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Meur S, Karati D. Fyn Kinase in Alzheimer's Disease: Unraveling Molecular Mechanisms and Therapeutic Implications. Mol Neurobiol 2024:10.1007/s12035-024-04286-2. [PMID: 38890236 DOI: 10.1007/s12035-024-04286-2] [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: 03/12/2024] [Accepted: 06/05/2024] [Indexed: 06/20/2024]
Abstract
Alzheimer's disease, characterized by the accumulation of abnormal protein aggregates and neuronal damage in the brain, leads to a gradual decline in cognitive function and memory. As a complex neurodegenerative disorder, it involves disruptions in various biochemical pathways and neurotransmitter systems, contributing to the progressive loss of neurons and synaptic connections. The complexity of Alzheimer's signaling pathways complicates treatment, presenting a formidable challenge in the quest for effective therapeutic interventions. A member of the Src family of kinases (SFKs), Fyn, is a type of non-receptor tyrosine kinase that has been linked to multiple essential CNS processes, such as myelination and synaptic transmission. Fyn is an appealing target for AD treatments because it is uniquely linked to the two major pathologies in AD by its interaction with tau, in addition to being activated by amyloid-beta (Aβ) through PrPC. Fyn mediates neurotoxicity and synaptic impairments caused by Aβ and is involved in regulating the process of Aβ synthesis.Additionally, the tau protein's tyrosine phosphorylation is induced by Fyn. Fyn is also a challenging target because of its widespread body expression and strong homology with other kinases of the Src family, which could cause unintentional off-target effects. This review emphasizes signaling pathways mediated by Fyn that govern neuronal development and plasticity while also summarizing the most noteworthy recent research relevant to Fyn kinase's function in the brain. Additionally, the therapeutic inhibition of Fyn kinase has been discussed, with a focus on the Fyn kinase inhibitors that are in clinical trials, which presents a fascinating opportunity for targeting Fyn kinase in the creation of possible therapeutic approaches for the management of Alzheimer's disease.
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Affiliation(s)
- Shreyasi Meur
- Department of Pharmaceutical Technology, School of Pharmacy, Techno India University, Kolkata, 700091, West Bengal, India
| | - Dipanjan Karati
- Department of Pharmaceutical Technology, School of Pharmacy, Techno India University, Kolkata, 700091, West Bengal, India.
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2
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Joghataei MT, Bakhtiarzadeh F, Dehghan S, Ketabforoush AHME, Golab F, Zarbakhsh S, Ahmadirad N. The role of neurotransmitters in glioblastoma multiforme-associated seizures. Int J Dev Neurosci 2023; 83:677-690. [PMID: 37563091 DOI: 10.1002/jdn.10294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 07/20/2023] [Accepted: 07/26/2023] [Indexed: 08/12/2023] Open
Abstract
GBM, or glioblastoma multiforme, is a brain tumor that poses a great threat to both children and adults, being the primary cause of death related to brain tumors. GBM is often associated with epilepsy, which can be debilitating. Seizures and the development of epilepsy are the primary symptoms that have a severe impact on the quality of life for GBM patients. It is increasingly apparent that the nervous system plays an essential role in the tumor microenvironment for all cancer types, including GBM. In recent years, there has been a growing understanding of how neurotransmitters control the progression of gliomas. Evidence suggests that neurotransmitters and neuromodulators found in the tumor microenvironment play crucial roles in the excitability, proliferation, quiescence, and differentiation of neurons, glial cells, and neural stem cells. The involvement of neurotransmitters appears to play a significant role in various stages of GBM. In this review, the focus is on presenting updated knowledge and emerging ideas regarding the interplay between neurotransmitters and neuromodulators, such as glutamate, GABA, norepinephrine, dopamine, serotonin, adenosine, and their relationship with GBM and the seizures induced by this condition. The review aims to explore the current understanding and provide new insights into the complex interactions between these neurotransmitters and neuromodulators in the context of GBM-related seizures.
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Affiliation(s)
| | - Fatemeh Bakhtiarzadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Samaneh Dehghan
- Eye Research Center, The Five Senses Institute, Rasool Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
- Stem Cell and Regenerative Medicine Research Center, Iran University of Medical Sciences, Tehran, Iran
| | | | - Fereshteh Golab
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Sam Zarbakhsh
- Nervous System Stem Cells Research Center, Semnan University of Medical Sciences, Semnan, Iran
| | - Nooshin Ahmadirad
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
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Hawash M. Thiazole Derivatives as Modulators of GluA2 AMPA Receptors: Potent Allosteric Effects and Neuroprotective Potential. Biomolecules 2023; 13:1694. [PMID: 38136566 PMCID: PMC10741633 DOI: 10.3390/biom13121694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/17/2023] [Accepted: 11/20/2023] [Indexed: 12/24/2023] Open
Abstract
Thiazole carboxamide derivatives were synthesized in this investigation, with a subsequent examination of their impact on GluA2 AMPA receptors. The synthesized compounds, namely MMH-1-5, were subjected to characterization using high-resolution mass spectrometry (HRMS), proton nuclear magnetic resonance (1H-NMR), and carbon-13 nuclear magnetic resonance (13C-NMR). The present work thoroughly investigates the impact of five thiazole derivatives on GluA2 AMPA receptors. This investigation examined their effects on both whole-cell currents and receptor kinetics. In addition, the cytotoxicity of the samples was assessed using the MTS test. The compound MMH-5 had the highest effect level, resulting in a notable drop in current amplitude by a factor of six. Similarly, MMH-4 and MMH-3 also caused major reductions in the current amplitude. The compounds mentioned above also influenced the rates of deactivation and desensitization. MMH-5 and MMH-4 exhibited an increase in deactivation, while MMH-5 showed reduced desensitization. Our research findings highlight the efficacy of MMH-5 as a negative allosteric modulator of GluA2 AMPA receptors, exerting substantial effects on both the magnitude and time course of receptor activity. Significantly, the compound MMH-2 demonstrated noteworthy cytotoxic effects, as evidenced by cell viability rates dropping below 6.79% for all cancer cell lines and 17.52% for the normal cell line (LX-2). Of particular interest is the pronounced cytotoxicity observed in MMH-5, suggesting its potential as a safe neuroprotective agent targeting the AMPA receptor, as indicated by cell viability percentages exceeding 85.44% across all cancer and normal cell lines. Docking simulations were performed to determine possible modes of interaction between MMH5 and the GluA2-AMPA receptor (PDB:7RZ5). The abovementioned facts and the well-documented effects of further thiazole derivatives provide a strong foundation for future research endeavors to enhance tailored treatments for neurological disorders that rely heavily on GluA2 signaling. The present study elucidates the intricate association between thiazole derivatives and GluA2 receptors, providing valuable perspectives on the prospects of enhanced and specific therapeutic interventions for diverse neurological conditions.
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Affiliation(s)
- Mohammed Hawash
- Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus P.O. Box 7, Palestine
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Livingstone RW, Elder MK, Singh A, Westlake CM, Tate WP, Abraham WC, Williams JM. Secreted Amyloid Precursor Protein-Alpha Enhances LTP Through the Synthesis and Trafficking of Ca 2+-Permeable AMPA Receptors. Front Mol Neurosci 2021; 14:660208. [PMID: 33867938 PMCID: PMC8047154 DOI: 10.3389/fnmol.2021.660208] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/10/2021] [Indexed: 11/13/2022] Open
Abstract
Regulation of AMPA receptor expression by neuronal activity and neuromodulators is critical to the expression of both long-term potentiation (LTP) and memory. In particular, Ca2+-permeable AMPARs (CP-AMPAR) play a unique role in these processes due to their transient, activity-regulated expression at synapses. Secreted amyloid precursor protein-alpha (sAPPα), a metabolite of the parent amyloid precursor protein (APP) has been previously shown to enhance hippocampal LTP as well as memory formation in both normal animals and in Alzheimer’s disease models. In earlier work we showed that sAPPα promotes trafficking of GluA1-containing AMPARs to the cell surface and specifically enhances synthesis of GluA1. To date it is not known whether de novo synthesized GluA1 form CP-AMPARs or how they contribute to sAPPα-mediated plasticity. Here, using fluorescent non-canonical amino acid tagging–proximity ligation assay (FUNCAT-PLA), we show that brief treatment of primary rat hippocampal neurons with sAPPα (1 nM, 30 min) rapidly enhanced the cell-surface expression of de novo GluA1 homomers and reduced levels of de novo GluA2, as well as extant GluA2/3-AMPARs. The de novo GluA1-containing AMPARs were localized to extrasynaptic sites and later internalized by sAPPα-driven expression of the activity-regulated cytoskeletal-associated protein, Arc. Interestingly, longer exposure to sAPPα increased synaptic levels of GluA1/2 AMPARs. Moreover, the sAPPα-mediated enhancement of LTP in area CA1 of acute hippocampal slices was dependent on CP-AMPARs. Together, these findings show that sAPPα engages mechanisms which specifically enhance the synthesis and cell-surface expression of GluA1 homomers, underpinning the sAPPα-driven enhancement of synaptic plasticity in the hippocampus.
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Affiliation(s)
- Rhys W Livingstone
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Megan K Elder
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Anurag Singh
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Courteney M Westlake
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Warren P Tate
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Joanna M Williams
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
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Yu Y, Shi Z, Xu D, Li Y, Qin J, Zhang Z, Wang H. Prenatal ethanol exposure increases susceptibility to depression- and anxiety-like behavior in adult female offspring and its underlying mechanism. Reprod Toxicol 2020; 96:36-46. [PMID: 32497709 DOI: 10.1016/j.reprotox.2020.05.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 05/25/2020] [Accepted: 05/27/2020] [Indexed: 12/19/2022]
Abstract
Epidemiological investigations have found that maternal alcohol intake increases the risk of mental illness in offspring. Our study investigated changes of depression- and anxiety-like behaviors in adult offspring caused by prenatal ethanol exposure (PEE) and explored the potential mechanism. After Wistar rats were intragastrically administered ethanol at a dose of 4 g/kg·d on the 9-20 t h days of pregnancy, the offspring were given 21 days of chronic unpredictable mild stress (CUMS) starting from the 9th week after birth. Before CUMS, the behavioral results showed that the PEE offspring appeared excited and anxious. After CUMS, the PEE offspring rats were more sensitive to the same intensity of stimulation, and then the behavioral disorders aggravated. In adult offspring from the PEE group, the intercellular space was enlarged in the hippocampus, and there was a loss of pyramidal cells. The expression of brain-derived neurotrophic factor (BDNF) decreased; the mRNA expression of the glucocorticoid receptor and synaptic plasticity-related genes decreased; the apoptosis-related genes expressed disrupted. In order to determine whether hippocampal injury and dysfunction resulted from ethanol directly or indirectly, we performed in vitro study. The outcome was accompanied by disrupted gene expression related to neurogenesis and synaptic plasticity. PEE increases the susceptibility of adult female offspring to depression- and anxiety-like behaviors, and its mechanism may be related to the toxic effects of ethanol, both directly and indirectly. The latter inhibits the hippocampal BDNF pathway, leading to the disruption of hippocampal neurogenesis, apoptosis and decreased synaptic plasticity.
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Affiliation(s)
- Ying Yu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China; Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071, China
| | - Zhaokun Shi
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Dan Xu
- Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071, China; Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071, China
| | - Ying Li
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Jun Qin
- Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Zhaohui Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Hui Wang
- Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071, China; Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071, China.
