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Le Dréan ME, Le Berre-Scoul C, Paillé V, Caillaud M, Oullier T, Gonzales J, Hulin P, Neunlist M, Talon S, Boudin H. The regulation of enteric neuron connectivity by semaphorin 5A is affected by the autism-associated S956G missense mutation. iScience 2024; 27:109638. [PMID: 38650986 PMCID: PMC11033180 DOI: 10.1016/j.isci.2024.109638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 02/29/2024] [Accepted: 03/26/2024] [Indexed: 04/25/2024] Open
Abstract
The neural network of the enteric nervous system (ENS) underlies gastrointestinal functions. However, the molecular mechanisms involved in enteric neuronal connectivity are poorly characterized. Here, we studied the role of semaphorin 5A (Sema5A), previously characterized in the central nervous system, on ENS neuronal connectivity. Sema5A is linked to autism spectrum disorder (ASD), a neurodevelopmental disorder frequently associated with gastrointestinal comorbidities, and potentially associated with ENS impairments. This study investigated in rat enteric neuron cultures and gut explants the role of Sema5A on enteric neuron connectivity and the impact of ASD-associated mutations on Sema5A activity. Our findings demonstrated that Sema5A promoted axonal complexity and reduced functional connectivity in enteric neurons. Strikingly, the ASD-associated mutation S956G in Sema5A strongly affected these activities. This study identifies a critical role of Sema5A in the ENS as a regulator of neuronal connectivity that might be compromised in ASD.
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Affiliation(s)
- Morgane E. Le Dréan
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Catherine Le Berre-Scoul
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Vincent Paillé
- Nantes Université, INRAE, UMR 1280, PhAN, IMAD, 44000 Nantes, France
| | - Martial Caillaud
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Thibauld Oullier
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Jacques Gonzales
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Philippe Hulin
- Plateforme MicroPICell Nantes Université, CHU Nantes, CNRS, INSERM, BioCore, US16, SFR Bonamy, Nantes, France
| | - Michel Neunlist
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Sophie Talon
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Hélène Boudin
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
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2
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Neumann S, Kuteykin-Teplyakov K, Heumann R. Neuronal Protection by Ha-RAS-GTPase Signaling through Selective Downregulation of Plasmalemmal Voltage-Dependent Anion Channel-1. Int J Mol Sci 2024; 25:3030. [PMID: 38474278 DOI: 10.3390/ijms25053030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/29/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024] Open
Abstract
The small GTPase RAS acts as a plasma membrane-anchored intracellular neurotrophin counteracting neuronal degeneration in the brain, but the underlying molecular mechanisms are largely unknown. In transgenic mice expressing constitutively activated V12-Ha-RAS selectively in neurons, proteome analysis uncovered a 70% decrease in voltage-dependent anion channel-1 (VDAC-1) in the cortex and hippocampus. We observed a corresponding reduction in the levels of mRNA splicing variant coding for plasma membrane-targeted VDAC-1 (pl-VDAC-1) while mRNA levels for mitochondrial membrane VDAC-1 (mt-VDAC-1) remained constant. In primary cortical neurons derived from V12-Ha-RAS animals, a decrease in pl-VDAC-1 mRNA levels was observed, accompanied by a concomitant reduction in the ferricyanide reductase activity associated with VDAC-1 protein. Application of MEK inhibitor U0126 to transgenic cortical neurons reconstituted pl-VDAC-1 mRNA to reach wild-type levels. Excitotoxic glutamate-induced cell death was strongly attenuated in transgenic V12-Ha-RAS overexpressing cortical cultures. Consistently, a neuroprotective effect could also be achieved in wild-type cortical cultures by the extracellular application of channel-blocking antibody targeting the N-terminus of VDAC-1. These results may encourage novel therapeutic approaches toward blocking pl-VDAC-1 by monoclonal antibody targeting for complementary treatments in transplantation and neurodegenerative disease.
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Affiliation(s)
- Sebastian Neumann
- Department of Biochemistry II-Molecular Neurobiochemistry, Faculty of Chemistry and Biochemistry, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Konstantin Kuteykin-Teplyakov
- Department of Biochemistry II-Molecular Neurobiochemistry, Faculty of Chemistry and Biochemistry, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Rolf Heumann
- Department of Biochemistry II-Molecular Neurobiochemistry, Faculty of Chemistry and Biochemistry, Ruhr-Universität Bochum, 44801 Bochum, Germany
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3
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Sims SK, Saddow M, McGonegal L, Sims-Robinson C. Intranasal Administration of BDNF Improves Recovery and Promotes Neural Plasticity in a Neonatal Mouse Model of Hypoxic Ischemia. Exp Neurobiol 2024; 33:25-35. [PMID: 38471802 PMCID: PMC10938072 DOI: 10.5607/en23030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 01/18/2024] [Accepted: 02/09/2024] [Indexed: 03/14/2024] Open
Abstract
The benefit of intranasal brain derived neurotrophic factor (BDNF) treatment on cognitive function in a neonatal postnatal day 7 (P7) mouse model of hypoxic ischemia (HI) was explored. Intranasal delivery is attractive in that it can promote widespread distribution of BDNF within both the brain and spinal cord. In this study we evaluated the effectiveness of intranasal BDNF to improve cognitive recovery following HI. HI is induced via ligation of the right carotid artery followed by a 45-minute exposure to an 8% oxygen/ 92% nitrogen mixture in an enclosed chamber. Male and female pups were subjected to a 2-hour hypothermia in a temperature-controlled chamber as a standard of care. A solution of saline (control) or recombinant human BDNF (Harlan Laboratories) was administered with a Gilson pipette at the same time each day for 7 days into each nasal cavity in awake mice beginning 24 hours after HI. We evaluated cognitive recovery using the novel object recognition (NOR) and western analysis to analyze neuro-markers and brain health such as synaptophysin and microtubule associated protein -2 (MAP2). The objective of this study was to evaluate the role and therapeutic potential of BDNF in neonatal HI recovery. Our results indicate that intranasal BDNF delivered within 24 hours after HI improved object discrimination at both 28 and 42 days after HI. Our results also demonstrate increased synaptophysin and MAP2 at day 42 in HI animals that received intranasal BDNF treatment compared to HI animals that were administered saline.
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Affiliation(s)
- Serena-Kaye Sims
- Department of Neurology, Medical University of South Carolina, Charleston, SC 29425, USA
- Department of Biology, College of Charleston, Charleston, SC 29424, USA
| | - Madelynne Saddow
- Department of Neurology, Medical University of South Carolina, Charleston, SC 29425, USA
- Department of Biology, College of Charleston, Charleston, SC 29424, USA
| | - Lilly McGonegal
- Department of Neurology, Medical University of South Carolina, Charleston, SC 29425, USA
- Department of Biology, College of Charleston, Charleston, SC 29424, USA
| | - Catrina Sims-Robinson
- Department of Neurology, Medical University of South Carolina, Charleston, SC 29425, USA
- Ralph H Johnson Veterans Affairs Medical Center, Charleston, SC 29401, USA
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4
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Guhathakurta D, Petrušková A, Akdaş EY, Perelló-Amorós B, Frischknecht R, Anni D, Weiss EM, Walter M, Fejtová A. Hydroxynorketamine, but not ketamine, acts via α7 nicotinic acetylcholine receptor to control presynaptic function and gene expression. Transl Psychiatry 2024; 14:47. [PMID: 38253622 PMCID: PMC10803733 DOI: 10.1038/s41398-024-02744-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 12/21/2023] [Accepted: 01/08/2024] [Indexed: 01/24/2024] Open
Abstract
Ketamine is clinically used fast-acting antidepressant. Its metabolite hydroxynorketamine (HNK) shows a robust antidepressant effect in animal studies. It is unclear, how these chemically distinct compounds converge on similar neuronal effects. While KET acts mostly as N-methyl-d-aspartate receptor (NMDAR) antagonist, the molecular target of HNK remains enigmatic. Here, we show that KET and HNK converge on rapid inhibition of glutamate release by reducing the release competence of synaptic vesicles and induce nuclear translocation of pCREB that controls expression of neuroplasticity genes connected to KET- and HNK-mediated antidepressant action. Ro25-6981, a selective antagonist of GluN2B, mimics effect of KET indicating that GluN2B-containing NMDAR might mediate the presynaptic effect of KET. Selective antagonist of α7 nicotinic acetylcholine receptors (α7nAChRs) or genetic deletion of Chrna7, its pore-forming subunit, fully abolishes HNK-induced synaptic and nuclear regulations, but leaves KET-dependent cellular effects unaffected. Thus, KET or HNK-induced modulation of synaptic transmission and nuclear translocation of pCREB can be mediated by selective signaling via NMDAR or α7nAChRs, respectively. Due to the rapid metabolism of KET to HNK, it is conceivable that subsequent modulation of glutamatergic and cholinergic neurotransmission affects circuits in a cell-type-specific manner and contributes to the therapeutic potency of KET. This finding promotes further exploration of new combined medications for mood disorders.
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Affiliation(s)
- Debarpan Guhathakurta
- Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Aneta Petrušková
- Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- National Institute of Mental Health, Klecany, Czech Republic
- Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Enes Yağız Akdaş
- Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Bartomeu Perelló-Amorós
- Department of Biology, Animal Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Renato Frischknecht
- Department of Biology, Animal Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Daniela Anni
- Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Eva-Maria Weiss
- Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Martin Walter
- Department of Psychiatry and Psychotherapy, Universitätsklinikum Jena, Jena, Germany
| | - Anna Fejtová
- Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
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Mao LM, Thallapureddy K, Wang JQ. Effects of propofol on presynaptic synapsin phosphorylation in the mouse brain in vivo. Brain Res 2024; 1823:148671. [PMID: 37952872 PMCID: PMC10806815 DOI: 10.1016/j.brainres.2023.148671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/24/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
The commonly used general anesthetic propofol can enhance the γ-aminobutyric acid-mediated inhibitory synaptic transmission and depress the glutamatergic excitatory synaptic transmission to achieve general anesthesia and other outcomes. In addition to the actions at postsynaptic sites, the modulation of presynaptic activity by propofol is thought to contribute to neurophysiological effects of the anesthetic, although potential targets of propofol within presynaptic nerve terminals are incompletely studied at present. In this study, we explored the possible linkage of propofol to synapsins, a family of neuron-specific phosphoproteins which are the most abundant proteins on presynaptic vesicles, in the adult mouse brain in vivo. We found that an intraperitoneal injection of propofol at a dose that caused loss of righting reflex increased basal levels of synapsin phosphorylation at the major representative phosphorylation sites (serine 9, serine 62/67, and serine 603) in the prefrontal cortex (PFC) of male and female mice. Propofol also elevated synapsin phosphorylation at these sites in the striatum and S9 and S62/67 phosphorylation in the hippocampus, while propofol had no effect on tyrosine hydroxylase phosphorylation in striatal nerve terminals. Total synapsin protein expression in the PFC, hippocampus, and striatum was not altered by propofol. These results reveal that synapsin could be a novel substrate of propofol in the presynaptic neurotransmitter release machinery. Propofol possesses the ability to upregulate synapsin phosphorylation in broad mouse brain regions.
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Affiliation(s)
- Li-Min Mao
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Khyathi Thallapureddy
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - John Q Wang
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA; Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA.
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6
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Rocha Caldas G, do Amaral L, Munhoz Rodrigues D, Mayrink de Miranda A, Aparecida Guinaim Dos Santos N, Machado Rocha L, Tame Parreira RL, Cardozo Dos Santos A, Kenupp Bastos J. Brazilian Green Propolis' Artepillin C and Its Acetylated Derivative Activate the NGF-Signaling Pathways and Induce Neurite Outgrowth in NGF-Deprived PC12 Cells. Chem Biodivers 2023; 20:e202301294. [PMID: 37953436 DOI: 10.1002/cbdv.202301294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/10/2023] [Accepted: 11/12/2023] [Indexed: 11/14/2023]
Abstract
Artepillin C is the most studied compound in Brazilian Green Propolis and, along with its acetylated derivative, displays neurotrophic activity on PC12 cells. Specific inhibitors of the trkA receptor (K252a), PI3K/Akt (LY294002), and MAPK/ERK (U0126) signaling pathways were used to investigate the neurotrophic mechanism. The expression of proteins involved in axonal and synaptic plasticity (GAP-43 and Synapsin I) was assessed by western blotting. Additionally, physicochemical properties, pharmacokinetics, and drug-likeness were evaluated by the SwissADME web tool. Both compounds induced neurite outgrowth by activating the NGF-signaling pathways but through different neuronal proteins. Furthermore, in silico analyses showed interesting physicochemical and pharmacokinetic properties of these compounds. Therefore, these compounds could play an important role in axonal and synaptic plasticity and should be further investigated.
