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Garcia JD, Wolfe SE, Stewart AR, Tiemeier E, Gookin SE, Guerrero MB, Quillinan N, Smith KR. Distinct mechanisms drive sequential internalization and degradation of GABA ARs during global ischemia and reperfusion injury. iScience 2023; 26:108061. [PMID: 37860758 PMCID: PMC10582478 DOI: 10.1016/j.isci.2023.108061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/30/2023] [Accepted: 09/22/2023] [Indexed: 10/21/2023] Open
Abstract
Synaptic inhibition is critical for controlling neuronal excitability and function. During global cerebral ischemia (GCI), inhibitory synapses are rapidly eliminated, causing hyper-excitability which contributes to cell-death and the pathophysiology of disease. Sequential disassembly of inhibitory synapses begins within minutes of ischemia onset: GABAARs are rapidly trafficked away from the synapse, the gephyrin scaffold is removed, followed by loss of the presynaptic terminal. GABAARs are endocytosed during GCI, but how this process accompanies synapse disassembly remains unclear. Here, we define the precise trafficking itinerary of GABAARs during the initial stages of GCI, placing them in the context of rapid synapse elimination. Ischemia-induced GABAAR internalization quickly follows their initial dispersal from the synapse, and is controlled by PP1α signaling. During reperfusion injury, GABAARs are then trafficked to lysosomes for degradation, leading to permanent removal of synaptic GABAARs and contributing to the profound reduction in synaptic inhibition observed hours following ischemia onset.
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Affiliation(s)
- Joshua D. Garcia
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA
| | - Sarah E. Wolfe
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA
| | - Amber R. Stewart
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA
| | - Erika Tiemeier
- Department of Anesthesiology, Neuronal Injury Program, University of Colorado School of Medicine, Anschutz Medical Campus, 12801 East 17th Avenue, Aurora, CO 80045, USA
| | - Sara E. Gookin
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA
| | - Mayra Bueno Guerrero
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA
| | - Nidia Quillinan
- Department of Anesthesiology, Neuronal Injury Program, University of Colorado School of Medicine, Anschutz Medical Campus, 12801 East 17th Avenue, Aurora, CO 80045, USA
| | - Katharine R. Smith
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA
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Ammonia induces amyloidogenesis in astrocytes by promoting amyloid precursor protein translocation into the endoplasmic reticulum. J Biol Chem 2022; 298:101933. [PMID: 35427648 PMCID: PMC9117890 DOI: 10.1016/j.jbc.2022.101933] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 03/26/2022] [Accepted: 03/26/2022] [Indexed: 11/25/2022] Open
Abstract
Hyperammonemia is known to cause various neurological dysfunctions such as seizures and cognitive impairment. Several studies have suggested that hyperammonemia may also be linked to the development of Alzheimer’s disease (AD). However, the direct evidence for a role of ammonia in the pathophysiology of AD remains to be discovered. Herein, we report that hyperammonemia increases the amount of mature amyloid precursor protein (mAPP) in astrocytes, the largest and most prevalent type of glial cells in the central nervous system that are capable of metabolizing glutamate and ammonia, and promotes amyloid beta (Aβ) production. We demonstrate the accumulation of mAPP in astrocytes was primarily due to enhanced endocytosis of mAPP from the plasma membrane. A large proportion of internalized mAPP was targeted not to the lysosome, but to the endoplasmic reticulum, where processing enzymes β-secretase BACE1 (beta-site APP cleaving enzyme 1) and γ-secretase presenilin-1 are expressed, and mAPP is cleaved to produce Aβ. Finally, we show the ammonia-induced production of Aβ in astrocytic endoplasmic reticulum was specific to Aβ42, a principal component of senile plaques in AD patients. Our studies uncover a novel mechanism of Aβ42 production in astrocytes and also provide the first evidence that ammonia induces the pathogenesis of AD by regulating astrocyte function.
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3
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Gao J, Mizokami A, Takeuchi H, Li A, Huang F, Nagano H, Kanematsu T, Jimi E, Hirata M. Phospholipase C-related catalytically inactive protein acts as a positive regulator for insulin signalling in adipocytes. J Cell Sci 2021; 135:273924. [PMID: 34859819 DOI: 10.1242/jcs.258584] [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: 03/02/2021] [Accepted: 11/15/2021] [Indexed: 11/20/2022] Open
Abstract
Insulin signalling is tightly controlled by various factors, but the exact molecular mechanism remains incompletely understood. We previously reported that phospholipase C-related but catalytically inactive protein (PRIP) interacts with Akt, the central molecule in insulin signalling. Here, we investigated whether PRIP is involved in the regulation of insulin signalling in adipocytes. We found that insulin signalling including insulin-stimulated phosphorylation of the insulin receptor (IR), insulin receptor substrate-1 (IRS-1), Akt, and glucose uptake, were impaired in adipocytes from PRIP-knockout (KO) mice compared with those from wild-type (WT) mice. The amount of IR expressed on the cell-surface was decreased in PRIP-KO adipocytes. Immunoprecipitation assay showed that PRIP interacted with IR. The reduced cell-surface IR in PRIP-KO adipocytes was comparable with that in WT cells when Rab5 expression was silenced using specific siRNA. In contrast, the dephosphorylation of IRS-1 at serine residues, some of which were reported to be involved in the internalisation of IR, was impaired in cells from PRIP-KO mice. These results suggest that PRIP facilitates insulin signalling by modulating the internalisation of IR in adipocytes.
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Affiliation(s)
- Jing Gao
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Akiko Mizokami
- Oral Health/Brain Health/Total Health Research Center, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Hiroshi Takeuchi
- Division of Applied Pharmacology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu 803-8580, Japan
| | - Aonan Li
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Fei Huang
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Haruki Nagano
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Takashi Kanematsu
- Department of Cell Biology and Pharmacology, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Eijiro Jimi
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.,Oral Health/Brain Health/Total Health Research Center, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Masato Hirata
- Oral Medicine Research Center, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka 814-0193, Japan
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Tubbs JD, Ding J, Baum L, Sham PC. Systemic neuro-dysregulation in depression: Evidence from genome-wide association. Eur Neuropsychopharmacol 2020; 39:1-18. [PMID: 32896454 DOI: 10.1016/j.euroneuro.2020.08.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 06/10/2020] [Accepted: 08/17/2020] [Indexed: 12/16/2022]
Abstract
Depression is the world's leading cause of disability. Greater understanding of the neurobiological basis of depression is necessary for developing novel treatments with improved efficacy and acceptance. Recently, major advances have been made in the search for genetic variants associated with depression which may help to elucidate etiological mechanisms. The present review has two major objectives. First, we offer a brief review of two major biological systems with strong evidence for involvement in depression pathology: neurotransmitter systems and the stress response. Secondly, we provide a synthesis of the functions of the 269 genes implicated by the most recent genome-wide meta-analysis, supporting the importance of these systems in depression and providing insights into other possible mechanisms involving neurodevelopment, neurogenesis, and neurodegeneration. Our goal is to undertake a broad, preliminary stock-taking of the most recent hypothesis-free findings and examine the weight of the evidence supporting these existing theories and highlighting novel directions. This qualitative review and accompanying gene function table provides a valuable resource and guide for basic and translational researchers, with suggestions for future mechanistic research, leveraging genetics to prioritize studies on the neurobiological processes involved in depression etiology and treatment.
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Affiliation(s)
- Justin D Tubbs
- Department of Psychiatry, The University of Hong Kong, Hong Kong
| | - Jiahong Ding
- Department of Psychiatry, The University of Hong Kong, Hong Kong
| | - Larry Baum
- Department of Psychiatry, The University of Hong Kong, Hong Kong; State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong
| | - Pak C Sham
- Department of Psychiatry, The University of Hong Kong, Hong Kong; State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong; Centre of PanorOmic Sciences, The University of Hong Kong, Hong Kong.
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5
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Nakamura Y, Morrow DH, Nathanson AJ, Henley JM, Wilkinson KA, Moss SJ. Phosphorylation on Ser-359 of the α2 subunit in GABA type A receptors down-regulates their density at inhibitory synapses. J Biol Chem 2020; 295:12330-12342. [PMID: 32620552 PMCID: PMC7458806 DOI: 10.1074/jbc.ra120.014303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/25/2020] [Indexed: 11/06/2022] Open
Abstract
GABA type A receptors (GABAARs) mediate fast synaptic inhibition and are trafficked to functionally diverse synapses. However, the precise molecular mechanisms that regulate the synaptic targeting of these receptors are unclear. Whereas it has been previously shown that phosphorylation events in α4, β, and γ subunits of GABAARs govern their function and trafficking, phosphorylation of other subunits has not yet been demonstrated. Here, we show that the α2 subunit of GABAARs is phosphorylated at Ser-359 and enables dynamic regulation of GABAAR binding to the scaffolding proteins gephyrin and collybistin. We initially identified Ser-359 phosphorylation by MS analysis, and additional experiments revealed that it is regulated by the activities of cAMP-dependent protein kinase (PKA) and the protein phosphatase 1 (PP1) and/or PP2A. GST-based pulldowns and coimmunoprecipitation experiments demonstrate preferential binding of both gephyrin and collybistin to WT and an S359A phosphonull variant, but not to an S359D phosphomimetic variant. Furthermore, the decreased capacity of the α2 S359D variant to bind collybistin and gephyrin decreased the density of synaptic α2-containing GABAAR clusters and caused an absence of α2 enrichment in the axon initial segment. These results suggest that PKA-mediated phosphorylation and PP1/PP2A-dependent dephosphorylation of the α2 subunit play a role in the dynamic regulation of GABAAR accumulation at inhibitory synapses, thereby regulating the strength of synaptic inhibition. The MS data have been deposited to ProteomeXchange, with the data set identifier PXD019597.
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Affiliation(s)
- Yasuko Nakamura
- School of Biochemistry, Centre for Synaptic Plasticity, University of Bristol, Bristol, United Kingdom
| | - Danielle H. Morrow
- Department of Neuroscience, Tufts University, School of Medicine, Boston, Massachusetts, USA
| | - Anna J. Nathanson
- Department of Neuroscience, Tufts University, School of Medicine, Boston, Massachusetts, USA
| | - Jeremy M. Henley
- School of Biochemistry, Centre for Synaptic Plasticity, University of Bristol, Bristol, United Kingdom
| | - Kevin A. Wilkinson
- School of Biochemistry, Centre for Synaptic Plasticity, University of Bristol, Bristol, United Kingdom
| | - Stephen J. Moss
- Department of Neuroscience, Tufts University, School of Medicine, Boston, Massachusetts, USA,Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom,For correspondence: S. J. Moss,
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6
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Charsouei S, Jabalameli MR, Karimi-Moghadam A. Molecular insights into the role of AMPA receptors in the synaptic plasticity, pathogenesis and treatment of epilepsy: therapeutic potentials of perampanel and antisense oligonucleotide (ASO) technology. Acta Neurol Belg 2020; 120:531-544. [PMID: 32152997 DOI: 10.1007/s13760-020-01318-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 02/27/2020] [Indexed: 02/07/2023]
Abstract
Glutamate is considered as the predominant excitatory neurotransmitter in the mammalian central nervous systems (CNS). Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) are the main glutamate-gated ionotropic channels that mediate the majority of fast synaptic excitation in the brain. AMPARs are highly dynamic that constitutively move into and out of the postsynaptic membrane. Changes in the postsynaptic number of AMPARs play a key role in controlling synaptic plasticity and also brain functions such as memory formation and forgetting development. Impairments in the regulation of AMPAR function, trafficking, and signaling pathway may also contribute to neuronal hyperexcitability and epileptogenesis process, which offers AMPAR as a potential target for epilepsy therapy. Over the last decade, various types of AMPAR antagonists such as perampanel and talampanel have been developed to treat epilepsy, but they usually show limited efficacy at low doses and produce unwanted cognitive and motor side effects when administered at higher doses. In the present article, the latest findings in the field of molecular mechanisms controlling AMPAR biology, as well as the role of these mechanism dysfunctions in generating epilepsy will be reviewed. Also, a comprehensive summary of recent findings from clinical trials with perampanel, in treating epilepsy, glioma-associated epilepsy and Parkinson's disease is provided. Finally, antisense oligonucleotide therapy as an alternative strategy for the efficient treatment of epilepsy is discussed.
