensitive autoreceptors with high affinity for LY379268 existed in spinal cord terminals. In EAE mice, mGlu2/3 autoreceptors completely lost their inhibitory activity in cortical, but not in spinal cord synaptosomes. In vivo LY379268 administration restored the glutamate exocytosis capability in spinal cord but not in cortical terminals in EAE mice. CONCLUSIONS AND IMPLICATIONS We propose the existence of mGlu2-preferring and mGlu3-preferring autoreceptors in mouse cortex and spinal cord respectively. The mGlu3 -preferring autoreceptors could represent a target for new pharmacological approaches for treating demyelinating diseases.
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Affiliation(s)
- Silvia Di Prisco
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy
| | - Elisa Merega
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy
| | - Tommaso Bonfiglio
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy
| | - Guendalina Olivero
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy
| | - Chiara Cervetto
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy
| | - Massimo Grilli
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy
| | - Cesare Usai
- Institute of Biophysics, National Research Council, Genoa, Italy
| | - Mario Marchi
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy.,Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Anna Pittaluga
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy.,Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
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Hikima T, Garcia-Munoz M, Arbuthnott GW. Presynaptic D1 heteroreceptors and mGlu autoreceptors act at individual cortical release sites to modify glutamate release. Brain Res 2016; 1639:74-87. [PMID: 26944299 DOI: 10.1016/j.brainres.2016.02.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 02/11/2016] [Accepted: 02/23/2016] [Indexed: 01/04/2023]
Abstract
The aim of this work was to study release of glutamic acid (GLU) from one-axon terminal or bouton at-a-time using cortical neurons grown in vitro to study the effect of presynaptic auto- and heteroreceptor stimulation. Neurons were infected with release reporters SypHx2 or iGluSnFR at 7 or 3 days-in-vitro (DIV) respectively. At 13-15 DIV single synaptic boutons were identified from images obtained from a confocal scanning microscope before and after field electrical stimulation. We further stimulated release by raising intracellular levels of cAMP with forskolin (10µM). Forskolin-mediated effects were dependent on protein kinase A (PKA) and did not result from an increase in endocytosis, but rather from an increase in the size of the vesicle readily releasable pool. Once iGluSnFR was confirmed as more sensitive than SypHx2, it was used to study the participation of presynaptic auto- and heteroreceptors on GLU release. Although most receptor agonizts (carbamylcholine, nicotine, dopamine D2, BDNF) did not affect electrically stimulated GLU release, a significant increase was observed in the presence of metabotropic D1/D5 heteroreceptor agonist (SKF38393 10µM) that was reversed by PKA inhibitors. Interestingly, stimulation of group II metabotropic mGLU2/3 autoreceptors (LY379268 50nM) induced a decrease in GLU release that was reversed by the specific mGLU2/3 receptor antagonist (LY341495 1µM) and also by PKA inhibitors (KT5720 200nM and PKI14-22 400nM). These changes in release probability at individual release sites suggest another level of control of the distribution of transmitter substances in cortical tissue.
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Affiliation(s)
- Takuya Hikima
- Brain Mechanism for Behaviour Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
| | - Marianela Garcia-Munoz
- Brain Mechanism for Behaviour Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
| | - Gordon William Arbuthnott
- Brain Mechanism for Behaviour Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
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25
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Nisticò R, Florenzano F, Mango D, Ferraina C, Grilli M, Di Prisco S, Nobili A, Saccucci S, D'Amelio M, Morbin M, Marchi M, Mercuri NB, Davis RJ, Pittaluga A, Feligioni M. Presynaptic c-Jun N-terminal Kinase 2 regulates NMDA receptor-dependent glutamate release. Sci Rep 2015; 5:9035. [PMID: 25762148 PMCID: PMC4357012 DOI: 10.1038/srep09035] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 02/13/2015] [Indexed: 12/17/2022] Open
Abstract
Activation of c-Jun N-terminal kinase (JNK) signaling pathway is a critical step for neuronal death occurring in several neurological conditions. JNKs can be activated via receptor tyrosine kinases, cytokine receptors, G-protein coupled receptors and ligand-gated ion channels, including the NMDA glutamate receptors. While JNK has been generally associated with postsynaptic NMDA receptors, its presynaptic role remains largely unexplored. Here, by means of biochemical, morphological and functional approaches, we demonstrate that JNK and its scaffold protein JIP1 are also expressed at the presynaptic level and that the NMDA-evoked glutamate release is controlled by presynaptic JNK-JIP1 interaction. Moreover, using knockout mice for single JNK isoforms, we proved that JNK2 is the essential isoform in mediating this presynaptic event. Overall the present findings unveil a novel JNK2 localization and function, which is likely to play a role in different physiological and pathological conditions.