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Affiliation(s)
- Gabriel Rocha Caldas
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Lilian do Amaral
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Débora Munhoz Rodrigues
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Aline Mayrink de Miranda
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | | | - Leandro Machado Rocha
- Natural Products Technology Laboratory-Fluminense Federal University, Niterói, RJ, Brazil
| | | | | | - Jairo Kenupp Bastos
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
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7
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Wang J, Cai Y, Sun J, Feng H, Zhu X, Chen Q, Gao F, Ni Q, Mao L, Yang M, Sun B. Administration of intramuscular AAV-BDNF and intranasal AAV-TrkB promotes neurological recovery via enhancing corticospinal synaptic connections in stroke rats. Exp Neurol 2023; 359:114236. [PMID: 36183811 DOI: 10.1016/j.expneurol.2022.114236] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 09/14/2022] [Accepted: 09/25/2022] [Indexed: 12/30/2022]
Abstract
Stroke causes long-term disability in survivors. BDNF/TrkB plays an important role in synaptic plasticity and synaptic transmission in the central nervous system (CNS), promoting neurological recovery. In this study, we performed non-invasive treatment methods focused on intramuscular injection into stroke-injured forelimb muscles, or intranasal administration using adeno-associated virus (AAV) vectors carrying genes encoding BDNF or TrkB. In a permanent rat middle cerebral artery occlusion (MCAO) model, we assessed the effects of combination therapy with AAV-BDNF and AAV-TrkB on motor functional recovery and synaptic plasticity of the corticospinal connections. Our results showed that BDNF or TrkB gene transduced in the spinal anterior horn neurons and cerebral cortical neurons. Compared to AAV vector treatment alone, behavioral and electrophysiological results showed that the combination therapy significantly improved upper limb motor functional recovery and neurotransmission efficiency after stroke. BDA tracing, immunofluorescence staining, qRT-PCR, and transmission electron microscopy of synaptic ultrastructure results revealed that the combination therapy not only potently increased the expression of Synapsin I, PSD-95, and GAP-43, but also promoted the axonal remodeling and restoration of abnormal synaptic structures. These findings provide a new strategy for enhancing neural plasticity and a potential means to treat stroke clinically.
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Affiliation(s)
- Jing Wang
- Medical College of Qingdao University, Qingdao 266021, Shandong, China; Institute for Neurological Research, The Second Affiliated Hospital; School of Basic Medical Sciences of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, Shandong, China
| | - Yichen Cai
- Institute for Neurological Research, The Second Affiliated Hospital; School of Basic Medical Sciences of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, Shandong, China
| | - Jingyi Sun
- Department of Spinal Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan 250021, Shandong, China
| | - Hua Feng
- Department of Otolaryngology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan 250011, Shandong, China
| | - Xiaoyu Zhu
- Institute for Neurological Research, The Second Affiliated Hospital; School of Basic Medical Sciences of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, Shandong, China
| | - Qian Chen
- Institute for Neurological Research, The Second Affiliated Hospital; School of Basic Medical Sciences of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, Shandong, China
| | - Feng Gao
- Institute for Neurological Research, The Second Affiliated Hospital; School of Basic Medical Sciences of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, Shandong, China
| | - Qingbin Ni
- Postdoctoral Workstation, Taian Central Hospital, Taian 271000, Shandong, China
| | - Leilei Mao
- Institute for Neurological Research, The Second Affiliated Hospital; School of Basic Medical Sciences of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, Shandong, China.
| | - Mingfeng Yang
- Institute for Neurological Research, The Second Affiliated Hospital; School of Basic Medical Sciences of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, Shandong, China.
| | - Baoliang Sun
- Medical College of Qingdao University, Qingdao 266021, Shandong, China; Institute for Neurological Research, The Second Affiliated Hospital; School of Basic Medical Sciences of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, Shandong, China.
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8
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Impaired synaptic plasticity in an animal model of autism exhibiting early hippocampal GABAergic-BDNF/TrkB signaling alterations. iScience 2022; 26:105728. [PMID: 36582822 PMCID: PMC9793278 DOI: 10.1016/j.isci.2022.105728] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/25/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
In Neurodevelopmental Disorders, alterations of synaptic plasticity may trigger structural changes in neuronal circuits involved in cognitive functions. This hypothesis was tested in mice carrying the human R451C mutation of Nlgn3 gene (NLG3R451C KI), found in some families with autistic children. To this aim, the spike time dependent plasticity (STDP) protocol was applied to immature GABAergic Mossy Fibers (MF)-CA3 connections in hippocampal slices from NLG3R451C KI mice. These animals failed to exhibit STD-LTP, an effect that persisted in adulthood when these synapses became glutamatergic. Similar results were obtained in mice lacking the Nlgn3 gene (NLG3 KO mice), suggesting a loss of function. The loss of STD-LTP was associated with a premature shift of GABA from the depolarizing to the hyperpolarizing direction, a reduced BDNF availability and TrkB phosphorylation at potentiated synapses. These effects may constitute a general mechanism underlying cognitive deficits in those forms of Autism caused by synaptic dysfunctions.
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Lu CW, Wu CC, Chiu KM, Lee MY, Lin TY, Wang SJ. Inhibition of Synaptic Glutamate Exocytosis and Prevention of Glutamate Neurotoxicity by Eupatilin from Artemisia argyi in the Rat Cortex. Int J Mol Sci 2022; 23:13406. [PMID: 36362193 PMCID: PMC9657139 DOI: 10.3390/ijms232113406] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 10/28/2022] [Accepted: 11/01/2022] [Indexed: 01/03/2024] Open
Abstract
The inhibition of synaptic glutamate release to maintain glutamate homeostasis contributes to the alleviation of neuronal cell injury, and accumulating evidence suggests that natural products can repress glutamate levels and associated excitotoxicity. In this study, we investigated whether eupatilin, a constituent of Artemisia argyi, affected glutamate release in rat cortical nerve terminals (synaptosomes). Additionally, we evaluated the effect of eupatilin in an animal model of kainic acid (KA) excitotoxicity, particularly on the levels of glutamate and N-methyl-D-aspartate (NMDA) receptor subunits (GluN2A and GluN2B). We found that eupatilin decreased depolarization-evoked glutamate release from rat cortical synaptosomes and that this effect was accompanied by a reduction in cytosolic Ca2+ elevation, inhibition of P/Q-type Ca2+ channels, decreased synapsin I Ca2+-dependent phosphorylation and no detectable effect on the membrane potential. In a KA-induced glutamate excitotoxicity rat model, the administration of eupatilin before KA administration prevented neuronal cell degeneration, glutamate elevation, glutamate-generating enzyme glutaminase increase, excitatory amino acid transporter (EAAT) decrease, GluN2A protein decrease and GluN2B protein increase in the rat cortex. Taken together, the results suggest that eupatilin depresses glutamate exocytosis from cerebrocortical synaptosomes by decreasing P/Q-type Ca2+ channels and synapsin I phosphorylation and alleviates glutamate excitotoxicity caused by KA by preventing glutamatergic alterations in the rat cortex. Thus, this study suggests that eupatilin can be considered a potential therapeutic agent in the treatment of brain impairment associated with glutamate excitotoxicity.
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Affiliation(s)
- Cheng-Wei Lu
- Department of Anesthesiology, Far-Eastern Memorial Hospital, New Taipei City 22060, Taiwan
- Department of Mechanical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Chia-Chan Wu
- Department of Anesthesiology, Far-Eastern Memorial Hospital, New Taipei City 22060, Taiwan
| | - Kuan-Ming Chiu
- Division of Cardiovascular Surgery, Cardiovascular Center, Far-Eastern Memorial Hospital, New Taipei City 22060, Taiwan
- Department of Electrical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Ming-Yi Lee
- Department of Medical Research, Far-Eastern Memorial Hospital, New Taipei City 22060, Taiwan
| | - Tzu-Yu Lin
- Department of Anesthesiology, Far-Eastern Memorial Hospital, New Taipei City 22060, Taiwan
- Department of Mechanical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Su-Jane Wang
- School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan
- Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 33303, Taiwan
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10
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Insulin-like growth factor 1 regulates excitatory synaptic transmission in pyramidal neurons from adult prefrontal cortex. Neuropharmacology 2022; 217:109204. [PMID: 35931212 DOI: 10.1016/j.neuropharm.2022.109204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 07/07/2022] [Accepted: 07/25/2022] [Indexed: 11/24/2022]
Abstract
Insulin-like growth factor 1 (IGF1) influences synaptic function in addition to its role in brain development and aging. Although the expression levels of IGF1 and IGF1 receptor (IGF1R) peak during development and decline with age, the adult brain has abundant IGF1 or IGF1R expression. Studies reveal that IGF1 regulates the synaptic transmission in neurons from young animals. However, the action of IGF1 on neurons in the adult brain is still unclear. Here, we used prefrontal cortical (PFC) slices from adult mice (∼8 weeks old) to characterize the role of IGF1 on excitatory synaptic transmission in pyramidal neurons and the underlying molecular mechanisms. We first validated IGF1R expression in pyramidal neurons using translating ribosomal affinity purification assay. Then, using whole-cell patch-clamp recording, we found that IGF1 attenuated the amplitude of evoked excitatory postsynaptic current (EPSC) without affecting the frequency and amplitude of miniature EPSC. Furthermore, this decrease in excitatory neurotransmission was blocked by pharmacological inhibition of IGF1R or conditionally knockdown of IGF1R in PFC pyramidal neurons. In addition, we determined that IGF1-induced decrease of EPSC amplitude was due to postsynaptic effect (internalization of a-amino-3-hydroxy-5-methyl-4- isoxazolepropionic acid receptors [AMPAR]) rather than presynaptic glutamate release. Finally, we found that inhibition of metabotropic glutamate receptor subtype-1 (mGluR1) abolished IGF1-induced attenuation of evoked EPSC amplitude and decrease of AMPAR expression at synaptic membrane, suggesting mGluR1-mediated endocytosis of AMPAR was involved. Taken together, these data provide the first evidence that IGF1 regulates excitatory synaptic transmission in adult PFC via the interaction between IGF1R-dependent signaling pathway and mGluR1-mediated AMPAR endocytosis.
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11
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Kim M, Hwang SU, Yoon JD, Lee J, Kim E, Cai L, Choi H, Oh D, Lee G, Hyun SH. Physiological and Functional Roles of Neurotrophin-4 During In Vitro Maturation of Porcine Cumulus–Oocyte Complexes. Front Cell Dev Biol 2022; 10:908992. [PMID: 35898394 PMCID: PMC9310091 DOI: 10.3389/fcell.2022.908992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
Neurotrophin-4 (NT-4), a granulosa cell-derived factor and a member of the neurotrophin family, is known to promote follicular development and oocyte maturation in mammals. However, the physiological and functional roles of NT-4 in porcine ovarian development are not yet known. The aim of this study was to investigate the physiological role of NT-4-related signaling in the in vitro maturation (IVM) of porcine cumulus–oocyte complexes (COCs). The NT-4 protein and its receptors were detected in matured porcine COCs via immunofluorescence analysis. NT-4 was shown to promote the maturation of COCs by upregulating NFKB1 transcription via the neurotrophin/p75NTR signaling pathway. Notably, the mRNA expression levels of the oocyte-secreted factors GDF9 and BMP15, sperm–oocyte interaction regulator CD9, and DNA methylase DNMT3A were significantly upregulated in NT-4-treated than in untreated porcine oocytes. Concurrently, there were no significant differences in the levels of total and phosphorylated epidermal growth factor receptor and p38 mitogen-activated protein kinase between NT-4-treated and untreated cumulus cells (CCs); however, the level of phosphorylated ERK1/2 was significantly higher in NT-4-treated CCs. Both total and phosphorylated ERK1/2 levels were significantly higher in NT-4-treated than in untreated oocytes. In addition, NT-4 improved subsequent embryonic development after in vitro fertilization and somatic cell nuclear transfer. Therefore, the physiological and functional roles of NT-4 in porcine ovarian development include the promotion of oocyte maturation, CC expansion, and ERK1/2 phosphorylation in porcine COCs during IVM.
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Affiliation(s)
- Mirae Kim
- Veterinary Medical Center and College of Veterinary Medicine, Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Chungbuk National University, Cheongju, South Korea
- Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea
| | - Seon-Ung Hwang
- Department of Biological Sciences, College of Arts and Sciences, University at Buffalo, The State University of New York (SUNY), Buffalo, NY, United States
| | - Junchul David Yoon
- Division of Animal Sciences, University of Missouri, Columbia, MO, United States
| | - Joohyeong Lee
- Veterinary Medical Center and College of Veterinary Medicine, Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Chungbuk National University, Cheongju, South Korea
- Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea
| | - Eunhye Kim
- Laboratory of Molecular Diagnostics and Cell Biology, College of Veterinary Medicine, Gyeongsang National University, Jinju, South Korea
| | - Lian Cai
- Veterinary Medical Center and College of Veterinary Medicine, Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Chungbuk National University, Cheongju, South Korea
- Graduate School of Veterinary Biosecurity and Protection, Chungbuk National University, Cheongju, South Korea
| | - Hyerin Choi
- Veterinary Medical Center and College of Veterinary Medicine, Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Chungbuk National University, Cheongju, South Korea
- Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea
| | - Dongjin Oh
- Veterinary Medical Center and College of Veterinary Medicine, Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Chungbuk National University, Cheongju, South Korea
- Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea
| | - Gabsang Lee
- Department of Neurology, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Sang-Hwan Hyun
- Veterinary Medical Center and College of Veterinary Medicine, Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), Chungbuk National University, Cheongju, South Korea
- Institute of Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, South Korea
- Graduate School of Veterinary Biosecurity and Protection, Chungbuk National University, Cheongju, South Korea
- *Correspondence: Sang-Hwan Hyun,
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12
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Vints WAJ, Levin O, Fujiyama H, Verbunt J, Masiulis N. Exerkines and long-term synaptic potentiation: Mechanisms of exercise-induced neuroplasticity. Front Neuroendocrinol 2022; 66:100993. [PMID: 35283168 DOI: 10.1016/j.yfrne.2022.100993] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 03/03/2022] [Accepted: 03/06/2022] [Indexed: 01/30/2023]
Abstract
Physical exercise may improve cognitive function by modulating molecular and cellular mechanisms within the brain. We propose that the facilitation of long-term synaptic potentiation (LTP)-related pathways, by products induced by physical exercise (i.e., exerkines), is a crucial aspect of the exercise-effect on the brain. This review summarizes synaptic pathways that are activated by exerkines and may potentiate LTP. For a total of 16 exerkines, we indicated how blood and brain exerkine levels are altered depending on the type of physical exercise (i.e., cardiovascular or resistance exercise) and how they respond to a single bout (i.e., acute exercise) or multiple bouts of physical exercise (i.e., chronic exercise). This information may be used for designing individualized physical exercise programs. Finally, this review may serve to direct future research towards fundamental gaps in our current knowledge regarding the biophysical interactions between muscle activity and the brain at both cellular and system levels.