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Namba H, Nagano T, Jodo E, Eifuku S, Horie M, Takebayashi H, Iwakura Y, Sotoyama H, Takei N, Nawa H. Epidermal growth factor signals attenuate phenotypic and functional development of neocortical GABA neurons. J Neurochem 2017; 142:886-900. [PMID: 28608461 DOI: 10.1111/jnc.14097] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 04/24/2017] [Accepted: 05/23/2017] [Indexed: 01/21/2023]
Abstract
Phenotypic development of neocortical GABA neurons is highly plastic and promoted by various neurotrophic factors such as neuregulin-1. A subpopulation of GABA neurons expresses not only neuregulin receptor (ErbB4) but also epidermal growth factor (EGF) receptor (ErbB1) during development, but the neurobiological action of EGF on this cell population is less understood than that of neuregulin-1. Here, we examined the effects of exogenous EGF on immature GABA neurons both in culture and in vivo and also explored physiological consequences in adults. We prepared low density cultures from the neocortex of rat embryos and treated neocortical neurons with EGF. EGF decreased protein levels of glutamic acid decarboxylases (GAD65 and GAD67), and EGF influences on neuronal survival and glial proliferation were negligible or limited. The EGF treatment also diminished the frequency of miniature inhibitory postsynaptic currents (mIPSCs). In vivo administration of EGF to mouse pups reproduced the above GABAergic phenomena in neocortical culture. In EGF-injected postnatal mice, GAD- and parvalbumin-immunoreactivities were reduced in the frontal cortex. In addition, postnatal EGF treatment decreased mIPSC frequency in, and the density of, GABAergic terminals on pyramidal cells. Although these phenotypic influences on GABA neurons became less marked during development, it later resulted in the reduced β- and γ-powers of sound-evoked electroencephalogram in adults, which is regulated by parvalbumin-positive GABA neurons and implicated in the schizophrenia pathophysiology. These findings suggest that, in contrast to the ErbB4 ligand of neuregulin-1, the ErbB1 ligand of EGF exerts unique maturation-attenuating influences on developing cortical GABAergic neurons.
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Affiliation(s)
- Hisaaki Namba
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Chuo-ku, Niigata, Japan
| | - Tadasato Nagano
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Chuo-ku, Niigata, Japan.,Department of Health and Nutrition, University of Niigata Prefecture, Higashi-ku, Niigata, Japan
| | - Eiichi Jodo
- Department of Neurophysiology, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Satoshi Eifuku
- Department of Neurophysiology, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Masao Horie
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Hirohide Takebayashi
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Yuriko Iwakura
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Chuo-ku, Niigata, Japan
| | - Hidekazu Sotoyama
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Chuo-ku, Niigata, Japan
| | - Nobuyuki Takei
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Chuo-ku, Niigata, Japan
| | - Hiroyuki Nawa
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Chuo-ku, Niigata, Japan
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Glutamatergic neurotransmission in the prefrontal cortex mediates the suppressive effect of intra-prelimbic cortical infusion of BDNF on cocaine-seeking. Eur Neuropsychopharmacol 2016; 26:1989-1999. [PMID: 27765467 PMCID: PMC5136511 DOI: 10.1016/j.euroneuro.2016.10.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 09/22/2016] [Accepted: 10/04/2016] [Indexed: 12/23/2022]
Abstract
Cocaine self-administration induces dysfunctional neuroadaptations in the prefrontal cortex that underlie relapse to cocaine-seeking. Cocaine self-administration disturbs glutamatergic transmission in the nucleus accumbens that is prevented by infusion of brain-derived neurotrophic factor (BDNF) into the prelimbic area of the prefrontal cortex. Intra-prelimbic infusion of BDNF decreases cocaine-seeking in a TrkB-ERK MAP kinase-dependent manner. Neuronal activity triggers an interaction between TrkB receptors and NMDA receptors, leading to ERK activation. In the present study, infusion of the GluN2A-containing NMDA receptor antagonist, TCN-201, or the GluN2B-containing NMDA receptor antagonist, Ro-25-6981, into the prelimbic cortex of rats blocked the suppressive effect of BDNF on cocaine-seeking. During early withdrawal from cocaine self-administration, tyrosine phosphorylation of ERK, GluN2A, and GluN2B in the prelimbic cortex was reduced and this reduction of phospho-proteins was prevented by intra-prelimbic BDNF infusion. TCN-201 infusion into the prelimbic cortex inhibited the BDNF-mediated increase in pERK and pGluN2A whereas Ro-25-6981 infusion into the prelimbic cortex blocked BDNF-induced elevation of pERK and pGluN2B, indicating that both GluN2A- and GluN2B-containing NMDA receptors underlie BDNF-induced ERK activation. These data demonstrate that BDNF-mediated activation of GluN2A- and GluN2B-containing NMDA receptors underlies ERK activation in the prelimbic cortex during early withdrawal, preventing subsequent relapse to cocaine-seeking.
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Reimers JM, Loweth JA, Wolf ME. BDNF contributes to both rapid and homeostatic alterations in AMPA receptor surface expression in nucleus accumbens medium spiny neurons. Eur J Neurosci 2014; 39:1159-69. [PMID: 24712995 DOI: 10.1111/ejn.12422] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 09/30/2013] [Accepted: 10/12/2013] [Indexed: 12/15/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) plays a critical role in plasticity at glutamate synapses and in the effects of repeated cocaine exposure. We recently showed that intracranial injection of BDNF into the rat nucleus accumbens (NAc), a key region for cocaine addiction, rapidly increases α-amino-3-hyroxy-5-methyl-4-isoxazole-propionic acid receptor (AMPAR) surface expression. To further characterize BDNF's role in both rapid AMPAR trafficking and slower, homeostatic changes in AMPAR surface expression, we investigated the effects of acute (30 min) and long-term (24 h) treatment with BDNF on AMPAR distribution in NAc medium spiny neurons from postnatal rats co-cultured with mouse prefrontal cortex neurons to restore excitatory inputs. Immunocytochemical studies showed that acute BDNF treatment increased cell surface GluA1 and GluA2 levels, as well as their co-localization, on NAc neurons. This effect of BDNF, confirmed using a protein crosslinking assay, was dependent on ERK but not AKT signaling. In contrast, long-term BDNF treatment decreased AMPAR surface expression on NAc neurons. Based on this latter result, we tested the hypothesis that BDNF plays a role in AMPAR 'scaling down' in response to a prolonged increase in neuronal activity produced by bicuculline (24 h). Supporting this hypothesis, decreasing BDNF signaling with the extracellular BDNF scavenger TrkB-Fc prevented the scaling down of GluA1 and GluA2 surface levels in NAc neurons normally produced by bicuculline. In conclusion, BDNF exerts bidirectional effects on NAc AMPAR surface expression, depending on duration of exposure. Furthermore, BDNF's involvement in synaptic scaling in the NAc differs from its previously described role in the visual cortex.
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Affiliation(s)
- Jeremy M Reimers
- Department of Neuroscience, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL, 60064-3095, USA
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Song QX, Chermansky CJ, Birder LA, Li L, Damaser MS. Brain-derived neurotrophic factor in urinary continence and incontinence. Nat Rev Urol 2014; 11:579-88. [PMID: 25224451 DOI: 10.1038/nrurol.2014.244] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Urinary incontinence adversely affects quality of life and results in an increased financial burden for the elderly. Accumulating evidence suggests a connection between neurotrophins, such as brain-derived neurotrophic factor (BDNF), and lower urinary tract function, particularly with regard to normal physiological function and the pathophysiological mechanisms of stress urinary incontinence (SUI) and bladder pain syndrome/interstitial cystitis (BPS/IC). The interaction between BDNF and glutamate receptors affects both bladder and external urethral sphincter function during micturition. Clinical findings indicate reduced BDNF levels in antepartum and postpartum women, potentially correlating with postpartum SUI. Experiments with animal models demonstrate that BDNF is decreased after simulated childbirth injury, thereby impeding the recovery of injured nerves and the restoration of continence. Treatment with exogenous BDNF facilitates neural recovery and the restoration of continence. Serotonin and noradrenaline reuptake inhibitors, used to treat both depression and SUI, result in enhanced BDNF levels. Understanding the neurophysiological roles of BDNF in maintaining normal urinary function and in the pathogenesis of SUI and BPS/IC could lead to future therapies based on these mechanisms.
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Affiliation(s)
- Qi-Xiang Song
- Department of Urology, Changhai Hospital, Shanghai, PR China
| | - Christopher J Chermansky
- Department of Urology, University of Pittsburgh School of Medicine, 3550 Terrace Street, Pittsburgh, PA 15261, USA
| | - Lori A Birder
- Department of Medicine, University of Pittsburgh School of Medicine, 3550 Terrace Street, Pittsburgh, PA 15261, USA
| | - Longkun Li
- Department of Urology, Second Affiliated Hospital of TMMU, Chongqing, PR China
| | - Margot S Damaser
- Department of Biomedical Engineering, The Cleveland Clinic, 9500 Euclid Avenue ND20, Cleveland, OH 44195, USA
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Infralimbic BDNF/TrkB enhancement of GluN2B currents facilitates extinction of a cocaine-conditioned place preference. J Neurosci 2014; 34:6057-64. [PMID: 24760865 DOI: 10.1523/jneurosci.4980-13.2014] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) regulates synaptic activity and behavioral flexibility, and reduction of BDNF strongly predicts psychiatric disorders and cognitive dysfunction. Restoration of BDNF-dependent activity could alleviate these impairments, but BDNF has limited clinical utility due to its pharmacokinetics. Here we demonstrate that activation of a primary BDNF target, the tropomyosin-related kinase B (TrkB) receptor, enhances the amplitude and prolongs the decay kinetics of N-methyl-d-aspartate receptor (NMDAR) currents in male rat infralimbic prefrontal pyramidal neurons. Moreover, these effects were prevented and reversed by blockade of NMDARs containing the GluN2B subunit. Our results show that this signaling cascade bidirectionally regulates extinction of a cocaine-induced conditioned place preference (CPP), a task that requires behavioral flexibility. Blockade of infralimbic TrkB receptors or GluN2B-containing NMDARs disrupted consolidation of extinction of the CPP. In contrast, extinction was strengthened by potentiation of TrkB receptor activity with infralimbic infusions of BDNF or systemic injections of 7,8 dihydroxyflavone (7,8DHF), the newly synthesized TrkB receptor agonist. The 7,8DHF-induced enhancement of extinction was prevented by infralimbic infusions of a GluN2B-specific receptor antagonist, demonstrating that TrkB receptor activation enhances extinction of cocaine-CPP via GluN2B-containing NMDARs. Together, infralimbic TrkB receptor activation strengthens GluN2B-containing NMDAR currents to support extinction learning. TrkB receptor agonists would therefore be useful as pharmacological adjuncts for extinction-based therapies for treatment of psychiatric disorders associated with reduced BDNF activity.
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Morin-Moncet O, Beaumont V, de Beaumont L, Lepage JF, Théoret H. BDNF Val66Met polymorphism is associated with abnormal interhemispheric transfer of a newly acquired motor skill. J Neurophysiol 2014; 111:2094-102. [PMID: 24572097 DOI: 10.1152/jn.00388.2013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Recent data suggest that the Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF) gene can alter cortical plasticity within the motor cortex of carriers, which exhibits abnormally low rates of cortical reorganization after repetitive motor tasks. To verify whether long-term retention of a motor skill is also modulated by the presence of the polymorphism, 20 participants (10 Val66Val, 10 Val66Met) were tested twice at a 1-wk interval. During each visit, excitability of the motor cortex was measured by transcranial magnetic stimulations (TMS) before and after performance of a procedural motor learning task (serial reaction time task) designed to study sequence-specific learning of the right hand and sequence-specific transfer from the right to the left hand. Behavioral results showed a motor learning effect that persisted for at least a week and task-related increases in corticospinal excitability identical for both sessions and without distinction for genetic group. Sequence-specific transfer of the motor skill from the right hand to the left hand was greater in session 2 than in session 1 only in the Val66Met genetic group. Further analysis revealed that the sequence-specific transfer occurred equally at both sessions in the Val66Val genotype group. In the Val66Met genotype group, sequence-specific transfer did not occur at session 1 but did at session 2. These data suggest a limited impact of Val66Met polymorphism on the learning and retention of a complex motor skill and its associated changes in corticospinal excitability over time, and a possible modulation of the interhemispheric transfer of procedural learning.