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Affiliation(s)
- Robert Nisticò
- 1] Laboratory of Pharmacology of Synaptic Plasticity, EBRI "Rita Levi-Montalcini" Foundation, Rome, 00143, Italy [2] Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, 00185, Italy
| | - Fulvio Florenzano
- Laboratory of Pharmacology of Synaptic Plasticity, EBRI "Rita Levi-Montalcini" Foundation, Rome, 00143, Italy
| | - Dalila Mango
- 1] Laboratory of Pharmacology of Synaptic Plasticity, EBRI "Rita Levi-Montalcini" Foundation, Rome, 00143, Italy [2] Laboratory of Experimental Neurology, IRCCS Fondazione Santa Lucia, Rome, 00143, Italy
| | - Caterina Ferraina
- Laboratory of Pharmacology of Synaptic Plasticity, EBRI "Rita Levi-Montalcini" Foundation, Rome, 00143, Italy
| | - Massimo Grilli
- Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, 16148, Italy
| | - Silvia Di Prisco
- Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, 16148, Italy
| | - Annalisa Nobili
- 1] Laboratory of Experimental Neurology, IRCCS Fondazione Santa Lucia, Rome, 00143, Italy [2] University Campus Biomedico, 00100 Rome
| | - Stefania Saccucci
- Neuropathology &Neurology V - IRCCS Foundation C. Besta Milan, 20133, Italy
| | - Marcello D'Amelio
- 1] Laboratory of Experimental Neurology, IRCCS Fondazione Santa Lucia, Rome, 00143, Italy [2] University Campus Biomedico, 00100 Rome
| | - Michela Morbin
- Neuropathology &Neurology V - IRCCS Foundation C. Besta Milan, 20133, Italy
| | - Mario Marchi
- 1] Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, 16148, Italy [2] Center of Excellence for Biomedical Research, University of Genoa, Genoa, 16132, Italy
| | - Nicola B Mercuri
- Laboratory of Experimental Neurology, IRCCS Fondazione Santa Lucia, Rome, 00143, Italy
| | - Roger J Davis
- Department of Biochemistry and Molecular Biology, Howard Hughes Medical Institute and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, 01605, USA
| | - Anna Pittaluga
- 1] Department of Pharmacy, Pharmacology and Toxicology Section, University of Genoa, Genoa, 16148, Italy [2] Center of Excellence for Biomedical Research, University of Genoa, Genoa, 16132, Italy
| | - Marco Feligioni
- Laboratory of Pharmacology of Synaptic Plasticity, EBRI "Rita Levi-Montalcini" Foundation, Rome, 00143, Italy
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Di Prisco S, Merega E, Lanfranco M, Casazza S, Uccelli A, Pittaluga A. Acute desipramine restores presynaptic cortical defects in murine experimental autoimmune encephalomyelitis by suppressing central CCL5 overproduction. Br J Pharmacol 2014; 171:2457-67. [PMID: 24528439 DOI: 10.1111/bph.12631] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 01/14/2014] [Accepted: 02/05/2014] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE Altered glutamate exocytosis and cAMP production in cortical terminals of experimental autoimmune encephalomyelitis (EAE) mice occur at the early stage of disease (13 days post-immunization, d.p.i.). Neuronal defects were paralleled by overexpression of the central chemokine CCL5 (also known as RANTES), suggesting it has a role in presynaptic impairments. We propose that drugs able to restore CCL5 content to physiological levels could also restore presynaptic defects. Because of its efficacy in controlling CCL5 overexpression, desipramine (DMI) appeared to be a suitable candidate to test our hypothesis. EXPERIMENTAL APPROACH Control and EAE mice at 13 d.p.i. were acutely or chronically administered DMI and monitored for behaviour and clinical scores. Noradrenaline and glutamate release, cAMP, CCL5 and TNF-α production were quantified in cortical synaptosomes and homogenates. Peripheral cytokine production was also determined. KEY RESULTS Noradrenaline exocytosis and α₂ -adrenoeceptor-mediated activity were unmodified in EAE mice at 13 d.p.i. when compared with control. Acute, but not chronic, DMI reduced CCL5 levels in cortical homogenates of EAE mice at 13 d.p.i., but did not affect peripheral IL-17 and TNF-α contents or CCL5 plasma levels. Acute DMI caused a long-lasting restoration of glutamate exocytosis, restored endogenous cAMP production and impeded the shift from inhibition to facilitation of the CCL5-mediated control of glutamate exocytosis. Finally, DMI ameliorated anxiety-related behaviour but not motor activity or severity of clinical signs. CONCLUSIONS We propose DMI as an add-on therapy to normalize neuropsychiatric symptoms in multiple sclerosis patients at the early stage of the disease.
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Affiliation(s)
- Silvia Di Prisco
- Department of Pharmacy, DiFAR, Pharmacology and Toxicology Section, Genoa, Italy
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27
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Quagliotto E, Casali KR, Dal Lago P, Rasia-Filho AA. Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats. ACTA ACUST UNITED AC 2014; 48:128-39. [PMID: 25424367 PMCID: PMC4321218 DOI: 10.1590/1414-431x20144095] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 09/22/2014] [Indexed: 11/21/2022]
Abstract
The rat posterodorsal medial amygdala (MePD) links emotionally charged sensory stimuli to social behavior, and is part of the supramedullary control of the cardiovascular system. We studied the effects of microinjections of neuroactive peptides markedly found in the MePD, namely oxytocin (OT, 10 ng and 25 pg; n=6/group), somatostatin (SST, 1 and 0.05 μM; n=8 and 5, respectively), and angiotensin II (Ang II, 50 pmol and 50 fmol; n=7/group), on basal cardiovascular activity and on baroreflex- and chemoreflex-mediated responses in awake adult male rats. Power spectral and symbolic analyses were applied to pulse interval and systolic arterial pressure series to identify centrally mediated sympathetic/parasympathetic components in the heart rate variability (HRV) and arterial pressure variability (APV). No microinjected substance affected basal parameters. On the other hand, compared with the control data (saline, 0.3 µL; n=7), OT (10 ng) decreased mean AP (MAP50) after baroreflex stimulation and increased both the mean AP response after chemoreflex activation and the high-frequency component of the HRV. OT (25 pg) increased overall HRV but did not affect any parameter of the symbolic analysis. SST (1 μM) decreased MAP50, and SST (0.05 μM) enhanced the sympathovagal cardiac index. Both doses of SST increased HRV and its low-frequency component. Ang II (50 pmol) increased HRV and reduced the two unlike variations pattern of the symbolic analysis (P<0.05 in all cases). These results demonstrate neuropeptidergic actions in the MePD for both the increase in the range of the cardiovascular reflex responses and the involvement of the central sympathetic and parasympathetic systems on HRV and APV.