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Affiliation(s)
- Wouter A J Vints
- Department of Health Promotion and Rehabilitation, Lithuanian Sports University, Sporto str. 6, LT-44221 Kaunas, Lithuania; Department of Rehabilitation Medicine Research School CAPHRI, Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; Centre of Expertise in Rehabilitation and Audiology, Adelante Zorggroep, P.O. Box 88, 6430 AB Hoensbroek, the Netherlands.
| | - Oron Levin
- Department of Health Promotion and Rehabilitation, Lithuanian Sports University, Sporto str. 6, LT-44221 Kaunas, Lithuania; Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, Catholic University Leuven, Tervuursevest 101, 3001 Heverlee, Belgium.
| | - Hakuei Fujiyama
- Department of Psychology, Murdoch University, 90 South St., WA 6150 Perth, Australia; Centre for Healthy Ageing, Health Futures Institute, Murdoch University, 90 South St., WA 6150 Perth, Australia; Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, 90 South St., WA 6150 Perth, Australia.
| | - Jeanine Verbunt
- Department of Rehabilitation Medicine Research School CAPHRI, Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; Centre of Expertise in Rehabilitation and Audiology, Adelante Zorggroep, P.O. Box 88, 6430 AB Hoensbroek, the Netherlands.
| | - Nerijus Masiulis
- Department of Health Promotion and Rehabilitation, Lithuanian Sports University, Sporto str. 6, LT-44221 Kaunas, Lithuania; Department of Rehabilitation, Physical and Sports Medicine, Institute of Health Science, Faculty of Medicine, Vilnius University, M. K. Čiurlionio Str. 21, LT-03101 Vilnius, Lithuania.
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13
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do Amaral L, Caldas GR, Dos Santos NAG, Parreira RLT, Bastos JK, Dos Santos AC. Baccharin from Brazilian green propolis induces neurotrophic signaling pathways in PC12 cells: potential for axonal and synaptic regeneration. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2022; 395:659-672. [PMID: 35246694 DOI: 10.1007/s00210-022-02224-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/24/2022] [Indexed: 11/30/2022]
Abstract
Neurodegenerative diseases are characterized by progressive loss of the structure and function of specific neuronal populations, and have been associated with reduced neurotrophic support. Neurotrophins, like NGF (nerve growth factor), are endogenous proteins that induce neuritogenesis and modulate axonal growth, branching, and synapsis; however, their therapeutic application is limited mainly by low stability, short half-life, and inability to cross the blood-brain barrier (BBB). Small neurotrophic molecules that have suitable pharmacokinetics and are able to cross the BBB are potential candidates for neuroprotection. Baccharin is a bioactive small molecule isolated from Brazilian green propolis. In the present study, we investigated the neurotrophic and neuroprotective potential of baccharin in the PC12 cell neuronal model. We used pharmacological inhibitors (K252a, LY294002, and U0126), and ELISA (phospho-trkA, phospho-Akt, and phospho-MEK) to investigate the involvement of trkA receptor, PI3k/Akt pathway, and MAPK/Erk pathway, respectively. Additionally, we evaluated the expression of axonal (GAP-43) and synaptic (synapsin I) proteins by western blot. The results showed that baccharin induces neuritogenesis in NGF-deprived PC12 cells, through activation of trkA receptor and the downstream signaling cascades (PI3K/Akt and MAPK/ERK), which is the same neurotrophic pathway activated by NGF in PC12 cells and neurons. Baccharin also induced the expression of GAP-43 and synapsin I, which mediate axonal and synaptic plasticity, respectively. Additionally, in silico predictions of baccharin showed favorable physicochemical properties, pharmacokinetics, drug-likeness, and medicinal chemistry friendliness. Altogether, these findings suggest that baccharin is a promising neurotrophic agent whose therapeutic application in neurodegeneration should be further investigated.
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Affiliation(s)
- Lilian do Amaral
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Gabriel Rocha Caldas
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | | | | | - Jairo Kennup Bastos
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Antonio Cardozo Dos Santos
- Departamento de Análises Clínicas, Toxicológicas E Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, USP, Avenida do Café s/n, Ribeirão Preto, SP, 14040-903, Brazil.
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14
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Brain-Derived Neurotrophic Factor and Nerve Growth Factor Therapeutics for Brain Injury: The Current Translational Challenges in Preclinical and Clinical Research. Neural Plast 2022; 2022:3889300. [PMID: 35283994 PMCID: PMC8906958 DOI: 10.1155/2022/3889300] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 02/04/2022] [Indexed: 01/11/2023] Open
Abstract
Ischemic stroke and traumatic brain injury (TBI) are among the leading causes of death and disability worldwide with impairments ranging from mild to severe. Many therapies are aimed at improving functional and cognitive recovery by targeting neural repair but have encountered issues involving efficacy and drug delivery. As a result, therapeutic options for patients are sparse. Neurotrophic factors are one of the key mediators of neural plasticity and functional recovery. Neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) serve as potential therapeutic options to increase neural repair and recovery as they promote neuroprotection and regeneration. BDNF and NGF have demonstrated the ability to improve functional recovery in preclinical and to a lesser extent clinical studies. Direct and indirect methods to increase levels of neurotrophic factors in animal models have been successful in improving postinjury outcome measures. However, the translation of these studies into clinical trials has been limited. Preclinical experiments have largely failed to result in significant impacts in clinical research. This review will focus on the administration of these neurotrophic factors in preclinical and clinical stroke and TBI and the challenges in translating these therapies from the bench to the clinic.
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15
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Yeh KC, Hung CF, Lee HL, Hsieh TY, Wang SJ. Soybean Meal Extract Preserves Memory Ability by Increasing Presynaptic Function and Modulating Gut Microbiota in Rats. Mol Neurobiol 2022; 59:1649-1664. [PMID: 35001354 DOI: 10.1007/s12035-021-02669-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/25/2021] [Indexed: 12/12/2022]
Abstract
Age-related degenerative brain diseases frequently manifest as memory deficits. Dietary interventions or nutraceuticals may provide efficacious treatments through prevention and cure. Soybean meal, a byproduct of soy oil refining, has health benefits, but its effect on memory function is unknown. Therefore, we evaluated the effect of the oral administration of soybean meal extract (SME) for 2 weeks on memory function using the Morris water maze (MWM) test in healthy rats and investigated the possible underlying mechanisms. First, analysis of the composition revealed that SME is rich in isoflavones; SME did not exhibit hepatotoxicity or renal toxicity at the different doses tested. The MWM results revealed that the escape latency and movement distance of rats were significantly shorter in the SME group than in the control group, indicating that SME can help in memory preservation. In addition, SME increased the levels of presynaptic proteins such as synaptophysin, synaptobrevin, synaptotagmin, syntaxin, synapsin I, and 25-kDa synaptosome-associated protein as well as protein kinases and their phosphorylated expression, including extracellular signal-regulated kinases 1 and 2 (ERK1/2), protein kinase C (PKC), and Ca2+/calmodulin-dependent protein kinase II (CaMKII) in the hippocampal nerve terminals (synaptosomes). Transmission electron microscopy also indicated that SME increased the number of synaptic vesicles in hippocampal synaptosomes. Furthermore, SME rats exhibited altered microbiota composition compared with control rats. Therefore, our data suggest that SME can increase presynaptic function and modulate gut microbiota, thus aiding in memory preservation in rats.
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Affiliation(s)
- Kun-Chieh Yeh
- School of Medicine, Fu Jen Catholic University, No.510, Zhongzheng Rd., Xinzhuang Dist, New Taipei City, 24205, Taiwan
- Department of Surgery, Taoyuan Armed Forces General Hospital, Taoyuan, Taiwan
- Department of Surgery, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Chi-Feng Hung
- School of Medicine, Fu Jen Catholic University, No.510, Zhongzheng Rd., Xinzhuang Dist, New Taipei City, 24205, Taiwan
| | - Hui-Ling Lee
- Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Ting-Yang Hsieh
- P.H.D. Program in Neutrition & Food Science, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Su-Jane Wang
- School of Medicine, Fu Jen Catholic University, No.510, Zhongzheng Rd., Xinzhuang Dist, 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.
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16
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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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17
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Berezovskaya AS, Tyganov SA, Nikolaeva SD, Naumova AA, Merkulyeva NS, Shenkman BS, Glazova MV. Dynamic Foot Stimulations During Short-Term Hindlimb Unloading Prevent Dysregulation of the Neurotransmission in the Hippocampus of Rats. Cell Mol Neurobiol 2021; 41:1549-1561. [PMID: 32683580 DOI: 10.1007/s10571-020-00922-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 07/11/2020] [Indexed: 12/11/2022]
Abstract
Spaceflight and simulated microgravity both affect learning and memory, which are mostly controlled by the hippocampus. However, data about molecular alterations in the hippocampus in real or simulated microgravity conditions are limited. Adult Wistar rats were recruited in the experiments. Here we analyzed whether short-term simulated microgravity caused by 3-day hindlimb unloading (HU) will affect the glutamatergic and GABAergic systems of the hippocampus and how dynamic foot stimulation (DFS) to the plantar surface applied during HU can contribute in the regulation of hippocampus functioning. The results demonstrated a decreased expression of vesicular glutamate transporters 1 and 2 (VGLUT1/2) in the hippocampus after 3 days of HU, while glutamate decarboxylase 67 (GAD67) expression was not affected. HU also significantly induced Akt signaling and transcriptional factor CREB that are supposed to activate the neuroprotective mechanisms. On the other hand, DFS led to normalization of VGLUT1/2 expression and activity of Akt and CREB. Analysis of exocytosis proteins revealed the inhibition of SNAP-25, VAMP-2, and syntaxin 1 expression in DFS group proposing attenuation of excitatory neurotransmission. Thus, we revealed that short-term HU causes dysregulation of glutamatergic system of the hippocampus, but, at the same time, stimulates neuroprotective Akt-dependent mechanism. In addition, most importantly, we demonstrated positive effect of DFS on the hippocampus functioning that probably depends on the regulation of neurotransmitter exocytosis.
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Affiliation(s)
- Anna S Berezovskaya
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez pr., 194223, St.Petersburg, Russia
| | - Sergey A Tyganov
- Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Svetlana D Nikolaeva
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez pr., 194223, St.Petersburg, Russia
| | - Alexandra A Naumova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez pr., 194223, St.Petersburg, Russia
| | - Natalia S Merkulyeva
- Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, Russia
- Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg, Russia
| | - Boris S Shenkman
- Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Margarita V Glazova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez pr., 194223, St.Petersburg, Russia.
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18
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Presynaptic AMPA Receptors in Health and Disease. Cells 2021; 10:cells10092260. [PMID: 34571906 PMCID: PMC8470629 DOI: 10.3390/cells10092260] [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: 07/01/2021] [Revised: 08/23/2021] [Accepted: 08/26/2021] [Indexed: 01/04/2023] Open
Abstract
AMPA receptors (AMPARs) are ionotropic glutamate receptors that play a major role in excitatory neurotransmission. AMPARs are located at both presynaptic and postsynaptic plasma membranes. A huge number of studies investigated the role of postsynaptic AMPARs in the normal and abnormal functioning of the mammalian central nervous system (CNS). These studies highlighted that changes in the functional properties or abundance of postsynaptic AMPARs are major mechanisms underlying synaptic plasticity phenomena, providing molecular explanations for the processes of learning and memory. Conversely, the role of AMPARs at presynaptic terminals is as yet poorly clarified. Accruing evidence demonstrates that presynaptic AMPARs can modulate the release of various neurotransmitters. Recent studies also suggest that presynaptic AMPARs may possess double ionotropic-metabotropic features and that they are involved in the local regulation of actin dynamics in both dendritic and axonal compartments. In addition, evidence suggests a key role of presynaptic AMPARs in axonal pathology, in regulation of pain transmission and in the physiology of the auditory system. Thus, it appears that presynaptic AMPARs play an important modulatory role in nerve terminal activity, making them attractive as novel pharmacological targets for a variety of pathological conditions.
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19
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Longhena F, Faustini G, Brembati V, Pizzi M, Benfenati F, Bellucci A. An updated reappraisal of synapsins: structure, function and role in neurological and psychiatric disorders. Neurosci Biobehav Rev 2021; 130:33-60. [PMID: 34407457 DOI: 10.1016/j.neubiorev.2021.08.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/29/2021] [Accepted: 08/09/2021] [Indexed: 01/02/2023]
Abstract
Synapsins (Syns) are phosphoproteins strongly involved in neuronal development and neurotransmitter release. Three distinct genes SYN1, SYN2 and SYN3, with elevated evolutionary conservation, have been described to encode for Synapsin I, Synapsin II and Synapsin III, respectively. Syns display a series of common features, but also exhibit distinctive localization, expression pattern, post-translational modifications (PTM). These characteristics enable their interaction with other synaptic proteins, membranes and cytoskeletal components, which is essential for the proper execution of their multiple functions in neuronal cells. These include the control of synapse formation and growth, neuron maturation and renewal, as well as synaptic vesicle mobilization, docking, fusion, recycling. Perturbations in the balanced expression of Syns, alterations of their PTM, mutations and polymorphisms of their encoding genes induce severe dysregulations in brain networks functions leading to the onset of psychiatric or neurological disorders. This review presents what we have learned since the discovery of Syn I in 1977, providing the state of the art on Syns structure, function, physiology and involvement in central nervous system disorders.