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Affiliation(s)
| | | | - Louis de Beaumont
- Université du Québec à Trois-Rivières, Montreal, Quebec, Canada; and
| | | | - Hugo Théoret
- Université de Montréal, Montreal, Quebec, Canada; Hôpital Sainte-Justine Research Center, Montreal, Quebec, Canada
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12
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Jourdi H, Kabbaj M. Acute BDNF treatment upregulates GluR1-SAP97 and GluR2-GRIP1 interactions: implications for sustained AMPA receptor expression. PLoS One 2013; 8:e57124. [PMID: 23460828 PMCID: PMC3584105 DOI: 10.1371/journal.pone.0057124] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 01/17/2013] [Indexed: 12/23/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) plays several prominent roles in synaptic plasticity and in learning and memory formation. Reduced BDNF levels and altered BDNF signaling have been reported in several brain diseases and behavioral disorders, which also exhibit reduced levels of AMPAr subunits. BDNF treatment acutely regulates AMPA receptor expression and function, including synaptic AMPAr subunit trafficking, and implicates several well defined signaling molecules that are required to elicit long term potentiation and depression (LTP and LTD, respectively). Long term encoding of synaptic events, as in long term memory formation, requires AMPAr stabilization and maintenance. However, factors regulating AMPAr stabilization in neuronal cell membranes and synaptic sites are not well characterized. In this study, we examine the effects of acute BDNF treatment on levels of AMPAr-associated scaffolding proteins and on AMPAr subunit-scaffolding protein interactions. We also examine the effects of BDNF-dependent enhanced interactions between AMPAr subunits with their specific scaffolding proteins on the accumulation of both types of proteins. Our results show that acute BDNF treatment upregulates the interactions between AMPAr subunits (GluR1 and GluR2) with their scaffold proteins SAP97 and GRIP1, respectively, leading to prolonged increased accumulation of both categories of proteins, albeit with distinct mechanisms for GluR1 and GluR2. Our findings reveal a new role for BDNF in the long term maintenance of AMPA receptor subunits and associated scaffolding proteins at synapses and further support the role of BDNF as a key regulator of synaptic consolidation. These results have potential implications for recent findings implicating BDNF and AMPAr subunits in various brain diseases and behavioral disorders.
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Affiliation(s)
- Hussam Jourdi
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America.
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13
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Prakash O, Lukiw WJ, Peruzzi F, Reiss K, Musto AE. Gliomas and seizures. Med Hypotheses 2012; 79:622-6. [PMID: 22959996 DOI: 10.1016/j.mehy.2012.07.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 07/28/2012] [Indexed: 10/27/2022]
Abstract
Glial neoplasms account for nearly 50% of all adult primary brain tumors. They originate from glial cells in the brain and/or spinal cord and include low-grade diffuse astrocytomas, anaplastic-astrocytomas, and glioblastomas. Of all brain tumors, glioblastoma multiforme (GBM) is the most aggressive and is characterized by rapid glial cell growth, resistance to radio- and chemo- therapies, and relentless infiltration and spreading throughout the central nervous system (CNS). In glioblastomas, primary tumor growth and CNS invasion are associated with the activation of complex structural molecular and metabolic changes within the tumor tissue, which profoundly affect the surrounding neuronal networks and may in part explain induction of epilepsy. In fact, epileptic seizures are very common among patients with glial tumors, reaching nearly 50% in glioblastoma patients and almost 90% in low-grade astrocytomas. The overall hypothesis presented here discusses the possibility that the aberrant tumor cell metabolism may act directly on neuronal network, and this leads to seizure susceptibility. Further invasion and growth of the malignant glial cells exacerbate this initial pathologic state which promotes recurrent seizures (epileptogenesis).
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Affiliation(s)
- O Prakash
- LSUHSC - Cancer Center, Neurosurgery Department and Neuroscience Center of Excellence, 2020 Gravier St., New Orleans, LA 70112, USA
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14
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Annamalai B, Mannangatti P, Arapulisamy O, Shippenberg TS, Jayanthi LD, Ramamoorthy S. Tyrosine phosphorylation of the human serotonin transporter: a role in the transporter stability and function. Mol Pharmacol 2011; 81:73-85. [PMID: 21992875 DOI: 10.1124/mol.111.073171] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The serotonin (5-HT) transporter (SERT) regulates serotoninergic neurotransmission by clearing 5-HT released into the synaptic space. Phosphorylation of SERT on serine and threonine mediates SERT regulation. Whether tyrosine phosphorylation regulates SERT is unknown. Here, we tested the hypothesis that tyrosine-phosphorylation of SERT regulates 5-HT transport. In support of this, alkali-resistant (32)P-labeled SERT was found in rat platelets, and Src-tyrosine kinase inhibitor 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo [3,4,d]pyrimidine (PP2) decreased platelet SERT function and expression. In human placental trophoblast cells expressing SERT, PP2 reduced transporter function, expression, and stability. Although siRNA silencing of Src expression decreased SERT function and expression, coexpression of Src resulted in PP2-sensitive increases in SERT function and expression. PP2 treatment markedly decreased SERT protein stability. Compared with WT-SERT, SERT tyrosine mutants Y47F and Y142F exhibited reduced 5-HT transport despite their higher total and cell surface expression levels. Moreover, Src-coexpression increased total and cell surface expression of Y47F and Y142F SERT mutants without affecting their 5-HT transport capacity. It is noteworthy that Y47F and Y142F mutants exhibited higher protein stability compared with WT-SERT. However, similar to WT-SERT, PP2 treatment decreased the stability of Y47F and Y142F mutants. Furthermore, compared with WT-SERT, Y47F and Y142F mutants exhibited lower basal tyrosine phosphorylation and no further enhancement of tyrosine phosphorylation in response to Src coexpression. These results provide the first evidence that SERT tyrosine phosphorylation supports transporter protein stability and 5HT transport.
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Affiliation(s)
- Balasubramaniam Annamalai
- Department of Neurosciences, Division of Neuroscience Research, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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15
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Carreño FR, Walch JD, Dutta M, Nedungadi TP, Cunningham JT. Brain-derived neurotrophic factor-tyrosine kinase B pathway mediates NMDA receptor NR2B subunit phosphorylation in the supraoptic nuclei following progressive dehydration. J Neuroendocrinol 2011; 23:894-905. [PMID: 21848649 PMCID: PMC3183156 DOI: 10.1111/j.1365-2826.2011.02209.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We studied the effects of water deprivation (WD) on the phosphorylation of tyrosine kinase B (TrkB) and NMDA receptor subunits in the supraoptic nucleus (SON) of the rat. Laser capture microdissection and quantitative reverse transcriptase polymerase chain reaction was used to demonstrate brain-derived neurotrophic factor (BDNF) and TrkB gene expression in vasopressin SON neurones. Immunohistochemistry confirmed BDNF staining in vasopressin neurones, whereas staining for phosphorylated TrkB was increased following WD. Western blot analysis of brain punches containing the SON revealed that tyrosine phosphorylation of TrkB (pTrkBY(515)), serine phosphorylation of NR1 (pNR1S(866) or pNR1) and tyrosine phosphorylation of NR2B subunits (pNR2BY(1472) or pNR2B) were significantly increased in WD animals compared to controls. Access to water for 2 h reduced pTrkBY(515) content to control levels without affecting pNR1 or pNR2B. Four hours of rehydration was needed to reduce pNR1 and pNR2B to control levels. To test whether increased phosphorylation of TrkB in the present study is mediated by BDNF, a group of animals were instrumented with right SON cannula coupled to mini-osmotic pumps filled with vehicle or TrkB-Fc fusion protein, which prevents BDNF binding to TrkB. In the left SON contralateral to the cannula, TrkB phosphorylation was significantly enhanced following WD. Separate analysis of the right SON, which received TrkB-Fc, showed that the TrkB receptor phosphorylation following WD was significantly attenuated. Although increased pNR1S(866) following WD was not affected by local infusion of TrkB-Fc, pNR2BY(1472) was significantly reduced. Co-immunoprecipitation revealed an increased physical interaction between Fyn kinase and NR2B and TrkB in the SON following WD. Thus, activation of TrkB in the SON following WD may affect cellular excitability through the phosphorylation of NR2B subunits.
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Affiliation(s)
- Flávia Regina Carreño
- Department of Integrative Physiology, and Cardiovascular Research Institute, University of North Texas Health Science Center at Fort Worth, 3500 Camp Bowie Blvd, Fort Worth, TX 76107
| | - Joseph D Walch
- Department of Integrative Physiology, and Cardiovascular Research Institute, University of North Texas Health Science Center at Fort Worth, 3500 Camp Bowie Blvd, Fort Worth, TX 76107
- Department of Pharmacology and Neuroscience, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229
| | - Mayurika Dutta
- Department of Integrative Physiology, and Cardiovascular Research Institute, University of North Texas Health Science Center at Fort Worth, 3500 Camp Bowie Blvd, Fort Worth, TX 76107
| | - Thekkethil P. Nedungadi
- Department of Integrative Physiology, and Cardiovascular Research Institute, University of North Texas Health Science Center at Fort Worth, 3500 Camp Bowie Blvd, Fort Worth, TX 76107
| | - J. Thomas Cunningham
- Department of Integrative Physiology, and Cardiovascular Research Institute, University of North Texas Health Science Center at Fort Worth, 3500 Camp Bowie Blvd, Fort Worth, TX 76107
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16
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Kraev I, Henneberger C, Rossetti C, Conboy L, Kohler LB, Fantin M, Jennings A, Venero C, Popov V, Rusakov D, Stewart MG, Bock E, Berezin V, Sandi C. A peptide mimetic targeting trans-homophilic NCAM binding sites promotes spatial learning and neural plasticity in the hippocampus. PLoS One 2011; 6:e23433. [PMID: 21887252 PMCID: PMC3160849 DOI: 10.1371/journal.pone.0023433] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Accepted: 07/17/2011] [Indexed: 01/10/2023] Open
Abstract
The key roles played by the neural cell adhesion molecule (NCAM) in plasticity and cognition underscore this membrane protein as a relevant target to develop cognitive-enhancing drugs. However, NCAM is a structurally and functionally complex molecule with multiple domains engaged in a variety of actions, which raise the question as to which NCAM fragment should be targeted. Synthetic NCAM mimetic peptides that mimic NCAM sequences relevant to specific interactions allow identification of the most promising targets within NCAM. Recently, a decapeptide ligand of NCAM—plannexin, which mimics a homophilic trans-binding site in Ig2 and binds to Ig3—was developed as a tool for studying NCAM's trans-interactions. In this study, we investigated plannexin's ability to affect neural plasticity and memory formation. We found that plannexin facilitates neurite outgrowth in primary hippocampal neuronal cultures and improves spatial learning in rats, both under basal conditions and under conditions involving a deficit in a key plasticity-promoting posttranslational modification of NCAM, its polysialylation. We also found that plannexin enhances excitatory synaptic transmission in hippocampal area CA1, where it also increases the number of mushroom spines and the synaptic expression of the AMPAR subunits GluA1 and GluA2. Altogether, these findings provide compelling evidence that plannexin is an important facilitator of synaptic functional, structural and molecular plasticity in the hippocampal CA1 region, highlighting the fragment in NCAM's Ig3 module where plannexin binds as a novel target for the development of cognition-enhancing drugs.
