1
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Takeda R, Ishii R, Parvin S, Shiozawa A, Nogi T, Sasaki Y. Novel presynaptic assay system revealed that metformin ameliorates exaggerated synaptic release and Munc18-1 accumulation in presynapses of neurons from Fragile X syndrome mouse model. Neurosci Lett 2023; 810:137317. [PMID: 37286070 DOI: 10.1016/j.neulet.2023.137317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 05/13/2023] [Accepted: 05/30/2023] [Indexed: 06/09/2023]
Abstract
Fragile X syndrome (FXS) is a developmental disorder characterized by intellectual disability and autistic-like behaviors. These symptoms are supposed to result from dysregulated translation in pre- and postsynapses, resulting in aberrant synaptic plasticity. Although most drug development research on FXS has focused on aberrant postsynaptic functions by excess translation in postsynapses, the effect of drug candidates on FXS in presynaptic release is largely unclear. In this report, we developed a novel assay system using neuron ball culture with beads to induce presynapse formation, allowing for the analysis of presynaptic phenotypes, including presynaptic release. Metformin, which is shown to rescue core phenotypes in FXS mouse model by normalizing dysregulated translation, ameliorated the exaggerated presynaptic release of neurons of FXS model mouse using this assay system. Furthermore, metformin suppressed the excess accumulation of the active zone protein Munc18-1, which is supposed to be locally translated in presynapses. These results suggest that metformin rescues both postsynaptic and presynaptic phenotypes by inhibiting excess translation in FXS neurons.
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Affiliation(s)
- Renoma Takeda
- Functional Structure Science Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Rie Ishii
- Functional Structure Science Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Shumaia Parvin
- Functional Structure Science Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Aki Shiozawa
- Structural Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Terukazu Nogi
- Structural Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Yukio Sasaki
- Functional Structure Science Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan.
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2
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Sun C, Schuman EM. Logistics of neuronal protein turnover: Numbers and mechanisms. Mol Cell Neurosci 2022; 123:103793. [PMID: 36396040 DOI: 10.1016/j.mcn.2022.103793] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
Research in the past twenty years or so has revealed that neurons synthesize and degrade proteins at their synapses to enable synaptic proteome remodelling on demand and in real-time. Here we provide a quantitative overview of the decentralized neuronal protein-turnover logistics. We first analyse the huge neuronal protein turnover demand that arises from subcellular compartments outside the cell body, followed by an overview of key quantities and modulation strategies in neuronal protein turnover logistics. In the end, we briefly review recent progress in neuronal local protein synthesis and summarize diverse protein-degradation mechanisms that are found near synapses.
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Affiliation(s)
- Chao Sun
- Max Planck Institute for Brain Research, 60438 Frankfurt am Main, Germany
| | - Erin M Schuman
- Max Planck Institute for Brain Research, 60438 Frankfurt am Main, Germany.
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3
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Bogdanov V, Soltisz AM, Moise N, Sakuta G, Orengo BH, Janssen PML, Weinberg SH, Davis JP, Veeraraghavan R, Györke S. Distributed synthesis of sarcolemmal and sarcoplasmic reticulum membrane proteins in cardiac myocytes. Basic Res Cardiol 2021; 116:63. [PMID: 34713358 DOI: 10.1007/s00395-021-00895-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 08/30/2021] [Accepted: 09/11/2021] [Indexed: 02/05/2023]
Abstract
It is widely assumed that synthesis of membrane proteins, particularly in the heart, follows the classical secretory pathway with mRNA translation occurring in perinuclear regions followed by protein trafficking to sites of deployment. However, this view is based on studies conducted in less-specialized cells, and has not been experimentally addressed in cardiac myocytes. Therefore, we undertook direct experimental investigation of protein synthesis in cardiac tissue and isolated myocytes using single-molecule visualization techniques and a novel proximity-ligated in situ hybridization approach for visualizing ribosome-associated mRNA molecules for a specific protein species, indicative of translation sites. We identify here, for the first time, that the molecular machinery for membrane protein synthesis occurs throughout the cardiac myocyte, and enables distributed synthesis of membrane proteins within sub-cellular niches where the synthesized protein functions using local mRNA pools trafficked, in part, by microtubules. We also observed cell-wide distribution of membrane protein mRNA in myocardial tissue from both non-failing and hypertrophied (failing) human hearts, demonstrating an evolutionarily conserved distributed mechanism from mouse to human. Our results identify previously unanticipated aspects of local control of cardiac myocyte biology and highlight local protein synthesis in cardiac myocytes as an important potential determinant of the heart’s biology in health and disease.