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Affiliation(s)
- Francesca Longhena
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Gaia Faustini
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Viviana Brembati
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Marina Pizzi
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Fabio Benfenati
- Italian Institute of Technology, Via Morego 30, Genova, Italy; IRCSS Policlinico San Martino Hospital, Largo Rosanna Benzi 10, 16132, Genova, Italy.
| | - Arianna Bellucci
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy; Laboratory for Preventive and Personalized Medicine, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
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20
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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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21
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Silbern I, Pan KT, Fiosins M, Bonn S, Rizzoli SO, Fornasiero EF, Urlaub H, Jahn R. Protein Phosphorylation in Depolarized Synaptosomes: Dissecting Primary Effects of Calcium from Synaptic Vesicle Cycling. Mol Cell Proteomics 2021; 20:100061. [PMID: 33582301 PMCID: PMC7995663 DOI: 10.1016/j.mcpro.2021.100061] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 02/02/2021] [Indexed: 01/20/2023] Open
Abstract
Synaptic transmission is mediated by the regulated exocytosis of synaptic vesicles. When the presynaptic membrane is depolarized by an incoming action potential, voltage-gated calcium channels open, resulting in the influx of calcium ions that triggers the fusion of synaptic vesicles (SVs) with the plasma membrane. SVs are recycled by endocytosis. Phosphorylation of synaptic proteins plays a major role in these processes, and several studies have shown that the synaptic phosphoproteome changes rapidly in response to depolarization. However, it is unclear which of these changes are directly linked to SV cycling and which might regulate other presynaptic functions that are also controlled by calcium-dependent kinases and phosphatases. To address this question, we analyzed changes in the phosphoproteome using rat synaptosomes in which exocytosis was blocked with botulinum neurotoxins (BoNTs) while depolarization-induced calcium influx remained unchanged. BoNT-treatment significantly alters the response of the synaptic phoshoproteome to depolarization and results in reduced phosphorylation levels when compared with stimulation of synaptosomes by depolarization with KCl alone. We dissect the primary Ca2+-dependent phosphorylation from SV-cycling-dependent phosphorylation and confirm an effect of such SV-cycling-dependent phosphorylation events on syntaxin-1a-T21/T23, synaptobrevin-S75, and cannabinoid receptor-1-S314/T322 on exo- and endocytosis in cultured hippocampal neurons.
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Affiliation(s)
- Ivan Silbern
- Institute of Clinical Chemistry, University Medical Center Goettingen, Goettingen, Germany; Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany
| | - Kuan-Ting Pan
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany
| | - Maksims Fiosins
- German Center for Neurodegenerative Diseases, Tübingen, Germany; Institute for Medical Systems Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefan Bonn
- German Center for Neurodegenerative Diseases, Tübingen, Germany; Institute for Medical Systems Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Silvio O Rizzoli
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Goettingen, Göttingen, Germany
| | - Eugenio F Fornasiero
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany.
| | - Henning Urlaub
- Institute of Clinical Chemistry, University Medical Center Goettingen, Goettingen, Germany; Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany.
| | - Reinhard Jahn
- Laboratory of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
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22
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Chen X, Xiao JW, Cao P, Zhang Y, Cai WJ, Song JY, Gao WM, Li B. Brain-derived neurotrophic factor protects against acrylamide-induced neuronal and synaptic injury via the TrkB-MAPK-Erk1/2 pathway. Neural Regen Res 2021; 16:150-157. [PMID: 32788470 PMCID: PMC7818888 DOI: 10.4103/1673-5374.286976] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Acrylamide has been shown to be neurotoxic. Brain-derived neurotrophic factor (BDNF) can alleviate acrylamide-induced synaptic injury; however, the underlying mechanism remains unclear. In this study, dibutyryl-cyclic adenosine monophosphate-induced mature human neuroblastoma (NB-1) cells were exposed with 0–100 μg/mL acrylamide for 24–72 hours. Acrylamide decreased cell viability and destroyed synapses. Exposure of co-cultured NB-1 cells and Schwann cells to 0–100 μg/mL acrylamide for 48 hours resulted in upregulated expression of synapsin I and BDNF, suggesting that Schwann cells can activate self-protection of neurons. Under co-culture conditions, activation of the downstream TrkB-MAPK-Erk1/2 pathway strengthened the protective effect. Exogenous BDNF can increase expression of TrkB, Erk1/2, and synapsin I, while exogenous BDNF or the TrkB inhibitor K252a could inhibit these changes. Taken together, Schwann cells may act through the BDNF-TrkB-MAPK-Erk1/2 signaling pathway, indicating that BDNF plays an important role in this process. Therefore, exogenous BDNF may be an effective treatment strategy for acrylamide-induced nerve injury. This study was approved by the Laboratory Animal Welfare and Ethics Committee of the National Institute of Occupational Health and Poison Control, a division of the Chinese Center for Disease Control and Prevention (approval No. EAWE-2017-008) on May 29, 2017.
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Affiliation(s)
- Xiao Chen
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jing-Wei Xiao
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Peng Cao
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yi Zhang
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Wen-Jian Cai
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jia-Yang Song
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Wei-Min Gao
- Department of Occupational and Environmental Health Sciences, School of Public Health, West Virginia University, Morgantown, WV, USA
| | - Bin Li
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
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23
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Losurdo M, Grilli M. Extracellular Vesicles, Influential Players of Intercellular Communication within Adult Neurogenic Niches. Int J Mol Sci 2020; 21:E8819. [PMID: 33233420 PMCID: PMC7700666 DOI: 10.3390/ijms21228819] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 12/14/2022] Open
Abstract
Adult neurogenesis, involving the generation of functional neurons from adult neural stem cells (NSCs), occurs constitutively in discrete brain regions such as hippocampus, sub-ventricular zone (SVZ) and hypothalamus. The intrinsic structural plasticity of the neurogenic process allows the adult brain to face the continuously changing external and internal environment and requires coordinated interplay between all cell types within the specialized microenvironment of the neurogenic niche. NSC-, neuronal- and glia-derived factors, originating locally, regulate the balance between quiescence and self-renewal of NSC, their differentiation programs and the survival and integration of newborn cells. Extracellular Vesicles (EVs) are emerging as important mediators of cell-to-cell communication, representing an efficient way to transfer the biologically active cargos (nucleic acids, proteins, lipids) by which they modulate the function of the recipient cells. Current knowledge of the physiological role of EVs within adult neurogenic niches is rather limited. In this review, we will summarize and discuss EV-based cross-talk within adult neurogenic niches and postulate how EVs might play a critical role in the regulation of the neurogenic process.
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Affiliation(s)
| | - Mariagrazia Grilli
- Laboratory of Neuroplasticity, Department of Pharmaceutical Sciences, University of Piemonte Orientale, 28100 Novara, Italy;
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24
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Silymarin Inhibits Glutamate Release and Prevents against Kainic Acid-Induced Excitotoxic Injury in Rats. Biomedicines 2020; 8:biomedicines8110486. [PMID: 33182349 PMCID: PMC7695262 DOI: 10.3390/biomedicines8110486] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/06/2020] [Accepted: 11/06/2020] [Indexed: 12/14/2022] Open
Abstract
Silymarin, a polyphenoic flavonoid derived from the seeds of milk thistle (Silybum marianum), exhibits neuroprotective effects. In this study, we used a model of rat cerebrocortical synaptosomes to investigate whether silymarin affects the release of glutamate, an essential neurotransmitter involved in excitotoxicity. Its possible neuroprotective effect on a rat model of kainic acid (KA)-induced excitotoxicity was also investigated. In rat cortical synaptosomes, silymarin reduced glutamate release and calcium elevation evoked by the K+ channel blocker 4-aminopyridine but did not affect glutamate release caused by the Na+ channel activator veratridine or the synaptosomal membrane potential. Decreased glutamate release by silymarin was prevented by removal of extracellular calcium and blocking of N- and P/Q-type Ca2+ channel or extracellular signal-regulated kinase 1/2 (ERK1/2) but not by blocking of intracellular Ca2+ release. Immunoblotting assay results revealed that silymarin reduced 4-aminopyridine-induced phosphorylation of ERK1/2. Moreover, systemic treatment of rats with silymarin (50 or 100 mg/kg) 30 min before systemic KA (15 mg/kg) administration attenuated KA-induced seizures, glutamate concentration elevation, neuronal damage, glial activation, and heat shock protein 70 expression as well as upregulated KA-induced decrease in Akt phosphorylation in the rat hippocampus. Taken together, the present study demonstrated that silymarin depressed synaptosomal glutamate release by suppressing voltage-dependent Ca2+ entry and ERK1/2 activity and effectively prevented KA-induced in vivo excitotoxicity.
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25
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Chen D, Zhang Y, Wang C, Wang X, Shi J, Zhang J, Guan W, Li B, Fan W. Modulation of hippocampal dopamine and synapse-related proteins by electroacupuncture improves memory deficit caused by sleep deprivation. Acupunct Med 2020; 38:343-351. [PMID: 32370535 DOI: 10.1177/0964528420902147] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Sleep is crucial for proper functioning of the brain, whereas lack of sleep is very common in modern society and can cause memory impairment. Hence, it is of great significance to find effective methods to intervene in the pathogenesis of memory impairment. OBJECTIVE We designed this study to explore the mechanism underlying the therapeutic effects of electroacupuncture (EA) on the deficits caused by sleep deprivation (SD). METHODS In this study, we first utilized the modified multiple platform method (MMPM) to establish a rat model of SD, which was followed by use of the Y-maze and Morris water maze (MWM) to assess the performance of rats following EA treatment. RESULTS We found that EA at GV20 and ST36 significantly decreased the number of error reactions, increased the number of active avoidance responses in the Y-maze and shortened the latency of finding the platform in the MWM test in SD + EA versus untreated SD groups. Moreover, EA treatment partially restored SD-induced reductions in hippocampal dopamine (DA) content and significantly increased the levels of phosphorylated (p) synapsin I, calcium/calmodulin-dependent protein kinase (CaMK) II, and tyrosine hydroxylase, which are related to the synthesis and release of DA. CONCLUSIONS In summary, we it appears that EA at GV20 and ST36 may improve SD-induced memory deficits by restoring the quantity of DA in the hippocampus, which is related to activation of CaMK II, synapsin I, and tyrosine hydroxylase. EA may have potential as an alternative therapy for SD and could improve learning and memory deficits among those suffering from sleep deficiency, although this needs verification by prospective clinical studies.
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Affiliation(s)
- Danmei Chen
- Research Center for Clinical Medicine, Jinshan Hospital, Fudan University, Shanghai, China
| | - Yunpeng Zhang
- Research Center for Clinical Medicine, Jinshan Hospital, Fudan University, Shanghai, China
| | - Cuiting Wang
- Research Center for Clinical Medicine, Jinshan Hospital, Fudan University, Shanghai, China
| | - Xiaokun Wang
- Research Center for Clinical Medicine, Jinshan Hospital, Fudan University, Shanghai, China
| | - Jimin Shi
- Research Center for Clinical Medicine, Jinshan Hospital, Fudan University, Shanghai, China
| | - Jihong Zhang
- Research Center for Clinical Medicine, Jinshan Hospital, Fudan University, Shanghai, China
| | - Wencai Guan
- Research Center for Clinical Medicine, Jinshan Hospital, Fudan University, Shanghai, China
| | - Bing Li
- Research Center for Clinical Medicine, Jinshan Hospital, Fudan University, Shanghai, China
| | - Wei Fan
- Research Center for Clinical Medicine, Jinshan Hospital, Fudan University, Shanghai, China
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26
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Poston RG, Murphy L, Rejepova A, Ghaninejad-Esfahani M, Segales J, Mulligan K, Saha RN. Certain ortho-hydroxylated brominated ethers are promiscuous kinase inhibitors that impair neuronal signaling and neurodevelopmental processes. J Biol Chem 2020; 295:6120-6137. [PMID: 32229587 PMCID: PMC7196656 DOI: 10.1074/jbc.ra119.011138] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 03/23/2020] [Indexed: 12/20/2022] Open
Abstract
The developing nervous system is remarkably sensitive to environmental signals, including disruptive toxins, such as polybrominated diphenyl ethers (PBDEs). PBDEs are an environmentally pervasive class of brominated flame retardants whose neurodevelopmental toxicity mechanisms remain largely unclear. Using dissociated cortical neurons from embryonic Rattus norvegicus, we found here that chronic exposure to 6-OH-BDE-47, one of the most prevalent hydroxylated PBDE metabolites, suppresses both spontaneous and evoked neuronal electrical activity. On the basis of our previous work on mitogen-activated protein kinase (MAPK)/extracellular signal-related kinase (ERK) (MEK) biology and our observation that 6-OH-BDE-47 is structurally similar to kinase inhibitors, we hypothesized that certain hydroxylated PBDEs mediate neurotoxicity, at least in part, by impairing the MEK-ERK axis of MAPK signal transduction. We tested this hypothesis on three experimental platforms: 1) in silico, where modeling ligand-protein docking suggested that 6-OH-BDE-47 is a promiscuous ATP-competitive kinase inhibitor; 2) in vitro in dissociated neurons, where 6-OH-BDE-47 and another specific hydroxylated BDE metabolite similarly impaired phosphorylation of MEK/ERK1/2 and activity-induced transcription of a neuronal immediate early gene; and 3) in vivo in Drosophila melanogaster, where developmental exposures to 6-OH-BDE-47 and a MAPK inhibitor resulted in offspring displaying similarly increased frequency of mushroom-body β-lobe midline crossing, a metric of axonal guidance. Taken together, our results support that certain ortho-hydroxylated PBDE metabolites are promiscuous kinase inhibitors and can cause disruptions of critical neurodevelopmental processes, including neuronal electrical activity, pre-synaptic functions, MEK-ERK signaling, and axonal guidance.