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Affiliation(s)
- Saeid Charsouei
- Department of Neurology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, IR, Iran
| | - M Reza Jabalameli
- Department of Genetics, Albert Einstein College of Medicine, 1301 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Amin Karimi-Moghadam
- Division of Genetics, Department of Biology, Faculty of Science, University of Isfahan, Isfahan, IR, Iran.
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7
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Nuwer JL, Fleck MW. Anterograde trafficking signals in GABA A subunits are required for functional expression. Channels (Austin) 2019; 13:440-454. [PMID: 31610743 PMCID: PMC6802930 DOI: 10.1080/19336950.2019.1676368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/30/2022] Open
Abstract
Pentameric GABAA receptors are composed from 19 possible subunits. The GABAA β subunit is unique because the β1 and β3 subunits can assemble and traffic to the cell surface as homomers, whereas most of the other subunits, including β2, are heteromers. The intracellular domain (ICD) of the GABAA subunits has been implicated in targeting and clustering GABAA receptors at the plasma membrane. Here, we sought to test whether and how the ICD is involved in functional expression of the β3 subunit. Since θ is the most homologous to β but does not form homomers, we created two reciprocal chimeric subunits, swapping the ICD between the β3 and θ subunits, and expressed them in HEK293 cells. Surface expression was detected with immunofluorescence and functional expression was quantified using whole-cell patch-clamp recording with fast perfusion. Results indicate that, unlike β3, neither the β3/θIC nor the θ/β3IC chimera can traffic to the plasma membrane when expressed alone; however, when expressed in combination with either wild-type α3 or β3, the β3/θIC chimera was functionally expressed. This suggests that the ICD of α3 and β3 each contain essential anterograde trafficking signals that are required to overcome ER retention of assembled GABAA homo- or heteropentamers.
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Affiliation(s)
- Jessica L Nuwer
- Neuroscience & Experimental Therapeutics, Albany Medical College , Albany , NY , USA
| | - Mark W Fleck
- Neuroscience & Experimental Therapeutics, Albany Medical College , Albany , NY , USA
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8
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Yamawaki Y, Shirawachi S, Mizokami A, Nozaki K, Ito H, Asano S, Oue K, Aizawa H, Yamawaki S, Hirata M, Kanematsu T. Phospholipase C-related catalytically inactive protein regulates lipopolysaccharide-induced hypothalamic inflammation-mediated anorexia in mice. Neurochem Int 2019; 131:104563. [PMID: 31589911 DOI: 10.1016/j.neuint.2019.104563] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 09/09/2019] [Accepted: 10/02/2019] [Indexed: 11/29/2022]
Abstract
Peripheral lipopolysaccharide (LPS) injection induces systemic inflammation through the activation of the inhibitor of nuclear factor kappa B (NF-κB) kinase (IKK)/NF-κB signaling pathway, which promotes brain dysfunction resulting in conditions including anorexia. LPS-mediated reduction of food intake is associated with activation of NF-κB signaling and phosphorylation of the transcription factor signal transducer and activator of transcription 3 (STAT3) in the hypothalamus. We recently reported phospholipase C-related catalytically inactive protein (PRIP) as a new negative regulator of phosphatidylinositol 3-kinase/AKT signaling. AKT regulates the IKK/NF-κB signaling pathway; therefore, this study aimed to investigate the role of PRIP/AKT signaling in LPS-mediated neuroinflammation-induced anorexia. PRIP gene (Prip1 and Prip2) knockout (Prip-KO) mice intraperitoneally (ip) administered with LPS exhibited increased anorexia responses compared with wild-type (WT) controls. Although few differences were observed between WT and Prip-KO mice in LPS-elicited plasma pro-inflammatory cytokine elevation, hypothalamic pro-inflammatory cytokines were significantly upregulated in Prip-KO rather than WT mice. Hypothalamic AKT and IKK phosphorylation and IκB degradation were significantly increased in Prip-KO rather than WT mice, indicating further promotion of AKT-mediated NF-κB signaling. Consistently, hypothalamic STAT3 was further phosphorylated in Prip-KO rather than WT mice. Furthermore, suppressor of cytokine signaling 3 (Socs3), a negative feedback regulator for STAT3 signaling, and cyclooxogenase-2 (Cox2), a candidate molecule in LPS-induced anorexigenic responses, were upregulated in the hypothalamus in Prip-KO rather than WT mice. Pro-inflammatory cytokines were upregulated in hypothalamic microglia isolated from Prip-KO rather than WT mice. Together, these findings indicate that PRIP negatively regulates LPS-induced anorexia caused by pro-inflammatory cytokine expression in the hypothalamus, which is mediated by AKT-activated NF-κB signaling. Importantly, hypothalamic microglia participate in this PRIP-mediated process. Elucidation of PRIP-mediated neuroinflammatory responses may provide novel insights into the pathophysiology of many brain dysfunctions.
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Affiliation(s)
- Yosuke Yamawaki
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan; Laboratory of Advanced Pharmacology, Daiichi University of Pharmacy, 22-1 Tamagawa-cho, Minami-ku, Fukuoka, 815-8511, Japan
| | - Satomi Shirawachi
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Akiko Mizokami
- OBT Research Center, Faculty of Dental Science, Kyushu University, Fukuoka, 812-8582, Japan
| | - Kanako Nozaki
- Department of Neurobiology, Division of Basic Life Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Hikaru Ito
- Department of Neurobiology, Division of Basic Life Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan; Center for Experimental Animals, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Satoshi Asano
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Kana Oue
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan; Department of Dental Anesthesiology, Division of Applied Life Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, 734-8553, Japan
| | - Hidenori Aizawa
- Department of Neurobiology, Division of Basic Life Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Shigeto Yamawaki
- Department of Psychiatry and Neurosciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Masato Hirata
- Oral Medicine Research Center, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka, 814-0193, Japan
| | - Takashi Kanematsu
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan; Department of Cell Biology and Pharmacology, Faculty of Dental Science, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
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9
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Furukawa T, Nikaido Y, Shimoyama S, Ogata Y, Kushikata T, Hirota K, Kanematsu T, Hirata M, Ueno S. Phospholipase C-related inactive protein type-1 deficiency affects anesthetic electroencephalogram activity induced by propofol and etomidate in mice. J Anesth 2019; 33:531-542. [PMID: 31332527 DOI: 10.1007/s00540-019-02663-z] [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: 03/03/2019] [Accepted: 07/08/2019] [Indexed: 11/25/2022]
Abstract
PURPOSE The general anesthetics propofol and etomidate mainly exert their anesthetic actions via GABA A receptor (GABAA-R). The GABAA-R activity is influenced by phospholipase C-related inactive protein type-1 (PRIP-1), which is related to trafficking and subcellular localization of GABAA-R. PRIP-1 deficiency attenuates the behavioral reactions to propofol but not etomidate. However, the effect of these anesthetics and of PRIP-1 deficiency on brain activity of CNS are still unclear. In this study, we examined the effects of propofol and etomidate on the electroencephalogram (EEG). METHODS The cortical EEG activity was recorded in wild-type (WT) and PRIP-1 knockout (PRIP-1 KO) mice. All recorded EEG data were offline analyzed, and the power spectral density and 95% spectral edge frequency of EEG signals were compared between genotypes before and after injections of anesthetics. RESULTS PRIP-1 deficiency induced increases in EEG absolute powers, but did not markedly change the relative spectral powers during waking and sleep states in the absence of anesthesia. Propofol administration induced increases in low-frequency relative EEG activity and decreases in SEF95 values in WT but not in PRIP-1 KO mice. Following etomidate injection, low-frequency EEG power was increased in both genotype groups. At high frequency, the relative power in PRIP-1 KO mice was smaller than that in WT mice. CONCLUSIONS The lack of PRIP-1 disrupted the EEG power distribution, but did not affect the depth of anesthesia after etomidate administration. Our analyses suggest that PRIP-1 is differentially involved in anesthetic EEG activity with the regulation of GABAA-R activity.
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Affiliation(s)
- Tomonori Furukawa
- Department of Neurophysiology, Hirosaki University Graduate School of Medicine, 5 Zaihu-cho, Hirosaki, Aomori, 036-8562, Japan
| | - Yoshikazu Nikaido
- Department of Neurophysiology, Hirosaki University Graduate School of Medicine, 5 Zaihu-cho, Hirosaki, Aomori, 036-8562, Japan.,Department of Anesthesiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Shuji Shimoyama
- Department of Neurophysiology, Hirosaki University Graduate School of Medicine, 5 Zaihu-cho, Hirosaki, Aomori, 036-8562, Japan
| | - Yoshiki Ogata
- Department of Neurophysiology, Hirosaki University Graduate School of Medicine, 5 Zaihu-cho, Hirosaki, Aomori, 036-8562, Japan
| | - Tetsuya Kushikata
- Department of Anesthesiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Kazuyoshi Hirota
- Department of Anesthesiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Takashi Kanematsu
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Masato Hirata
- School of Dental Medicine, Fukuoka Dental College, Fukuoka, Japan
| | - Shinya Ueno
- Department of Neurophysiology, Hirosaki University Graduate School of Medicine, 5 Zaihu-cho, Hirosaki, Aomori, 036-8562, Japan. .,Research Center for Child Mental Development, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
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10
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Kanematsu T, Oue K, Okumura T, Harada K, Yamawaki Y, Asano S, Mizokami A, Irifune M, Hirata M. Phospholipase C-related catalytically inactive protein: A novel signaling molecule for modulating fat metabolism and energy expenditure. J Oral Biosci 2019; 61:65-72. [DOI: 10.1016/j.job.2019.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 04/17/2019] [Accepted: 04/19/2019] [Indexed: 11/25/2022]
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11
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Szodorai E, Bampali K, Romanov RA, Kasper S, Hökfelt T, Ernst M, Lubec G, Harkany T. Diversity matters: combinatorial information coding by GABA A receptor subunits during spatial learning and its allosteric modulation. Cell Signal 2018; 50:142-159. [DOI: 10.1016/j.cellsig.2018.07.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 07/08/2018] [Accepted: 07/09/2018] [Indexed: 01/11/2023]
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12
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Nicholson MW, Sweeney A, Pekle E, Alam S, Ali AB, Duchen M, Jovanovic JN. Diazepam-induced loss of inhibitory synapses mediated by PLCδ/ Ca 2+/calcineurin signalling downstream of GABAA receptors. Mol Psychiatry 2018; 23:1851-1867. [PMID: 29904150 PMCID: PMC6232101 DOI: 10.1038/s41380-018-0100-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 04/09/2018] [Accepted: 05/01/2018] [Indexed: 11/29/2022]
Abstract
Benzodiazepines facilitate the inhibitory actions of GABA by binding to γ-aminobutyric acid type A receptors (GABAARs), GABA-gated chloride/bicarbonate channels, which are the key mediators of transmission at inhibitory synapses in the brain. This activity underpins potent anxiolytic, anticonvulsant and hypnotic effects of benzodiazepines in patients. However, extended benzodiazepine treatments lead to development of tolerance, a process which, despite its important therapeutic implications, remains poorly characterised. Here we report that prolonged exposure to diazepam, the most widely used benzodiazepine in clinic, leads to a gradual disruption of neuronal inhibitory GABAergic synapses. The loss of synapses and the preceding, time- and dose-dependent decrease in surface levels of GABAARs, mediated by dynamin-dependent internalisation, were blocked by Ro 15-1788, a competitive benzodiazepine antagonist, and bicuculline, a competitive GABA antagonist, indicating that prolonged enhancement of GABAAR activity by diazepam is integral to the underlying molecular mechanism. Characterisation of this mechanism has revealed a metabotropic-type signalling downstream of GABAARs, involving mobilisation of Ca2+ from the intracellular stores and activation of the Ca2+/calmodulin-dependent phosphatase calcineurin, which, in turn, dephosphorylates GABAARs and promotes their endocytosis, leading to disassembly of inhibitory synapses. Furthermore, functional coupling between GABAARs and Ca2+ stores was sensitive to phospholipase C (PLC) inhibition by U73122, and regulated by PLCδ, a PLC isoform found in direct association with GABAARs. Thus, a PLCδ/Ca2+/calcineurin signalling cascade converts the initial enhancement of GABAARs by benzodiazepines to a long-term downregulation of GABAergic synapses, this potentially underpinning the development of pharmacological and behavioural tolerance to these widely prescribed drugs.