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4
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Li L, Yu J, Ji SJ. Axonal mRNA localization and translation: local events with broad roles. Cell Mol Life Sci 2021; 78:7379-95. [PMID: 34698881 DOI: 10.1007/s00018-021-03995-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 09/17/2021] [Accepted: 10/14/2021] [Indexed: 12/19/2022]
Abstract
Messenger RNA (mRNA) can be transported and targeted to different subcellular compartments and locally translated. Local translation is an evolutionally conserved mechanism that in mammals, provides an important tool to exquisitely regulate the subcellular proteome in different cell types, including neurons. Local translation in axons is involved in processes such as neuronal development, function, plasticity, and diseases. Here, we summarize the current progress on axonal mRNA transport and translation. We focus on the regulatory mechanisms governing how mRNAs are transported to axons and how they are locally translated in axons. We discuss the roles of axonally synthesized proteins, which either function locally in axons, or are retrogradely trafficked back to soma to achieve neuron-wide gene regulation. We also examine local translation in neurological diseases. Finally, we give a critical perspective on the remaining questions that could be answered to uncover the fundamental rules governing local translation, and discuss how this could lead to new therapeutic targets for neurological diseases.
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5
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Park AJ, Shetty MS, Baraban JM, Abel T. Selective role of the translin/trax RNase complex in hippocampal synaptic plasticity. Mol Brain 2020; 13:145. [PMID: 33172471 PMCID: PMC7653721 DOI: 10.1186/s13041-020-00691-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 10/30/2020] [Indexed: 01/09/2023] Open
Abstract
Activity-dependent local protein synthesis is critical for synapse-specific, persistent plasticity. Abnormalities in local protein synthesis have been implicated in psychiatric disorders. We have recently identified the translin/trax microRNA-degrading enzyme as a novel mediator of protein synthesis at activated synapses. Additionally, translin knockout (KO) mice, which lack translin/trax, exhibit some of the behavioral abnormalities found in a mouse model of fragile X syndrome (fragile X mental retardation protein-FMRP-KO mice). Therefore, identifying signaling pathways interacting with translin/trax to support persistent synaptic plasticity is a translationally relevant goal. Here, as a first step to achieve this goal, we have assessed the requirement of translin/trax for multiple hippocampal synaptic plasticity paradigms that rely on distinct molecular mechanisms. We found that mice lacking translin/trax exhibited selective impairment in a form of persistent hippocampal plasticity, which requires postsynaptic protein kinase A (PKA) activity. In contrast, enduring forms of plasticity that are dependent on presynaptic PKA were unaffected. Furthermore, these mice did not display exaggerated metabotropic glutamate receptor-mediated long-term synaptic depression (mGluR-LTD), a hallmark of the FMRP KO mice. On the contrary, translin KO mice exhibited deficits in N-methyl-d-aspartate receptor (NMDAR) dependent LTD, a phenotype not observed in the FMRP knockouts. Taken together, these findings demonstrate that translin/trax mediates long-term synaptic plasticity that is dependent on postsynaptic PKA signaling and suggest that translin/trax and FMRP play distinct roles in hippocampal synaptic plasticity.
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Affiliation(s)
- Alan Jung Park
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA. .,Gogos Lab, Mortimer B. Zuckerman Mind Brain Behavior Institute, Jerome L. Greene Science Center, Columbia University, L5-053, 3227 Broadway, New York, NY, 10027, USA.
| | - Mahesh Shivarama Shetty
- Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, 2-471 Bowen Science Building, 51 Newton Road, Iowa City, IA, 52242, USA.,Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, 2312 Pappajohn Biomedical Discovery Building, 169 Newton Road, Iowa City, 52242, IA, USA
| | - Jay M Baraban
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ted Abel
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA. .,Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, 2-471 Bowen Science Building, 51 Newton Road, Iowa City, IA, 52242, USA. .,Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, 2312 Pappajohn Biomedical Discovery Building, 169 Newton Road, Iowa City, 52242, IA, USA.