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Affiliation(s)
- Robert G Poston
- Molecular and Cell Biology Department, School of Natural Sciences, University of California, Merced, Merced, California 95343
| | - Lillian Murphy
- Department of Biological Sciences, Center for Interdisciplinary Molecular Biology: Education, Research and Advancement (CIMERA), California State University, Sacramento, California 95819
| | - Ayna Rejepova
- Molecular and Cell Biology Department, School of Natural Sciences, University of California, Merced, Merced, California 95343
| | - Mina Ghaninejad-Esfahani
- Molecular and Cell Biology Department, School of Natural Sciences, University of California, Merced, Merced, California 95343
| | - Joshua Segales
- Molecular and Cell Biology Department, School of Natural Sciences, University of California, Merced, Merced, California 95343
| | - Kimberly Mulligan
- Department of Biological Sciences, Center for Interdisciplinary Molecular Biology: Education, Research and Advancement (CIMERA), California State University, Sacramento, California 95819
| | - Ramendra N Saha
- Molecular and Cell Biology Department, School of Natural Sciences, University of California, Merced, Merced, California 95343.
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27
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Chen QY, Zhang ZL, Liu Q, Chen CJ, Zhang XK, Xu PY, Zhuo M. Presynaptic long-term potentiation requires extracellular signal-regulated kinases in the anterior cingulate cortex. Mol Pain 2020; 16:1744806920917245. [PMID: 32264746 PMCID: PMC7144679 DOI: 10.1177/1744806920917245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Extracellular signal-regulated kinases are widely expressed protein kinases in neurons, which serve as important intracellular signaling molecules for central plasticity such as long-term potentiation. Recent studies demonstrate that there are two major forms of long-term potentiation in cortical areas related to pain: postsynaptic long-term potentiation and presynaptic long-term potentiation. In particular, presynaptic long-term potentiation in the anterior cingulate cortex has been shown to contribute to chronic pain-related anxiety. In this review, we briefly summarized the components and roles of extracellular signal-regulated kinases in neuronal signaling, especially in the presynaptic long-term potentiation of anterior cingulate cortex, and discuss the possible molecular mechanisms and functional implications in pain-related emotional disorders.
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Affiliation(s)
- Qi-Yu Chen
- Center for Neuron and Disease, Frontier Institutes of Science and Technology, Xi'an Jiaotong University, Xi'an, China.,Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Zhi-Ling Zhang
- Department of Neurology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Qin Liu
- Department of Neurology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Chao-Jun Chen
- Department of Neurology, Guangzhou Chinese Medical Integrated Hospital (Huadu), Guangdong, China
| | - Xiao-Kang Zhang
- The First Affiliated Hospital of Gan-Nan Medical University, Ganzhopu, China
| | - Ping-Yi Xu
- Department of Neurology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Min Zhuo
- Center for Neuron and Disease, Frontier Institutes of Science and Technology, Xi'an Jiaotong University, Xi'an, China.,Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Department of Neurology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
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28
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Zanese M, Tomaselli G, Roullot-Lacarrière V, Moreau M, Bellocchio L, Grel A, Marsicano G, Sans N, Vallée M, Revest JM. Alpha technology: A powerful tool to detect mouse brain intracellular signaling events. J Neurosci Methods 2020; 332:108543. [PMID: 31830543 DOI: 10.1016/j.jneumeth.2019.108543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 11/15/2019] [Accepted: 12/05/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND Phosphorylation by protein kinases is a fundamental molecular process involved in the regulation of signaling activities in living organisms. Understanding this complex network of phosphorylation, especially phosphoproteins, is a necessary step for grasping the basis of cellular pathophysiology. Studying brain intracellular signaling is a particularly complex task due to the heterogeneous complex nature of the brain tissue, which consists of many embedded structures. NEW METHOD Overcoming this degree of complexity requires a technology with a high throughput and economical in the amount of biological material used, so that a large number of signaling pathways may be analyzed in a large number of samples. We have turned to Alpha (Amplified Luminescent Proximity Homogeneous Assay) technology. COMPARISON WITH EXISTING METHOD Western blot is certainly the most commonly used method to measure the phosphorylation state of proteins. Even though Western blot is an accurate and reliable method for analyzing modifications of proteins, it is a time-consuming and large amounts of samples are required. Those two parameters are critical when the goal of the research is to comprehend multi-signaling proteic events so as to analyze several targets from small brain areas. RESULT Here we demonstrate that Alpha technology is particularly suitable for studying brain signaling pathways by allowing rapid, sensitive, reproducible and semi-quantitative detection of phosphoproteins from individual mouse brain tissue homogenates and from cell fractionation and synaptosomal preparations of mouse hippocampus. CONCLUSION Alpha technology represents a major experimental step forward in unraveling the brain phosphoprotein-related molecular mechanisms involved in brain-related disorders.
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Affiliation(s)
- Marion Zanese
- INSERM U1215, NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Giovanni Tomaselli
- INSERM U1215, NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Valérie Roullot-Lacarrière
- INSERM U1215, NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Maïté Moreau
- INSERM U1215, NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Luigi Bellocchio
- INSERM U1215, NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Agnès Grel
- INSERM U1215, NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Giovanni Marsicano
- INSERM U1215, NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Nathalie Sans
- INSERM U1215, NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Monique Vallée
- INSERM U1215, NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France
| | - Jean-Michel Revest
- INSERM U1215, NeuroCentre Magendie, 33077 Bordeaux, France; University of Bordeaux, 33077 Bordeaux, France.
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Maiole F, Tedeschi G, Candiani S, Maragliano L, Benfenati F, Zullo L. Synapsins are expressed at neuronal and non-neuronal locations in Octopus vulgaris. Sci Rep 2019; 9:15430. [PMID: 31659209 PMCID: PMC6817820 DOI: 10.1038/s41598-019-51899-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 10/10/2019] [Indexed: 12/19/2022] Open
Abstract
Synapsins are a family of phosphoproteins fundamental to the regulation of neurotransmitter release. They are typically neuron-specific, although recent evidence pointed to their expression in non-neuronal cells where they play a role in exocytosis and vesicle trafficking. In this work, we characterized synapsin transcripts in the invertebrate mollusk Octopus vulgaris and present evidence of their expression not only in the brain but also in male and female reproductive organs. We identified three synapsin isoforms phylogenetically correlated to that of other invertebrates and with a modular structure characteristic of mammalian synapsins with a central, highly conserved C domain, important for the protein functions, and less conserved A, B and E domains. Our molecular modeling analysis further provided a solid background for predicting synapsin functional binding to ATP, actin filaments and secretory vesicles. Interestingly, we found that synapsin expression in ovary and testis increased during sexual maturation in cells with a known secretory role, potentially matching the occurrence of a secretion process. This might indicate that its secretory role has evolved across animals according to cell activity in spite of cell identity. We believe that this study may yield insights into the convergent evolution of ubiquitously expressed proteins between vertebrates and invertebrates.
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Affiliation(s)
- Federica Maiole
- Center for Micro-BioRobotics & Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genova, Italy.,Department of Experimental Medicine, University of Genova, viale Benedetto XV, 3, 16132, Genova, Italy
| | - Giulia Tedeschi
- Department of Experimental Medicine, University of Genova, viale Benedetto XV, 3, 16132, Genova, Italy.,Department of Biomedical Engineering, Laboratory for Fluorescence Dynamics, University of California, Irvine, 92697, CA, USA
| | - Simona Candiani
- Laboratory of Developmental Neurobiology, Department of Earth, Environment and Life Sciences, University of Genoa, Viale Benedetto XV 5, 16132, Genoa, Italy.
| | - Luca Maragliano
- Center for Micro-BioRobotics & Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genova, Italy.,IRCSS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genova, Italy
| | - Fabio Benfenati
- Center for Micro-BioRobotics & Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genova, Italy.,IRCSS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genova, Italy
| | - Letizia Zullo
- Center for Micro-BioRobotics & Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genova, Italy. .,IRCSS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genova, Italy.
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30
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Regulation of Acetylcholine Quantal Release by Coupled Thrombin/BDNF Signaling in Mouse Motor Synapses. Cells 2019; 8:cells8070762. [PMID: 31336670 PMCID: PMC6678150 DOI: 10.3390/cells8070762] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 07/13/2019] [Accepted: 07/22/2019] [Indexed: 12/23/2022] Open
Abstract
The aim of this study was to compare the acute effects of thrombin and brain-derived neurotrophic factor (BDNF) on spontaneous miniature endplate potentials (MEPPs) and multiquantal evoked endplate potentials (EPPs) in mouse neuromuscular junctions (NMJs) of m. diaphragma and m. EDL. Intracellular microelectrode recordings of MEPPs and EPPs were used to evaluate the changes in acetylcholine (ACh) release in mature and newly-formed mouse NMJs. Thrombin (1 nM) increased the amplitude of MEPPs and EPPs by 25–30% in mature and newly-formed NMJs. This effect was due to an enhanced loading of synaptic vesicles with ACh and increase of ACh quantal size, since it was fully prevented by blocking of vesicular ACh transporter. It was also prevented by tropomyosin-related kinase B (TrkB) receptors inhibitor ANA12. Exogenous BDNF (1 nM) mimicked thrombin effect and increased the amplitude of MEPPs and EPPs by 25–30%. It required involvement of protein kinase A (PKA) and mitogen-activated protein kinase (MEK1/2)-mediated pathway, but not phospholipase C (PLC). Blocking A2A adenosine receptors by ZM241385 abolished the effect of BDNF, whereas additional stimulation of A2A receptors by CGS21680 increased MEPP amplitudes, which was prevented by MEK1/2 inhibitor U0126. At mature NMJs, BDNF enhanced MEPPs frequency by 30–40%. This effect was selectively prevented by inhibition of PLC, but not PKA or MEK1/2. It is suggested that interrelated effects of thrombin/BDNF in mature and newly-formed NMJs are realized via enhancement of vesicular ACh transport and quantal size increase. BDNF-induced potentiation of synaptic transmission involves the functional coupling between A2A receptor-dependent active PKA and neurotrophin-triggered MAPK pathway, as well as PLC-dependent increase in frequency of MEPPs.
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31
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Marte A, Russo I, Rebosio C, Valente P, Belluzzi E, Pischedda F, Montani C, Lavarello C, Petretto A, Fedele E, Baldelli P, Benfenati F, Piccoli G, Greggio E, Onofri F. Leucine‐rich repeat kinase 2 phosphorylation on synapsin I regulates glutamate release at pre‐synaptic sites. J Neurochem 2019; 150:264-281. [PMID: 31148170 DOI: 10.1111/jnc.14778] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 05/20/2019] [Accepted: 05/28/2019] [Indexed: 12/25/2022]
Abstract
Leucine-rich repeat kinase 2 (LRRK2) is a large multidomain scaffolding protein with kinase and GTPase activities involved in synaptic vesicle (SV) dynamics. While its role in Parkinson's disease has been largely investigated, little is known about LRRK2 physiological role and until now few proteins have been described as substrates. We have previously demonstrated that LRRK2 through its WD40 domain interacts with synapsin I, an important SV-associated phosphoprotein involved in neuronal development and in the regulation of neurotransmitter release. To test whether synapsin I is substrate for LRRK2 and characterize the properties of its phosphorylation, we used in vitro kinase and binding assays as well as cellular model and site-direct mutagenesis. Using synaptosomes in superfusion, patch-clamp recordings in autaptic WT and synapsin I KO cortical neurons and SypHy assay on primary cortical culture from wild-type and BAC human LRRK2 G2019S mice we characterized the role of LRRK2 kinase activity on glutamate release and SV trafficking. Here we reported that synapsin I is phosphorylated by LRRK2 and demonstrated that the interaction between LRRK2 WD40 domain and synapsin I is crucial for this phosphorylation. Moreover, we showed that LRRK2 phosphorylation of synapsin I at threonine 337 and 339 significantly reduces synapsin I-SV/actin interactions. Using complementary experimental approaches, we demonstrated that LRRK2 controls glutamate release and SV dynamics in a kinase activity and synapsin I-dependent manner. Our findings show that synapsin I is a LRRK2 substrate and describe a novel mechanisms of regulation of glutamate release by LRRK2 kinase activity.