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Affiliation(s)
- E Quagliotto
- Departamento de Ciências Básicas da Saúde/Fisiologia, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brasil
| | - K R Casali
- Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo, São José dos Campos, SP, Brasil
| | - P Dal Lago
- Departamento de Fisioterapia, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brasil
| | - A A Rasia-Filho
- Departamento de Ciências Básicas da Saúde/Fisiologia, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brasil
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28
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Di Prisco S, Merega E, Pittaluga A. Functional adaptation of presynaptic chemokine receptors in EAE mouse central nervous system. Synapse 2014; 68:529-35. [DOI: 10.1002/syn.21774] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/18/2014] [Accepted: 07/25/2014] [Indexed: 12/26/2022]
Affiliation(s)
- Silvia Di Prisco
- Department of Pharmacy; Section of Pharmacology and Toxicology, University of Genoa; Viale Cembrano 4 Genoa 16148 Italy
| | - Elisa Merega
- Department of Pharmacy; Section of Pharmacology and Toxicology, University of Genoa; Viale Cembrano 4 Genoa 16148 Italy
| | - Anna Pittaluga
- Department of Pharmacy; Section of Pharmacology and Toxicology, University of Genoa; Viale Cembrano 4 Genoa 16148 Italy
- Center of Excellence for Biomedical Research, University of Genoa; Viale Benedetto XV Genoa 16132 Italy
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29
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Chen W, Ke JB, Wu HJ, Miao Y, Li F, Yang XL, Wang Z. Somatostatin receptor-mediated suppression of gabaergic synaptic transmission in cultured rat retinal amacrine cells. Neuroscience 2014; 273:118-27. [PMID: 24846611 DOI: 10.1016/j.neuroscience.2014.05.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 05/05/2014] [Accepted: 05/06/2014] [Indexed: 01/03/2023]
Abstract
Somatostatin (SRIF) modulates neurotransmitter release by activating the specific receptors (sst1-sst5). Our previous study showed that sst5 receptors are expressed in rat retinal GABAergic amacrine cells. Here, we investigated modulation of GABA release by SRIF in cultured amacrine cells, using patch-clamp techniques. The frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) in the amacrine cells was significantly reduced by SRIF, which was partially reversed by BIM 23056, an sst5 receptor antagonist, and was further rescued by addition of CYN-154806, an sst2 receptor antagonist. Both nimodipine, an L-type Ca2+ channel blocker, and ω-conotoxin GVIA, an N-type Ca2+ channel blocker, suppressed the sIPSC frequency, and in the presence of nimodipine and ω-conotoxin GVIA, SRIF failed to further suppress the sIPSC frequency. Extracellular application of forskolin, an activator of adenylate cyclase, increased the sIPSC frequency, while the membrane permeable protein kinase A (PKA) inhibitor Rp-cAMP reduced it, and in the presence of Rp-cAMP, SRIF did not change sIPSCs. However, SRIF persisted to suppress the sIPSCs in the presence of KT5823, a protein kinase G (PKG) inhibitor. Moreover, pre-incubation with Bis IV, a protein kinase C (PKC) inhibitor, or pre-application of xestospongin C, an inositol 1,4,5-trisphosphate receptor (IP3R) inhibitor, SRIF still suppressed the sIPSC frequency. All these results suggest that SRIF suppresses GABA release from the amacrine cells by inhibiting presynaptic Ca2+ channels, in part through activating sst5/sst2 receptors, a process that is mediated by the intracellular cAMP-PKA signaling pathway.
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Affiliation(s)
- W Chen
- Institutes of Brain Science, Institute of Neurobiology and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - J B Ke
- Institutes of Brain Science, Institute of Neurobiology and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - H J Wu
- Institutes of Brain Science, Institute of Neurobiology and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Y Miao
- Institutes of Brain Science, Institute of Neurobiology and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - F Li
- Institutes of Brain Science, Institute of Neurobiology and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - X L Yang
- Institutes of Brain Science, Institute of Neurobiology and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Z Wang
- Institutes of Brain Science, Institute of Neurobiology and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China.
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30
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Merega E, Prisco SD, Lanfranco M, Severi P, Pittaluga A. Complement selectively elicits glutamate release from nerve endings in different regions of mammal central nervous system. J Neurochem 2014; 129:473-83. [DOI: 10.1111/jnc.12650] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 12/29/2013] [Accepted: 01/02/2014] [Indexed: 02/05/2023]
Affiliation(s)
- Elisa Merega
- Department of Pharmacy; Pharmacology and Toxicology Section; University of Genoa; Genoa Italy
| | - Silvia Di Prisco
- Department of Pharmacy; Pharmacology and Toxicology Section; University of Genoa; Genoa Italy
| | | | - Paolo Severi
- Division of Neurosurgery; Galliera Hospital; Genoa Italy
| | - Anna Pittaluga
- Department of Pharmacy; Pharmacology and Toxicology Section; University of Genoa; Genoa Italy
- Center of Excellence for Biomedical Research; University of Genoa; Genoa Italy
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31
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Bali A, Jaggi AS. Multifunctional aspects of allopregnanolone in stress and related disorders. Prog Neuropsychopharmacol Biol Psychiatry 2014; 48:64-78. [PMID: 24044974 DOI: 10.1016/j.pnpbp.2013.09.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 09/05/2013] [Accepted: 09/05/2013] [Indexed: 12/22/2022]
Abstract
Allopregnanolone (3α-hydroxy-5α-pregnan-20-one) is a major cholesterol-derived neurosteroid in the central nervous system and is synthesized from progesterone by steroidogenic enzymes, 5α-reductase (the rate-limiting enzyme) and 3α-hydroxysteroid dehydrogenase. The pathophysiological role of allopregnanolone in neuropsychiatric disorders has been highlighted in several investigations. The changes in neuroactive steroid levels are detected in stress and stress-related disorders including anxiety, panic and depression. The changes in allopregnanolone in response to acute stressor tend to restore the homeostasis by dampening the hyper-activated HPA axis. However, long standing stressors leading to development of neuropsychiatric disorders including depression and anxiety are associated with decrease in the allopregnanolone levels. GABAA receptor complex has been considered as the primary target of allopregnanolone and majority of its inhibitory actions are mediated through GABA potentiation or direct activation of GABA currents. The role of progesterone receptors in producing the late actions of allopregnanolone particularly in lordosis facilitation has also been described. Moreover, recent studies have also described the involvement of other multiple targets including brain-derived neurotrophic factor (BDNF), glutamate, dopamine, opioids, oxytocin, and calcium channels. The present review discusses the various aspects of allopregnanolone in stress and stress-related disorders including anxiety, depression and panic.