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Affiliation(s)
| | - Aaron Sweeney
- UCL School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Eva Pekle
- UCL School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Sabina Alam
- UCL School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Afia B Ali
- UCL School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Michael Duchen
- Neuroscience, Physiology and Pharmacology, University College London, WC1E 6BT, London, UK
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13
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Abstract
Status epilepticus (SE) is a medical emergency characterized by uncontrolled, prolonged seizures with rapid and widespread neuronal damage. Patients that suffer from longer episodes of SE are more likely to have poorer clinical outcomes and a higher cost of healthcare. Understanding novel molecular mechanisms that regulate inhibitory and excitatory neurotransmission that initiate SE and the necessary medical infrastructure to stop SE could help identify targets for early intervention. Intranasal administration of benzodiazepines may shorten the time between initiation and cessation of seizures when compared to other routes of administration. Current pharmaceutical administration guidelines are appropriate for sporadic incidences of SE, but exploring other approaches is necessary to prepare for situations involving multiple patients outside of a hospital, such as a massive chemical weapons attack. Intranasal drug delivery helps to circumvent the blood–brain barrier and offers a noninvasive way to quickly administer drugs in settings that require an immediate response, such as nerve agent exposure. In addition, examining the intranasal delivery of new drugs, such as nanotherapeutics, may lead to more effective, noninvasive, scalable, and portable methods of treating SE.
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14
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Lorenz-Guertin JM, Bambino MJ, Jacob TC. γ2 GABA AR Trafficking and the Consequences of Human Genetic Variation. Front Cell Neurosci 2018; 12:265. [PMID: 30190672 PMCID: PMC6116786 DOI: 10.3389/fncel.2018.00265] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 08/02/2018] [Indexed: 11/13/2022] Open
Abstract
GABA type A receptors (GABAARs) mediate the majority of fast inhibitory neurotransmission in the central nervous system (CNS). Most prevalent as heteropentamers composed of two α, two β, and a γ2 subunit, these ligand-gated ionotropic chloride channels are capable of extensive genetic diversity (α1-6, β1-3, γ1-3, δ, 𝜀, 𝜃, π, ρ1-3). Part of this selective GABAAR assembly arises from the critical role for γ2 in maintaining synaptic receptor localization and function. Accordingly, mutations in this subunit account for over half of the known epilepsy-associated genetic anomalies identified in GABAARs. Fundamental structure-function studies and cellular pathology investigations have revealed dynamic GABAAR trafficking and synaptic scaffolding as critical regulators of GABAergic inhibition. Here, we introduce in vitro and in vivo findings regarding the specific role of the γ2 subunit in receptor trafficking. We then examine γ2 subunit human genetic variation and assess disease related phenotypes and the potential role of altered GABAAR trafficking. Finally, we discuss new-age imaging techniques and their potential to provide novel insight into critical regulatory mechanisms of GABAAR function.
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Affiliation(s)
- Joshua M Lorenz-Guertin
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Matthew J Bambino
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Tija C Jacob
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
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15
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Lorenz-Guertin JM, Jacob TC. GABA type a receptor trafficking and the architecture of synaptic inhibition. Dev Neurobiol 2018; 78:238-270. [PMID: 28901728 PMCID: PMC6589839 DOI: 10.1002/dneu.22536] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/08/2017] [Accepted: 09/08/2017] [Indexed: 12/21/2022]
Abstract
Ubiquitous expression of GABA type A receptors (GABAA R) in the central nervous system establishes their central role in coordinating most aspects of neural function and development. Dysregulation of GABAergic neurotransmission manifests in a number of human health disorders and conditions that in certain cases can be alleviated by drugs targeting these receptors. Precise changes in the quantity or activity of GABAA Rs localized at the cell surface and at GABAergic postsynaptic sites directly impact the strength of inhibition. The molecular mechanisms constituting receptor trafficking to and from these compartments therefore dictate the efficacy of GABAA R function. Here we review the current understanding of how GABAA Rs traffic through biogenesis, plasma membrane transport, and degradation. Emphasis is placed on discussing novel GABAergic synaptic proteins, receptor and scaffolding post-translational modifications, activity-dependent changes in GABAA R confinement, and neuropeptide and neurosteroid mediated changes. We further highlight modern techniques currently advancing the knowledge of GABAA R trafficking and clinically relevant neurodevelopmental diseases connected to GABAergic dysfunction. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 238-270, 2018.
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Affiliation(s)
- Joshua M Lorenz-Guertin
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, 15261
| | - Tija C Jacob
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, 15261
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16
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Ge Y, Kang Y, Cassidy RM, Moon KM, Lewis R, Wong ROL, Foster LJ, Craig AM. Clptm1 Limits Forward Trafficking of GABA A Receptors to Scale Inhibitory Synaptic Strength. Neuron 2018; 97:596-610.e8. [PMID: 29395912 DOI: 10.1016/j.neuron.2017.12.038] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 11/17/2017] [Accepted: 12/22/2017] [Indexed: 12/11/2022]
Abstract
In contrast with numerous studies of glutamate receptor-associated proteins and their involvement in the modulation of excitatory synapses, much less is known about mechanisms controlling postsynaptic GABAA receptor (GABAAR) numbers. Using tandem affinity purification from tagged GABAAR γ2 subunit transgenic mice and proteomic analysis, we isolated several GABAAR-associated proteins, including Cleft lip and palate transmembrane protein 1 (Clptm1). Clptm1 interacted with all GABAAR subunits tested and promoted GABAAR trapping in the endoplasmic reticulum. Overexpression of Clptm1 reduced GABAAR-mediated currents in a recombinant system, in cultured hippocampal neurons, and in brain, with no effect on glycine or AMPA receptor-mediated currents. Conversely, knockdown of Clptm1 increased phasic and tonic inhibitory transmission with no effect on excitatory synaptic transmission. Furthermore, altering the expression level of Clptm1 mimicked activity-induced inhibitory synaptic scaling. Thus, in complement to other GABAAR-associated proteins that promote receptor surface expression, Clptm1 limits GABAAR forward trafficking and regulates inhibitory homeostatic plasticity.
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Affiliation(s)
- Yuan Ge
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Yunhee Kang
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Robert M Cassidy
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Kyung-Mee Moon
- Department of Biochemistry and Molecular Biology and Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Renate Lewis
- Department of Anatomy and Neurobiology, Washington University, St. Louis, MO 63110, USA
| | - Rachel O L Wong
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Leonard J Foster
- Department of Biochemistry and Molecular Biology and Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Ann Marie Craig
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada.
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17
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Vien TN, Moss SJ, Davies PA. Regulating the Efficacy of Inhibition Through Trafficking of γ-Aminobutyric Acid Type A Receptors. Anesth Analg 2017; 123:1220-1227. [PMID: 27285004 DOI: 10.1213/ane.0000000000001349] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Trafficking of anesthetic-sensitive receptors within the plasma membrane, or from one cellular component to another, occurs continuously. Changes in receptor trafficking have implications in altering anesthetic sensitivity. γ-Aminobutyric acid type A receptors (GABAARs) are anion-permeable ion channels and are the major class of receptor in the adult mammalian central nervous system that mediates inhibition. GABAergic signaling allows for precise synchronized firing of action potentials within brain circuits that is critical for cognition, behavior, and consciousness. This precision depends upon tightly controlled trafficking of GABAARs into the membrane. General anesthetics bind to and allosterically enhance GABAARs by prolonging the open state of the receptor and thereby altering neuronal and brain circuit activity. Subunit composition and GABAAR localization strongly influence anesthetic end points; therefore, changes in GABAAR trafficking could have significant consequences to anesthetic sensitivity. GABAARs are not static membrane structures but are in a constant state of flux between extrasynaptic and synaptic locations and are continually endocytosed and recycled from and to the membrane. Neuronal activity, posttranslational modifications, and some naturally occurring and synthetic compounds can influence the expression and trafficking of GABAARs. In this article, we review GABAARs, their trafficking, and how phosphorylation of GABAAR subunits can influence the surface expression and function of the receptor. Ultimately, alterations of GABAAR trafficking could modify anesthetic end points, both unintentionally through pathologic processes but potentially as a therapeutic target to adjust anesthetic-sensitive GABAARs.
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Affiliation(s)
- Thuy N Vien
- From the *Department of Neuroscience, Tufts University School of Medicine, Sackler School of Graduate Biomedical Sciences, Boston, Massachusetts; and †Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts
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Matsuda M, Hirata M. Phospholipase C-related but catalytically inactive proteins regulate ovarian follicle development. J Biol Chem 2017; 292:8369-8380. [PMID: 28360101 DOI: 10.1074/jbc.m116.759928] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 03/29/2017] [Indexed: 11/06/2022] Open
Abstract
Phospholipase C-related but catalytically inactive proteins PRIP-1 and -2 are inositol-1,4,5-trisphosphate binding proteins that are encoded by independent genes. Ablation of the Prip genes in mice impairs female fertility, which is manifested by fewer pregnancies, a decreased number of pups, and the decreased and increased secretion of gonadal steroids and gonadotropins, respectively. We investigated the involvement of the PRIPs in fertility, focusing on the ovaries of Prip-1 and -2 double-knock-out (DKO) mice. Multiple cystic follicles were observed in DKO ovaries, and a superovulation assay showed a markedly decreased number of ovulated oocytes. Cumulus-oocyte complexes showed normal expansion, and artificial gonadotropin stimulation regulated the ovulation-related genes in a normal fashion, suggesting that the ovulation itself was probably normal. A histological analysis showed atresia in fewer follicles of the DKO ovaries, particularly in the secondary follicle stages. The expression of luteinizing hormone receptor (LHR) was aberrantly higher in developing follicles, and the phosphorylation of extracellular signal-regulated protein kinase, a downstream target of LH-LHR signaling, was higher in DKO granulosa cells. This suggests that the up-regulation of LH-LHR signaling is the cause of impaired follicle development. The serum estradiol level was lower, but estradiol production was unchanged in the DKO ovaries. These results suggest that PRIPs are positively involved in the development of follicles via their regulation of LH-LHR signaling and estradiol secretion. Female DKO mice had higher serum levels of insulin, testosterone, and uncarboxylated osteocalcin, which, together with reduced fertility, are reminiscent of polycystic ovary syndrome in humans.