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Affiliation(s)
- Antonella Marte
- Department of Experimental Medicine University of Genova Genova Italy
| | | | | | - Pierluigi Valente
- Department of Experimental Medicine University of Genova Genova Italy
- IRCCS Ospedale Policlinico San Martino Genova Italy
| | - Elisa Belluzzi
- Rheumatology Unit, Department of Medicine‐DIMED University Hospital of Padova Padova Italy
| | - Francesca Pischedda
- Center for Integrative Biology (CIBIO) University of Trento Trento Italy
- Dulbecco Telethon Institute Trento Italy
| | - Caterina Montani
- Center for Integrative Biology (CIBIO) University of Trento Trento Italy
- Dulbecco Telethon Institute Trento Italy
| | - Chiara Lavarello
- Laboratory of Mass Spectrometry ‐ Core Facilities Istituto Giannina Gaslini Genova Italy
| | - Andrea Petretto
- Laboratory of Mass Spectrometry ‐ Core Facilities Istituto Giannina Gaslini Genova Italy
| | - Ernesto Fedele
- Department of Pharmacy University of Genova Genova Italy
- IRCCS Ospedale Policlinico San Martino Genova Italy
| | - Pietro Baldelli
- Department of Experimental Medicine University of Genova Genova Italy
- IRCCS Ospedale Policlinico San Martino Genova Italy
| | - Fabio Benfenati
- IRCCS Ospedale Policlinico San Martino Genova Italy
- Center for Synaptic Neuroscience and Technology Istituto Italiano di Tecnologia Genova Italy
| | - Giovanni Piccoli
- Center for Integrative Biology (CIBIO) University of Trento Trento Italy
- Dulbecco Telethon Institute Trento Italy
| | - Elisa Greggio
- Department of Biology University of Padova Padova Italy
| | - Franco Onofri
- Department of Experimental Medicine University of Genova Genova Italy
- IRCCS Ospedale Policlinico San Martino Genova Italy
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SIV-Mediated Synaptic Dysfunction Is Associated with an Increase in Synapsin Site 1 Phosphorylation and Impaired PP2A Activity. J Neurosci 2019; 39:7006-7018. [PMID: 31270156 DOI: 10.1523/jneurosci.0178-19.2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 05/31/2019] [Accepted: 06/22/2019] [Indexed: 11/21/2022] Open
Abstract
Although the reduction of viral loads in people with HIV undergoing combination antiretroviral therapy has mitigated AIDS-related symptoms, the prevalence of neurological impairments has remained unchanged. HIV-associated CNS dysfunction includes impairments in memory, attention, memory processing, and retrieval. Here, we show a significant site-specific increase in the phosphorylation of Syn I serine 9, site 1, in the frontal cortex lysates and synaptosome preparations of male rhesus macaques infected with simian immunodeficiency virus (SIV) but not in uninfected or SIV-infected antiretroviral therapy animals. Furthermore, we found that a lower protein phosphatase 2A (PP2A) activity, a phosphatase responsible for Syn I (S9) dephosphorylation, is primarily associated with the higher S9 phosphorylation in the frontal cortex of SIV-infected macaques. Comparison of brain sections confirmed higher Syn I (S9) in the frontal cortex and greater coexpression of Syn I and PP2A A subunit, which was observed as perinuclear aggregates in the somata of the frontal cortex of SIV-infected macaques. Synaptosomes from SIV-infected animals were physiologically tested using a synaptic vesicle endocytosis assay and FM4-64 dye showing a significantly higher baseline depolarization levels in synaptosomes of SIV+-infected than uninfected control or antiretroviral therapy animals. A PP2A-activating FDA-approved drug, FTY720, decreased the higher synaptosome depolarization in SIV-infected animals. Our results suggest that an impaired distribution and lower activity of serine/threonine phosphatases in the context of HIV infection may cause an indirect effect on the phosphorylation levels of essential proteins involving in synaptic transmission, supporting the occurrence of specific impairments in the synaptic activity during SIV infection.SIGNIFICANCE STATEMENT Even with antiretroviral therapy, neurocognitive deficits, including impairments in attention, memory processing, and retrieval, are still major concerns in people living with HIV. Here, we used the rhesus macaque simian immunodeficiency virus model with and without antiretroviral therapy to study the dynamics of phosphorylation of key amino acid residues of synapsin I, which critically impacts synaptic vesicle function. We found a significant increase in synapsin I phosphorylation at serine 9, which was driven by dysfunction of serine/threonine protein phosphatase 2A in the nerve terminals. Our results suggest that an impaired distribution and lower activity of serine/threonine phosphatases in the context of HIV infection may cause an indirect effect on the phosphorylation levels of essential proteins involved in synaptic transmission.
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Fu T, Wang J, Ding Y, Zhang Y, Han S, Li J. Modulation of cPKCγ on Synapsin-Ia/b-Specific Phosphorylation Sites in the Developing Visual Cortex of Mice. Invest Ophthalmol Vis Sci 2019; 60:2676-2684. [PMID: 31242289 DOI: 10.1167/iovs.19-26675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To explore the role of synapsin-Ia/b in visual cortical plasticity, the dynamic changes in total protein expression (T-) and conventional protein kinase C (cPKC)γ-modulated phosphorylation (P-) levels of synapsin-Ia/b were observed in the developing visual cortex of mice. Methods The Western blot analysis was used to determine the levels of T- and P-synapsin-Ia/b at site of Ser9, 549, and 603; the cPKCγ gene wild-type (cPKCγ+/+) and knockout (cPKCγ-/-) mice were applied to explore the modulation of cPKCγ on synapsin-Ia/b phosphorylation status in visual cortex of mice at postnatal 7 to 60 days (P7-P60, n = 6 per group). Results The results showed that T-synapsin-Ia/b protein levels significantly increased at P14 to P35 and peaked at P42 to 60 (P < 0.001) in visual cortex when compared with that of P7 cPKCγ+/+ mice, and cPKCγ-/- did not affect this pattern of T-synapsin-Ia/b protein expressions. For synapsin-Ia/b phosphorylation status, the levels of P-Ser9 and 603 synapsin-Ia/b significantly elevated at P21 to P28 (P < 0.05 or 0.001), and then went down and maintained at lower levels at P35 to P60 (P < 0.05 or 0.001) compared with P7 cPKCγ+/+ mice. In addition, the cPKCγ gene knockout could significantly (P < 0.001) inhibit both the increase and decrease of P-Ser9 and 603 synapsin-Ia/b levels when compared with cPKCγ+/+ mice at P7 to P60. However, there were no significant changes of P-Ser549 synapsin-Ia/b in the developing visual cortex of both cPKCγ+/+ and cPKCγ-/- mice at P7 to P60. Conclusions These results suggested that both protein expression levels and cPKCγ-modulated phosphorylation status at Ser9 and 603 of synapsin-Ia/b may play important role in developing visual cortex of mice.
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Affiliation(s)
- Tao Fu
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Science Key Laboratory, Beijing, China
| | - Jing Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Science Key Laboratory, Beijing, China
| | - Yichao Ding
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Science Key Laboratory, Beijing, China
| | - Yunxia Zhang
- Department of Neurobiology and Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Song Han
- Department of Neurobiology and Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Junfa Li
- Department of Neurobiology and Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
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Horton KKA, Goonawardena AV, Sesay J, Howlett AC, Hampson RE. Systemic Blockade of the CB 1 Receptor Augments Hippocampal Gene Expression Involved in Synaptic Plasticity but Perturbs Hippocampus-Dependent Learning Task. Cannabis Cannabinoid Res 2019; 4:33-41. [PMID: 31032421 DOI: 10.1089/can.2018.0061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Chronic and acute agonism as well as acute antagonism of CB1 receptors reveal modulation of learning and memory during stable performance of a delayed-nonmatch-to-sample (DNMS) memory task. However, it remains unclear how chronic blockade of the CB1 receptor alters acquisition of the behavioral task. We examined the effects of chronic rimonabant exposure during DNMS task acquisition to determine if blockade of the CB1 receptor with the antagonist rimonabant enhanced acquisition of operant task. Long-Evans rats, trained in the DNMS task before imposition of the trial delay, were surgically implanted with osmotic mini pumps to administer rimonabant (1.0 mg/kg/day) or vehicle (dimethyl sulfoxide/Tween-80/Saline). Following surgical recovery, DNMS training was resumed with the imposition of gradually longer delays (1-30 sec). The number of days required to achieve stable performance with either increasing length of delay or reversal of task contingency was compared between vehicle and rimonabant-treated rats. Following the completion of DNMS training, animals were euthanized, and both hippocampi were harvested for gene expression assay analysis. Rimonabant treatment animals required more time to achieve stable DNMS performance than vehicle-treated controls. Quantitative real-time polymerase chain reaction analysis revealed that the expressions of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunit, brain-derived neurotrophic factor, and synapsin 1 (Syn1) were significantly increased. These results are consistent with rimonabant increasing mRNAs for proteins associated with hippocampal synapse remodeling, but that those alterations did not necessarily accelerate the acquisition of an operant behavioral task that required learning new contingencies.
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Affiliation(s)
- Kofi-Kermit A Horton
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina.,Division of Pulmonary, Critical Care and Sleep Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Anushka V Goonawardena
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina.,Biosciences Division, SRI International, Menlo Park, California
| | - John Sesay
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina
| | - Allyn C Howlett
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina
| | - Robert E Hampson
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina
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Howe A, Kiffer F, Alexander TC, Sridharan V, Wang J, Ntagwabira F, Rodriguez A, Boerma M, Allen AR. Long-Term Changes in Cognition and Physiology after Low-Dose 16O Irradiation. Int J Mol Sci 2019; 20:ijms20010188. [PMID: 30621014 PMCID: PMC6337104 DOI: 10.3390/ijms20010188] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 12/30/2018] [Accepted: 01/03/2019] [Indexed: 12/17/2022] Open
Abstract
Astronauts traveling to Mars will be exposed to high levels of ionizing radiation upon leaving low-Earth orbit. During prolonged space travel, astronauts are exposed to galactic cosmic rays (GCRs) composed of protons; oxygen molecules; and high energy, high mass charged particles. Notably, oxygen molecules can travel through the shielding of spacecraft, potentially impacting 25% of the hippocampus. The aim of the current study was to assess whether 16O-particle radiation induced a behavioral deficit and histological changes in mice. Mice were sent to the National Aeronautics and Space Administration (NASA) Space Radiation Laboratory at Brookhaven National Laboratory and exposed to particulate 16O radiation at doses of 0 and 0.05 Gy. Nine months after irradiation, the mice were tested for novel object recognition and in the Y-maze, after which the animals were sacrificed. The brains were then dissected along the midsagittal plane for Golgi staining. Exposure to 0.05 Gy significantly impaired novel object recognition. However, short term memory and exploratory activity in the Y-maze were not affected. Micromorphometric analysis revealed significant decreases in mushroom spine density in the dentate gyrus and cornu Ammonis-1 and -3 of the hippocampus. Sholl analysis revealed a significant decrease in dendritic complexity in the dentate gyrus. The present data provide evidence that space radiation has deleterious effects on mature neurons associated with hippocampal learning and memory.
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Affiliation(s)
- Alexis Howe
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Frederico Kiffer
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Tyler C Alexander
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Vijayalakshmi Sridharan
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Jing Wang
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Fabio Ntagwabira
- Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Analiz Rodriguez
- Department of Neurosurgery, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Marjan Boerma
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Antiño R Allen
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
- Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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Barfield ET, Gourley SL. Prefrontal cortical trkB, glucocorticoids, and their interactions in stress and developmental contexts. Neurosci Biobehav Rev 2018; 95:535-558. [PMID: 30477984 PMCID: PMC6392187 DOI: 10.1016/j.neubiorev.2018.10.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 09/14/2018] [Accepted: 10/23/2018] [Indexed: 02/07/2023]
Abstract
The tropomyosin/tyrosine receptor kinase B (trkB) and glucocorticoid receptor (GR) regulate neuron structure and function and the hormonal stress response. Meanwhile, disruption of trkB and GR activity (e.g., by chronic stress) can perturb neuronal morphology in cortico-limbic regions implicated in stressor-related illnesses like depression. Further, several of the short- and long-term neurobehavioral consequences of stress depend on the developmental timing and context of stressor exposure. We review how the levels and activities of trkB and GR in the prefrontal cortex (PFC) change during development, interact, are modulated by stress, and are implicated in depression. We review evidence that trkB- and GR-mediated signaling events impact the density and morphology of dendritic spines, the primary sites of excitatory synapses in the brain, highlighting effects in adolescents when possible. Finally, we review the role of neurotrophin and glucocorticoid systems in stress-related metaplasticity. We argue that better understanding the long-term effects of developmental stressors on PFC trkB, GR, and related factors may yield insights into risk for chronic, remitting depression and related neuropsychiatric illnesses.
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Affiliation(s)
- Elizabeth T Barfield
- Department of Pediatrics, Emory University, 954 Gatewood Rd. NE, Atlanta, GA, 30329, USA; Graduate Program in Neuroscience, Emory University, 954 Gatewood Rd. NE, Atlanta, GA, 30329, USA; Yerkes National Primate Research Center, Emory University, 954 Gatewood Rd. NE, Atlanta, GA, 30329, USA; Department of Psychiatry and Behavioral Sciences, Emory University, 954 Gatewood Rd. NE, Atlanta, GA, 30329, USA.
| | - Shannon L Gourley
- Department of Pediatrics, Emory University, 954 Gatewood Rd. NE, Atlanta, GA, 30329, USA; Graduate Program in Neuroscience, Emory University, 954 Gatewood Rd. NE, Atlanta, GA, 30329, USA; Yerkes National Primate Research Center, Emory University, 954 Gatewood Rd. NE, Atlanta, GA, 30329, USA; Department of Psychiatry and Behavioral Sciences, Emory University, 954 Gatewood Rd. NE, Atlanta, GA, 30329, USA; Molecular and Systems Pharmacology Program, Emory University, 954 Gatewood Rd. NE, Atlanta, GA, 30329, USA.
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Jin DZ, Mao LM, Wang JQ. The Role of Extracellular Signal-Regulated Kinases (ERK) in the Regulation of mGlu5 Receptors in Neurons. J Mol Neurosci 2018; 66:629-638. [PMID: 30430306 PMCID: PMC6312115 DOI: 10.1007/s12031-018-1193-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 10/01/2018] [Indexed: 12/21/2022]
Abstract
The metabotropic glutamate (mGlu) receptor 5 is a G protein-coupled receptor and is densely expressed in the mammalian brain. Like other glutamate receptors, mGlu5 receptors are tightly regulated by posttranslational modifications such as phosphorylation, although underlying mechanisms are incompletely investigated. In this study, we investigated the role of a prime kinase, extracellular signal-regulated kinase 1 (ERK1), in the phosphorylation and regulation of mGlu5 receptors in vitro and in striatal neurons. We found that recombinant ERK1 proteins directly bound to the C-terminal tail (CT) of mGlu5 receptors in vitro. Endogenous ERK1 also interacted with mGlu5 receptor proteins in adult rat striatal neurons in vivo. The kinase showed the ability to phosphorylate mGlu5 receptors. A serine residue in the distal region of mGlu5 CT was found to be a primary phosphorylation site sensitive to ERK1. In functional studies, we found that pharmacological inhibition of ERK with an inhibitor U0126 reduced the efficacy of mGlu5 receptors in stimulating production of cytoplasmic inositol-1,4,5-triphosphate, a major downstream conventional signaling event, in striatal neurons under normal conditions. These results identify mGlu5 as a new biochemical substrate of ERK1. The kinase can interact with and phosphorylate an intracellular domain of mGlu5 receptors in striatal neurons and thereby control its signaling efficacy.