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6
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Nihonmatsu I, Ohkawa N, Saitoh Y, Okubo-Suzuki R, Inokuchi K. Selective targeting of mRNA and the following protein synthesis of CaMKIIα at the long-term potentiation-induced site. Biol Open 2020; 9:bio.042861. [PMID: 31874853 PMCID: PMC6994928 DOI: 10.1242/bio.042861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Late-phase long-term potentiation (L-LTP) in hippocampus, thought to be the cellular basis of long-term memory, requires new protein synthesis. Neural activity enhances local protein synthesis in dendrites, which in turn mediates long-lasting synaptic plasticity. Ca2+/calmodulin-dependent protein kinase IIα (CaMKIIα) is a locally synthesized protein crucial for this plasticity, as L-LTP is impaired when its local synthesis is eliminated. However, the distribution of Camk2a mRNA during L-LTP induction remains unclear. In this study, we investigated the dendritic targeting of Camk2a mRNA after high-frequency stimulation, which induces L-LTP in synapses of perforant path and granule cells in the dentate gyrus in vivo. In situ hybridization studies revealed that Camk2a mRNA was immediately but transiently targeted to the site receiving high-frequency stimulation. This was associated with an increase in de novo protein synthesis of CaMKIIα. These results suggest that dendritic translation of CaMKIIα is locally mediated where L-LTP is induced. This phenomenon may be one of the essential processes for memory establishment. Summary: Selective targeting of mRNA and the following protein synthesis of CaMKIIalpha at neuronal plasticity-induced sites may be one of important processes for establishment of long-term memory.
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Affiliation(s)
- Itsuko Nihonmatsu
- Mitsubishi Kagaku Institute of Life Sciences, MITILS, 11 Minamiooya, Machida, Tokyo 194-8511, Japan
| | - Noriaki Ohkawa
- Mitsubishi Kagaku Institute of Life Sciences, MITILS, 11 Minamiooya, Machida, Tokyo 194-8511, Japan .,Division for Memory and Cognitive Function, Research Center for Advanced Medical Science, Comprehensive Research Facilities for Advanced Medical Science, Dokkyo Medical University, 880 Kita-kobayashi, Mibu-machi, Shimotsuga-gun, Tochigi 321-0293, Japan.,Department of Biochemistry, University of Toyama Graduate School of Medicine and Pharmaceutical Sciences, 2630 Sugitani, Toyama 930-0194, Japan.,PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.,CREST, JST, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Yoshito Saitoh
- Mitsubishi Kagaku Institute of Life Sciences, MITILS, 11 Minamiooya, Machida, Tokyo 194-8511, Japan.,Division for Memory and Cognitive Function, Research Center for Advanced Medical Science, Comprehensive Research Facilities for Advanced Medical Science, Dokkyo Medical University, 880 Kita-kobayashi, Mibu-machi, Shimotsuga-gun, Tochigi 321-0293, Japan.,Department of Biochemistry, University of Toyama Graduate School of Medicine and Pharmaceutical Sciences, 2630 Sugitani, Toyama 930-0194, Japan.,PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.,CREST, JST, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Reiko Okubo-Suzuki
- Mitsubishi Kagaku Institute of Life Sciences, MITILS, 11 Minamiooya, Machida, Tokyo 194-8511, Japan.,Department of Biochemistry, University of Toyama Graduate School of Medicine and Pharmaceutical Sciences, 2630 Sugitani, Toyama 930-0194, Japan.,CREST, JST, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Kaoru Inokuchi
- Mitsubishi Kagaku Institute of Life Sciences, MITILS, 11 Minamiooya, Machida, Tokyo 194-8511, Japan.,Department of Biochemistry, University of Toyama Graduate School of Medicine and Pharmaceutical Sciences, 2630 Sugitani, Toyama 930-0194, Japan.,CREST, JST, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
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7
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Cefaliello C, Penna E, Barbato C, Di Ruberto G, Mollica MP, Trinchese G, Cigliano L, Borsello T, Chun JT, Giuditta A, Perrone-Capano C, Miniaci MC, Crispino M. Deregulated Local Protein Synthesis in the Brain Synaptosomes of a Mouse Model for Alzheimer's Disease. Mol Neurobiol 2019; 57:1529-1541. [PMID: 31784883 DOI: 10.1007/s12035-019-01835-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 11/12/2019] [Indexed: 12/27/2022]
Abstract
While protein synthesis in neurons is largely attributed to cell body and dendrites, the capability of synaptic regions to synthesize new proteins independently of the cell body has been widely demonstrated as an advantageous mechanism subserving synaptic plasticity. Thus, the contribution that local protein synthesis at synapses makes to physiology and pathology of brain plasticity may be more prevalent than initially thought. In this study, we tested if local protein synthesis at synapses is deregulated in the brains of TgCRND8 mice, an animal model for Alzheimer's disease (AD) overexpressing mutant human amyloid precursor protein (APP). To this end, we used synaptosomes as a model system to study the functionality of the synaptic regions in mouse brains. Our results showed that, while TgCRND8 mice exhibit early signs of brain inflammation and deficits in learning, the electrophoretic profile of newly synthesized proteins in their synaptosomes was subtly different from that of the control mice. Interestingly, APP itself was, in part, locally synthesized in the synaptosomes, underscoring the potential importance of local translation at synapses. More importantly, after the contextual fear conditioning, de novo synthesis of some individual proteins was significantly enhanced in the synaptosomes of control animals, but the TgCRND8 mice failed to display such synaptic modulation by training. Taken together, our results demonstrate that synaptic synthesis of proteins is impaired in the brain of a mouse model for AD, and raise the possibility that this deregulation may contribute to the early progression of the pathology.