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Affiliation(s)
- Miho Matsuda
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan.
| | - Masato Hirata
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan; Fukuoka Dental College, Fukuoka 814-0193, Japan
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19
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Murakami A, Matsuda M, Harada Y, Hirata M. Phospholipase C-related, but catalytically inactive protein (PRIP) up-regulates osteoclast differentiation via calcium-calcineurin-NFATc1 signaling. J Biol Chem 2017; 292:7994-8006. [PMID: 28341745 PMCID: PMC5427276 DOI: 10.1074/jbc.m117.784777] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 03/23/2017] [Indexed: 01/08/2023] Open
Abstract
Phospholipase C-related, but catalytically inactive protein (PRIP) was previously identified as a novel inositol 1,4,5-trisphosphate-binding protein with a domain organization similar to that of phospholipase C-δ but lacking phospholipase activity. We recently showed that PRIP gene knock-out (KO) in mice increases bone formation and concomitantly decreases bone resorption, resulting in increased bone mineral density and trabecular bone volume. However, the role of PRIP in osteoclastogenesis has not yet been fully elucidated. Here, we investigated the effects of PRIP on bone remodeling by investigating dynamic tooth movement in mice fitted with orthodontic devices. Morphological analysis indicated that the extent of tooth movement was smaller in the PRIP-KO mice than in wild-type mice. Histological analysis revealed fewer osteoclasts on the bone-resorption side in maxillary bones of PRIP-KO mice, and osteoclast formation assays and flow cytometry indicated lower osteoclast differentiation in bone marrow cells isolated from these mice. The expression of genes implicated in bone resorption was lower in differentiated PRIP-KO cells, and genes involved in osteoclast differentiation, such as the transcription factor NFATc1, exhibited lower expression in immature PRIP-KO cells initiated by M-CSF. Moreover, calcineurin expression and activity were also lower in the PRIP-KO cells. The PRIP-KO cells also displayed fewer M-CSF-induced changes in intracellular Ca2+ and exhibited reduced nuclear localization of NFATc1. Up-regulation of intracellular Ca2+ restored osteoclastogenesis of the PRIP-KO cells. These results indicate that PRIP deficiency impairs osteoclast differentiation, particularly at the early stages, and that PRIP stimulates osteoclast differentiation through calcium-calcineurin-NFATc1 signaling via regulating intracellular Ca2.
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Affiliation(s)
- Ayako Murakami
- From the Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, and
| | - Miho Matsuda
- From the Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, and
| | - Yui Harada
- R&D Laboratory for Innovative Biotherapeutics, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan and
| | - Masato Hirata
- From the Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, and
- the Fukuoka Dental College, Fukuoka 814-0175, Japan
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20
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Phospholipase C-related catalytically inactive protein-knockout mice exhibit uncoupling protein 1 upregulation in adipose tissues following chronic cold exposure. J Oral Biosci 2017. [DOI: 10.1016/j.job.2017.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Nikaido Y, Furukawa T, Shimoyama S, Yamada J, Migita K, Koga K, Kushikata T, Hirota K, Kanematsu T, Hirata M, Ueno S. Propofol Anesthesia Is Reduced in Phospholipase C-Related Inactive Protein Type-1 Knockout Mice. J Pharmacol Exp Ther 2017; 361:367-374. [PMID: 28404686 DOI: 10.1124/jpet.116.239145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 04/04/2017] [Indexed: 11/22/2022] Open
Abstract
The GABA type A receptor (GABAA-R) is a major target of intravenous anesthetics. Phospholipase C-related inactive protein type-1 (PRIP-1) is important in GABAA-R phosphorylation and membrane trafficking. In this study, we investigated the role of PRIP-1 in general anesthetic action. The anesthetic effects of propofol, etomidate, and pentobarbital were evaluated in wild-type and PRIP-1 knockout (PRIP-1 KO) mice by measuring the latency and duration of loss of righting reflex (LORR) and loss of tail-pinch withdrawal response (LTWR). The effect of pretreatment with okadaic acid (OA), a protein phosphatase 1/2A inhibitor, on propofol- and etomidate-induced LORR was also examined. PRIP-1 deficiency provided the reduction of LORR and LTWR induced by propofol but not by etomidate or pentobarbital, indicating that PRIP-1 could determine the potency of the anesthetic action of propofol. Pretreatment with OA recovered the anesthetic potency induced by propofol in PRIP-1 KO mice. OA injection enhanced phosphorylation of cortical the GABAA-R β3 subunit in PRIP-1 KO mice. These results suggest that PRIP-1-mediated GABAA-R β3 subunit phosphorylation might be involved in the general anesthetic action induced by propofol but not by etomidate or pentobarbital.
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Affiliation(s)
- Yoshikazu Nikaido
- Graduate School of Medicine (Y.N.), Department of Neurophysiology (Y.N., T.F., K.K., S.U.) and Department of Anesthesiology, Graduate School of Medicine (Y.N., T.Ku., K.H.), Research Center for Child Mental Development, Graduate School of Medicine (S.S., S.U.), and Department of Biomedical Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences (J.Y.), Hirosaki University, Hirosaki, Japan; Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan (K.M.); Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.Ka.); Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan (M.H.); Fukuoka Dental College, Fukuoka, Japan (M.H.)
| | - Tomonori Furukawa
- Graduate School of Medicine (Y.N.), Department of Neurophysiology (Y.N., T.F., K.K., S.U.) and Department of Anesthesiology, Graduate School of Medicine (Y.N., T.Ku., K.H.), Research Center for Child Mental Development, Graduate School of Medicine (S.S., S.U.), and Department of Biomedical Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences (J.Y.), Hirosaki University, Hirosaki, Japan; Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan (K.M.); Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.Ka.); Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan (M.H.); Fukuoka Dental College, Fukuoka, Japan (M.H.)
| | - Shuji Shimoyama
- Graduate School of Medicine (Y.N.), Department of Neurophysiology (Y.N., T.F., K.K., S.U.) and Department of Anesthesiology, Graduate School of Medicine (Y.N., T.Ku., K.H.), Research Center for Child Mental Development, Graduate School of Medicine (S.S., S.U.), and Department of Biomedical Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences (J.Y.), Hirosaki University, Hirosaki, Japan; Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan (K.M.); Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.Ka.); Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan (M.H.); Fukuoka Dental College, Fukuoka, Japan (M.H.)
| | - Junko Yamada
- Graduate School of Medicine (Y.N.), Department of Neurophysiology (Y.N., T.F., K.K., S.U.) and Department of Anesthesiology, Graduate School of Medicine (Y.N., T.Ku., K.H.), Research Center for Child Mental Development, Graduate School of Medicine (S.S., S.U.), and Department of Biomedical Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences (J.Y.), Hirosaki University, Hirosaki, Japan; Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan (K.M.); Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.Ka.); Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan (M.H.); Fukuoka Dental College, Fukuoka, Japan (M.H.)
| | - Keisuke Migita
- Graduate School of Medicine (Y.N.), Department of Neurophysiology (Y.N., T.F., K.K., S.U.) and Department of Anesthesiology, Graduate School of Medicine (Y.N., T.Ku., K.H.), Research Center for Child Mental Development, Graduate School of Medicine (S.S., S.U.), and Department of Biomedical Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences (J.Y.), Hirosaki University, Hirosaki, Japan; Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan (K.M.); Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.Ka.); Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan (M.H.); Fukuoka Dental College, Fukuoka, Japan (M.H.)
| | - Kohei Koga
- Graduate School of Medicine (Y.N.), Department of Neurophysiology (Y.N., T.F., K.K., S.U.) and Department of Anesthesiology, Graduate School of Medicine (Y.N., T.Ku., K.H.), Research Center for Child Mental Development, Graduate School of Medicine (S.S., S.U.), and Department of Biomedical Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences (J.Y.), Hirosaki University, Hirosaki, Japan; Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan (K.M.); Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.Ka.); Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan (M.H.); Fukuoka Dental College, Fukuoka, Japan (M.H.)
| | - Tetsuya Kushikata
- Graduate School of Medicine (Y.N.), Department of Neurophysiology (Y.N., T.F., K.K., S.U.) and Department of Anesthesiology, Graduate School of Medicine (Y.N., T.Ku., K.H.), Research Center for Child Mental Development, Graduate School of Medicine (S.S., S.U.), and Department of Biomedical Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences (J.Y.), Hirosaki University, Hirosaki, Japan; Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan (K.M.); Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.Ka.); Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan (M.H.); Fukuoka Dental College, Fukuoka, Japan (M.H.)
| | - Kazuyoshi Hirota
- Graduate School of Medicine (Y.N.), Department of Neurophysiology (Y.N., T.F., K.K., S.U.) and Department of Anesthesiology, Graduate School of Medicine (Y.N., T.Ku., K.H.), Research Center for Child Mental Development, Graduate School of Medicine (S.S., S.U.), and Department of Biomedical Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences (J.Y.), Hirosaki University, Hirosaki, Japan; Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan (K.M.); Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.Ka.); Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan (M.H.); Fukuoka Dental College, Fukuoka, Japan (M.H.)
| | - Takashi Kanematsu
- Graduate School of Medicine (Y.N.), Department of Neurophysiology (Y.N., T.F., K.K., S.U.) and Department of Anesthesiology, Graduate School of Medicine (Y.N., T.Ku., K.H.), Research Center for Child Mental Development, Graduate School of Medicine (S.S., S.U.), and Department of Biomedical Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences (J.Y.), Hirosaki University, Hirosaki, Japan; Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan (K.M.); Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.Ka.); Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan (M.H.); Fukuoka Dental College, Fukuoka, Japan (M.H.)
| | - Masato Hirata
- Graduate School of Medicine (Y.N.), Department of Neurophysiology (Y.N., T.F., K.K., S.U.) and Department of Anesthesiology, Graduate School of Medicine (Y.N., T.Ku., K.H.), Research Center for Child Mental Development, Graduate School of Medicine (S.S., S.U.), and Department of Biomedical Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences (J.Y.), Hirosaki University, Hirosaki, Japan; Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan (K.M.); Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.Ka.); Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan (M.H.); Fukuoka Dental College, Fukuoka, Japan (M.H.)
| | - Shinya Ueno
- Graduate School of Medicine (Y.N.), Department of Neurophysiology (Y.N., T.F., K.K., S.U.) and Department of Anesthesiology, Graduate School of Medicine (Y.N., T.Ku., K.H.), Research Center for Child Mental Development, Graduate School of Medicine (S.S., S.U.), and Department of Biomedical Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences (J.Y.), Hirosaki University, Hirosaki, Japan; Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan (K.M.); Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.Ka.); Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan (M.H.); Fukuoka Dental College, Fukuoka, Japan (M.H.)
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General anesthetic actions on GABA A receptors in vivo are reduced in phospholipase C-related catalytically inactive protein knockout mice. J Anesth 2017; 31:531-538. [PMID: 28389811 DOI: 10.1007/s00540-017-2350-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 03/26/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE The aim of this study was to investigate the action of general anesthetics in phospholipase C-related catalytically inactive protein (PRIP)-knockout (KO) mice that alter GABAA receptor signaling. METHODS PRIP regulates the intracellular trafficking of β subunit-containing GABAA receptors in vitro. In this study, we examined the effects of intravenous anesthetics, propofol and etomidate that act via β subunit-containing GABAA receptors, in wild-type and Prip-KO mice. Mice were intraperitoneally injected with a drug, and a loss of righting reflex (LORR) assay and an electroencephalogram analysis were performed. RESULTS The cell surface expression of GABAA receptor β3 subunit detected by immunoblotting was decreased in Prip-knockout brain compared with that in wild-type brain without changing the expression of other GABAA receptor subunits. Propofol-treated Prip-KO mice exhibited significantly shorter duration of LORR and had lower total anesthetic score than wild-type mice in the LORR assay. The average duration of sleep time in an electroencephalogram analysis was shorter in propofol-treated Prip-KO mice than in wild-type mice. The hypnotic action of etomidate was also reduced in Prip-KO mice. However, ketamine, an NMDA receptor antagonist, had similar effects in the two genotypes. CONCLUSION PRIP regulates the cell surface expression of the GABAA receptor β3 subunit and modulates general anesthetic action in vivo. Elucidation of the involved regulatory mechanisms of GABAA receptor-dependent signaling would inform the development of safer anesthetic therapies for clinical applications.