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Affiliation(s)
- Igor Kraev
- Department of Life Sciences, The Open University, Milton Keynes, United Kingdom
| | - Christian Henneberger
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London (UCL), London, United Kingdom
| | - Clara Rossetti
- Laboratory of Behavioral Genetics, Brain Mind Institute, EPFL, Lausanne, Switzerland
| | - Lisa Conboy
- Laboratory of Behavioral Genetics, Brain Mind Institute, EPFL, Lausanne, Switzerland
| | - Lene B. Kohler
- Protein Laboratory, Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Martina Fantin
- Laboratory of Behavioral Genetics, Brain Mind Institute, EPFL, Lausanne, Switzerland
| | - Alistair Jennings
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London (UCL), London, United Kingdom
| | - Cesar Venero
- Department of Psychobiology, UNED, Ciudad Universitaria, Madrid, Spain
| | - Victor Popov
- Department of Life Sciences, The Open University, Milton Keynes, United Kingdom
| | - Dmitri Rusakov
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London (UCL), London, United Kingdom
| | - Michael G. Stewart
- Department of Life Sciences, The Open University, Milton Keynes, United Kingdom
- * E-mail: (CS); (MGS)
| | - Elisabeth Bock
- Protein Laboratory, Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Vladimir Berezin
- Protein Laboratory, Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Carmen Sandi
- Laboratory of Behavioral Genetics, Brain Mind Institute, EPFL, Lausanne, Switzerland
- * E-mail: (CS); (MGS)
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Watanabe Y, Someya T, Nawa H. Cytokine hypothesis of schizophrenia pathogenesis: evidence from human studies and animal models. Psychiatry Clin Neurosci 2010; 64:217-30. [PMID: 20602722 DOI: 10.1111/j.1440-1819.2010.02094.x] [Citation(s) in RCA: 156] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The pathogenesis of schizophrenia has yet to be fully characterized. Gene-environment interactions have been found to play a crucial role in the vulnerability to this disease. Among various environmental factors, inflammatory immune processes have been most clearly implicated in the etiology and pathology of schizophrenia. Cytokines, regulators of immune/inflammatory reactions and brain development, emerge as part of a common pathway of genetic and environmental components of schizophrenia. Maternal infection, obstetric complications, neonatal hypoxia and brain injury all recruit cytokines to mediate inflammatory processes. Abnormal expression levels of specific cytokines such as epidermal growth factor, interleukins (IL) and neuregulin-1 are found both in the brain and peripheral blood of patients with schizophrenia. Accordingly, cytokines have been proposed to transmit peripheral immune/inflammatory signals to immature brain tissue through the developing blood-brain barrier, perturbing structural and phenotypic development of the brain. This cytokine hypothesis of schizophrenia is also supported by modeling experiments in animals. Animals treated with specific cytokines of epidermal growth factor, IL-1, IL-6, and neuregulin-1 as embryos or neonates exhibit schizophrenia-like behavioral abnormalities after puberty, some of which are ameliorated by treatment with antipsychotics. In this review, we discuss the neurobiological mechanisms underlying schizophrenia and novel antipsychotic candidates based on the cytokine hypothesis.
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Affiliation(s)
- Yuichiro Watanabe
- Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
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18
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Patil SS, Schlick F, Höger H, Lubec G. Involvement of individual hippocampal signaling protein levels in spatial memory formation is strain-dependent. Amino Acids 2009; 39:75-87. [PMID: 19890699 DOI: 10.1007/s00726-009-0379-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Accepted: 10/14/2009] [Indexed: 12/30/2022]
Abstract
Although a series of signaling cascades involved in spatial memory have been identified, their link to spatial memory and strain-dependent expression has not been reported so far. Hippocampal levels of the abovementioned signaling proteins were determined in laboratory inbred strain C57BL/6J, the wild-derived inbred strain PWD/PhJ and the wild caught mouse Apodemus sylvaticus (AS) by immunoblotting. The resulting hippocampal protein levels were correlated with results from MWM. Hippocampal signaling protein (hSP) levels were tested also in yoked controls. Within-strain comparison between trained and yoked controls revealed significant differences between levels of Phospho-CaMKII (alpha), Phospho-CREB, Egr-1, c-Src, Phospho-ERK5, Phospho-MEK5 and NOS1 in all of the three strains tested. In addition, the three strains revealed different involvement of individual hSP levels clearly indicating that individual mouse strains were linked to individual hSPs in spatial memory. Phospho-ERK5 levels were not detectable in hippocampi of yoked controls of each strain. We learn from this study that a series of hSPs are associated with spatial memory and that different hSPs are linked to spatial memory in different strains that show different outcome in the MWM. Even correlational patterns in the individual hSPs differed between mouse strains. This is of importance for the interpretation of previous studies on the abovementioned signaling cascades as well as for the design of future studies on these hippocampal proteins. It is intriguing that individual mouse strains, laboratory or wild caught, may use different signaling pathways for spatial memory in the Morris water maze.
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Affiliation(s)
- Sudarshan S Patil
- Division of Pediatric Neuroscience, Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
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19
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Jin I, Huang H, Smith B, Farley J. Protein tyrosine kinase involvement in learning-produced changes in Hermissenda type B photoreceptors. J Neurophysiol 2009; 102:3573-95. [PMID: 19812284 DOI: 10.1152/jn.90732.2008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Learning-correlated changes in the excitability and photoresponses of Hermissenda's ocular type B photoreceptors are mediated by reductions in two distinct K(+) currents, I(A) and I(K-Ca). The suppression of these K(+) currents has been linked to conditioning-produced activation of protein kinase C (PKC). The question of whether PKC accounts completely for the changes in excitability and K(+) currents or whether other kinase(s) are involved has received little attention. In the present experiments, we asked whether protein tyrosine kinases (PTKs) might also contribute to conditioning-produced alterations in B cells. We found that the PTK inhibitors genistein and lavendustin A greatly reduced cumulative depolarization of type B cells, a short-term correlate of associative learning. This disruption occurred even when PKC activation had been either occluded by preexposure of type B cells to a phorbol ester or otherwise prevented by the pseudosubstrate inhibitor peptide PKC[19-31]. PTK inhibitors also increased the amplitude of the transient (I(A)) and delayed (I(Delayed)) components of voltage-dependent K(+) current that have previously been shown to be selectively reduced by conditioning and to contribute to cumulative depolarization. Genistein partially prevented the reduction of I(A) and I(Delayed) due to in vitro conditioning and blocked the changes in their voltage dependencies. Ionophoresis of pervanadate ion, a potent inhibitor of protein tyrosine phosphatases, depolarized type B photoreceptors and occluded conditioning-produced cumulative depolarization. Pervanadate also suppressed I(A) and I(Delayed), reduced their voltage dependence, and altered inactivation kinetics for I(A), mimicking conditioning. Western blot analysis using a phosphotyrosine antibody indicated that conditioning increased the phosphotyrosine content of many proteins within the Hermissenda CNS. Collectively, our results suggest that in addition to PKC, one or more PTKs play an important role in conditioning-produced changes in type B cell excitability. PTKs and PKCs converge to effect reductions in B cell K(+) currents during conditioning, apparently through distinct biophysical mechanisms.
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Affiliation(s)
- Iksung Jin
- Program in Neuroscience, Indiana University, Bloomington, IN 47405-7007, USA
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20
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Positive AMPA receptor modulation rapidly stimulates BDNF release and increases dendritic mRNA translation. J Neurosci 2009; 29:8688-97. [PMID: 19587275 DOI: 10.1523/jneurosci.6078-08.2009] [Citation(s) in RCA: 175] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) stimulates local dendritic mRNA translation and is involved in formation and consolidation of memory. 2H,3H,6aH-pyrrolidino[2'',1''-3',2']1,3-oxazino[6',5'-5,4]-benzo[e]1,4-dioxan-10-one (CX614), one of the best-studied positive AMPA receptor modulators (also known as ampakines), increases BDNF mRNA and protein and facilitates long-term potentiation (LTP) induction. Several other ampakines also improve performance in various behavioral and learning tasks. Since local dendritic protein synthesis has been implicated in LTP stabilization and in memory consolidation, this study investigated whether CX614 could influence synaptic plasticity by upregulating dendritic protein translation. CX614 treatment of primary neuronal cultures and acute hippocampal slices rapidly activated the translation machinery and increased local dendritic protein synthesis. CX614-induced activation of translation was blocked by K252a [(9S,10R,12R)-2,3,9,10,11,12-hexahydro-10-hydroxy-9-methyl-1-oxo-9,12-epoxy-1H-diindolo[1,2,3-fg:3',2',1'-kl]pyrrolo[3,4-i][1,6]benzodiazocine-10-carboxylic acid methyl ester], CNQX, APV, and TTX, and was inhibited in the presence of an extracellular BDNF scavenger, TrkB-Fc. The acute effect of CX614 on translation was mediated by increased BDNF release as demonstrated with a BDNF scavenging assay using TrkB-Fc during CX614 treatment of cultured primary neurons and was blocked by nifedipine, ryanodine, and lack of extracellular Ca(2+) in acute hippocampal slices. Finally, CX614, like BDNF, rapidly increased dendritic translation of an exogenous translation reporter. Together, our results demonstrate that positive modulation of AMPA receptors rapidly stimulates dendritic translation, an effect mediated by BDNF secretion and TrkB receptor activation. They also suggest that increased BDNF secretion and stimulation of local protein synthesis contribute to the effects of ampakines on synaptic plasticity.
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Abe Y, Nawa H, Namba H. Activation of epidermal growth factor receptor ErbB1 attenuates inhibitory synaptic development in mouse dentate gyrus. Neurosci Res 2009; 63:138-48. [DOI: 10.1016/j.neures.2008.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Revised: 11/13/2008] [Accepted: 11/14/2008] [Indexed: 10/21/2022]
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22
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De Franceschi L, Biondani A, Carta F, Turrini F, Laudanna C, Deana R, Brunati AM, Turretta L, Iolascon A, Perrotta S, Elson A, Bulato C, Brugnara C. PTPepsilon has a critical role in signaling transduction pathways and phosphoprotein network topology in red cells. Proteomics 2008; 8:4695-708. [PMID: 18924107 PMCID: PMC3008556 DOI: 10.1002/pmic.200700596] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Indexed: 12/31/2022]
Abstract
Protein tyrosine phosphatases (PTPs) are crucial components of cellular signal transduction pathways. Here, we report that red blood cells (RBCs) from mice lacking PTPepsilon (Ptpre(-/-)) exhibit (i) abnormal morphology; (ii) increased Ca(2+)-activated-K(+) channel activity, which was partially blocked by the Src family kinases (SFKs) inhibitor PP1; and (iii) market perturbation of the RBC membrane tyrosine (Tyr-) phosphoproteome, indicating an alteration of RBC signal transduction pathways. Using the signaling network computational analysis of the Tyr-phosphoproteomic data, we identified seven topological clusters. We studied cluster 1 containing Fyn, SFK, and Syk another tyrosine kinase. In Ptpre(-/-)mouse RBCs, the activity of Fyn was increased while Syk kinase activity was decreased compared to wild-type RBCs, validating the network computational analysis, and indicating a novel signaling pathway, which involves Fyn and Syk in regulation of red cell morphology.
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Affiliation(s)
- Lucia De Franceschi
- Department of Clinical and Experimental Medicine, Section of Internal Medicine, University of Verona, Verona, Italy.