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Affiliation(s)
- Carolina Cefaliello
- Department of Biology, University of Naples Federico II, Naples, Italy.,current address: Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Eduardo Penna
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Carmela Barbato
- Department of Biology, University of Naples Federico II, Naples, Italy
| | | | | | | | - Luisa Cigliano
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Tiziana Borsello
- Department of Pharmacological and Biomolecular Sciences, Milan University, Milan, Italy.,Department of Neuroscience, Mario Negri Institute for Pharmacological Research-IRCCS, Milan, Italy
| | | | - Antonio Giuditta
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Carla Perrone-Capano
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy.,Institute of Genetics and Biophysics "Adriano Buzzati Traverso," CNR, Naples, Italy
| | - Maria Concetta Miniaci
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy.
| | - Marianna Crispino
- Department of Biology, University of Naples Federico II, Naples, Italy.
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8
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Stackpole EE, Akins MR, Ivshina M, Murthy AC, Fawzi NL, Fallon JR. EGFP insertional mutagenesis reveals multiple FXR2P fibrillar states with differing ribosome association in neurons. Biol Open 2019; 8:8/8/bio046383. [PMID: 31434643 PMCID: PMC6737979 DOI: 10.1242/bio.046383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
RNA-binding proteins (RBPs) function in higher-order assemblages such as RNA granules to regulate RNA localization and translation. The Fragile X homolog FXR2P is an RBP essential for formation of neuronal Fragile X granules that associate with axonal mRNA and ribosomes in the intact brain. However, the FXR2P domains important for assemblage formation in a cellular system are unknown. Here we used an EGFP insertional mutagenesis approach to probe for FXR2P intrinsic features that influence its structural states. We tested 18 different in-frame FXR2PEGFP fusions in neurons and found that the majority did not impact assemblage formation. However, EGFP insertion within a 23 amino acid region of the low complexity (LC) domain induced FXR2PEGFP assembly into two distinct fibril states that were observed in isolation or in highly-ordered bundles. FXR2PEGFP fibrils exhibited different developmental timelines, ultrastructures and ribosome associations. Formation of both fibril types was dependent on an intact RNA-binding domain. These results suggest that restricted regions of the LC domain, together with the RNA-binding domain, may be important for FXR2P structural state organization in neurons. Summary: A mutagenesis study reveals that the higher-order structural states of the RBP FXR2P in neurons can be regulated by manipulation of the LC and RNA-binding domains.