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Mele M, Leal G, Duarte CB. Role of GABAAR trafficking in the plasticity of inhibitory synapses. J Neurochem 2016; 139:997-1018. [DOI: 10.1111/jnc.13742] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 07/12/2016] [Accepted: 07/13/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Miranda Mele
- Center for Neuroscience and Cell Biology; University of Coimbra; Coimbra Portugal
| | - Graciano Leal
- Center for Neuroscience and Cell Biology; University of Coimbra; Coimbra Portugal
| | - Carlos B. Duarte
- Center for Neuroscience and Cell Biology; University of Coimbra; Coimbra Portugal
- Department of Life Sciences; University of Coimbra; Coimbra Portugal
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Kotani M, Matsuda M, Murakami A, Takahashi I, Katagiri T, Hirata M. Involvement of PRIP (Phospholipase C-Related But Catalytically Inactive Protein) in BMP-Induced Smad Signaling in Osteoblast Differentiation. J Cell Biochem 2016; 116:2814-23. [PMID: 25981537 DOI: 10.1002/jcb.25228] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 05/11/2015] [Indexed: 01/08/2023]
Abstract
Phospholipase C-related but catalytically inactive protein (PRIP) was first isolated as an inositol 1,4,5-trisphosphate binding protein. We generated PRIP gene-deficient mice which exhibited the increased bone mineral density and trabecular bone volume, indicating that PRIP is implicated in the regulation of bone properties. In this study, we investigated the possible mechanisms by which PRIP plays a role in bone morphogenetic protein (BMP) signaling, by analyzing the culture of primary cells isolated from calvaria of two genotypes, the wild type and a mutant. In the mutant culture, enhanced osteoblast differentiation was observed by measuring alkaline phosphatase staining and activity. The promoter activity of Id1 gene, responding immediately to BMP, was also more increased. Smad1/5 phosphorylation in response to BMP showed an enhanced peak and was more persistent in mutant cells, but the dephosphorylation process was not different between the two genotypes. The luciferase assay using calvaria cells transfected with the Smad1 mutated as a constitutive active form showed increased transcriptional activity at similar levels between the genotypes. The expression of BMP receptors was not different between the genotypes. BMP-induced phosphorylation of Smad1/5 was robustly decreased in wild type cells, but not in mutant cells, by pretreatment with DB867, an inhibitor of methyltransferase of inhibitory Smad6. Furthermore, BMP-induced translocation of Smad6 from nucleus to cytosol was not much observed in PRIP-deficient cells. These results indicate that PRIP is implicated in BMP-induced osteoblast differentiation by the negative regulation of Smad phosphorylation, through the methylation of inhibitory Smad6.
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Affiliation(s)
- Miho Kotani
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan.,Division of Orthodontics, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Miho Matsuda
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Ayako Murakami
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Ichiro Takahashi
- Division of Orthodontics, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Takenobu Katagiri
- Division of Pathophysiology, Research Center for Genomic Medicine, Saitama Medical University, Hidaka, Saitama 350-1241, Japan
| | - Masato Hirata
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
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25
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Yamawaki Y, Oue K, Shirawachi S, Asano S, Harada K, Kanematsu T. Phospholipase C-related catalytically inactive protein can regulate obesity, a state of peripheral inflammation. JAPANESE DENTAL SCIENCE REVIEW 2016; 53:18-24. [PMID: 28408965 PMCID: PMC5390332 DOI: 10.1016/j.jdsr.2016.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Revised: 05/23/2016] [Accepted: 06/06/2016] [Indexed: 11/28/2022] Open
Abstract
Obesity is defined as abnormal or excessive fat accumulation. Chronic inflammation in fat influences the development of obesity-related diseases. Many reports state that obesity increases the risk of morbidity in many diseases, including hypertension, dyslipidemia, type 2 diabetes, coronary heart disease, stroke, sleep apnea, and breast, prostate and colon cancers, leading to increased mortality. Obesity is also associated with chronic neuropathologic conditions such as depression and Alzheimer's disease. However, there is strong evidence that weight loss reduces these risks, by limiting blood pressure and improving levels of serum triglycerides, total cholesterol, low-density lipoprotein (LDL)-cholesterol, and high-density lipoprotein (HDL)-cholesterol. Prevention and control of obesity is complex, and requires a multifaceted approach. The elucidation of molecular mechanisms driving fat metabolism (adipogenesis and lipolysis) aims at developing clinical treatments to control obesity. We recently reported a new regulatory mechanism in fat metabolism: a protein phosphatase binding protein, phospholipase C-related catalytically inactive protein (PRIP), regulates lipolysis in white adipocytes and heat production in brown adipocytes via phosphoregulation. Deficiency of PRIP in mice led to reduced fat accumulation and increased energy expenditure, resulting in a lean phenotype. Here, we evaluate PRIP as a new therapeutic target for the control of obesity.
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Affiliation(s)
- Yosuke Yamawaki
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Kana Oue
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan.,Department of Dental Anesthesiology, Division of Applied Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Satomi Shirawachi
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Satoshi Asano
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Kae Harada
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Takashi Kanematsu
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
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26
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Fu YL, Wang YJ, Mu TW. Proteostasis Maintenance of Cys-Loop Receptors. ION CHANNELS AS THERAPEUTIC TARGETS, PART A 2016; 103:1-23. [DOI: 10.1016/bs.apcsb.2015.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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27
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Oue K, Zhang J, Harada-Hada K, Asano S, Yamawaki Y, Hayashiuchi M, Furusho H, Takata T, Irifune M, Hirata M, Kanematsu T. Phospholipase C-related Catalytically Inactive Protein Is a New Modulator of Thermogenesis Promoted by β-Adrenergic Receptors in Brown Adipocytes. J Biol Chem 2015; 291:4185-96. [PMID: 26706316 DOI: 10.1074/jbc.m115.705723] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Indexed: 11/06/2022] Open
Abstract
Phospholipase C-related catalytically inactive protein (PRIP) was first identified as an inositol 1,4,5-trisphosphate-binding protein, and was later found to be involved in a variety of cellular events, particularly those related to protein phosphatases. We previously reported that Prip knock-out (KO) mice exhibit a lean phenotype with a small amount of white adipose tissue. In the present study, we examined whether PRIP is involved in energy metabolism, which could explain the lean phenotype, using high-fat diet (HFD)-fed mice. Prip-KO mice showed resistance to HFD-induced obesity, resulting in protection from glucose metabolism dysfunction and insulin resistance. Energy expenditure and body temperature at night were significantly higher in Prip-KO mice than in wild-type mice. Gene and protein expression of uncoupling protein 1 (UCP1), a thermogenic protein, was up-regulated in Prip-KO brown adipocytes in thermoneutral or cold environments. These phenotypes were caused by the promotion of lipolysis in Prip-KO brown adipocytes, which is triggered by up-regulation of phosphorylation of the lipolysis-related proteins hormone-sensitive lipase and perilipin, followed by activation of UCP1 and/or up-regulation of thermogenesis-related genes (e.g. peroxisome proliferator-activated receptor-γ coactivator-1α). The results indicate that PRIP negatively regulates UCP1-mediated thermogenesis in brown adipocytes.
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Affiliation(s)
- Kana Oue
- From the Departments of Cellular and Molecular Pharmacology, Dental Anesthesiology, and
| | - Jun Zhang
- From the Departments of Cellular and Molecular Pharmacology
| | | | - Satoshi Asano
- From the Departments of Cellular and Molecular Pharmacology
| | | | | | - Hisako Furusho
- Oral and Maxillofacial Pathobiology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553 and
| | - Takashi Takata
- Oral and Maxillofacial Pathobiology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553 and
| | | | - Masato Hirata
- the Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
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28
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Oue K, Harada-Hada K, Kanematsu T. [New molecular basis in the regulation of lipolysis via dephosphorylation]. Nihon Yakurigaku Zasshi 2015; 146:93-7. [PMID: 26256747 DOI: 10.1254/fpj.146.93] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Nakamura Y, Darnieder LM, Deeb TZ, Moss SJ. Regulation of GABAARs by phosphorylation. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2015; 72:97-146. [PMID: 25600368 PMCID: PMC5337123 DOI: 10.1016/bs.apha.2014.11.008] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
γ-Aminobutyric acid type A receptors (GABAARs) are the principal mediators of fast synaptic inhibition in the brain as well as the low persistent extrasynaptic inhibition, both of which are fundamental to proper brain function. Thus unsurprisingly, deficits in GABAARs are implicated in a number of neurological disorders and diseases. The complexity of GABAAR regulation is determined not only by the heterogeneity of these receptors but also by its posttranslational modifications, the foremost, and best characterized of which is phosphorylation. This review will explore the details of this dynamic process, our understanding of which has barely scratched the surface. GABAARs are regulated by a number of kinases and phosphatases, and its phosphorylation plays an important role in governing its trafficking, expression, and interaction partners. Here, we summarize the progress in understanding the role phosphorylation plays in the regulation of GABAARs. This includes how phosphorylation can affect the allosteric modulation of GABAARs, as well as signaling pathways that affect GABAAR phosphorylation. Finally, we discuss the dysregulation of GABAAR phosphorylation and its implication in disease processes.
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30
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Korrodi-Gregório L, Esteves SLC, Fardilha M. Protein phosphatase 1 catalytic isoforms: specificity toward interacting proteins. Transl Res 2014; 164:366-91. [PMID: 25090308 DOI: 10.1016/j.trsl.2014.07.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 06/26/2014] [Accepted: 07/01/2014] [Indexed: 01/21/2023]
Abstract
The coordinated and reciprocal action of serine-threonine protein kinases and protein phosphatases produces transitory phosphorylation, a fundamental regulatory mechanism for many biological processes. Phosphoprotein phosphatase 1 (PPP1), a major serine-threonine phosphatase, in particular, is ubiquitously distributed and regulates a broad range of cellular functions, including glycogen metabolism, cell cycle progression, and muscle relaxation. PPP1 has evolved effective catalytic machinery but in vitro lacks substrate specificity. In vivo, its specificity is achieved not only by the existence of different PPP1 catalytic isoforms, but also by binding of the catalytic moiety to a large number of regulatory or targeting subunits. Here, we will address exhaustively the existence of diverse PPP1 catalytic isoforms and the relevance of their specific partners and consequent functions.
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Affiliation(s)
- Luís Korrodi-Gregório
- Laboratório de Transdução de Sinais, Departamento de Biologia, Secção Autónoma de Ciências de Saúde, Centro de Biologia Celular, Universidade de Aveiro, Aveiro, Portugal
| | - Sara L C Esteves
- Laboratório de Transdução de Sinais, Departamento de Biologia, Secção Autónoma de Ciências de Saúde, Centro de Biologia Celular, Universidade de Aveiro, Aveiro, Portugal
| | - Margarida Fardilha
- Laboratório de Transdução de Sinais, Departamento de Biologia, Secção Autónoma de Ciências de Saúde, Centro de Biologia Celular, Universidade de Aveiro, Aveiro, Portugal.
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31
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Gerarduzzi C, He Q, Antoniou J, Di Battista JA. Quantitative phosphoproteomic analysis of signaling downstream of the prostaglandin e2/g-protein coupled receptor in human synovial fibroblasts: potential antifibrotic networks. J Proteome Res 2014; 13:5262-80. [PMID: 25223752 DOI: 10.1021/pr500495s] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The Prostaglandin E2 (PGE2) signaling mechanism within fibroblasts is of growing interest as it has been shown to prevent numerous fibrotic features of fibroblast activation with limited evidence of downstream pathways. To understand the mechanisms of fibroblasts producing tremendous amounts of PGE2 with autocrine effects, we apply a strategy of combining a wide-screening of PGE2-induced kinases with quantitative phosphoproteomics. Our large-scale proteomic approach identified a PKA signal transmitted through phosphorylation of its substrates harboring the R(R/X)X(S*/T*) motif. We documented 115 substrates, of which 72 had 89 sites with a 2.5-fold phosphorylation difference in PGE2-treated cells than in untreated cells, where approximately half of such sites were defined as being novel. They were compiled by networking software to focus on highlighted activities and to associate them with a functional readout of fibroblasts. The substrates were associated with a variety of cellular functions including cytoskeletal structures (migration/motility), regulators of G-protein coupled receptor function, protein kinases, and transcriptional/translational regulators. For the first time, we extended the PGE2 pathway into an elaborate network of interconnecting phosphoproteins, providing vital information to a once restricted signalosome. These data provide new insights into eicosanoid-initiated cell signaling with regards to the regulation of fibroblast activation and the identification of new targets for evidenced-based pharmacotherapy against fibrosis.