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23
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Mathew S, George SP, Wang Y, Siddiqui MR, Srinivasan K, Tan L, Khurana S. Potential molecular mechanism for c-Src kinase-mediated regulation of intestinal cell migration. J Biol Chem 2008; 283:22709-22. [PMID: 18482983 DOI: 10.1074/jbc.m801319200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The ubiquitously expressed Src tyrosine kinases (c-Src, c-Yes, and c-Fyn) regulate intestinal cell growth and differentiation. Src activity is also elevated in the majority of malignant and premalignant tumors of the colon. The development of fibroblasts with the three ubiquitously expressed kinases deleted (SYF cells) has identified the role of Src proteins in the regulation of actin dynamics associated with increased cell migration and invasion. Despite this, unexpectedly nothing is known about the role of the individual Src kinases on intestinal cell cytoskeleton and/or cell migration. We have previously reported that villin, an epithelial cell-specific actin-modifying protein that regulates actin reorganization, cell morphology, cell migration, cell invasion, and apoptosis, is tyrosine-phosphorylated. In this report using the SYF cells reconstituted individually with c-Src, c-Yes, c-Fyn, and wild type or phosphorylation site mutants of villin, we demonstrate for the first time the absolute requirement for c-Src in villin-induced regulation of cell migration. The other major finding of our study is that contrary to previous reports, the nonreceptor tyrosine kinase, Jak3 (Janus kinase 3), does not regulate phosphorylation of villin or villin-induced cell migration and is, in fact, not expressed in intestinal epithelial cells. Further, we identify SHP-2 and PTP-PEST (protein-tyrosine phosphatase proline-, glutamate-, serine-, and threonine-rich sequence) as negative regulators of c-Src kinase and demonstrate a new function for these phosphatases in intestinal cell migration. Together, these data suggest that in colorectal carcinogenesis, elevation of c-Src or down-regulation of SHP-2 and/or PTP-PEST may promote cancer metastases and invasion by regulating villin-induced cell migration and cell invasion.
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Affiliation(s)
- Sijo Mathew
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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Nagano T, Namba H, Abe Y, Aoki H, Takei N, Nawa H. In vivo administration of epidermal growth factor and its homologue attenuates developmental maturation of functional excitatory synapses in cortical GABAergic neurons. Eur J Neurosci 2007; 25:380-90. [PMID: 17284178 DOI: 10.1111/j.1460-9568.2007.05297.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ErbB1 ligand family includes epidermal growth factor (EGF), transforming growth factor-alpha (TGFalpha), heparin-binding EGF-like growth factor, amphiregulin and betacellulin. Previously, we demonstrated that TGFalpha decreases alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors in cultured neocortical gamma-aminobutyric acid (GABA) neurons. In the present study, we examined in vivo effects of EGF and TGFalpha in the mouse neocortex using electrophysiological and biochemical techniques. In mouse neonates, subcutaneously administered EGF penetrated the blood-brain barrier and activated ErbB1 in the neocortex. Daily administration of EGF or TGFalpha attenuates developmental increases in expression of the AMPA receptor subunits (GluR1 and GluR2/3) in the neocortex of postnatal mice. Immunohistochemistry revealed that the reduction in AMPA receptor expression was significant in the GABAergic neurons, especially those positive for parvalbumin. Using cortical slices prepared from EGF-treated mice, we recorded miniature excitatory postsynaptic currents (mEPSCs) in both GABAergic and pyramidal neurons. Subchronic treatment with EGF decreased the amplitude and frequency of mEPSCs in GABAergic neurons, but its effects were negligible on pyramidal neurons. We conclude that EGF or other ErbB1 ligand(s) attenuates a developmental increase in AMPA receptor expression and function in cortical GABAergic neurons.
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Affiliation(s)
- Tadasato Nagano
- Molecular Neurobiology, Brain Research Institute, Niigata University, 951-8585 Japan
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25
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Effects of chronic multiple stress on learning and memory and the expression of Fyn, BDNF, TrkB in the hippocampus of rats. Chin Med J (Engl) 2007. [DOI: 10.1097/00029330-200704020-00011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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26
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Caldeira MV, Melo CV, Pereira DB, Carvalho RF, Carvalho AL, Duarte CB. BDNF regulates the expression and traffic of NMDA receptors in cultured hippocampal neurons. Mol Cell Neurosci 2007; 35:208-19. [PMID: 17428676 DOI: 10.1016/j.mcn.2007.02.019] [Citation(s) in RCA: 179] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2006] [Revised: 02/20/2007] [Accepted: 02/22/2007] [Indexed: 12/19/2022] Open
Abstract
The neurotrophin BDNF regulates the activity-dependent modifications of synaptic strength in the CNS. Physiological and biochemical evidences implicate the NMDA glutamate receptor as one of the targets for BDNF modulation. In the present study, we investigated the effect of BDNF on the expression and plasma membrane abundance of NMDA receptor subunits in cultured hippocampal neurons. Acute stimulation of hippocampal neurons with BDNF differentially upregulated the protein levels of the NR1, NR2A and NR2B NMDA receptor subunits, by a mechanism sensitive to transcription and translation inhibitors. Accordingly, BDNF also increased the mRNA levels for NR1, NR2A and NR2B subunits. The neurotrophin NT3 also upregulated the protein levels of NR2A and NR2B subunits, but was without effect on the NR1 subunit. The amount of NR1, NR2A and NR2B proteins associated with the plasma membrane of hippocampal neurons was differentially increased by BDNF stimulation for 30 min or 24 h. The rapid upregulation of plasma membrane-associated NMDA receptor subunits was correlated with an increase in NMDA receptor activity. The results indicate that BDNF increases the abundance of NMDA receptors and their delivery to the plasma membrane, thereby upregulating receptor activity in cultured hippocampal neurons.
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Affiliation(s)
- Margarida V Caldeira
- Center for Neuroscience and Cell Biology, Department of Zoology, University of Coimbra, 3004-517 Coimbra, Portugal
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27
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Caldeira MV, Melo CV, Pereira DB, Carvalho R, Correia SS, Backos DS, Carvalho AL, Esteban JA, Duarte CB. Brain-derived neurotrophic factor regulates the expression and synaptic delivery of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor subunits in hippocampal neurons. J Biol Chem 2007; 282:12619-28. [PMID: 17337442 DOI: 10.1074/jbc.m700607200] [Citation(s) in RCA: 183] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) plays an important role in synaptic plasticity in the hippocampus, but the mechanisms involved are not fully understood. The neurotrophin couples synaptic activation to changes in gene expression underlying long term potentiation and short term plasticity. Here we show that BDNF acutely up-regulates GluR1, GluR2, and GluR3 alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor subunits in 7-day in vitro cultured hippocampal neurons. The increase in GluR1 and GluR2 protein levels in developing cultures was impaired by K252a, a tropomyosin-related [corrected] kinase (Trk) inhibitor, and by translation (emetine and anisomycin) and transcription (alpha-amanitine and actinomycin D) inhibitors [corrected] The increase in GluR1 and GluR2 protein levels in developing cultures was impaired by K252a, a Trk inhibitor, and by translation (emetine and anisomycin) and transcription (alpha-amanitine and actinomycin D) inhibitors. Accordingly, BDNF increased the mRNA levels for GluR1 and GluR2 subunits. Biotinylation studies showed that stimulation with BDNF for 30 min selectively increased the amount of GluR1 associated with the plasma membrane, and this effect was abrogated by emetine. Under the same conditions, BDNF induced GluR1 phosphorylation on Ser-831 through activation of protein kinase C and Ca(2+)-calmodulin-dependent protein kinase II. Chelation of endogenous extracellular BDNF with TrkB-IgG selectively decreased GluR1 protein levels in 14-day in vitro cultures of hippocampal neurons. Moreover, BDNF promoted synaptic delivery of homomeric GluR1 AMPA receptors in cultured organotypic slices, by a mechanism independent of NMDA receptor activation. Taken together, the results indicate that BDNF up-regulates the protein levels of AMPA receptor subunits in hippocampal neurons and induces the delivery of AMPA receptors to the synapse.
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Affiliation(s)
- Margarida V Caldeira
- Center for Neuroscience and Cell Biology, Department of Zoology, University of Coimbra, 3004-517 Coimbra, Portugal
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Kotani T, Morone N, Yuasa S, Nada S, Okada M. Constitutive activation of neuronal Src causes aberrant dendritic morphogenesis in mouse cerebellar Purkinje cells. Neurosci Res 2007; 57:210-9. [PMID: 17137665 DOI: 10.1016/j.neures.2006.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Revised: 10/04/2006] [Accepted: 10/19/2006] [Indexed: 01/06/2023]
Abstract
Src family tyrosine kinases are essential for neural development, but their in vivo functions remain elusive because of functional compensation among family members. To elucidate the roles of individual Src family members in vivo, we generated transgenic mice expressing the neuronal form of c-Src (n-Src), Fyn, and their constitutively active forms in cerebellar Purkinje cells using the L7 promoter. The expression of the constitutively active n-Src retarded the postnatal development of Purkinje cells and disrupted dendritic morphogenesis, whereas the wild-type n-Src had only moderate effects. Neither wild-type nor constitutively active Fyn over-expression significantly affected Purkinje-cell morphology. The aberrant Purkinje cells in n-Src transgenic mice retained multiple dendritic shafts extending in non-polarized directions and were located heterotopically in the molecular layer. Ultrastructural observation of the dendritic shafts revealed that the microtubules of n-Src transgenic mice were more densely and irregularly arranged, and had structural deformities. In primary culture, Purkinje cells from n-Src transgenic mice developed abnormally thick dendritic shafts and large growth-cone-like structures with poorly extended dendrites, which could be rescued by treatment with a selective inhibitor of Src family kinases, PP2. These results suggest that n-Src activity regulates the dendritic morphogenesis of Purkinje cells through affecting microtubule organization.
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Affiliation(s)
- Takenori Kotani
- Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, Japan
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Abstract
Nonreceptor protein tyrosine kinases of the Src family regulate the survival, proliferation, differentiation, and motility of many cell types, but their roles in brain development are unclear. Biochemical and in vitro experiments implicate Src and Fyn in the Reelin-dependent tyrosine phosphorylation of Dab1, which controls the positioning of radially migrating neurons in many brain regions. However, genetic evidence that either Src or Fyn mediates Reelin-dependent migrations in vivo has been lacking. Here, we report that, although Src is dispensable and although the absence of Fyn causes an intermediate phenotype, the combined absence of Src and Fyn almost abolishes tyrosine phosphorylation of Dab1 and causes defects in the fetal cortex and cerebellum very similar to those of dab1 mutants of the same age. Neurogenesis is not detectably affected, but the layering of neurons in the cortex is inverted, and the formation of the Purkinje plate is impaired. This implies that Src and Fyn are needed for Reelin-dependent events during brain development.
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Affiliation(s)
- Gloria Kuo
- Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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Namba H, Nagano T, Iwakura Y, Xiong H, Jourdi H, Takei N, Nawa H. Transforming growth factor alpha attenuates the functional expression of AMPA receptors in cortical GABAergic neurons. Mol Cell Neurosci 2006; 31:628-41. [PMID: 16443372 PMCID: PMC3683556 DOI: 10.1016/j.mcn.2005.12.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Revised: 11/05/2005] [Accepted: 12/08/2005] [Indexed: 02/04/2023] Open
Abstract
In the developing neocortex, brain-derived neurotrophic factor (BDNF) exerts a trophic activity to increase the expression and channel activity of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptor subunits. Here, we demonstrate that the epidermal growth factor (EGF) receptor (ErbB1) ligands exert the opposite biological activity in cultured neocortical neurons. Subchronic stimulation of ErbB1 with transforming growth factor alpha (TGFalpha), EGF, or heparin-binding EGF (HB-EGF) down-regulated protein expression of the GluR1 AMPA receptor subunit in cultured neocortical neurons. In agreement, TGFalpha treatment decreased the Bmax of [3H] AMPA binding and GluR1 mRNA levels. Immunocytochemistry revealed that the decrease in GluR1 was most pronounced in multipolar GABAergic neurons. To examine the physiological consequences, we recorded AMPA-evoked currents as well as miniature excitatory postsynaptic currents in morphologically identified putative GABAergic neurons in culture. Subchronic TGFalpha treatment decreased AMPA-triggered currents as well as the amplitude and frequency of miniature excitatory postsynaptic currents. An ErbB1 tyrosine kinase inhibitor, PD153035, inhibited the TGFalpha effect. Moreover, TGFalpha counteracted the neurotrophic activity of BDNF on AMPA receptor expression. Co-application of TGFalpha with BDNF blocked the BDNF-triggered up-regulation of AMPA receptor expression and currents. These observations reveal a negative regulatory activity of the ErbB1 ligand, TGFalpha, which reduces the input sensitivity of cortical GABAergic neurons to attenuate their inhibitory function.