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Affiliation(s)
- Dao-Zhong Jin
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, 2411 Holmes Street, Kansas City, MO, 64108, USA.
| | - Li-Min Mao
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, 2411 Holmes Street, Kansas City, MO, 64108, USA
| | - John Q Wang
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, 2411 Holmes Street, Kansas City, MO, 64108, USA.
- Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, 2411 Holmes Street, Kansas City, MO, 64108, USA.
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Cheng Q, Song SH, Augustine GJ. Molecular Mechanisms of Short-Term Plasticity: Role of Synapsin Phosphorylation in Augmentation and Potentiation of Spontaneous Glutamate Release. Front Synaptic Neurosci 2018; 10:33. [PMID: 30425632 PMCID: PMC6218601 DOI: 10.3389/fnsyn.2018.00033] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/20/2018] [Indexed: 12/24/2022] Open
Abstract
We used genetic and pharmacological approaches to identify the signaling pathways involved in augmentation and potentiation, two forms of activity dependent, short-term synaptic plasticity that enhance neurotransmitter release. Trains of presynaptic action potentials produced a robust increase in the frequency of miniature excitatory postsynaptic currents (mEPSCs). Following the end of the stimulus, mEPSC frequency followed a bi-exponential decay back to basal levels. The time constants of decay identified these two exponential components as the decay of augmentation and potentiation, respectively. Augmentation increased mEPSC frequency by 9.3-fold, while potentiation increased mEPSC frequency by 2.4-fold. In synapsin triple-knockout (TKO) neurons, augmentation was reduced by 83% and potentiation was reduced by 74%, suggesting that synapsins are key signaling elements in both forms of plasticity. To examine the synapsin isoforms involved, we expressed individual synapsin isoforms in TKO neurons. While synapsin IIIa rescued both augmentation and potentiation, none of the other synapsin isoforms produced statistically significant amounts of rescue. To determine the involvement of protein kinases in these two forms of short-term plasticity, we examined the effects of inhibitors of protein kinases A (PKA) and C (PKC). While inhibition of PKC had little effect, PKA inhibition reduced augmentation by 76% and potentiation by 60%. Further, elevation of intracellular cAMP concentration, by either forskolin or IBMX, greatly increased mEPSC frequency and occluded the amount of augmentation and potentiation evoked by electrical stimulation. Finally, mutating a PKA phosphorylation site to non-phosphorylatable alanine largely abolished the ability of synapsin IIIa to rescue both augmentation and potentiation. Together, these results indicate that PKA activation is required for both augmentation and potentiation of spontaneous neurotransmitter release and that PKA-mediated phosphorylation of synapsin IIIa underlies both forms of presynaptic short-term plasticity.
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Affiliation(s)
- Qing Cheng
- Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States
| | - Sang-Ho Song
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - George J Augustine
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,Institute of Molecular and Cell Biology, Singapore, Singapore
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Chen X, Wang X, Yang Y, Li Z, Zhang Y, Gao W, Xiao J, Li B. Schwann cells protect against CaMKII- and PKA-dependent Acrylamide-induced Synapsin I phosphorylation. Brain Res 2018; 1701:18-27. [PMID: 30028969 DOI: 10.1016/j.brainres.2018.07.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 07/11/2018] [Accepted: 07/13/2018] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To explore the effects of Acrylamide (ACR), as well as the influence of Schwann cells (SCs), on the signal transduction pathway and phosphorylation of Synapsin I in a Human neuroblastoma cell line (NB-1). METHODS NB-1s, NB-1s co-cultured with SCs, and a negative control group (NB-1 cells without ACR) were exposed to gradient concentrations of ACR for 48 h. Cell proliferation and viability were determined by MTT. Protein and mRNA expression levels of typical kinases (i.e., cAMP-dependent protein kinase [PKA], calcium/calmodulin-dependent protein kinase II [CaMKII], and mitogen-activated protein kinase-extracellular signal-regulated kinases [MAPK-Erk]), their phosphorylation status, as well as Synapsin I and its phosphorylation status, were tested by western blotting and polymerase chain reaction, respectively. Further, the effect of SCs on ACR-induced NB-1 cell toxicity was evaluated. RESULTS (1) The MTT assay showed a sustained, dose- and time-dependent inhibition of NB-1s exposed to ACR. (2) ACR exposure increased the phosphorylation of CaMKII and PKA, which subsequently increased the phosphorylation of Synapsin I (at Serine603 [a substrate site of CaMKII] and Serine9 [a substrate site of PKA]). Pretreatment with CaMKII and PKA inhibitors blocked the ACR-mediated increase in phosphorylation. The above-described results were all significantly different when compared to the control group (p < 0.05). (3) When co-cultured with SCs, ACR-induced NB-1 inhibition was obviously decreased, and the trend of change of phosphorylated CaMKII, PKA, and Synapsin I were changed (first slightly increased and then decreased), which was inconsistent with what we observed in NB-1s cultured alone. CONCLUSIONS The toxic effects of ACR on neurons may be mediated by CaMKII and PKA-dependent signaling pathways in which Synapsin I may act as a downstream effector. Furthermore, glial cells (SCs) may be able to prevent a certain degree of ACR-induced neuronal damage.
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Affiliation(s)
- Xiao Chen
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing 100050, China
| | - Xiuhui Wang
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing 100050, China
| | - Yiguang Yang
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing 100050, China
| | - Zhongsheng Li
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing 100050, China
| | - Yi Zhang
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing 100050, China
| | - Weimin Gao
- Department of Occupational and Environmental Health Sciences, School of Public Health, West Virginia University, West Virginia, USA
| | - Jingwei Xiao
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
| | - Bin Li
- Department of Toxicology, Key Lab of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
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Joshi H, Sharma R, Prashar S, Ho J, Thomson S, Mishra R. Differential Expression of Synapsin I and II upon Treatment by Lithium and Valproic Acid in Various Brain Regions. Int J Neuropsychopharmacol 2018; 21:616-622. [PMID: 29618019 PMCID: PMC6007270 DOI: 10.1093/ijnp/pyy023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
INTRODUCTION Due to the heterogeneity of psychiatric illnesses and overlapping mechanisms, patients with psychosis are differentially responsive to pharmaceutical drugs. In addition to having therapeutic effects for schizophrenia and bipolar disorder, antipsychotics and mood stabilizers have many clinical applications and are used unconventionally due to their direct and indirect effects on neurotransmitters. Synapsins, a family of neuronal phosphoproteins, play a key regulatory role in neurotransmitter release at synapses. In this study, we investigated the effects of mood stabilizers, lithium, and valproic acid on synapsin gene expression in the rat brain. METHODS Intraperitoneal injections of saline, lithium, and valproic acid were administered to male Sprague Dawley rats twice daily for 14 d, corresponding to their treatment group. Following decapitation and brain tissue isolation, mRNA was extracted from various brain regions including the hippocampus, striatum, prefrontal cortex, and frontal cortex. RESULTS Biochemical analysis revealed that lithium significantly increased gene expression of synapsin I in the striatum, synapsin IIa in the hippocampus and prefrontal cortex, and synapsin IIb in the hippocampus and striatum. Valproic acid significantly increased synapsin IIa in the hippocampus and prefrontal cortex, as well as synapsin IIb in the hippocampus and striatum. CONCLUSION These significant changes in synapsin I and II expression may implicate a common transcription factor, early growth response 1, in its mechanistic pathway. Overall, these results elucidate mechanisms through which lithium and valproic acid act on downstream targets compared with antipsychotics and provide deeper insight on the involvement of synaptic proteins in treating neuropsychiatric illnesses.
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Affiliation(s)
- Hetshree Joshi
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Roohie Sharma
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Shreya Prashar
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Joella Ho
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Sharon Thomson
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Ram Mishra
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada,Correspondence: Ram K. Mishra, PhD, Department of Psychiatry and Behavioural Neurosciences, McMaster University, 1280 Main St W. Hamilton, ON L8S 4L8 Canada ()
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41
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Altered Intracellular Calcium Homeostasis Underlying Enhanced Glutamatergic Transmission in Striatal-Enriched Tyrosine Phosphatase (STEP) Knockout Mice. Mol Neurobiol 2018; 55:8084-8102. [PMID: 29508281 DOI: 10.1007/s12035-018-0980-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 02/22/2018] [Indexed: 10/17/2022]
Abstract
The striatal-enriched protein tyrosine phosphatase (STEP) is a brain-specific phosphatase involved in synaptic transmission. The current hypothesis on STEP function holds that it opposes synaptic strengthening by dephosphorylating and inactivating key neuronal proteins involved in synaptic plasticity and intracellular signaling, such as the MAP kinases ERK1/2 and p38, as well as the tyrosine kinase Fyn. Although STEP has a predominant role at the post-synaptic level, it is also expressed in nerve terminals. To better investigate its physiological role at the presynaptic level, we functionally investigated brain synaptosomes and autaptic hippocampal neurons from STEP knockout (KO) mice. Synaptosomes purified from mutant mice were characterized by an increased basal and evoked glutamate release compared with wild-type animals. Under resting conditions, STEP KO synaptosomes displayed increased cytosolic Ca2+ levels accompanied by an enhanced basal activity of Ca2+/calmodulin-dependent protein kinase type II (CaMKII) and hyperphosphorylation of synapsin I at CaMKII sites. Moreover, STEP KO hippocampal neurons exhibit an increase of excitatory synaptic strength attributable to an increased size of the readily releasable pool of synaptic vesicles. These results provide new evidence that STEP plays an important role at nerve terminals in the regulation of Ca2+ homeostasis and neurotransmitter release.
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Guarnieri FC, Bellani S, Yekhlef L, Bergamaschi A, Finardi A, Fesce R, Pozzi D, Monzani E, Fornasiero EF, Matteoli M, Martino G, Furlan R, Taverna S, Muzio L, Valtorta F. Synapsin I deletion reduces neuronal damage and ameliorates clinical progression of experimental autoimmune encephalomyelitis. Brain Behav Immun 2018; 68:197-210. [PMID: 29066310 DOI: 10.1016/j.bbi.2017.10.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/10/2017] [Accepted: 10/20/2017] [Indexed: 11/20/2022] Open
Abstract
The classical view of multiple sclerosis (MS) pathogenesis states that inflammation-mediated demyelination is responsible for neuronal damage and loss. However, recent findings show that impairment of neuronal functions and demyelination can be independent events, suggesting the coexistence of other pathogenic mechanisms. Due to the inflammatory milieu, subtle alterations in synaptic function occur, which are probably at the basis of the early cognitive decline that often precedes the neurodegenerative phases in MS patients. In particular, it has been reported that inflammation enhances excitatory synaptic transmission while it decreases GABAergic transmission in vitro and ex vivo. This evidence points to the idea that an excitation/inhibition imbalance occurs in the inflamed MS brain, even though the exact molecular mechanisms leading to this synaptic dysfunction are as yet not completely clear. Along this line, we observed that acute treatment of primary hippocampal neurons in culture with pro-inflammatory cytokines leads to an increased phosphorylation of synapsin I (SynI) by ERK1/2 kinase and to an increase in the frequency of spontaneous synaptic vesicle release events, which is prevented by SynI deletion. In vivo, the ablation of SynI expression is protective in terms of disease progression and neuronal damage in the experimental autoimmune encephalomyelitis mouse model of MS. Our results point to a possible key role in MS pathogenesis of the neuronal protein SynI, a regulator of excitation/inhibition balance in neuronal networks.
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Affiliation(s)
- Fabrizia C Guarnieri
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy; Vita-Salute San Raffaele University, Via Olgettina 58, 20132 Milan, Italy
| | - Serena Bellani
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Latefa Yekhlef
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Andrea Bergamaschi
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Annamaria Finardi
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Riccardo Fesce
- Centre of Neuroscience and DISTA, University of Insubria, Via Ravasi 2, 21100 Varese, Italy
| | - Davide Pozzi
- Humanitas Clinical and Research Centre, Via Manzoni 113, 20089 Rozzano, Milan, Italy
| | - Elena Monzani
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Eugenio F Fornasiero
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Michela Matteoli
- Humanitas Clinical and Research Centre, Via Manzoni 113, 20089 Rozzano, Milan, Italy; CNR Institute of Neuroscience, via Vanvitelli 32, 20129 Milan, Italy
| | - Gianvito Martino
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy; Vita-Salute San Raffaele University, Via Olgettina 58, 20132 Milan, Italy
| | - Roberto Furlan
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Stefano Taverna
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Luca Muzio
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Flavia Valtorta
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy; Vita-Salute San Raffaele University, Via Olgettina 58, 20132 Milan, Italy.
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43
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He B, Xu D, Zhang C, Zhang L, Wang H. Prenatal food restriction induces neurobehavioral abnormalities in adult female offspring rats and alters intrauterine programming. Toxicol Res (Camb) 2018; 7:293-306. [PMID: 30090583 DOI: 10.1039/c7tx00133a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 01/21/2018] [Indexed: 12/25/2022] Open
Abstract
The higher risk of adult neuropsychiatric diseases in individuals with low fetal birth weight may be related to brain-derived neurotrophic factor (BDNF) signaling pathway inhibition. Here, we investigated whether prenatal food restriction (PFR) induces neurobehavioral alterations in adult female offspring and explored the underlying intrauterine programming mechanism. Pregnant Wistar rats in the PFR group were fed 50% of the daily food intake of control rats from gestational day (GD) 11 to 20; some pregnant rats were sacrificed at GD20, and the remaining female pups had normal delivery and were fed a post-weaning high-fat diet (HFD) and half of them were exposed to an unpredictable chronic stress (UCS) from postnatal week (PW) 21. All adult female offspring were sacrificed at PW24. At GD20, PFR altered fetal hippocampal structure and function, increased glucocorticoid receptor (GR) expression, and decreased mineralocorticoid receptor (MR), BDNF and synaptic plasticity-related gene expressions. At PW24, PFR induced depression-like behavioral abnormalities in adult rat offspring fed an HFD. These rats exhibited depression- and anxiety-like behavioral changes after HFD/UCS. Furthermore, the hippocampal morphology of the PFR group showed abnormal changes in adult offspring fed an HFD and more serious damage after HFD/UCS. These changes were accompanied by increased serum corticosterone levels, elevated GR expression, and reduced expression of the BDNF signaling pathway and synaptic plasticity-related genes in the hippocampus. In conclusion, PFR may induce neurobehavioral abnormalities in adult offspring, especially those exposed to UCS, through high levels of glucocorticoids, which increase hippocampal GR expression and decrease BDNF expression.