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Affiliation(s)
- Casimiro Gerarduzzi
- Department of Experimental Medicine, McGill University , 687 Pine Avenue West, Montreal, Quebec H3A 1A1, Canada
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32
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Comenencia-Ortiz E, Moss SJ, Davies PA. Phosphorylation of GABAA receptors influences receptor trafficking and neurosteroid actions. Psychopharmacology (Berl) 2014; 231:3453-65. [PMID: 24847959 PMCID: PMC4135009 DOI: 10.1007/s00213-014-3617-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 05/02/2014] [Indexed: 01/06/2023]
Abstract
RATIONALE Gamma-aminobutyric acid type A receptors (GABAARs) are the principal mediators of inhibitory transmission in the mammalian central nervous system. GABAARs can be localized at post-synaptic inhibitory specializations or at extrasynaptic sites. While synaptic GABAARs are activated transiently following the release of GABA from presynaptic vesicles, extrasynaptic GABAARs are typically activated continuously by ambient GABA concentrations and thus mediate tonic inhibition. The tonic inhibitory currents mediated by extrasynaptic GABAARs control neuronal excitability and the strength of synaptic transmission. However, the mechanisms by which neurons control the functional properties of extrasynaptic GABAARs had not yet been explored. OBJECTIVES We review GABAARs, how they are assembled and trafficked, and the role phosphorylation has on receptor insertion and membrane stabilization. Finally, we review the modulation of GABAARs by neurosteroids and how GABAAR phosphorylation can influence the actions of neurosteroids. CONCLUSIONS Trafficking and stability of functional channels to the membrane surface are critical for inhibitory efficacy. Phosphorylation of residues within GABAAR subunits plays an essential role in the assembly, trafficking, and cell surface stability of GABAARs. Neurosteroids are produced in the brain and are highly efficacious allosteric modulators of GABAAR-mediated current. This allosteric modulation by neurosteroids is influenced by the phosphorylated state of the GABAAR which is subunit dependent, adding temporal and regional variability to the neurosteroid response. Possible links between neurosteroid actions, phosphorylation, and GABAAR trafficking remain to be explored, but potential novel therapeutic targets may exist for numerous neurological and psychological disorders which are linked to fluctuations in neurosteroid levels and GABAA subunit expression.
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SidAhmed-Mezi M, Kurcewicz I, Rose C, Louvel J, Sokoloff P, Pumain R, Laschet JJ. Mass spectrometric detection and characterization of atypical membrane-bound zinc-sensitive phosphatases modulating GABAA receptors. PLoS One 2014; 9:e100612. [PMID: 24967814 PMCID: PMC4072668 DOI: 10.1371/journal.pone.0100612] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 05/29/2014] [Indexed: 12/17/2022] Open
Abstract
Background GABAA receptor (GABAAR) function is maintained by an endogenous phosphorylation mechanism for which the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is the kinase. This phosphorylation is specific to the long intracellular loop I2 of the α1 subunit at two identified serine and threonine residues. The phosphorylation state is opposed by an unknown membrane-bound phosphatase, which inhibition favors the phosphorylated state of the receptor and contributes to the maintenance of its function. In cortical nervous tissue from epileptogenic areas in patients with drug-resistant epilepsies, both the endogenous phosphorylation and the functional state of the GABAAR are deficient. Methodology/Principal Findings The aim of this study is to characterize the membrane-bound phosphatases counteracting the endogenous phosphorylation of GABAAR. We have developed a new analytical tool for in vitro detection of the phosphatase activities in cortical washed membranes by liquid chromatography coupled to mass spectrometry. The substrates are two synthetic phosphopeptides, each including one of the identified endogenous phosphorylation sites of the I2 loop of GABAAR α1 subunit. We have shown the presence of multiple and atypical phosphatases sensitive to zinc ions. Patch-clamp studies of the rundown of the GABAAR currents on acutely isolated rat pyramidal cells using the phosphatase inhibitor okadaic acid revealed a clear heterogeneity of the phosphatases counteracting the function of the GABAAR. Conclusion/Significance Our results provide new insights on the regulation of GABAAR endogenous phosphorylation and function by several and atypical membrane-bound phosphatases specific to the α1 subunit of the receptor. By identifying specific inhibitors of these enzymes, novel development of antiepileptic drugs in patients with drug-resistant epilepsies may be proposed.
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Affiliation(s)
- Mounia SidAhmed-Mezi
- Inserm, Infantile Epilepsies and Brain Plasticity U1129, Paris, France
- University Paris Descartes, Paris, France
- CEA, Gif sur Yvette, France
- * E-mail: (MS); (JJL)
| | - Irène Kurcewicz
- University Paris Descartes, Paris, France
- Inserm, Centre de Psychiatrie et de Neurosciences U894, Paris, France
| | - Christiane Rose
- University Paris Descartes, Paris, France
- Inserm, Centre de Psychiatrie et de Neurosciences U894, Paris, France
| | - Jacques Louvel
- University Paris Descartes, Paris, France
- Inserm, Centre de Psychiatrie et de Neurosciences U894, Paris, France
| | - Pierre Sokoloff
- Institut de Recherche Pierre Fabre, Neurologie & Psychiatrie, Castres, France
| | - René Pumain
- Inserm, Infantile Epilepsies and Brain Plasticity U1129, Paris, France
- University Paris Descartes, Paris, France
- CEA, Gif sur Yvette, France
| | - Jacques J. Laschet
- Inserm, Infantile Epilepsies and Brain Plasticity U1129, Paris, France
- University Paris Descartes, Paris, France
- CEA, Gif sur Yvette, France
- * E-mail: (MS); (JJL)
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Okumura T, Harada K, Oue K, Zhang J, Asano S, Hayashiuchi M, Mizokami A, Tanaka H, Irifune M, Kamata N, Hirata M, Kanematsu T. Phospholipase C-related catalytically inactive protein (PRIP) regulates lipolysis in adipose tissue by modulating the phosphorylation of hormone-sensitive lipase. PLoS One 2014; 9:e100559. [PMID: 24945349 PMCID: PMC4064000 DOI: 10.1371/journal.pone.0100559] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Accepted: 05/28/2014] [Indexed: 01/15/2023] Open
Abstract
Phosphorylation of hormone-sensitive lipase (HSL) and perilipin by protein kinase A (PKA) promotes the hydrolysis of lipids in adipocytes. Although activation of lipolysis by PKA has been well studied, inactivation via protein phosphatases is poorly understood. Here, we investigated whether phospholipase C-related catalytically inactive protein (PRIP), a binding partner for protein phosphatase 1 and protein phosphatase 2A (PP2A), is involved in lipolysis by regulating phosphatase activity. PRIP knockout (PRIP-KO) mice displayed reduced body-fat mass as compared with wild-type mice fed with standard chow ad libitum. Most other organs appeared normal, suggesting that mutant mice had aberrant fat metabolism in adipocytes. HSL in PRIP-KO adipose tissue was highly phosphorylated compared to that in wild-type mice. Starvation of wild-type mice or stimulation of adipose tissue explants with the catabolic hormone, adrenaline, translocated both PRIP and PP2A from the cytosol to lipid droplets, but the translocation of PP2A was significantly reduced in PRIP-KO adipocytes. Consistently, the phosphatase activity associated with lipid droplet fraction in PRIP-KO adipocytes was significantly reduced and was independent of adrenaline stimulation. Lipolysis activity, as assessed by measurement of non-esterified fatty acids and glycerol, was higher in PRIP-KO adipocytes. When wild-type adipocytes were treated with a phosphatase inhibitor, they showed a high lipolysis activity at the similar level to PRIP-KO adipocytes. Collectively, these results suggest that PRIP promotes the translocation of phosphatases to lipid droplets to trigger the dephosphorylation of HSL and perilipin A, thus reducing PKA-mediated lipolysis.
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Affiliation(s)
- Toshiya Okumura
- Department of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
- Department of Oral Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Kae Harada
- Department of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Kana Oue
- Department of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
- Department of Dental Anesthesiology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Jun Zhang
- Department of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Satoshi Asano
- Department of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Masaki Hayashiuchi
- Department of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Akiko Mizokami
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Hiroto Tanaka
- Department of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Masahiro Irifune
- Department of Dental Anesthesiology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Nobuyuki Kamata
- Department of Oral Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Masato Hirata
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Takashi Kanematsu
- Department of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
- * E-mail:
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Harada-Hada K, Harada K, Kato F, Hisatsune J, Tanida I, Ogawa M, Asano S, Sugai M, Hirata M, Kanematsu T. Phospholipase C-related catalytically inactive protein participates in the autophagic elimination of Staphylococcus aureus infecting mouse embryonic fibroblasts. PLoS One 2014; 9:e98285. [PMID: 24865216 PMCID: PMC4035314 DOI: 10.1371/journal.pone.0098285] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 04/29/2014] [Indexed: 01/22/2023] Open
Abstract
Autophagy is an intrinsic host defense system that recognizes and eliminates invading bacterial pathogens. We have identified microtubule-associated protein 1 light chain 3 (LC3), a hallmark of autophagy, as a binding partner of phospholipase C-related catalytically inactive protein (PRIP) that was originally identified as an inositol trisphosphate-binding protein. Here, we investigated the involvement of PRIP in the autophagic elimination of Staphylococcus aureus in infected mouse embryonic fibroblasts (MEFs). We observed significantly more LC3-positive autophagosome-like vacuoles enclosing an increased number of S. aureus cells in PRIP-deficient MEFs than control MEFs, 3 h and 4.5 h post infection, suggesting that S. aureus proliferates in LC3-positive autophagosome-like vacuoles in PRIP-deficient MEFs. We performed autophagic flux analysis using an mRFP-GFP-tagged LC3 plasmid and found that autophagosome maturation is significantly inhibited in PRIP-deficient MEFs. Furthermore, acidification of autophagosomes was significantly inhibited in PRIP-deficient MEFs compared to the wild-type MEFs, as determined by LysoTracker staining and time-lapse image analysis performed using mRFP-GFP-tagged LC3. Taken together, our data show that PRIP is required for the fusion of S. aureus-containing autophagosome-like vacuoles with lysosomes, indicating that PRIP is a novel modulator in the regulation of the innate immune system in non-professional phagocytic host cells.
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Affiliation(s)
- Kae Harada-Hada
- Department of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Kana Harada
- Department of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Fuminori Kato
- Department of Bacteriology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Junzo Hisatsune
- Department of Bacteriology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Isei Tanida
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Michinaga Ogawa
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Satoshi Asano
- Department of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Motoyuki Sugai
- Department of Bacteriology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Masato Hirata
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Takashi Kanematsu
- Department of Cellular and Molecular Pharmacology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
- * E-mail:
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Deidda G, Bozarth IF, Cancedda L. Modulation of GABAergic transmission in development and neurodevelopmental disorders: investigating physiology and pathology to gain therapeutic perspectives. Front Cell Neurosci 2014; 8:119. [PMID: 24904277 PMCID: PMC4033255 DOI: 10.3389/fncel.2014.00119] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 04/14/2014] [Indexed: 01/30/2023] Open
Abstract
During mammalian ontogenesis, the neurotransmitter GABA is a fundamental regulator of neuronal networks. In neuronal development, GABAergic signaling regulates neural proliferation, migration, differentiation, and neuronal-network wiring. In the adult, GABA orchestrates the activity of different neuronal cell-types largely interconnected, by powerfully modulating synaptic activity. GABA exerts these functions by binding to chloride-permeable ionotropic GABAA receptors and metabotropic GABAB receptors. According to its functional importance during development, GABA is implicated in a number of neurodevelopmental disorders such as autism, Fragile X, Rett syndrome, Down syndrome, schizophrenia, Tourette's syndrome and neurofibromatosis. The strength and polarity of GABAergic transmission is continuously modulated during physiological, but also pathological conditions. For GABAergic transmission through GABAA receptors, strength regulation is achieved by different mechanisms such as modulation of GABAA receptors themselves, variation of intracellular chloride concentration, and alteration in GABA metabolism. In the never-ending effort to find possible treatments for GABA-related neurological diseases, of great importance would be modulating GABAergic transmission in a safe and possibly physiological way, without the dangers of either silencing network activity or causing epileptic seizures. In this review, we will discuss the different ways to modulate GABAergic transmission normally at work both during physiological and pathological conditions. Our aim is to highlight new research perspectives for therapeutic treatments that reinstate natural and physiological brain functions in neuro-pathological conditions.