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Affiliation(s)
- Hisaaki Namba
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, 1-757 Asahimachi, Niigata 951-8585, Japan
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YOKOMAKU D, JOURDI H, KAKITA A, NAGANO T, TAKAHASHI H, TAKEI N, NAWA H. ErbB1 receptor ligands attenuate the expression of synaptic scaffolding proteins, GRIP1 and SAP97, in developing neocortex. Neuroscience 2005; 136:1037-47. [PMID: 16226841 PMCID: PMC3659789 DOI: 10.1016/j.neuroscience.2005.08.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Revised: 07/23/2005] [Accepted: 08/04/2005] [Indexed: 01/01/2023]
Abstract
Scaffolding proteins containing postsynaptic density-95/discs large/zone occludens-1 (PDZ) domains interact with synaptic receptors and cytoskeletal components and are therefore implicated in synaptic development and plasticity. Little is known, however, about what regulates the expression of PDZ proteins and how the levels of these proteins influence synaptic development. Here, we show that ligands for epidermal growth factor receptors (ErbB1) decrease a particular set of PDZ proteins and negatively influence synaptic formation or maturation. In short-term neocortical cultures, concentrations of epidermal growth factor and amphiregulin (2-9 pM) decreased the expression of glutamate receptor interacting protein 1 (GRIP1) and synapse-associated protein 97 kDa (SAP97) without affecting postsynaptic density-95 (PSD-95) levels and glial proliferation. In long-term cultures, epidermal growth factor treatment resulted in a decrease in the frequency of pan-PDZ-immunoreactive aggregates on dendritic processes. A similar activity on the same PDZ proteins was observed in the developing neocortex following epidermal growth factor administration to rat neonates. Immunoblotting revealed that administered epidermal growth factor from the periphery activated brain ErbB1 receptors and decreased GRIP1 and SAP97 protein levels in the neocortex. Laser-confocal imaging indicated that epidermal growth factor administration suppressed the formation of pan-PDZ-immunoreactive puncta and dispersed those structures in vivo as well. These findings revealed a novel negative activity of ErbB1 receptor ligands that attenuates the expression of the PDZ proteins and inhibits postsynaptic maturation in developing neocortex.
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Affiliation(s)
- D. YOKOMAKU
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan
| | - H. JOURDI
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan
| | - A. KAKITA
- Brain Resource Center, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - T. NAGANO
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan
| | - H. TAKAHASHI
- Department of Pathology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - N. TAKEI
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan
| | - H. NAWA
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan
- Corresponding author. Fax: +81-25-227-0815. (H. Nawa)
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O'Neill MJ, Murray TK, Whalley K, Ward MA, Hicks CA, Woodhouse S, Osborne DJ, Skolnick P. Neurotrophic actions of the novel AMPA receptor potentiator, LY404187, in rodent models of Parkinson's disease. Eur J Pharmacol 2004; 486:163-74. [PMID: 14975705 DOI: 10.1016/j.ejphar.2003.12.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2003] [Indexed: 11/29/2022]
Abstract
Recent developments in the molecular biology and pharmacology of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors has led to the discovery of selective, potent and systemically active AMPA receptor potentiators. These molecules enhance synaptic transmission and evidence suggests that they play important roles in plasticity and cognitive processes. Activation of AMPA receptors also increases neuronal activation and activity-dependent signalling, which may increase brain-derived neurotrophic factor (BDNF) expression and enhance cell proliferation in the brain. We therefore hypothesised that an AMPA receptor potentiator may provide neurotrophic effects in rodent models of Parkinson's disease. In the present studies we report that the potent and selective AMPA receptor potentiator, R,S-N-2-(4-(4-Cyanophenyl)phenyl)propyl 2-propanesulfonamide (LY404187), provides both functional, neurochemical and histological protection against unilateral infusion of 6-hydroxydopamine into the substantia nigra or striatum of rats. The compound also reduced 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced toxicity in mice. Interestingly, we were also able to observe large functional and histological effects when we delayed treatment until after cell death had occurred (3 or 6 days after 6-hydroxydopamine infusion), supporting a neurotrophic mechanism of action. In addition, LY404187 provided a dose-dependent increase in growth-associated protein-43 expression in the striatum. Therefore, we propose that AMPA receptor potentiators offer the potential of a new therapy to halt the progression and perhaps repair the degeneration in Parkinson's disease.
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MESH Headings
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine
- Animals
- Corpus Striatum/metabolism
- Corpus Striatum/pathology
- Disease Models, Animal
- Dose-Response Relationship, Drug
- GAP-43 Protein/biosynthesis
- In Vitro Techniques
- Injections, Subcutaneous
- Male
- Mice
- Mice, Inbred C57BL
- Motor Activity/drug effects
- Neuroprotective Agents/administration & dosage
- Neuroprotective Agents/pharmacology
- Neuroprotective Agents/therapeutic use
- Oxidopamine
- Parkinson Disease, Secondary/chemically induced
- Parkinson Disease, Secondary/drug therapy
- Parkinson Disease, Secondary/pathology
- Rats
- Rats, Sprague-Dawley
- Receptors, AMPA/agonists
- Substantia Nigra/metabolism
- Substantia Nigra/pathology
- Sulfonamides/administration & dosage
- Sulfonamides/pharmacology
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Affiliation(s)
- Michael J O'Neill
- Eli Lilly and Co. Ltd., Lilly Research Centre, Erl Wood Manor, Windlesham, Surrey GU20 6PH, UK.
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Jourdi H, Iwakura Y, Narisawa-Saito M, Ibaraki K, Xiong H, Watanabe M, Hayashi Y, Takei N, Nawa H. Brain-derived neurotrophic factor signal enhances and maintains the expression of AMPA receptor-associated PDZ proteins in developing cortical neurons. Dev Biol 2003; 263:216-30. [PMID: 14597197 PMCID: PMC3683555 DOI: 10.1016/j.ydbio.2003.07.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Postsynaptic molecules with PDZ domains (PDZ proteins) interact with various glutamate receptors and regulate their subcellular trafficking and stability. In rat neocortical development, the protein expression of AMPA-type glutamate receptor GluR1 lagged behind its mRNA expression and rather paralleled an increase in PDZ protein levels. One of the neurotrophins, brain-derived neurotrophic factor (BDNF), appeared to contribute to this process, regulating the PDZ protein expression. In neocortical cultures, BDNF treatment upregulated SAP97, GRIP1, and Pick1 PDZ proteins. Conversely, BDNF gene targeting downregulated these same PDZ molecules. The BDNF-triggered increases in PDZ proteins resulted in the elevation of their total association with the AMPA receptors GluR1 and GluR2/3, which led to the increase in AMPA receptor proteins. When Sindbis viruses carrying GluR1 or GluR2 C-terminal decoys disrupted their interactions, GluR2 C-terminal decoys inhibited both BDNF-triggered GluR1 and GluR2/3 increases, whereas GluR1 C-terminal decoys blocked only the BDNF-triggered GluR1 increase. In agreement, coexpression of SAP97 and GluR1 in nonneuronal HEK293 cells increased both proteins compared with their single transfection, implying mutual stabilization. This work reveals a novel function of BDNF in postsynaptic development by regulating the PDZ protein expression.
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Affiliation(s)
- Hussam Jourdi
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Yuriko Iwakura
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Mako Narisawa-Saito
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Kyoko Ibaraki
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Huabao Xiong
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Masahiko Watanabe
- Department of Anatomy and Embryology, Graduate School of Medicine, Hokkaido University, Sapporo, 060-8638, Japan
| | - Yasunori Hayashi
- RIKEN-MIT Neuroscience Research Center, Center for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Nobuyuki Takei
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Hiroyuki Nawa
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
- Corresponding author. Fax: +81-25-227-0815. (H. Nawa)
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Martinez MC, Ochiishi T, Majewski M, Kosik KS. Dual regulation of neuronal morphogenesis by a delta-catenin-cortactin complex and Rho. J Cell Biol 2003; 162:99-111. [PMID: 12835311 PMCID: PMC2172717 DOI: 10.1083/jcb.200211025] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Delta-catenin is a neuronal protein that contains 10 Armadillo motifs and binds to the juxtamembrane segment of classical cadherins. We report that delta-catenin interacts with cortactin in a tyrosine phosphorylation-dependent manner. This interaction occurs within a region of the delta-catenin sequence that is also essential for the neurite elongation effects. Src family kinases can phosphorylate delta-catenin and bind to delta-catenin through its polyproline tract. Under conditions when tyrosine phosphorylation is reduced, delta-catenin binds to cortactin and cells extend unbranched primary processes. Conversely, increasing tyrosine phosphorylation disrupts the delta-catenin-cortactin complex. When RhoA is inhibited, delta-catenin enhances the effects of Rho inhibition on branching. We conclude that delta-catenin contributes to setting a balance between neurite elongation and branching in the elaboration of a complex dendritic tree.
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Affiliation(s)
- Maria Cruz Martinez
- Dept. of Neurology, Brigham and Women's Hospital and Harvard Medical School, Harvard Institute of Medicine, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
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35
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Futamura T, Toyooka K, Iritani S, Niizato K, Nakamura R, Tsuchiya K, Someya T, Kakita A, Takahashi H, Nawa H. Abnormal expression of epidermal growth factor and its receptor in the forebrain and serum of schizophrenic patients. Mol Psychiatry 2003; 7:673-82. [PMID: 12192610 DOI: 10.1038/sj.mp.4001081] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2001] [Revised: 12/13/2001] [Accepted: 01/16/2002] [Indexed: 11/09/2022]
Abstract
Epidermal growth factor (EGF) comprises a structurally related family of proteins containing heparin-binding EGF-like growth factor (HB-EGF) and transforming growth factor alpha (TGFalpha) that regulates the development of dopaminergic neurons as well as monoamine metabolism. We assessed the contribution of EGF to schizophrenia by measuring EGF family protein levels in postmortem brains and in fresh serum of schizophrenic patients and control subjects. EGF protein levels were decreased in the prefrontal cortex and striatum of schizophrenic patients, whereas the levels of HB-EGF and TGFalpha were not significantly different in any of the regions examined. Conversely, EGF receptor expression was elevated in the prefrontal cortex. Serum EGF levels were markedly reduced in schizophrenic patients, even in young, drug-free patients. Chronic treatment of animals with the antipsychotic drug haloperidol had no influence on EGF levels in the brain or serum. These findings suggest that there is abnormal EGF production in various central and peripheral tissues of patients with both acute and chronic schizophrenia. EGF might thus provide a molecular substrate for the pathologic manifestation of the illness, although additional studies are required to determine a potential link between impaired EGF signaling and the pathology/etiology of schizophrenia.