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Affiliation(s)
- Anjana Bali
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University Patiala, 147002, India
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CCL5-glutamate interaction in central nervous system: Early and acute presynaptic defects in EAE mice. Neuropharmacology 2013; 75:337-46. [PMID: 23958452 DOI: 10.1016/j.neuropharm.2013.07.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 07/24/2013] [Accepted: 07/30/2013] [Indexed: 01/15/2023]
Abstract
We investigated the CCL5-glutamate interaction in the cortex and in the spinal cord from mice with Experimental Autoimmune Encephalomyelitis (EAE) at 13 and 21/30 days post immunization (d.p.i.), representing the onset and the peak of the disease, respectively. An early reduction of the KCl-evoked glutamate release was observed in cortical terminals from EAE mice at 13 d.p.i., persisting until 21/30 d.p.i. A concomitant reduction of the depolarization-evoked cyclic adenosine monophosphate (cAMP), but not of the inositol 1,4,5-trisphosphate (IP3) cortical production also occurred at 13 d.p.i, that still was detectable at the acute stage of disease (21 dp.i.). Inasmuch, the CCL5-mediated inhibition of glutamate exocytosis observed in control mice turned to facilitation in EAE mouse cortex at 13 d.p.i., then becoming undetectable at 21/30 d.p.i. Differently, glutamate exocytosis, as well as IP3 and cAMP productions were unaltered in spinal cord synaptosomes from EAE mice at 13 d.p.i., but significantly increased at 21/30 d.p.i., while the presynaptic CCL5-mediated facilitation of glutamate exocytosis observed in control mice remained unchanged. In both CNS regions, the presynaptic defects were parallelled by increased CCL5 availability. Inasmuch, the presynaptic defects so far described in EAE mice were reminiscent of the effects acute CCL5 exerts in control conditions. Based on these observations we propose that increased CCL5 bioavailability could have a role in determining the abovedescribed impaired presynaptic impairments in both CNS regions. These presynaptic defects could be relevant to the onset of early cognitive impairments and acute neuroinflammation and demyelinating processes observed in multiple sclerosis patients.
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Kozhemyakin M, Rajasekaran K, Todorovic MS, Kowalski SL, Balint C, Kapur J. Somatostatin type-2 receptor activation inhibits glutamate release and prevents status epilepticus. Neurobiol Dis 2013; 54:94-104. [PMID: 23473742 DOI: 10.1016/j.nbd.2013.02.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 02/06/2013] [Accepted: 02/25/2013] [Indexed: 02/07/2023] Open
Abstract
Newer therapies are needed for the treatment of status epilepticus (SE) refractory to benzodiazepines. Enhanced glutamatergic neurotransmission leads to SE, and AMPA receptors are modified during SE. Reducing glutamate release during SE is a potential approach to terminate SE. The neuropeptide somatostatin (SST) is proposed to diminish presynaptic glutamate release by activating SST type-2 receptors (SST2R). SST exerts an anticonvulsant action in some experimental models of seizures. Here, we investigated the mechanism of action of SST on excitatory synaptic transmission at the Schaffer collateral-CA1 synapses and the ability of SST to treat SE in rats using patch-clamp electrophysiology and video-EEG monitoring of seizures. SST reduced action potential-dependent EPSCs (sEPSCs) at Schaffer collateral-CA1 synapses at concentrations up to 1μM; higher concentrations had no effect or increased the sEPSC frequency. SST also prevented paired-pulse facilitation of evoked EPSCs and did not alter action-potential-independent miniature EPSCs (mEPSCs). The effect of SST on EPSCs was inhibited by the SST2R antagonist cyanamid-154806 and was mimicked by the SST2R agonists, octreotide and lanreotide. Both SST and octreotide reduced the firing rate of CA1 pyramidal neurons. Intraventricular administration of SST, within a range of doses, either prevented or attenuated pilocarpine-induced SE or delayed the median time to the first grade 5 seizure by 11min. Similarly, octreotide or lanreotide prevented or attenuated SE in more than 65% of animals. Compared to the pilocarpine model, octreotide was highly potent in preventing or attenuating continuous hippocampal stimulation-induced SE in all animals within 60min of SE onset. Our results demonstrate that SST, through the activation of SST2Rs, diminishes presynaptic glutamate release and attenuates SE.