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Affiliation(s)
- Gabriele Deidda
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genova, Italy
| | - Ignacio F Bozarth
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genova, Italy
| | - Laura Cancedda
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genova, Italy
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Asano S, Nemoto T, Kitayama T, Harada K, Zhang J, Harada K, Tanida I, Hirata M, Kanematsu T. Phospholipase C-related catalytically inactive protein (PRIP) controls KIF5B-mediated insulin secretion. Biol Open 2014; 3:463-74. [PMID: 24812354 PMCID: PMC4058080 DOI: 10.1242/bio.20147591] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously reported that phospholipase C-related catalytically inactive protein (PRIP)-knockout mice exhibited hyperinsulinemia. Here, we investigated the role of PRIP in insulin granule exocytosis using Prip-knockdown mouse insulinoma (MIN6) cells. Insulin release from Prip-knockdown MIN6 cells was higher than that from control cells, and Prip knockdown facilitated movement of GFP-phogrin-labeled insulin secretory vesicles. Double-immunofluorescent staining and density step-gradient analyses showed that the KIF5B motor protein co-localized with insulin vesicles in Prip-knockdown MIN6 cells. Knockdown of GABAA-receptor-associated protein (GABARAP), a microtubule-associated PRIP-binding partner, by Gabarap silencing in MIN6 cells reduced the co-localization of insulin vesicles with KIF5B and the movement of vesicles, resulting in decreased insulin secretion. However, the co-localization of KIF5B with microtubules was not altered in Prip- and Gabarap-knockdown cells. The presence of unbound GABARAP, freed either by an interference peptide or by Prip silencing, in MIN6 cells enhanced the co-localization of insulin vesicles with microtubules and promoted vesicle mobility. Taken together, these data demonstrate that PRIP and GABARAP function in a complex to regulate KIF5B-mediated insulin secretion, providing new insights into insulin exocytic mechanisms.
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Affiliation(s)
- Satoshi Asano
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Tomomi Nemoto
- Laboratory of Molecular and Cellular Biophysics, Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0020, Japan
| | - Tomoya Kitayama
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Kae Harada
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Jun Zhang
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Kana Harada
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Isei Tanida
- Laboratory of Biomembranes, Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Masato Hirata
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Takashi Kanematsu
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
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Postsynaptic GABAB receptor activity regulates excitatory neuronal architecture and spatial memory. J Neurosci 2014; 34:804-16. [PMID: 24431439 DOI: 10.1523/jneurosci.3320-13.2013] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cognitive dysfunction is a common symptom in many neuropsychiatric disorders and directly correlates with poor patient outcomes. The majority of prolonged inhibitory signaling in the brain is mediated via GABAB receptors (GABABRs), but the molecular function of these receptors in cognition is ill defined. To explore the significance of GABABRs in neuronal activity and cognition, we created mice with enhanced postsynaptic GABABR signaling by mutating the serine 783 in receptor R2 subunit (S783A), which decreased GABABR degradation. Enhanced GABABR activity reduced the expression of immediate-early gene-encoded protein Arc/Arg3.1, effectors that are critical for long-lasting memory. Intriguingly, S783A mice exhibited increased numbers of excitatory synapses and surface AMPA receptors, effects that are consistent with decreased Arc/Arg3.1 expression. These deficits in Arc/Arg3.1 and neuronal morphology lead to a deficit in spatial memory consolidation. Collectively our results suggest a novel and unappreciated role for GABABR activity in determining excitatory neuronal architecture and spatial memory via their ability to regulate Arc/Arg3.1.
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TNF-α downregulates inhibitory neurotransmission through protein phosphatase 1-dependent trafficking of GABA(A) receptors. J Neurosci 2013; 33:15879-93. [PMID: 24089494 DOI: 10.1523/jneurosci.0530-13.2013] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Inflammation has been implicated in the progression of neurological disease, yet precisely how inflammation affects neuronal function remains unclear. Tumor necrosis factor-α (TNFα) is a proinflammatory cytokine that regulates synapse function by controlling neurotransmitter receptor trafficking and homeostatic synaptic plasticity. Here we characterize the mechanisms through which TNFα regulates inhibitory synapse function in mature rat and mouse hippocampal neurons. Acute application of TNFα induces a rapid and persistent decrease of inhibitory synaptic strength and downregulation of cell-surface levels of GABA(A)Rs containing α1, α2, β2/3, and γ2 subunits. We show that trafficking of GABA(A)Rs in response to TNFα is mediated by neuronally expressed TNF receptor 1 and requires activation of p38 MAPK, phosphatidylinositol 3-kinase, protein phosphatase 1 (PP1), and dynamin GTPase. Furthermore, TNFα enhances the association of PP1 with GABA(A)R β3 subunits and dephosphorylates a site on β3 known to regulate phospho-dependent interactions with the endocytic machinery. Conversely, we find that calcineurin and PP2A are not essential components of the signaling pathway and that clustering of the scaffolding protein gephyrin is only reduced after the initial receptor endocytosis. Together, these findings demonstrate a distinct mechanism of regulated GABA(A)R endocytosis that may contribute to the disruption of circuit homeostasis under neuroinflammatory conditions.
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Sugiyama G, Takeuchi H, Kanematsu T, Gao J, Matsuda M, Hirata M. Phospholipase C-related but catalytically inactive protein, PRIP as a scaffolding protein for phospho-regulation. Adv Biol Regul 2013; 53:331-340. [PMID: 23911386 DOI: 10.1016/j.jbior.2013.07.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Accepted: 07/01/2013] [Indexed: 06/02/2023]
Abstract
PRIP, phospholipase C (PLC)-related but catalytically inactive protein is a protein with a domain organization similar to PLC-δ1. We have reported that PRIP interacts with the catalytic subunits of protein phosphatase 1 and 2A (PP1c and PP2Ac), depending on the phosphorylation of PRIP. We also found that Akt was precipitated along with PRIP by anti-PRIP antibody from neuronal cells. In this article, we summarize our current reach regarding the interaction of PRIP with Akt and protein phosphatases, in relation to the cellular phospho-regulations. PP1 and PP2A are major members of the protein serine/threonine phosphatase families. We have identified PP1 and PP2A as interacting partners of PRIP. We first investigated the interaction of PRIP with two phosphatases, using purified recombinant proteins. PRIP immobilized on beads pulled-down the catalytic subunits of both PP1 and PP2A, indicating that the interactions were in a direct manner, and the binding of PP1 and PP2A to PRIP were mutually exclusive. Site-directed mutagenesis experiments revealed that the binding sites for PP1 and PP2A on PRIP were not identical, but in close proximity. Phosphorylation of PRIP by protein kinase A (PKA) resulted in the reduced binding of PP1, but not PP2A. Rather, the dissociation of PP1 from PRIP by phosphorylation accompanied the increased binding of PP2A in in vitro experiments. This binding regulation of PP1 and PP2A to PRIP by PKA-dependent phosphorylation was also observed in living cells treated with forskolin or isoproterenol. These results suggested that PRIP directly interacts with the catalytic subunits of two distinct phosphatases in a mutually exclusive manner and the interactions are regulated by phosphorylation, thus functioning as a scaffold to regulate the activities and subcellular localizations of both PP1 and PP2A in phospho-dependent cellular signaling.
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Affiliation(s)
- Goro Sugiyama
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
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Abstract
Phosphoinositides (PIs) make up only a small fraction of cellular phospholipids, yet they control almost all aspects of a cell's life and death. These lipids gained tremendous research interest as plasma membrane signaling molecules when discovered in the 1970s and 1980s. Research in the last 15 years has added a wide range of biological processes regulated by PIs, turning these lipids into one of the most universal signaling entities in eukaryotic cells. PIs control organelle biology by regulating vesicular trafficking, but they also modulate lipid distribution and metabolism via their close relationship with lipid transfer proteins. PIs regulate ion channels, pumps, and transporters and control both endocytic and exocytic processes. The nuclear phosphoinositides have grown from being an epiphenomenon to a research area of its own. As expected from such pleiotropic regulators, derangements of phosphoinositide metabolism are responsible for a number of human diseases ranging from rare genetic disorders to the most common ones such as cancer, obesity, and diabetes. Moreover, it is increasingly evident that a number of infectious agents hijack the PI regulatory systems of host cells for their intracellular movements, replication, and assembly. As a result, PI converting enzymes began to be noticed by pharmaceutical companies as potential therapeutic targets. This review is an attempt to give an overview of this enormous research field focusing on major developments in diverse areas of basic science linked to cellular physiology and disease.
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Affiliation(s)
- Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Kitayama T, Morita K, Sultana R, Kikushige N, Mgita K, Ueno S, Hirata M, Kanematsu T. Phospholipase C-related but catalytically inactive protein modulates pain behavior in a neuropathic pain model in mice. Mol Pain 2013; 9:23. [PMID: 23639135 PMCID: PMC3651726 DOI: 10.1186/1744-8069-9-23] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 04/30/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND An inositol 1,4,5-trisphosphate binding protein, comprising 2 isoforms termed PRIP-1 and PRIP-2, was identified as a novel modulator for GABAA receptor trafficking. It has been reported that naive PRIP-1 knockout mice have hyperalgesic responses. FINDINGS To determine the involvement of PRIP in pain sensation, a hind paw withdrawal test was performed before and after partial sciatic nerve ligation (PSNL) in PRIP-1 and PRIP-2 double knockout (DKO) mice. We found that naive DKO mice exhibited normal pain sensitivity. However, DKO mice that underwent PSNL surgery showed increased ipsilateral paw withdrawal threshold. To further investigate the inverse phenotype in PRIP-1 KO and DKO mice, we produced mice with specific siRNA-mediated knockdown of PRIPs in the spinal cord. Consistent with the phenotypes of KO mice, PRIP-1 knockdown mice showed allodynia, while PRIP double knockdown (DKD) mice with PSNL showed decreased pain-related behavior. This indicates that reduced expression of both PRIPs in the spinal cord induces resistance towards a painful sensation. GABAA receptor subunit expression pattern was similar between PRIP-1 KO and DKO spinal cord, while expression of K(+)-Cl(-)-cotransporter-2 (KCC2), which controls the balance of neuronal excitation and inhibition, was significantly upregulated in DKO mice. Furthermore, in the DKD PSNL model, an inhibitor-induced KCC2 inhibition exhibited an altered phenotype from painless to painful sensations. CONCLUSIONS Suppressed expression of PRIPs induces an elevated expression of KCC2 in the spinal cord, resulting in inhibition of nociception and amelioration of neuropathic pain in DKO mice.