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Affiliation(s)
- T Futamura
- Molecular Neurobiology, Brain Research Institute, Niigata University, Japan
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36
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Narisawa-Saito M, Iwakura Y, Kawamura M, Araki K, Kozaki S, Takei N, Nawa H. Brain-derived neurotrophic factor regulates surface expression of alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid receptors by enhancing the N-ethylmaleimide-sensitive factor/GluR2 interaction in developing neocortical neurons. J Biol Chem 2002; 277:40901-10. [PMID: 12130635 DOI: 10.1074/jbc.m202158200] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In hippocampal neurons, the exocytotic process of alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA)-type glutamate receptors is known to depend on activation of N-methyl-d-aspartate channels and its resultant Ca(2+) influx from extracellular spaces. Here we found that brain-derived neurotrophic factor (BDNF) induced a rapid surface translocation of AMPA receptors in an activity-independent manner in developing neocortical neurons. The receptor translocation became evident within hours as monitored by [(3)H]AMPA binding and was resistant against ionotropic glutamate receptor antagonists as evidenced with surface biotinylation assay. This process required intracellular Ca(2+) and was inhibited by the blockers of conventional exocytosis, brefeldin A, botulinum toxin B, and N-ethylmaleimide. To explore the translocation mechanism of individual AMPA receptor subunits, we utilized the human embryonic kidney (HEK) 293 cells carrying the BDNF receptor TrkB. After the single transfection of GluR2 cDNA or GluR1 cDNA into HEK/TrkB cells, BDNF triggered the translocation of GluR2 but not that of GluR1. Subsequent mutation analysis of GluR2 carboxyl-terminal region indicated that the translocation of GluR2 subunit in HEK293 cells involved its N-ethylmaleimide-sensitive factor-binding domain but not its PDZ-interacting site. Following co-transfection of GluR1 and GluR2 cDNAs, solid phase cell sorting revealed that GluR1 subunits were also able to translocate to the cell surface in response to BDNF. An immunoprecipitation assay confirmed that BDNF stimulation can enhance the interaction of GluR2 with N-ethylmaleimide-sensitive factor. These results reveal a novel role of BDNF in regulating the surface expression of AMPA receptors through a GluR2-NSF interaction.
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Affiliation(s)
- Mako Narisawa-Saito
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
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Yu Z, Cheng G, Wen X, Wu GD, Lee WT, Pleasure D. Tumor necrosis factor alpha increases neuronal vulnerability to excitotoxic necrosis by inducing expression of the AMPA-glutamate receptor subunit GluR1 via an acid sphingomyelinase- and NF-kappaB-dependent mechanism. Neurobiol Dis 2002; 11:199-213. [PMID: 12460558 DOI: 10.1006/nbdi.2002.0530] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Acid sphingomyelinase (ASMase) and NF-kappaB participate in tumor necrosis factor alpha (TNFalpha) signal transduction. Mice in which the genes encoding ASMase or the p50 subunit of NF-kappaB are disrupted have been reported to be less vulnerable than wild-type mice to focal brain ischemia. We now demonstrate selective diminution in expression of GluR1, an alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate-type glutamate receptor (AMPA-GluR) protein subunit, in these two groups of knockout mice. To confirm that neuronal GluR1 expression is regulated by ASMase and NF-kappaB, and to learn whether this regulation has pathophysiological significance, we treated cultured human NT2-N neurons with TNFalpha. This induced GluR1 expression and increased susceptibility of the neurons to kainate necrosis. Both induction of GluR1 and heightened vulnerability to kainate were blocked by inhibiting ASMase or by antisense knockdown of NF-kappaB p50. We conclude that TNFalpha can sensitize neurons to excitotoxic necrosis by inducing expression of GluR1 via an ASMase- and NF-kappaB-dependent mechanism. TNFalpha levels are frequently elevated during ischemia and other CNS diseases in which excitotoxicity contributes to neuronal loss. Our results suggest that inhibiting TNFalpha signal transduction will diminish neuronal necrosis in these diseases.
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Affiliation(s)
- ZaiFang Yu
- Department of Neurology Research, University of Pennsylvania School of Medicine, Philadelphia 19104, USA
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38
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Mackowiak M, O'Neill MJ, Hicks CA, Bleakman D, Skolnick P. An AMPA receptor potentiator modulates hippocampal expression of BDNF: an in vivo study. Neuropharmacology 2002; 43:1-10. [PMID: 12213254 DOI: 10.1016/s0028-3908(02)00066-7] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
AMPA receptor activation has been demonstrated to increase the neuronal expression of brain derived neurotrophic factor (BDNF). In the present study, we investigated the effect of a novel AMPA receptor potentiator (LY404187) and its active isomer (LY451646) on the expression of BDNF protein and mRNA, as well as TrkB mRNA in rat hippocampus. LY404187 administered for 7 days (1 mg/kg) significantly increased the number of BDNF immunopositive cells in the dentate gyrus, but not other hippocampal subfields. Chronic treatment (7 days) with LY451646 (0.5 mg/kg, comparable to 1 mg/kg of LY404187) increased the level of both BDNF and TrkB mRNA expression in the dentate gyrus, CA3 and CA4 of the hippocampus. However, chronic treatment with lower doses of LY451646 (0.125 and 0.25 mg/kg) decreased the level of BDNF and TrkB mRNA in hippocampus, whilst the highest used dose of LY451646 (1 mg/kg) had no effect on BDNF and TrkB mRNA in hippocampus. In contrast, acute treatment with LY451646 produced an increase in BDNF mRNA levels at doses of 0.125 and 0.25 mg/kg in the hippocampus (CA4, CA3 and dentate gyrus, but not in CA1). LY451646 at 0.5 mg/kg had no effect, but at 1.0 mg/kg decreased the level of BDNF mRNA in hippocampus. Acute treatment with LY451646 did not affect the TrkB receptor mRNA levels in hippocampus. Our results demonstrate that biarylpropylsulfonamide AMPA receptor potentiators are capable of modulating the expression of BDNF and TrkB mRNA in a dose- and time-dependent manner. The increase in both BDNF protein and mRNA expression in the dentate gyrus but not in CA1 indicates a specific role of AMPA receptors in the regulation of BDNF expression in this hippocampal subfield. The regulation of BDNF expression by biarylpropylsulfonamids such as LY451646 may have important therapeutical implications for this class of molecule in the treatment of depression and other CNS disorders.
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Affiliation(s)
- Marzena Mackowiak
- Eli Lilly and Co Ltd, Lilly Corporate Center, Indianapolis, IN 46285-0814, USA.
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Palestini P, Botto L, Guzzi F, Calvi C, Ravasi D, Masserini M, Pitto M. Developmental changes in the protein composition of sphingolipid- and cholesterol-enriched membrane domains of rat cerebellar granule cells. J Neurosci Res 2002; 67:729-38. [PMID: 11891786 DOI: 10.1002/jnr.10170] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The biological role of cell membrane domains has been investigated in a number of eukariotic cells, but less attention has been paid to the neuron. In the present investigation, we assessed the changes in lipid and protein composition of detergent-resistant membrane fractions prepared from cultured rat cerebellar granule cells, during differentiation and maturation in vitro. At any stage of the cell life, low-density, detergent-resistant fractions, characterised by the specific presence of prion protein, were enriched in glycolipids, cholesterol, and sphingomyelin. The enrichment in sphingomyelin was developmentally regulated, increasing continuously during cell differentiation and maturation. Concerning proteins, domains were enriched in Fyn and TAG-1, which present exclusively within this fraction at any stage of cell culture, and in GAP-43, mainly during the differentiation stage. On the other side, proteins affecting signal transduction and cytoskeleton-related proteins (heterotrimeric G-proteins, protein kinase C, MARCKS, tubulin), were not enriched within detergent-resistant fractions during cell differentiation, but were recovered within this fraction in mature neurons. These results indicate that during different cellular life stages, specific proteins are recruited within detergent-resistant membrane domains of the neuron and suggest their involvement in specific physiological phenomena (differentiation, maturation and/or aging).
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Affiliation(s)
- Paola Palestini
- Department of Experimental, Environmental Medicine and Biotechnologies (DIMESAB), University of Milano-Bicocca, Monza, Italy.
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40
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Jourdi H, Nawa H. Basic Fibroblast Growth Factor Modulates the Expression of PDZ Domain-containing Proteins in Cultured Cortical Neurons. ACTA MEDICA ET BIOLOGICA 2002; 50:107-115. [PMID: 23794785 PMCID: PMC3685851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Different cytokines and growth factors, together with their receptors, are expressed in brain tissue. One such molecule is the basic fibroblast growth factor (bFGF) that has recently been shown to promote survival following insults to neurons in vivo or in vitro. In this study, we found that repeated treatment of neocortical cultures with bFGF modulated the expression of various PDZ domain-containing proteins (SAP97, GRIP1, Pick1, and PSD-93) and that the patterns of their immunostaining matched the bFGF effects on their total protein expression. For instance, bFGF decreased the expression of SAP97, GRIP1, and Pick1 (PDZ proteins that interact with the AMPA-type glutamate receptor subunits GluR1 and GluR2/3). PSD-93, which associates with the NMDA-type glutamate receptor, was increased by bFGF. Moreover, the interactions of GluR1 with SAP97 and GluR2 with GRIP1 were down-regulated by the repeated bFGF stimulation, as revealed by co-immunoprecipitation. Together, these results describe a novel function of bFGF in the regulation of expression of PDZ proteins.
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Affiliation(s)
- Hussam Jourdi
- Department of Molecular Neurobiology, Brain Research Institute, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
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41
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Nawa H, Takei N. BDNF as an anterophin; a novel neurotrophic relationship between brain neurons. Trends Neurosci 2001; 24:683-4; discussion 684-5. [PMID: 11718853 DOI: 10.1016/s0166-2236(00)01955-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Studies of the peripheral nervous system have led to the concept of target-derived neurotrophic support. Neurotrophic factors such as nerve growth factor are now known to act as retrograde trophic factors--retrophins--that are produced in the target cells and released to presynaptic neurons. However, using brain-derived neurotrophic factor (BDNF) tagged with green-fluorescent protein to monitor the subcellular dynamics of BDNF in neurites, Tsumoto and colleagues have provided persuasive visual evidence that BDNF can be released at the synapses of brain neurons in an activity-dependent manner to act on postsynaptic neurons. Accordingly, BDNF serves as an anterophin to regulate postsynaptic development and plasticity in the central nervous system.
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Affiliation(s)
- H Nawa
- Division of Molecular Neurobiology, Brain Research Institute, Niigata University, 951-8585 Japan.
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42
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Rong Y, Lu X, Bernard A, Khrestchatisky M, Baudry M. Tyrosine phosphorylation of ionotropic glutamate receptors by Fyn or Src differentially modulates their susceptibility to calpain and enhances their binding to spectrin and PSD-95. J Neurochem 2001; 79:382-90. [PMID: 11677266 DOI: 10.1046/j.1471-4159.2001.00565.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Both tyrosine phosphorylation and calpain-mediated truncation of ionotropic glutamate receptors are important mechanisms for synaptic plasticity. Previous work from our laboratory has shown that calpain activation results in truncation of the C-terminal domains of several glutamate receptor subunits. To test whether and how tyrosine phosphorylation of glutamate ionotropic receptor subunits modulates calpain susceptibility, synaptic membranes were phosphorylated by Fyn or Src, two members of the Src family tyrosine kinases. Tyrosine phosphorylation of synaptic membranes by Src significantly reduced calpain-mediated truncation of both NR2A and NR2B subunits of NMDA receptors, but not of GluR1 subunits of AMPA receptors. In contrast, phosphorylation with Fyn significantly protected calpain-mediated truncation of GluR1 subunits of AMPA receptors, but enhanced calpain-mediated truncation of NR2A subunits of NMDA receptors. Similar results were observed with NR2A and NR2B C-terminal domain fusion proteins phosphorylated by Fyn or Src before incubation with calpain and calcium. In addition, phosphorylation of NR2A and NR2B C-terminal fusion proteins by Fyn or Src enhanced their binding to spectrin and PSD-95. Thus, tyrosine phosphorylation impairs or facilitates calpain-mediated truncation of glutamate receptor subunits, depending on which tyrosine kinase is activated. Such mechanisms could serve to regulate receptor integrity and location, in addition to modulating channel properties.