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Affiliation(s)
- Maxim Kozhemyakin
- Department of Neurology and Neuroscience, University of Virginia Health Sciences Center, Charlottesville, VA 22908, USA
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Effects of the neoclerodane Hardwickiic acid on the presynaptic opioid receptors which modulate noradrenaline and dopamine release in mouse central nervous system. Neurochem Int 2013; 62:354-9. [DOI: 10.1016/j.neuint.2013.01.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 01/15/2013] [Accepted: 01/18/2013] [Indexed: 11/17/2022]
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Wei XY, Zhao Y, Wong-Riley MTT, Ju G, Liu YY. Synaptic relationship between somatostatin- and neurokinin-1 receptor-immunoreactive neurons in the pre-Bötzinger complex of rats. J Neurochem 2012; 122:923-33. [DOI: 10.1111/j.1471-4159.2012.07862.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Rossi PIA, Musante I, Summa M, Pittaluga A, Emionite L, Ikehata M, Rastaldi MP, Ravazzolo R, Puliti A. Compensatory molecular and functional mechanisms in nervous system of the Grm1(crv4) mouse lacking the mGlu1 receptor: a model for motor coordination deficits. ACTA ACUST UNITED AC 2012; 23:2179-89. [PMID: 22791805 DOI: 10.1093/cercor/bhs200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The metabotropic glutamate type 1 (mGlu1) and type 5 (mGlu5) receptors, the only members of group I mGlu receptors, are implicated in synaptic plasticity and mechanisms of feedback control of glutamate release. They exhibit nearly complementary distributions throughout the central nervous system, well evident in the cerebellum, where mGlu1 receptor is most intensely expressed while mGlu5 receptor is not. Despite their different distribution, they show a similar subcellular localization and use common transducing pathways. We recently described the Grm1(crv4) mouse with motor coordination deficits and renal anomalies caused by a spontaneous mutation inactivating the mGlu1 receptor. To define the neuropathological mechanisms in these mice, we evaluated expression and function of the mGlu5 receptor in cerebral and cerebellar cortices. Western blot and immunofluorescence analyses showed mGlu5 receptor overexpression. Quantitative reverse transcriptase-polymerase chain reaction results indicated that the up-regulation is already evident at RNA level. Functional studies confirmed an enhanced glutamate release from cortical cerebral and cerebellar synaptosomes when compared with wild-type that is abolished by the mGlu5 receptor-specific inhibitor, 2-methyl-6-(phenylethynyl) pyridine hydrochloride (MPEP). Finally, acute MPEP treatment of Grm1(crv4/crv4) mice induced an evident although incomplete improvement of motor coordination, suggesting that mGlu5 receptors enhanced activity worsens, instead of improving, the motor-coordination defects in the Grm1(crv4/crv4) mice.
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Lin TY, Lu CW, Wang CC, Lu JF, Wang SJ. Hispidulin inhibits the release of glutamate in rat cerebrocortical nerve terminals. Toxicol Appl Pharmacol 2012; 263:233-43. [PMID: 22759588 DOI: 10.1016/j.taap.2012.06.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 06/15/2012] [Accepted: 06/22/2012] [Indexed: 11/25/2022]
Abstract
Hispidulin, a naturally occurring flavone, has been reported to have an antiepileptic profile. An excessive release of glutamate is considered to be related to neuropathology of epilepsy. We investigated whether hispidulin affected endogenous glutamate release in rat cerebral cortex nerve terminals (synaptosomes) and explored the possible mechanism. Hispidulin inhibited the release of glutamate evoked by the K⁺ channel blocker 4-aminopyridine (4-AP). The effects of hispidulin on the evoked glutamate release were prevented by the chelation of extracellular Ca²⁺ ions and the vesicular transporter inhibitor bafilomycin A1. However, the glutamate transporter inhibitor dl-threo-beta-benzyl-oxyaspartate did not have any effect on hispidulin action. Hispidulin reduced the depolarization-induced increase in cytosolic free Ca²⁺ concentration ([Ca²⁺](C)), but did not alter 4-AP-mediated depolarization. Furthermore, the effect of hispidulin on evoked glutamate release was abolished by blocking the Ca(v)2.2 (N-type) and Ca(v)2.1 (P/Q-type) channels, but not by blocking ryanodine receptors or mitochondrial Na⁺/Ca²⁺ exchange. Mitogen-activated protein kinase kinase (MEK) inhibition also prevented the inhibitory effect of hispidulin on evoked glutamate release. Western blot analyses showed that hispidulin decreased the 4-AP-induced phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and synaptic vesicle-associated protein synapsin I, a major presynaptic substrate for ERK; this decrease was also blocked by the MEK inhibitor. Moreover, the inhibition of glutamate release by hispidulin was strongly attenuated in mice without synapsin I. These results show that hispidulin inhibits glutamate release from cortical synaptosomes in rats through the suppression of presynaptic voltage-dependent Ca²⁺ entry and ERK/synapsin I signaling pathway.