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Affiliation(s)
- Emily E Stackpole
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Michael R Akins
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Maria Ivshina
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Anastasia C Murthy
- Graduate Program in Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912, USA.,Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912, USA
| | - Nicolas L Fawzi
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912, USA
| | - Justin R Fallon
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
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9
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Parvin S, Takeda R, Sugiura Y, Neyazaki M, Nogi T, Sasaki Y. Fragile X mental retardation protein regulates accumulation of the active zone protein Munc18-1 in presynapses via local translation in axons during synaptogenesis. Neurosci Res 2018; 146:36-47. [PMID: 30240639 DOI: 10.1016/j.neures.2018.09.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 08/27/2018] [Accepted: 09/14/2018] [Indexed: 11/26/2022]
Abstract
Fragile X mental retardation protein (FMRP), a causative gene (FMR1) product of Fragile X syndrome (FXS), is an RNA-binding protein to regulate local protein synthesis in dendrites for postsynaptic functions. However, involvement of FMRP in local protein synthesis in axons for presynaptic functions remains unclear. Here we investigated role of FMRP in local translation of the active zone protein Munc18-1 during presynapse formation. We found that leucine-rich repeat transmembrane neuronal 2 (LRRTM2)-conjugated beads, which promotes synchronized presynapse formation, induced simultaneous accumulation of FMRP and Munc18-1 in presynapses of axons of mouse cortical neurons in neuronal cell aggregate culture. The LRRTM2-induced accumulation of Munc18-1 in presynapses was observed in axons protein-synthesis-dependently, even physically separated from cell bodies. The accumulation of Munc18-1 was enhanced in Fmr1-knockout (KO) axons as compared to wild type (WT), suggesting FMRP-regulated suppression for local translation of Munc18-1 in axons during presynapse formation. Using naturally formed synapses of dissociated culture, structured illumination microscope revealed that accumulation of Munc18-1 puncta in Fmr1-KO neurons increased significantly at 19 days in vitro, as compared to WT. Our findings lead the possibility that excessive accumulation of Munc18-1 in presynapses at early stage of synaptic development in Fmr1-KO neurons may have a critical role in impaired presynaptic functions in FXS.
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Affiliation(s)
- Shumaia Parvin
- Functional Structure Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Renoma Takeda
- Functional Structure Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Yu Sugiura
- Functional Structure Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Makiko Neyazaki
- Structural Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Terukazu Nogi
- Structural Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan
| | - Yukio Sasaki
- Functional Structure Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsurumi-ward, Yokohama 230-0045, Japan.
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10
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Moine H, Vitale N. Of local translation control and lipid signaling in neurons. Adv Biol Regul 2018; 71:194-205. [PMID: 30262213 DOI: 10.1016/j.jbior.2018.09.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 09/12/2018] [Accepted: 09/12/2018] [Indexed: 12/12/2022]
Abstract
Fine-tuned regulation of new proteins synthesis is key to the fast adaptation of cells to their changing environment and their response to external cues. Protein synthesis regulation is particularly refined and important in the case of highly polarized cells like neurons where translation occurs in the subcellular dendritic compartment to produce long-lasting changes that enable the formation, strengthening and weakening of inter-neuronal connection, constituting synaptic plasticity. The changes in local synaptic proteome of neurons underlie several aspects of synaptic plasticity and new protein synthesis is necessary for long-term memory formation. Details of how neuronal translation is locally controlled only start to be unraveled. A generally accepted view is that mRNAs are transported in a repressed state and are translated locally upon externally cued triggering signaling cascades that derepress or activate translation machinery at specific sites. Some important yet poorly considered intermediates in these cascades of events are signaling lipids such as diacylglycerol and its balancing partner phosphatidic acid. A link between these signaling lipids and the most common inherited cause of intellectual disability, Fragile X syndrome, is emphasizing the important role of these secondary messages in synaptically controlled translation.
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Affiliation(s)
- Hervé Moine
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404, Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, 67404, Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U1258, 67404, Illkirch, France; Université de Strasbourg, 67084, Strasbourg, France.
| | - Nicolas Vitale
- Université de Strasbourg, 67084, Strasbourg, France; Institut des Neurosciences Cellulaires et Intégratives, UPR3212 CNRS, 67084, Strasbourg, France
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11
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Jiang C, Lin WJ, Salton SR. Role of a VGF/BDNF/TrkB Autoregulatory Feedback Loop in Rapid-Acting Antidepressant Efficacy. J Mol Neurosci 2018; 68:504-509. [PMID: 30022437 DOI: 10.1007/s12031-018-1124-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 07/11/2018] [Indexed: 12/15/2022]
Abstract
Members of the neurotrophin family and in particular brain-derived neurotrophic factor (BDNF) regulate the response to rapid- and slow-acting chemical antidepressants and voluntary exercise. Recent work suggests that rapid-acting antidepressants that modulate N-methyl-D-aspartate receptor (NMDA-R) signaling (e.g., ketamine and GLYX-13) require expression of VGF (non-acronymic), the BDNF-inducible secreted neuronal protein and peptide precursor, for efficacy. In addition, the VGF-derived C-terminal peptide TLQP-62 (named by its 4 N-terminal amino acids and length) has antidepressant efficacy following icv or intra-hippocampal administration, in the forced swim test (FST). Similar to ketamine, the rapid antidepressant actions of TLQP-62 require BDNF expression, mTOR activation (rapamycin-sensitive), and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor activation (NBQX-sensitive) and are associated with GluR1 insertion. We review recent findings that identify a rapidly induced autoregulatory feedback loop, which likely plays a critical role in sustained efficacy of rapid-acting antidepressants, depression-like behavior, and cognition, and requires VGF, its C-terminal peptide TLQP-62, BDNF/TrkB signaling, the mTOR pathway, and AMPA receptor activation and insertion.