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Affiliation(s)
- Y Rong
- Neuroscience Program, University of Southern California, Los Angeles 90089-2520, USA
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43
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Yamada M, Tanabe K, Wada K, Shimoke K, Ishikawa Y, Ikeuchi T, Koizumi S, Hatanaka H. Differences in survival-promoting effects and intracellular signaling properties of BDNF and IGF-1 in cultured cerebral cortical neurons. J Neurochem 2001; 78:940-51. [PMID: 11553668 DOI: 10.1046/j.1471-4159.2001.00497.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) and insulin-like growth factor-1 (IGF-1) act on various neurons of the CNS as neurotrophic factors promoting neuronal differentiation and survival. We examined the survival-promoting effects of BDNF and IGF-1 on serum deprivation-induced death in cultured cerebral cortical neurons, and compared the intracellular signaling pathways stimulated by BDNF and IGF-1 in the neurons. We found that the survival-promoting effect of BDNF was much weaker than that of IGF-1 in serum deprivation-induced death of cultured cortical neurons. We found no differences in the levels of phosphatidylinositol 3-kinase (PtdIns3-K) activity or Akt (also called PKB) phosphorylation induced by BDNF and IGF-1 in the cultured cortical neurons, although many reports suggest that PtdIns3-K and Akt are involved in survival promotion. In addition, phosphorylation signals of mitogen-activated protein kinase (MAPK) and cAMP responsive element-binding protein (CREB), which have also been reported to be involved in survival promotion, were stimulated by BDNF much more potently than by IGF-1. These results show that there may be, as yet unidentified, intracellular signaling pathways other than the PtdIns3-K-Akt, MAPK and CREB signaling, to regulate survival promotion. These unidentified signaling pathways may be responsible for the distinct strengths of the survival-promoting effects of BDNF and IGF-1.
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Affiliation(s)
- M Yamada
- Institute for Protein Research, Osaka University, Osaka, Japan.
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44
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Li W, Okano A, Tian QB, Nakayama K, Furihata T, Nawa H, Suzuki T. Characterization of a novel synGAP isoform, synGAP-beta. J Biol Chem 2001; 276:21417-24. [PMID: 11278737 DOI: 10.1074/jbc.m010744200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We cloned a cDNA encoding a novel synGAP, synGAP-d (GenBank(TM) accession number ), from a rat brain cDNA library. The clone consisted of 4801 nucleotides with a coding sequence of 3501 nucleotides, encoded a protein consisting of 1166 amino acids with >99% homology with 1092 amino acid overlaps to synGAP, and contained a 13-nucleotide insertion to the previously reported synGAP mRNAs, which suggested that the clone was a splice variant of synGAP. We also found that there are at least seven variants in the 3' portion of the synGAP mRNA and that they encoded five different protein isoforms. The coding sequence of these C-terminal variants were classified into alpha1, alpha2, beta1, beta2, beta3, beta4, and gamma, and synGAP-d was classified as the beta1 form. The previously reported synGAPs (synGAP-a, -b, and -c and p135synGAP) can be classified as the alpha1 isoform. All isoforms were expressed specifically in the brain. Unexpectedly, the beta isoform, which lacks a C-terminal PSD-95-binding motif ((S/T)XV), was more restricted to the postsynaptic density fraction than the motif-containing alpha1 isoform. The beta isoform did not interact with PSD-95 but specifically interacted with a nonphosphorylated alpha subunit of Ca(2+)/calmodulin-dependent protein kinase II through its unique C-terminal tail.
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Affiliation(s)
- W Li
- Department of Neuroplasticity, Research Center on Aging and Adaptation, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
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Gonzalez de la Vega A, Buño W, Pons S, Garcia-Calderat MS, Garcia-Galloway E, Torres-Aleman I. Insulin-like growth factor I potentiates kainate receptors through a phosphatidylinositol 3-kinase dependent pathway. Neuroreport 2001; 12:1293-6. [PMID: 11338209 DOI: 10.1097/00001756-200105080-00047] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Neurotrophic factors modulate synaptic plasticity through mechanisms that include regulation of membrane ion channels and neurotransmitter receptors. Recently, it was shown that insulin-like growth factor I (IGF-I) induces depression of AMPA-mediated currents without affecting NMDA-receptor function in neurons. We now report that IGF-I markedly potentiates the kainate-preferring ionotropic glutamate receptor in young cerebellar granule neurons expressing functional kainate-, but not AMPA-mediated currents. Potentiation of kainate responses by IGF-I is blocked by wortmannin, a phosphatidylinositol 3-kinase (P13K) inhibitor, indicating a role for this kinase in the effect of IGF-I. These results reinforce the notion that modulation of ionotropic glutamate receptors are involved in the regulatory actions of IGF-I on neuronal plasticity.
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Kovács AD, Cebers G, Cebere A, Moreira T, Liljequist S. Cortical and striatal neuronal cultures of the same embryonic origin show intrinsic differences in glutamate receptor expression and vulnerability to excitotoxicity. Exp Neurol 2001; 168:47-62. [PMID: 11170720 DOI: 10.1006/exnr.2000.7576] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cortical and striatal cultures were prepared from the same embryonic rat brains and maintained in identical culture conditions. In this way, the intrinsic, genetically imprinted differences determine the responses of cortical and striatal neurons in comparative studies. Cortical and striatal neurons differed in their sensitivity to glutamate receptor-mediated neurotoxicity as measured by the MTT cell viability assay. On the 8th day in vitro, striatal cultures were less sensitive to N-methyl-d-aspartate (NMDA)-induced toxicity than cortical, although both cultures were equally vulnerable to alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)- or kainate-induced toxicity. The AMPA receptor-mediated cell death in cortical cultures, however, was much more dependent on preventing AMPA receptor desensitization than in striatal cultures. Furthermore, glutamate-induced neurotoxicity was primarily mediated by NMDA receptors in cortical cultures, while blockade of either NMDA or AMPA receptors gave almost complete protection against glutamate in striatal cultures. To elucidate the molecular mechanisms responsible for the observed differences, we analyzed the expression of NMDA receptor subunits (NR1, NR2A-C) at the mRNA and the protein level in cortical and striatal cultures as well as in standard cerebellar granule cell cultures. The lowest expression level of NMDA receptor subunits was found in striatal cultures, thereby providing a possible explanation for their lower sensitivity to NMDA. Remarkable differences were found between the relative rates of mRNA and protein expression for NR1 and NR2B in the three cultures, indicative of intrinsic differences in the posttranscriptional regulation of NMDA receptor subunit expression in cultures from various brain regions.
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Affiliation(s)
- A D Kovács
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176 Stockholm, Sweden
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47
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Nawa H, Takahashi M, Patterson PH. Cytokine and growth factor involvement in schizophrenia--support for the developmental model. Mol Psychiatry 2000; 5:594-603. [PMID: 11126390 DOI: 10.1038/sj.mp.4000730] [Citation(s) in RCA: 161] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Medical treatment with various cytokines can provoke psychiatric symptoms. Conversely, psychiatric patients can display abnormalities in cytokine and neurotrophic factor expression. Such observations have pointed to the potential contribution of cytokines and growth factors to schizophrenic pathology and/or etiology. The cellular targets of the relevant factors and the nature of their actions remain to be explored in mental illness, however. Recent physiological studies demonstrate that cytokines and neurotrophic factors can markedly influence synaptic transmission and plasticity upon acute or chronic application. Moreover, many of the molecular alterations observed in the schizophrenic brain are consistent with abnormalities in cytokine and neurotrophic factor regulation of these molecules. In this review, we summarize these molecular pathology findings for schizophrenia and highlight the neurodevelopmental activities of cytokines and neurotrophic factors that may contribute to the etiology or pathology of this illness.
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Affiliation(s)
- H Nawa
- Division of Molecular Neurobiology, Brain Research Institute, Niigata University, Japan
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Courtney KD, Grove M, Vandongen H, Vandongen A, LaMantia AS, Pendergast AM. Localization and phosphorylation of Abl-interactor proteins, Abi-1 and Abi-2, in the developing nervous system. Mol Cell Neurosci 2000; 16:244-57. [PMID: 10995551 DOI: 10.1006/mcne.2000.0865] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Abl-interactor (Abi) proteins are targets of Abl-family nonreceptor tyrosine kinases and are required for Rac-dependent cytoskeletal reorganization in response to growth factor stimulation. We asked if the expression, phosphorylation, and cellular localization of Abi-1 and Abi-2 supports a role for these proteins in Abl signaling in the developing and adult mouse nervous system. In mid- to late-gestation embryos, abi-2 message is elevated in the central and peripheral nervous systems (CNS and PNS). Abi-1 mRNA is present, but not enhanced, in the CNS, and is not observed in PNS structures. Abi proteins from brain lysates undergo changes in apparent molecular weight and phosphorylation with increasing age. In the postnatal brain, abi-1 and abi-2 are expressed most prominently in cortical layers populated by projection neurons. In cultured neurons, Abi-1 and Abi-2 are concentrated in puncta throughout the cell body and processes. Both Abi and Abl proteins are present in synaptosomes and growth cone particles. Therefore, the Abi adaptors exhibit proper expression patterns and subcellular localization to participate in Abl kinase signaling in the nervous system.
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Affiliation(s)
- K D Courtney
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, 27710, USA
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Brain-derived neurotrophic factor differentially regulates excitatory and inhibitory synaptic transmission in hippocampal cultures. J Neurosci 2000. [PMID: 10777787 DOI: 10.1523/jneurosci.20-09-03221.2000] [Citation(s) in RCA: 141] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) has been postulated to be a key signaling molecule in regulating synaptic strength and overall circuit activity. In this context, we have found that BDNF dramatically increases the frequency of spontaneously initiated action potentials in hippocampal neurons in dissociated culture. Using analysis of unitary synaptic transmission and immunocytochemical methods, we determined that chronic treatment with BDNF potentiates both excitatory and inhibitory transmission, but that it does so via different mechanisms. BDNF strengthens excitation primarily by augmenting the amplitude of AMPA receptor-mediated miniature EPSCs (mEPSCs) but enhances inhibition by increasing the frequency of mIPSC and increasing the size of GABAergic synaptic terminals. In contrast to observations in other systems, BDNF-mediated increases in AMPA-receptor mediated mEPSC amplitudes did not require activity, because blocking action potentials with tetrodotoxin for the entire duration of BDNF treatment had no effect on the magnitude of this enhancement. These forms of synaptic regulations appear to be a selective action of BDNF because intrinsic excitability, synapse number, and neuronal survival are not affected in these cultures. Thus, although BDNF induces a net increase in overall circuit activity, this results from potentiation of both excitatory and inhibitory synaptic drive through distinct and selective physiological mechanisms.
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50
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Boxall AR. GABAergic mIPSCs in rat cerebellar Purkinje cells are modulated by TrkB and mGluR1-mediated stimulation of Src. J Physiol 2000; 524 Pt 3:677-84. [PMID: 10790150 PMCID: PMC2269899 DOI: 10.1111/j.1469-7793.2000.00677.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Whilst protein tyrosine kinase (PTK) activity can modulate expressed GABAA receptors in cell culture, the physiological consequences on synaptic GABAA receptors are unknown. This was examined using whole-cell recording of bicuculline-sensitive mIPSCs in Purkinje cells (PCs) in cerebellar slices. Postsynaptic application of a peptide activator of the non-receptor PTK Src (Src-peptide) enhanced mIPSC amplitudes by 39 % in the presence of brain-derived neurotrophic factor (BDNF) only; neurotrophin-3 (NT-3) was ineffective in this regard. Thus Src and TrkB (the receptor for BDNF) can physiologically interact to modulate synaptic GABAA receptors. In the presence of BDNF, pharmacological activation of metabotrophic glutamate receptor subtype 1 (mGluR1) by (S)-3, 5-dihydrophenylglycine (3,5-DHPG) also lead to a 32 % enhancement of mIPSCs. This enhancement was blocked by intracellular dialysis of PCs with PP1, a selective inhibitor of Src. It is concluded that, whilst GABAA receptors are not constitutively regulated by endogenous PTK activity in PCs, co-activation of TrkB by BDNF and Src by mGluR1 is required to modulate GABAergic synapses in PCs.
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Affiliation(s)
- A R Boxall
- Arbeitsgruppe zellulare Neurobiologie (AG142), Max-Planck-Institut fur biophysikalische Chemie, Am Fassberg 11, D-37077 Gottingen, Germany.
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