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Affiliation(s)
- Tzu-Yu Lin
- Department of Anesthesiology, Far-Eastern Memorial Hospital, Pan-Chiao District, New Taipei 22060, Taiwan
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Presynaptic mGlu7 receptors control GABA release in mouse hippocampus. Neuropharmacology 2012; 66:215-24. [PMID: 22564442 DOI: 10.1016/j.neuropharm.2012.04.020] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 04/05/2012] [Accepted: 04/19/2012] [Indexed: 11/24/2022]
Abstract
The functional role of presynaptic release-regulating metabotropic glutamate type 7 (mGlu7) receptors in hippocampal GABAergic terminals was investigated. Mouse hippocampal synaptosomes were preloaded with [(3)H]D-γ-aminobutyric acid ([(3)H]GABA) and then exposed in superfusion to 12 mM KCl. The K(+)-evoked [(3)H]GABA release was inhibited by the mGlu7 allosteric agonist N,N'-dibenzyhydryl-ethane-1,2-diamine dihydrochloride (AMN082, 0.001-10 μM), as well as by the group III mGlu receptor agonist l-(+)-2-amino-4-phosphonobutyric acid [(l)-AP4, 0.01-1 mM]. The mGlu8 receptor agonist (S)-3,4-dicarboxyphenylglycine [(S)-3,4-DCPG, 10-100 nM] was ineffective. AMN082 and (l)-AP4-induced effects were recovered by the mGlu7 negative allosteric modulator (NAM) 6-(4-methoxyphenyl)-5-methyl-3-(4-pyridinyl)-isoxazolo[4,5-c]pyridin-4(5H)-one hydrochloride (MMPIP). AMN082 also inhibited in a MMPIP-sensitive manner the K(+)-evoked release of endogenous GABA. AMN082 and the adenylyl cyclase (AC) inhibitor MDL-12,330A reduced [(3)H]GABA exocytosis in a 8-Br-cAMP-sensitive. AMN082-inhibitory effect was additive to that caused by (-)baclofen, but insensitive to the GABA(B) antagonist 3-[[(3,4-Dichlorophenyl)methyl]amino]propyl] diethoxymethyl) phosphinic acid (CGP52432). Conversely, (-)baclofen-induced inhibition of GABA exocytosis was insensitive to MMPIP. Finally, the forskolin-evoked [(3)H]GABA release was reduced by AMN082 or (-)baclofen but abolished when the two agonists were added concomitantly. Mouse hippocampal synaptosomal plasmamembranes posses mGlu7 receptor proteins; confocal microscopy analysis unveiled that mGlu7 proteins colocalize with syntaxin-1A (Stx-1A), with vesicular GABA transporter (VGAT)-proteins and with GABA(B) receptor subunit proteins. We propose that presynaptic inhibitory mGlu7 heteroreceptors, negatively coupled to AC-dependent intraterminal pathway, exist in mouse hippocampal GABA-containing terminals, where they colocalize, but do not functionally cross-talk, with GABA(B) autoreceptors. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.
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Di Prisco S, Summa M, Chellakudam V, Rossi PIA, Pittaluga A. RANTES-mediated control of excitatory amino acid release in mouse spinal cord. J Neurochem 2012; 121:428-37. [DOI: 10.1111/j.1471-4159.2012.07720.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Martel G, Dutar P, Epelbaum J, Viollet C. Somatostatinergic systems: an update on brain functions in normal and pathological aging. Front Endocrinol (Lausanne) 2012; 3:154. [PMID: 23230430 PMCID: PMC3515867 DOI: 10.3389/fendo.2012.00154] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 11/20/2012] [Indexed: 11/29/2022] Open
Abstract
Somatostatin is highly expressed in mammalian brain and is involved in many brain functions such as motor activity, sleep, sensory, and cognitive processes. Five somatostatin receptors have been described: sst(1), sst(2) (A and B), sst(3), sst(4), and sst(5), all belonging to the G-protein-coupled receptor family. During the recent years, numerous studies contributed to clarify the role of somatostatin systems, especially long-range somatostatinergic interneurons, in several functions they have been previously involved in. New advances have also been made on the alterations of somatostatinergic systems in several brain diseases and on the potential therapeutic target they represent in these pathologies.
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Affiliation(s)
| | | | | | - Cécile Viollet
- *Correspondence: Cécile Viollet, Inserm UMR894 - Center for Psychiatry and Neuroscience, Université Paris Descartes, Sorbonne Paris Cité, 2 ter rue d’Alésia, 75014 Paris, France. e-mail:
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Cellular mechanisms of acute decrease of glutamate release induced by raloxifene in rat cerebral cortex. Neuropharmacology 2011; 61:293-304. [DOI: 10.1016/j.neuropharm.2011.04.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 03/29/2011] [Accepted: 04/12/2011] [Indexed: 11/24/2022]
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Bencivinni I, Ferrini F, Salio C, Beltramo M, Merighi A. The somatostatin analogue octreotide inhibits capsaicin-mediated activation of nociceptive primary afferent fibres in spinal cord lamina II (substantia gelatinosa). Eur J Pain 2010; 15:591-9. [PMID: 21109472 DOI: 10.1016/j.ejpain.2010.11.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 10/01/2010] [Accepted: 11/01/2010] [Indexed: 11/17/2022]
Abstract
Somatostatin (SST) in spinal cord has been linked with the inhibition of nociceptive neurotransmission in several experimental paradigms. The SST2 receptor (SSTR2) is the main SST receptor subtype in the superficial dorsal horn (DH) and is activated, besides to the naïve peptide, by the SST synthetic analogue octreotide (OCT). In the present work, we have studied the central effects of SSTR2 activation on capsaicin (CAP)-induced glutamate release in mouse DH. In neurons of the lamina II of DH, CAP (2 μM) induced a strong increase of mEPSC frequency that was significantly reduced (70%) by OCT. SSTR2 involvement was assessed by using the specific antagonist CYN 154806. No differences were observed between frequency increase in CAP alone vs. CAP in the presence of CYN 154806+OCT. The effect of OCT was further investigated by studying c-fos expression in spinal cord slices. The CAP-induced increase in density of Fos immunoreactive nuclei in the superficial DH was strongly prevented by OCT. SSTR2a (a splicing variant of SSTR2) immunoreactivity was found in both pre- and post-synaptic compartments of laminae I-II synapses. By light and electron microscopy, SSTR2a was mainly localized onto non-peptidergic isolectin B4 (IB4)-positive primary afferent fibres (PAFs). A subset of them was also found to express the CAP receptor TRPV1. These data show that the SST analogue OCT inhibits CAP-mediated activation of non-peptidergic nociceptive PAFs in lamina II. Our data indicate that SSTR2a plays an important role in the pre-synaptic modulation of central excitatory nociceptive transmission in mouse.