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Affiliation(s)
- Cheng Jiang
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1639, New York, NY, 10029, USA
| | - Wei-Jye Lin
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1639, New York, NY, 10029, USA.,Medical Research Center of Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Stephen R Salton
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1639, New York, NY, 10029, USA. .,Brookdale Department of Geriatrics and Palliative Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. .,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
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Hoshi O, Sugizaki A, Cho Y, Takei N. BDNF Reduces eEF2 Phosphorylation and Enhances Novel Protein Synthesis in the Growth Cones of Dorsal Root Ganglia Neurons. Neurochem Res 2018; 43:1242-1249. [PMID: 29736615 DOI: 10.1007/s11064-018-2541-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 04/19/2018] [Accepted: 04/27/2018] [Indexed: 11/26/2022]
Abstract
The local translation, which is regulated by extracellular stimuli such as guidance molecules, in growth cones of neurons provides a molecular mechanism for axonal development. In this study, we performed immunocytochemistry together with atomic force microscopy to investigate the localization of ribosomal proteins in the growth cones of rat dorsal root ganglion (DRG) neurons. The immunoreactivity of ribosomal protein P0/1/2 and S6, and novel protein synthesis were observed in the central, sterically bulky region of growth cones. Brain derived neurotrophic factor (BDNF) reduced the eEF2 phosphorylation, indicating its activation, and enhanced protein synthesis within 30 min. The effects of BDNF were completely inhibited by rapamycin, an inhibitor of mammalian target of rapamycin (mTOR). These results indicated that BDNF rapidly activates translation and enhances novel protein synthesis in growth cones of DRG though the mTOR signaling.
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Affiliation(s)
- Osamu Hoshi
- Department of Anatomy and Physiological Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
| | - Ayana Sugizaki
- Department of Anatomy and Physiological Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Yuichiro Cho
- Department of Anatomy and Physiological Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Nobuyuki Takei
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan.
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Gainer H, House S, Kim DS, Chin H, Pant HC. Squid Giant Axon Contains Neurofilament Protein mRNA but does not Synthesize Neurofilament Proteins. Cell Mol Neurobiol 2017; 37:475-86. [PMID: 27207029 DOI: 10.1007/s10571-016-0382-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 05/06/2016] [Indexed: 12/16/2022]
Abstract
When isolated squid giant axons are incubated in radioactive amino acids, abundant newly synthesized proteins are found in the axoplasm. These proteins are translated in the adaxonal Schwann cells and subsequently transferred into the giant axon. The question as to whether any de novo protein synthesis occurs in the giant axon itself is difficult to resolve because the small contribution of the proteins possibly synthesized intra-axonally is not easily distinguished from the large amounts of the proteins being supplied from the Schwann cells. In this paper, we reexamine this issue by studying the synthesis of endogenous neurofilament (NF) proteins in the axon. Our laboratory previously showed that NF mRNA and protein are present in the squid giant axon, but not in the surrounding adaxonal glia. Therefore, if the isolated squid axon could be shown to contain newly synthesized NF protein de novo, it could not arise from the adaxonal glia. The results of experiments in this paper show that abundant 3H-labeled NF protein is synthesized in the squid giant fiber lobe containing the giant axon's neuronal cell bodies, but despite the presence of NF mRNA in the giant axon no labeled NF protein is detected in the giant axon. This lends support to the glia-axon protein transfer hypothesis which posits that the squid giant axon obtains newly synthesized protein by Schwann cell transfer and not through intra-axonal protein synthesis, and further suggests that the NF mRNA in the axon is in a translationally repressed state.