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Affiliation(s)
- Tomoya Kitayama
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Katsuya Morita
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Rizia Sultana
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Nami Kikushige
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Keisuke Mgita
- Department of Neurophysiology, Hirosaki University Graduate School of Medicine, 5 Zaifucho, Hirosaki, Aomori 036-8562, Japan
| | - Shinya Ueno
- Department of Neurophysiology, Hirosaki University Graduate School of Medicine, 5 Zaifucho, Hirosaki, Aomori 036-8562, Japan
| | - Masato Hirata
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Takashi Kanematsu
- Department of Cellular and Molecular Pharmacology, Division of Basic Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
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43
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Umebayashi H, Mizokami A, Matsuda M, Harada K, Takeuchi H, Tanida I, Hirata M, Kanematsu T. Phospholipase C-related catalytically inactive protein, a novel microtubule-associated protein 1 light chain 3-binding protein, negatively regulates autophagosome formation. Biochem Biophys Res Commun 2013; 432:268-74. [DOI: 10.1016/j.bbrc.2013.01.119] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 01/31/2013] [Indexed: 10/27/2022]
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44
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Sugiyama G, Takeuchi H, Nagano K, Gao J, Ohyama Y, Mori Y, Hirata M. Regulated Interaction of Protein Phosphatase 1 and Protein Phosphatase 2A with Phospholipase C-Related but Catalytically Inactive Protein. Biochemistry 2012; 51:3394-403. [DOI: 10.1021/bi2018128] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Goro Sugiyama
- Laboratory
of Molecular and Cellular Biochemistry and ‡Division of Maxillofacial Surgery,
Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Hiroshi Takeuchi
- Laboratory
of Molecular and Cellular Biochemistry and ‡Division of Maxillofacial Surgery,
Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Koki Nagano
- Laboratory
of Molecular and Cellular Biochemistry and ‡Division of Maxillofacial Surgery,
Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Jing Gao
- Laboratory
of Molecular and Cellular Biochemistry and ‡Division of Maxillofacial Surgery,
Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Yukiko Ohyama
- Laboratory
of Molecular and Cellular Biochemistry and ‡Division of Maxillofacial Surgery,
Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Yoshihide Mori
- Laboratory
of Molecular and Cellular Biochemistry and ‡Division of Maxillofacial Surgery,
Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Masato Hirata
- Laboratory
of Molecular and Cellular Biochemistry and ‡Division of Maxillofacial Surgery,
Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
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45
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Gao J, Takeuchi H, Zhang Z, Fukuda M, Hirata M. Phospholipase C-related but catalytically inactive protein (PRIP) modulates synaptosomal-associated protein 25 (SNAP-25) phosphorylation and exocytosis. J Biol Chem 2012; 287:10565-10578. [PMID: 22311984 DOI: 10.1074/jbc.m111.294645] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Exocytosis is one of the most fundamental cellular events. The basic mechanism of the final step, membrane fusion, is mediated by the formation of the SNARE complex, which is modulated by the phosphorylation of proteins controlled by the concerted actions of protein kinases and phosphatases. We have previously shown that a protein phosphatase-1 (PP1) anchoring protein, phospholipase C-related but catalytically inactive protein (PRIP), has an inhibitory role in regulated exocytosis. The current study investigated the involvement of PRIP in the phospho-dependent modulation of exocytosis. Dephosphorylation of synaptosome-associated protein of 25 kDa (SNAP-25) was mainly catalyzed by PP1, and the process was modulated by wild-type PRIP but not by the mutant (F97A) lacking PP1 binding ability in in vitro studies. We then examined the role of PRIP in phospho-dependent regulation of exocytosis in cell-based studies using pheochromocytoma cell line PC12 cells, which secrete noradrenalin. Exogenous expression of PRIP accelerated the dephosphorylation process of phosphorylated SNAP-25 after forskolin or phorbol ester treatment of the cells. The phospho-states of SNAP-25 were correlated with noradrenalin secretion, which was enhanced by forskolin or phorbol ester treatment and modulated by PRIP expression in PC12 cells. Both SNAP-25 and PP1 were co-precipitated in anti-PRIP immunocomplex isolated from PC12 cells expressing PRIP. Collectively, together with our previous observation regarding the roles of PRIP in PP1 regulation, these results suggest that PRIP is involved in the regulation of the phospho-states of SNAP-25 by modulating the activity of PP1, thus regulating exocytosis.
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Affiliation(s)
- Jing Gao
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan and
| | - Hiroshi Takeuchi
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan and
| | - Zhao Zhang
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan and
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Masato Hirata
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan and.
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46
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Zhu G, Yoshida S, Migita K, Yamada J, Mori F, Tomiyama M, Wakabayashi K, Kanematsu T, Hirata M, Kaneko S, Ueno S, Okada M. Dysfunction of Extrasynaptic GABAergic Transmission in Phospholipase C-Related, but Catalytically Inactive Protein 1 Knockout Mice Is Associated with an Epilepsy Phenotype. J Pharmacol Exp Ther 2011; 340:520-8. [DOI: 10.1124/jpet.111.182386] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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47
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Migita K, Tomiyama M, Yamada J, Fukuzawa M, Kanematsu T, Hirata M, Ueno S. Phenotypes of pain behavior in phospholipase C-related but catalytically inactive protein type 1 knockout mice. Mol Pain 2011; 7:79. [PMID: 22008183 PMCID: PMC3215965 DOI: 10.1186/1744-8069-7-79] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2011] [Accepted: 10/18/2011] [Indexed: 11/10/2022] Open
Abstract
Phospholipase C-related inactive protein (PRIP) plays important roles in trafficking to the plasma membrane of GABA(A) receptor, which is involved in the dominant inhibitory neurotransmission in the spinal cord and plays an important role in nociceptive transmission. However, the role of PRIP in pain sensation remains unknown. In this study, we investigated the phenotypes of pain behaviors in PRIP type 1 knockout (PRIP-1 (-/-)) mice. The mutant mice showed hyperalgesic responses in the second phase of the formalin test and the von Frey test as compared with those in wild-type mice. In situ hybridization studies of GABA(A) receptors revealed significantly decreased expression of γ2 subunit mRNA in the dorsal and ventral horns of the spinal cord in PRIP-1 (-/-) mice, but no difference in α1 subunit mRNA expression. β2 subunit mRNA expression was significantly higher in PRIP-1 (-/-) mice than in wild-type mice in all areas of the spinal cord. On the other hand, the slow decay time constant for the spontaneous inhibitory current was significantly increased by treatment with diazepam in wild-type mice, but not in PRIP-1 (-/-) mice. These results suggest that PRIP-1 (-/-) mice exhibit the changes of the function and subunits expression of GABA(A) receptor in the spinal cord, which may be responsible for abnormal pain sensation in these mice.
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Affiliation(s)
- Keisuke Migita
- Department of Neurophysiology, Hirosaki University Graduate School of Medicine, Aomori, Japan
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48
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Vithlani M, Terunuma M, Moss SJ. The dynamic modulation of GABA(A) receptor trafficking and its role in regulating the plasticity of inhibitory synapses. Physiol Rev 2011; 91:1009-22. [PMID: 21742794 DOI: 10.1152/physrev.00015.2010] [Citation(s) in RCA: 148] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Inhibition in the adult mammalian central nervous system (CNS) is mediated by γ-aminobutyric acid (GABA). The fast inhibitory actions of GABA are mediated by GABA type A receptors (GABA(A)Rs); they mediate both phasic and tonic inhibition in the brain and are the principle sites of action for anticonvulsant, anxiolytic, and sedative-hypnotic agents that include benzodiazepines, barbiturates, neurosteroids, and some general anesthetics. GABA(A)Rs are heteropentameric ligand-gated ion channels that are found concentrated at inhibitory postsynaptic sites where they mediate phasic inhibition and at extrasynaptic sites where they mediate tonic inhibition. The efficacy of inhibition and thus neuronal excitability is critically dependent on the accumulation of specific GABA(A)R subtypes at inhibitory synapses. Here we evaluate how neurons control the number of GABA(A)Rs on the neuronal plasma membrane together with their selective stabilization at synaptic sites. We then go on to examine the impact that these processes have on the strength of synaptic inhibition and behavior.
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Affiliation(s)
- Mansi Vithlani
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, USA
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49
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Tsutsumi K, Matsuda M, Kotani M, Mizokami A, Murakami A, Takahashi I, Terada Y, Kanematsu T, Fukami K, Takenawa T, Jimi E, Hirata M. Involvement of PRIP, phospholipase C-related, but catalytically inactive protein, in bone formation. J Biol Chem 2011; 286:31032-31042. [PMID: 21757756 PMCID: PMC3162462 DOI: 10.1074/jbc.m111.235903] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 07/08/2011] [Indexed: 11/06/2022] Open
Abstract
PRIP (phospholipase C-related, but catalytically inactive protein) is a novel protein isolated in this laboratory. PRIP-deficient mice showed increased serum gonadotropins, but decreased gonadal steroid hormones. This imbalance was similar to that for the cause of bone disease, such as osteoporosis. In the present study, therefore, we analyzed mutant mice with special reference to the bone property. We first performed three-dimensional analysis of the femur of female mice. The bone mineral density and trabecular bone volume were higher in mutant mice. We further performed histomorphometrical assay of bone formation parameters: bone formation rate, mineral apposition rate, osteoid thickness, and osteoblast number were up-regulated in the mutant, indicating that increased bone mass is caused by the enhancement of bone formation ability. We then cultured primary cells isolated from calvaria prepared from both genotypes. In mutant mice, osteoblast differentiation, as assessed by alkaline phosphatase activity and the expression of osteoblast differentiation marker genes, was enhanced. Moreover, we analyzed the phosphorylation of Smad1/5/8 in response to bone morphogenetic protein, with longer phosphorylation in the mutant. These results indicate that PRIP is implicated in the negative regulation of bone formation.
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Affiliation(s)
- Koshiro Tsutsumi
- Laboratory of Molecular and Cellular Biochemistry, Kyushu University, Fukuoka 812-8582, Japan; Division of Fixed Prosthodontics, Kyushu University, Fukuoka 812-8582, Japan
| | - Miho Matsuda
- Laboratory of Molecular and Cellular Biochemistry, Kyushu University, Fukuoka 812-8582, Japan
| | - Miho Kotani
- Laboratory of Molecular and Cellular Biochemistry, Kyushu University, Fukuoka 812-8582, Japan; Division of Orthodontics, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Akiko Mizokami
- Laboratory of Molecular and Cellular Biochemistry, Kyushu University, Fukuoka 812-8582, Japan
| | - Ayako Murakami
- Division of Orthodontics, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Ichiro Takahashi
- Division of Orthodontics, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Yoshihiro Terada
- Division of Fixed Prosthodontics, Kyushu University, Fukuoka 812-8582, Japan
| | - Takashi Kanematsu
- Laboratory of Molecular and Cellular Biochemistry, Kyushu University, Fukuoka 812-8582, Japan
| | - Kiyoko Fukami
- Laboratory of Genome and Biosignal, Tokyo University of Pharmacy and Life Science, Tokyo 192-0392, Japan
| | - Tadaomi Takenawa
- Division of Lipid Biochemistry, Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan
| | - Eijiro Jimi
- Department of Molecular Signaling and Biochemistry, Kyushu Dental College, Kitakyushu 803-8580, Japan
| | - Masato Hirata
- Laboratory of Molecular and Cellular Biochemistry, Kyushu University, Fukuoka 812-8582, Japan.
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Luscher B, Fuchs T, Kilpatrick CL. GABAA receptor trafficking-mediated plasticity of inhibitory synapses. Neuron 2011; 70:385-409. [PMID: 21555068 DOI: 10.1016/j.neuron.2011.03.024] [Citation(s) in RCA: 316] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2011] [Indexed: 12/22/2022]
Abstract
Proper developmental, neural cell-type-specific, and activity-dependent regulation of GABAergic transmission is essential for virtually all aspects of CNS function. The number of GABA(A) receptors in the postsynaptic membrane directly controls the efficacy of GABAergic synaptic transmission. Thus, regulated trafficking of GABA(A) receptors is essential for understanding brain function in both health and disease. Here we summarize recent progress in the understanding of mechanisms that allow dynamic adaptation of cell surface expression and postsynaptic accumulation and function of GABA(A) receptors. This includes activity-dependent and cell-type-specific changes in subunit gene expression, assembly of subunits into receptors, as well as exocytosis, endocytic recycling, diffusion dynamics, and degradation of GABA(A) receptors. In particular, we focus on the roles of receptor-interacting proteins, scaffold proteins, synaptic adhesion proteins, and enzymes that regulate the trafficking and function of receptors and associated proteins. In addition, we review neuropeptide signaling pathways that affect neural excitability through changes in GABA(A)R trafficking.
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Affiliation(s)
- Bernhard Luscher
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA.
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