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Affiliation(s)
- Ileana Bencivinni
- Department of Veterinary Morphophysiology, Via Leonardo da Vinci 44, 10095 Grugliasco, Italy
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Boer S, Sanchez D, Reinieren I, van den Boom T, Udawela M, Scarr E, Ganfornina MD, Dean B. Decreased kainate receptors in the hippocampus of apolipoprotein D knockout mice. Prog Neuropsychopharmacol Biol Psychiatry 2010; 34:271-8. [PMID: 19963028 DOI: 10.1016/j.pnpbp.2009.11.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 11/06/2009] [Accepted: 11/18/2009] [Indexed: 10/20/2022]
Abstract
Apolipoprotein D (ApoD) has many actions critical to maintaining mammalian CNS function. It is therefore significant that levels of ApoD have been shown to be altered in the CNS of subjects with schizophrenia, suggesting a role for ApoD in the pathophysiology of the disorder. There is also a large body of evidence that cortical and hippocampal glutamatergic, serotonergic and cholinergic systems are affected by the pathophysiology of schizophrenia. Thus, we decided to use in vitro radioligand binding and autoradiography to measure levels of ionotropic glutamate, some muscarinic and serotonin 2A receptors in the CNS of ApoD(-/-) and isogenic wild-type mice. These studies revealed a 20% decrease (mean+/-SEM: 104+/-10.2 vs. 130+/-10.4 fmol/mg ETE) in the density of kainate receptors in the CA 2-3 of the ApoD(-/-) mice. In addition there was a global decrease in AMPA receptors (F(1,214)=4.67, p<0.05) and a global increase in muscarinic M2/M4 receptors (F(1,208)=22.77, p<0.0001) in the ApoD(-/-) mice that did not reach significance in any single cytoarchitectural region. We conclude that glutamatergic pathways seem to be particularly affected in ApoD(-/-) mice and this may contribute to the changes in learning and memory, motor tasks and orientation-based tasks observed in these animals, all of which involve glutamatergic neurotransmission.
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Affiliation(s)
- Simone Boer
- The Rebecca L. Cooper Research Laboratories, The Mental Health Research Institute, Australia
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Luo R, Guo Y, Cao DY, Pickar JG, Li L, Wang J, Zhao Y. Local effects of octreotide on glutamate-evoked activation of Aδ and C afferent fibers in rat hairy skin. Brain Res 2010; 1322:50-8. [DOI: 10.1016/j.brainres.2010.01.058] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 01/19/2010] [Accepted: 01/22/2010] [Indexed: 10/19/2022]
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Cavallero A, Marte A, Fedele E. L-aspartate as an amino acid neurotransmitter: mechanisms of the depolarization-induced release from cerebrocortical synaptosomes. J Neurochem 2009; 110:924-34. [PMID: 19549007 DOI: 10.1111/j.1471-4159.2009.06187.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The role of L-aspartate as a classical neurotransmitter of the CNS has been a matter of great debate. In this study, we have characterized the main mechanisms of its depolarization-induced release from rat purified cerebrocortical synaptosomes in superfusion and compared them with those of the well known excitatory neurotransmitter L-glutamate. High KCl and 4-aminopyridine were used as depolarizing agents. At 15 mM KCl, the overflows of both transmitters were almost completely dependent on external Ca2+. At 35 and 50 mM KCl, the overflows of L-aspartate, but not those of L-glutamate, became sensitive to DL-threo-b-benzyloxy aspartic acid (DL-TBOA), an excitatory amino acid transporter inhibitor. In the presence of DL-TBOA, the 50 mM KCl-evoked release of L-aspartate was still largely external Ca2+-dependent. The DL-TBOA insensitive,external Ca2+-independent component of the 50 mM KCl-evoked overflows of L-aspartate and L-glutamate was significantly decreased by the mitochondrial Na+/Ca2+ exchanger blocker CGP 37157. The Ca2+-dependent, KCl-evoked overflows of L-aspartate and L-glutamate were diminished by botulinum neurotoxin C, although to a significantly different extent. The 4-aminopyridine-induced L-aspartate and L-glutamate release was completely external Ca2+-dependent and never affected by DL-TBOA. Superimposable results have been obtained by pre-labeling synaptosomes with [3H]D aspartate and [3H]L-glutamate. Therefore, our data showing that L-aspartate is released from nerve terminals by calcium dependent,exocytotic mechanisms support the neurotransmitter role of this amino acid.