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Orefice LL, Shih CC, Xu H, Waterhouse EG, Xu B. Control of spine maturation and pruning through proBDNF synthesized and released in dendrites. Mol Cell Neurosci 2015; 71:66-79. [PMID: 26705735 DOI: 10.1016/j.mcn.2015.12.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 12/11/2015] [Accepted: 12/15/2015] [Indexed: 12/27/2022] Open
Abstract
Excess synapses formed during early postnatal development are pruned over an extended period, while the remaining synapses mature. Synapse pruning is critical for activity-dependent refinement of neuronal connections and its dysregulation has been found in neurodevelopmental disorders such as autism spectrum disorders; however, the mechanism underlying synapse pruning remains largely unknown. As dendritic spines are the postsynaptic sites for the vast majority of excitatory synapses, spine maturation and pruning are indicators for maturation and elimination of these synapses. Our previous studies have found that dendritically localized mRNA for brain-derived neurotrophic factor (BDNF) regulates spine maturation and pruning. Here we investigated the mechanism by which dendritic Bdnf mRNA, but not somatically restricted Bdnf mRNA, promotes spine maturation and pruning. We found that neuronal activity stimulates both translation of dendritic Bdnf mRNA and secretion of its translation product mainly as proBDNF. The secreted proBDNF promotes spine maturation and pruning, and its effect on spine pruning is in part mediated by the p75(NTR) receptor via RhoA activation. Furthermore, some proBDNF is extracellularly converted to mature BDNF and then promotes maturation of stimulated spines by activating Rac1 through the TrkB receptor. In contrast, translation of somatic Bdnf mRNA and the release of its translation product mainly as mature BDNF are independent of action potentials. These results not only reveal a biochemical pathway regulating synapse pruning, but also suggest that BDNF synthesized in the soma and dendrites is released through distinct secretory pathways.
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Affiliation(s)
- Lauren L Orefice
- Department of Neuroscience, The Scripps Research Institute Florida, 130 Scripps Way, Jupiter, FL 33458, USA; Department of Pharmacology and Physiology, Georgetown University Medical Center, 3900 Reservoir Road NW, Washington, DC 20057, USA
| | - Chien-Cheng Shih
- Department of Neuroscience, The Scripps Research Institute Florida, 130 Scripps Way, Jupiter, FL 33458, USA; Department of Pharmacology and Physiology, Georgetown University Medical Center, 3900 Reservoir Road NW, Washington, DC 20057, USA
| | - Haifei Xu
- Department of Neuroscience, The Scripps Research Institute Florida, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Emily G Waterhouse
- Department of Pharmacology and Physiology, Georgetown University Medical Center, 3900 Reservoir Road NW, Washington, DC 20057, USA
| | - Baoji Xu
- Department of Neuroscience, The Scripps Research Institute Florida, 130 Scripps Way, Jupiter, FL 33458, USA; Department of Pharmacology and Physiology, Georgetown University Medical Center, 3900 Reservoir Road NW, Washington, DC 20057, USA.
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Nihonmatsu I, Ohkawa N, Saitoh Y, Inokuchi K. Targeting of ribosomal protein S6 to dendritic spines by in vivo high frequency stimulation to induce long-term potentiation in the dentate gyrus. Biol Open 2015; 4:1387-94. [PMID: 26432888 PMCID: PMC4728348 DOI: 10.1242/bio.013243] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Late phase long-term potentiation (L-LTP) in the hippocampus is believed to be the cellular basis of long-term memory. Protein synthesis is required for persistent forms of synaptic plasticity, including L-LTP. Neural activity is thought to enhance local protein synthesis in dendrites, and one of the mechanisms required to induce or maintain the long-lasting synaptic plasticity is protein translation in the dendrites. One regulator of translational processes is ribosomal protein S6 (rpS6), a component of the small 40S ribosomal subunit. Although polyribosomes containing rpS6 are observed in dendritic spines, it remains unclear whether L-LTP induction triggers selective targeting of the translational machinery to activated synapses in vivo. Therefore, we investigated synaptic targeting of the translational machinery by observing rpS6 immunoreactivity during high frequency stimulation (HFS) for L-LTP induction in vivo. Immunoelectron microscopic analysis revealed a selective but transient increase in rpS6 immunoreactivity occurring as early as 15 min after the onset of HFS in dendritic spine heads at synaptic sites receiving HFS. Concurrently, levels of the rpS6 protein rapidly declined in somata of granule cells, as determined using immunofluorescence microscopy. These results suggest that the translational machinery is rapidly targeted to activated spines and that this targeting mechanism may contribute to the establishment of L-LTP.