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Affiliation(s)
- Bo He
- Department of Pharmacology , Wuhan University School of Basic Medical Sciences , Wuhan 430071 , China . ; ; ; Tel: +86 27 68758665.,Hubei Provincial Key Laboratory of Developmentally Originated Disease , Wuhan 430071 , China
| | - Dan Xu
- Department of Pharmacology , Wuhan University School of Basic Medical Sciences , Wuhan 430071 , China . ; ; ; Tel: +86 27 68758665.,Hubei Provincial Key Laboratory of Developmentally Originated Disease , Wuhan 430071 , China
| | - Chong Zhang
- Department of Pharmacology , Wuhan University School of Basic Medical Sciences , Wuhan 430071 , China . ; ; ; Tel: +86 27 68758665
| | - Li Zhang
- Department of Pharmacology , Wuhan University School of Basic Medical Sciences , Wuhan 430071 , China . ; ; ; Tel: +86 27 68758665
| | - Hui Wang
- Department of Pharmacology , Wuhan University School of Basic Medical Sciences , Wuhan 430071 , China . ; ; ; Tel: +86 27 68758665.,Hubei Provincial Key Laboratory of Developmentally Originated Disease , Wuhan 430071 , China
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44
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Mirza FJ, Zahid S. The Role of Synapsins in Neurological Disorders. Neurosci Bull 2017; 34:349-358. [PMID: 29282612 DOI: 10.1007/s12264-017-0201-7] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 10/27/2017] [Indexed: 12/12/2022] Open
Abstract
Synapsins serve as flagships among the presynaptic proteins due to their abundance on synaptic vesicles and contribution to synaptic communication. Several studies have emphasized the importance of this multi-gene family of neuron-specific phosphoproteins in maintaining brain physiology. In the recent times, increasing evidence has established the relevance of alterations in synapsins as a major determinant in many neurological disorders. Here, we give a comprehensive description of the diverse roles of the synapsin family and the underlying molecular mechanisms that contribute to several neurological disorders. These physiologically important roles of synapsins associated with neurological disorders are just beginning to be understood. A detailed understanding of the diversified expression of synapsins may serve to strategize novel therapeutic approaches for these debilitating neurological disorders.
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Affiliation(s)
- Fatima Javed Mirza
- Neurobiology Research Laboratory, Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Saadia Zahid
- Neurobiology Research Laboratory, Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan.
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45
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Vargas KJ, Schrod N, Davis T, Fernandez-Busnadiego R, Taguchi YV, Laugks U, Lucic V, Chandra SS. Synucleins Have Multiple Effects on Presynaptic Architecture. Cell Rep 2017; 18:161-173. [PMID: 28052246 DOI: 10.1016/j.celrep.2016.12.023] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/21/2016] [Accepted: 12/07/2016] [Indexed: 02/01/2023] Open
Abstract
Synucleins (α, β, γ-synuclein) are a family of abundant presynaptic proteins. α-Synuclein is causally linked to the pathogenesis of Parkinson's disease (PD). In an effort to define their physiological and pathological function or functions, we investigated the effects of deleting synucleins and overexpressing α-synuclein PD mutations, in mice, on synapse architecture using electron microscopy (EM) and cryoelectron tomography (cryo-ET). We show that synucleins are regulators of presynapse size and synaptic vesicle (SV) pool organization. Using cryo-ET, we observed that deletion of synucleins increases SV tethering to the active zone but decreases the inter-linking of SVs by short connectors. These ultrastructural changes were correlated with discrete protein phosphorylation changes in αβγ-synuclein-/- neurons. We also determined that α-synuclein PD mutants (PARK1/hA30P and PARK4/hα-syn) primarily affected presynaptic cytomatrix proximal to the active zone, congruent with previous findings that these PD mutations decrease neurotransmission. Collectively, our results suggest that synucleins are important orchestrators of presynaptic terminal topography.
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Affiliation(s)
- Karina J Vargas
- Department of Neurology, Yale University, New Haven, CT 06536, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University, New Haven, CT 06536, USA
| | - Nikolas Schrod
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Taylor Davis
- Department of Neurology, Yale University, New Haven, CT 06536, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University, New Haven, CT 06536, USA
| | - Ruben Fernandez-Busnadiego
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University, New Haven, CT 06536, USA; Department of Cell Biology, School of Medicine, Yale University, New Haven, CT 06510, USA; Howard Hughes Medical Institute, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Yumiko V Taguchi
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University, New Haven, CT 06536, USA; Department of Cell Biology, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Ulrike Laugks
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Vladan Lucic
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
| | - Sreeganga S Chandra
- Department of Neurology, Yale University, New Haven, CT 06536, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University, New Haven, CT 06536, USA; Department of Neuroscience, Yale University, New Haven, CT 06519, USA.
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46
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High Fat Diet- Induced Neurotoxicity Alters Following vitamin E and C Administration in Hippocampus of Male Rats. ACTA ACUST UNITED AC 2017. [DOI: 10.5812/gct.58383] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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47
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The Progestin Receptor Interactome in the Female Mouse Hypothalamus: Interactions with Synaptic Proteins Are Isoform Specific and Ligand Dependent. eNeuro 2017; 4:eN-NWR-0272-17. [PMID: 28955722 PMCID: PMC5605756 DOI: 10.1523/eneuro.0272-17.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 08/31/2017] [Accepted: 09/01/2017] [Indexed: 01/06/2023] Open
Abstract
Progestins bind to the progestin receptor (PR) isoforms, PR-A and PR-B, in brain to influence development, female reproduction, anxiety, and stress. Hormone-activated PRs associate with multiple proteins to form functional complexes. In the present study, proteins from female mouse hypothalamus that associate with PR were isolated using affinity pull-down assays with glutathione S-transferase–tagged mouse PR-A and PR-B. Using complementary proteomics approaches, reverse phase protein array (RPPA) and mass spectrometry, we identified hypothalamic proteins that interact with PR in a ligand-dependent and isoform-specific manner and were confirmed by Western blot. Synaptic proteins, including synapsin-I and synapsin-II, interacted with agonist-bound PR isoforms, suggesting that both isoforms function in synaptic plasticity. In further support, synaptogyrin-III and synapsin-III associated with PR-A and PR-B, respectively. PR also interacted with kinases, including c-Src, mTOR, and MAPK1, confirming phosphorylation as an integral process in rapid effects of PR in the brain. Consistent with a role in transcriptional regulation, PR associated with transcription factors and coactivators in a ligand-specific and isoform-dependent manner. Interestingly, both PR isoforms associated with a key regulator of energy homeostasis, FoxO1, suggesting a novel role for PR in energy metabolism. Because many identified proteins in this PR interactome are synaptic proteins, we tested the hypothesis that progestins function in synaptic plasticity. Indeed, progesterone enhanced synaptic density, by increasing synapsin-I–positive synapses, in rat primary cortical neuronal cultures. This novel combination of RPPA and mass spectrometry allowed identification of PR action in synaptic remodeling and energy homeostasis and reveals unique roles for progestins in brain function and disease.
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48
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Shioda N, Yabuki Y, Wang Y, Uchigashima M, Hikida T, Sasaoka T, Mori H, Watanabe M, Sasahara M, Fukunaga K. Endocytosis following dopamine D 2 receptor activation is critical for neuronal activity and dendritic spine formation via Rabex-5/PDGFRβ signaling in striatopallidal medium spiny neurons. Mol Psychiatry 2017; 22:1205-1222. [PMID: 27922607 DOI: 10.1038/mp.2016.200] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 09/28/2016] [Accepted: 10/04/2016] [Indexed: 02/06/2023]
Abstract
Aberrant dopamine D2 receptor (D2R) activity is associated with neuropsychiatric disorders, making those receptors targets for antipsychotic drugs. Here, we report that novel signaling through the intracellularly localized D2R long isoform (D2LR) elicits extracellular signal-regulated kinase (ERK) activation and dendritic spine formation through Rabex-5/platelet-derived growth factor receptor-β (PDGFRβ)-mediated endocytosis in mouse striatum. We found that D2LR directly binds to and activates Rabex-5, promoting early-endosome formation. Endosomes containing D2LR and PDGFRβ are then transported to the Golgi apparatus, where those complexes trigger Gαi3-mediated ERK signaling. Loss of intracellular D2LR-mediated ERK activation decreased neuronal activity and dendritic spine density in striatopallidal medium spiny neurons (MSNs). In addition, dendritic spine density in striatopallidal MSNs significantly increased following treatment of striatal slices from wild-type mice with quinpirole, a D2R agonist, but those changes were lacking in D2LR knockout mice. Moreover, intracellular D2LR signaling mediated effects of a typical antipsychotic drug, haloperidol, in inducing catalepsy behavior. Taken together, intracellular D2LR signaling through Rabex-5/PDGFRβ is critical for ERK activation, dendritic spine formation and neuronal activity in striatopallidal MSNs of mice.
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Affiliation(s)
- N Shioda
- Department of Biofunctional Analysis Laboratory of Molecular Biology, Gifu Pharmaceutical University, Gifu, Japan
| | - Y Yabuki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Y Wang
- Department of Pharmacology, Beckman Institute, University of Illinois, Urbana, IL, USA
| | - M Uchigashima
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - T Hikida
- Department of Research and Drug Discovery, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - T Sasaoka
- Department of Comparative and Experimental Medicine, Brain Research Institute, Niigata University, Niigata, Japan
| | - H Mori
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - M Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - M Sasahara
- Department of Pathology, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Toyama, Japan
| | - K Fukunaga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
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Chen Z, Xu YY, Ge JF, Chen FH. CRHR1 Mediates the Up-Regulation of Synapsin I Induced by Nesfatin-1 Through ERK 1/2 Signaling in SH-SY5Y Cells. Cell Mol Neurobiol 2017; 38:627-633. [DOI: 10.1007/s10571-017-0509-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 06/06/2017] [Indexed: 10/19/2022]
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50
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Cheng Q, Song SH, Augustine GJ. Calcium-Dependent and Synapsin-Dependent Pathways for the Presynaptic Actions of BDNF. Front Cell Neurosci 2017; 11:75. [PMID: 28392759 PMCID: PMC5364187 DOI: 10.3389/fncel.2017.00075] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 03/02/2017] [Indexed: 11/19/2022] Open
Abstract
We used cultured hippocampal neurons to determine the signaling pathways mediating brain-derived neurotrophic factor (BDNF) regulation of spontaneous glutamate and GABA release. BDNF treatment elevated calcium concentration in presynaptic terminals; this calcium signal reached a peak within 1 min and declined in the sustained presence of BDNF. This BDNF-induced transient rise in presynaptic calcium was reduced by SKF96365, indicating that BDNF causes presynaptic calcium influx via TRPC channels. BDNF treatment increased the frequency of miniature excitatory postsynaptic currents (mEPSCs). This response consisted of two components: a transient component that peaked within 1 min of initiating BDNF application and a second component that was sustained, at a lower mEPSC frequency, for the duration of BDNF application. The initial transient component was greatly reduced by removing external calcium or by treatment with SKF96365, as well as by Pyr3, a selective blocker of TRPC3 channels. In contrast, the sustained component was unaffected in these conditions but was eliminated by U0126, an inhibitor of the MAP kinase (MAPK) pathway, as well as by genetic deletion of synapsins in neurons from a synapsin triple knock-out (TKO) mouse. Thus, two pathways mediate the ability of BDNF to enhance spontaneous glutamate release: the transient component arises from calcium influx through TRPC3 channels, while the sustained component is mediated by MAPK phosphorylation of synapsins. We also examined the ability of these two BDNF-dependent pathways to regulate spontaneous release of the inhibitory neurotransmitter, GABA. BDNF had no effect on the frequency of spontaneous miniature inhibitory postsynaptic currents (mIPSCs) in neurons from wild-type (WT) mice, but surprisingly did increase mIPSC frequency in synapsin TKO mice. This covert BDNF response was blocked by removal of external calcium or by treatment with SKF96365 or Pyr3, indicating that it results from calcium influx mediated by TRPC3 channels. Thus, the BDNF-activated calcium signaling pathway can also enhance spontaneous GABA release, though this effect is suppressed by synapsins under normal physiological conditions.
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Affiliation(s)
- Qing Cheng
- Department of Neurobiology, Duke University Medical Center Durham, NC, USA
| | - Sang-Ho Song
- Center for Functional Connectomics, Korea Institute of Science and TechnologySeoul, South Korea; Lee Kong Chian School of Medicine, Nanyang Technological UniversitySingapore, Singapore; Institute of Molecular and Cell BiologySingapore, Singapore
| | - George J Augustine
- Center for Functional Connectomics, Korea Institute of Science and TechnologySeoul, South Korea; Lee Kong Chian School of Medicine, Nanyang Technological UniversitySingapore, Singapore; Institute of Molecular and Cell BiologySingapore, Singapore
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