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Affiliation(s)
- Anna Cavallero
- Department of Experimental Medicine, Section of Pharmacology and Toxicology, University of Genoa, Genoa, Italy
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Abstract
The effects of the recombinant chemokine human RANTES (hRANTES) on the release of glutamate from human neocortex glutamatergic nerve endings were investigated. hRANTES facilitated the spontaneous release of d [(3)H]D-aspartate ([(3)H]DASP-) by binding Pertussis toxin-sensitive G-protein-coupled receptors (GPCRs), whose activation caused Ca(2+) mobilization from inositol trisphosphate-sensitive stores and cytosolic tyrosine kinase-mediated phosphorylations. Facilitation of release switched to inhibition when the effects of hRANTES on the 12 mM K(+)-evoked [(3)H]D-ASP exocytosis were studied. Inhibition of exocytosis relied on activation of Pertussis toxin-sensitive GPCRs negatively coupled to adenylyl cyclase. Both hRANTES effects were prevented by met-RANTES, an antagonist at the chemokine receptors (CCRs) of the CCR1, CCR3, and CCR5 subtypes. Interestingly, human neocortex glutamatergic nerve endings seem to possess all three receptor subtypes. Blockade of CCR1 and CCR5 by antibodies against the extracellular domain of CCRs prevented both the hRANTES effect on [(3)H]D-ASP release, whereas blockade of CCR3 prevented inhibition, but not facilitation, of release. The effects of RANTES on the spontaneous and the evoked release of [(3)H]D-ASP were also observed in experiments with mouse cortical synaptosomes, which may therefore represent an appropriate animal model to study RANTES-induced effects on neurotransmission. It is concluded that glutamate transmission can be modulated in opposite directions by RANTES acting at distinct CCR receptor subtypes coupled to different transduction pathways, consistent with the multiple and sometimes contrasting effects of the chemokine.
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Somatostatin inhibits activation of dorsal cutaneous primary afferents induced by antidromic stimulation of primary afferents from an adjacent thoracic segment in the rat. Brain Res 2008; 1229:61-71. [PMID: 18640104 DOI: 10.1016/j.brainres.2008.06.111] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 06/30/2008] [Accepted: 06/30/2008] [Indexed: 01/17/2023]
Abstract
To investigate the effect of somatostatin on the cross-excitation between adjacent primary afferent terminals in the rats, we recorded single unit activity from distal cut ends of dorsal cutaneous branches of the T10 and T12 spinal nerves in response to antidromic stimulation of the distal cut end of the T11 dorsal root in the presence and absence of somatostatin and its receptor antagonist applied to the receptive field of the recorded nerve. Afferent fibers were classified based upon their conduction velocity. Mean mechanical thresholds decreased and spontaneous discharge rates increased significantly in C and Adelta but not Abeta fibers of the T10 and T12 spinal nerves in both male and female rats following antidromic electrical stimulation (ADES) of the dorsal root from adjacent spinal segment (DRASS) indicating cross-excitation of thin fiber afferents. The cross-excitation was not significantly different between male and female rats. Microinjection of somatostatin into the receptive field of recorded units inhibited the cross-excitation. This inhibitory effect, in turn, was reversed by the somatostation receptor antagonist cyclo-somatostatin (c-SOM). Application of c-SOM alone followed by ADES of DRASS significantly decreased the mechanical thresholds and increased the discharge rates of C and Adelta fibers, indicating that endogenous release of somatostatin plays a tonic inhibitory role on the cross-excitation between peripheral nerves. These results suggest that somatostatin could inhibit the cross-excitation involved in peripheral hyperalgesia and have a peripheral analgesic effect.
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Viollet C, Lepousez G, Loudes C, Videau C, Simon A, Epelbaum J. Somatostatinergic systems in brain: networks and functions. Mol Cell Endocrinol 2008; 286:75-87. [PMID: 17997029 DOI: 10.1016/j.mce.2007.09.007] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Revised: 09/10/2007] [Accepted: 09/19/2007] [Indexed: 12/21/2022]
Abstract
Somatostatin is abundantly expressed in mammalian brain. The peptide binds with high affinity to six somatostatin receptors, sst1, sst2A and B, sst3 to 5, all belonging to the G-protein-coupled receptor family. Recent advances in the neuroanatomy of somatostatin neurons and cellular distribution of sst receptors shed light on their functional roles in the neuronal network. Beside their initially described neuroendocrine role, somatostatin systems subserve neuromodulatory roles in the brain, influencing motor activity, sleep, sensory processes and cognitive functions, and are altered in brain diseases like affective disorders, epilepsia and Alzheimer's disease.
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49
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Han L, Yang D, Kundra V. Signaling Can Be Uncoupled from Imaging of the Somatostatin Receptor Type 2. Mol Imaging 2007. [DOI: 10.2310/7290.2007.00038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Lin Han
- From the Departments of Experimental Diagnostic Imaging and Diagnostic Radiology, Division of Diagnostic Imaging, The University of Texas M. D. Anderson Cancer Center, Houston, TX
| | - Dan Yang
- From the Departments of Experimental Diagnostic Imaging and Diagnostic Radiology, Division of Diagnostic Imaging, The University of Texas M. D. Anderson Cancer Center, Houston, TX
| | - Vikas Kundra
- From the Departments of Experimental Diagnostic Imaging and Diagnostic Radiology, Division of Diagnostic Imaging, The University of Texas M. D. Anderson Cancer Center, Houston, TX
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Cervia D, Bagnoli P. An update on somatostatin receptor signaling in native systems and new insights on their pathophysiology. Pharmacol Ther 2007; 116:322-41. [PMID: 17719647 DOI: 10.1016/j.pharmthera.2007.06.010] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Accepted: 06/28/2007] [Indexed: 12/20/2022]
Abstract
The peptide somatostatin (SRIF) has important physiological effects, mostly inhibitory, which have formed the basis for the clinical use of SRIF compounds. SRIF binding to its 5 guanine nucleotide-binding proteins-coupled receptors leads to the modulation of multiple transduction pathways. However, our current understanding of signaling exerted by receptors endogenously expressed in different cells/tissues reflects a rather complicated picture. On the other hand, the complexity of SRIF receptor signaling in pathologies, including pituitary and nervous system diseases, may be studied not only as alternative intervention points for the modulation of SRIF function but also to exploit new chemical space for drug-like molecules.
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Affiliation(s)
- Davide Cervia
- Department of Environmental Sciences, University of Tuscia, largo dell'Università snc, blocco D, 01100 Viterbo, Italy.
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