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Affiliation(s)
- Itsuko Nihonmatsu
- Mitsubishi Kagaku Institute of Life Sciences, MITILS, 11 Minamiooya, Machida, Tokyo 194-8511, Japan Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Honcho 4-1-8, Kawaguchi 332-0012, Japan
| | - Noriaki Ohkawa
- Mitsubishi Kagaku Institute of Life Sciences, MITILS, 11 Minamiooya, Machida, Tokyo 194-8511, Japan Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Honcho 4-1-8, Kawaguchi 332-0012, Japan Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Yoshito Saitoh
- Mitsubishi Kagaku Institute of Life Sciences, MITILS, 11 Minamiooya, Machida, Tokyo 194-8511, Japan Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Honcho 4-1-8, Kawaguchi 332-0012, Japan Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Kaoru Inokuchi
- Mitsubishi Kagaku Institute of Life Sciences, MITILS, 11 Minamiooya, Machida, Tokyo 194-8511, Japan Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Honcho 4-1-8, Kawaguchi 332-0012, Japan Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
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Lai KO, Ip NY. Structural plasticity of dendritic spines: the underlying mechanisms and its dysregulation in brain disorders. Biochim Biophys Acta Mol Basis Dis 2013; 1832:2257-63. [PMID: 24012719 DOI: 10.1016/j.bbadis.2013.08.012] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 08/13/2013] [Accepted: 08/28/2013] [Indexed: 12/17/2022]
Abstract
Dendritic spines are specialized structures on neuronal processes where the majority of excitatory synapses are localized. Spines are highly dynamic, and their stabilization and morphology are influenced by synaptic activity. This extrinsic regulation of spine morphogenesis underlies experience-dependent brain development and information storage within the brain circuitry. In this review, we summarize recent findings that demonstrate the phenomenon of activity-dependent structural plasticity and the molecular mechanisms by which synaptic activity sculpt neuronal connections. Impaired structural plasticity is associated with perturbed brain function in neurodevelopmental disorders such as autism. Information from the mechanistic studies therefore provides important insights into the design of therapeutic strategies for these brain disorders.
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Affiliation(s)
- Kwok-On Lai
- Division of Life Science, Molecular Neuroscience Center and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong
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Chen L, Lau AG, Sarti F. Synaptic retinoic acid signaling and homeostatic synaptic plasticity. Neuropharmacology 2012; 78:3-12. [PMID: 23270606 DOI: 10.1016/j.neuropharm.2012.12.004] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 12/08/2012] [Accepted: 12/14/2012] [Indexed: 01/03/2023]
Abstract
One of the defining features of the nervous system is its ability to modify synaptic strength in an experience-dependent manner. Chronic elevation or reduction of network activity activates compensatory mechanisms that modulate synaptic strength in the opposite direction (i.e. reduced network activity leads to increased synaptic strength), a process called homeostatic synaptic plasticity. Among the many mechanisms that mediate homeostatic synaptic plasticity, retinoic acid (RA) has emerged as a novel signaling molecule that is critically involved in homeostatic synaptic plasticity induced by blockade of synaptic activity. In neurons, silencing of synaptic transmission triggers RA synthesis. RA then acts at synapses by a non-genomic mechanism that is independent of its well-known function as a transcriptional regulator, but operates through direct activation of protein translation in neuronal dendrites. Protein synthesis is activated by RA-binding to its receptor RARα, which functions locally in dendrites in a non-canonical manner as an RNA-binding protein that mediate RA's effect on translation. The present review will discuss recent progress in our understanding of the novel role of RA, which led to the identification of RA as a critical synaptic signaling molecule that mediates activity-dependent regulation of protein synthesis in neuronal dendrites. This article is part of the Special Issue entitled 'Homeostatic Synaptic Plasticity'.
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Affiliation(s)
- Lu Chen
- Stanford Institute of Neuro-Innovation and Translational Neuroscience, and Department of Psychiatry and Behavioral Sciences, Stanford University, School of Medicine, Stanford, CA 94305-5453, USA.
| | - Anthony G Lau
- Stanford Institute of Neuro-Innovation and Translational Neuroscience, and Department of Psychiatry and Behavioral Sciences, Stanford University, School of Medicine, Stanford, CA 94305-5453, USA
| | - Federica Sarti
- Stanford Institute of Neuro-Innovation and Translational Neuroscience, and Department of Psychiatry and Behavioral Sciences, Stanford University, School of Medicine, Stanford, CA 94305-5453, USA; University of California, Department of Molecular and Cell Biology, Berkeley, CA 94720-3200, USA
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