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Beletskiy A, Zolotar A, Fortygina P, Chesnokova E, Uroshlev L, Balaban P, Kolosov P. Downregulation of Ribosomal Protein Genes Is Revealed in a Model of Rat Hippocampal Neuronal Culture Activation with GABA(A)R/GlyRa2 Antagonist Picrotoxin. Cells 2024; 13:383. [PMID: 38474347 DOI: 10.3390/cells13050383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 02/13/2024] [Accepted: 02/20/2024] [Indexed: 03/14/2024] Open
Abstract
Long-read transcriptome sequencing provides us with a convenient tool for the thorough study of biological processes such as neuronal plasticity. Here, we aimed to perform transcriptional profiling of rat hippocampal primary neuron cultures after stimulation with picrotoxin (PTX) to further understand molecular mechanisms of neuronal activation. To overcome the limitations of short-read RNA-Seq approaches, we performed an Oxford Nanopore Technologies MinION-based long-read sequencing and transcriptome assembly of rat primary hippocampal culture mRNA at three time points after the PTX activation. We used a specific approach to exclude uncapped mRNAs during sample preparation. Overall, we found 23,652 novel transcripts in comparison to reference annotations, out of which ~6000 were entirely novel and mostly transposon-derived loci. Analysis of differentially expressed genes (DEG) showed that 3046 genes were differentially expressed, of which 2037 were upregulated and 1009 were downregulated at 30 min after the PTX application, with only 446 and 13 genes differentially expressed at 1 h and 5 h time points, respectively. Most notably, multiple genes encoding ribosomal proteins, with a high basal expression level, were downregulated after 30 min incubation with PTX; we suggest that this indicates redistribution of transcriptional resources towards activity-induced genes. Novel loci and isoforms observed in this study may help us further understand the functional mRNA repertoire in neuronal plasticity processes. Together with other NGS techniques, differential gene expression analysis of sequencing data obtained using MinION platform might provide a simple method to optimize further study of neuronal plasticity.
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Affiliation(s)
- Alexander Beletskiy
- Institute of Higher Nervous Activity and Neurophysiology, The Russian Academy of Sciences, 117485 Moscow, Russia
| | - Anastasia Zolotar
- Institute of Higher Nervous Activity and Neurophysiology, The Russian Academy of Sciences, 117485 Moscow, Russia
| | - Polina Fortygina
- Institute of Higher Nervous Activity and Neurophysiology, The Russian Academy of Sciences, 117485 Moscow, Russia
| | - Ekaterina Chesnokova
- Institute of Higher Nervous Activity and Neurophysiology, The Russian Academy of Sciences, 117485 Moscow, Russia
| | - Leonid Uroshlev
- Institute of Higher Nervous Activity and Neurophysiology, The Russian Academy of Sciences, 117485 Moscow, Russia
| | - Pavel Balaban
- Institute of Higher Nervous Activity and Neurophysiology, The Russian Academy of Sciences, 117485 Moscow, Russia
| | - Peter Kolosov
- Institute of Higher Nervous Activity and Neurophysiology, The Russian Academy of Sciences, 117485 Moscow, Russia
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia
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2
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Koesters AG, Rich MM, Engisch KL. Diverging from the Norm: Reevaluating What Miniature Excitatory Postsynaptic Currents Tell Us about Homeostatic Synaptic Plasticity. Neuroscientist 2024; 30:49-70. [PMID: 35904350 DOI: 10.1177/10738584221112336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The idea that the nervous system maintains a set point of network activity and homeostatically returns to that set point in the face of dramatic disruption-during development, after injury, in pathologic states, and during sleep/wake cycles-is rapidly becoming accepted as a key plasticity behavior, placing it alongside long-term potentiation and depression. The dramatic growth in studies of homeostatic synaptic plasticity of miniature excitatory synaptic currents (mEPSCs) is attributable, in part, to the simple yet elegant mechanism of uniform multiplicative scaling proposed by Turrigiano and colleagues: that neurons sense their own activity and globally multiply the strength of every synapse by a single factor to return activity to the set point without altering established differences in synaptic weights. We have recently shown that for mEPSCs recorded from control and activity-blocked cultures of mouse cortical neurons, the synaptic scaling factor is not uniform but is close to 1 for the smallest mEPSC amplitudes and progressively increases as mEPSC amplitudes increase, which we term divergent scaling. Using insights gained from simulating uniform multiplicative scaling, we review evidence from published studies and conclude that divergent synaptic scaling is the norm rather than the exception. This conclusion has implications for hypotheses about the molecular mechanisms underlying synaptic scaling.
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Affiliation(s)
- Andrew G Koesters
- Department of Behavior, Cognition, and Neurophysiology, Environmental Health Effects Laboratory, Naval Medical Research Unit-Dayton, Wright-Patterson AFB, OH, USA
| | - Mark M Rich
- Department of Neuroscience, Cell Biology, and Physiology, College of Science and Mathematics, and Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
| | - Kathrin L Engisch
- Department of Neuroscience, Cell Biology, and Physiology, College of Science and Mathematics, and Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
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3
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Wang S, DeLeon C, Sun W, Quake SR, Roth BL, Südhof TC. Alternative splicing of latrophilin-3 controls synapse formation. Nature 2024; 626:128-135. [PMID: 38233523 PMCID: PMC10830413 DOI: 10.1038/s41586-023-06913-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 11/29/2023] [Indexed: 01/19/2024]
Abstract
The assembly and specification of synapses in the brain is incompletely understood1-3. Latrophilin-3 (encoded by Adgrl3, also known as Lphn3)-a postsynaptic adhesion G-protein-coupled receptor-mediates synapse formation in the hippocampus4 but the mechanisms involved remain unclear. Here we show in mice that LPHN3 organizes synapses through a convergent dual-pathway mechanism: activation of Gαs signalling and recruitment of phase-separated postsynaptic protein scaffolds. We found that cell-type-specific alternative splicing of Lphn3 controls the LPHN3 G-protein-coupling mode, resulting in LPHN3 variants that predominantly signal through Gαs or Gα12/13. CRISPR-mediated manipulation of Lphn3 alternative splicing that shifts LPHN3 from a Gαs- to a Gα12/13-coupled mode impaired synaptic connectivity as severely as the overall deletion of Lphn3, suggesting that Gαs signalling by LPHN3 splice variants mediates synapse formation. Notably, Gαs-coupled, but not Gα12/13-coupled, splice variants of LPHN3 also recruit phase-transitioned postsynaptic protein scaffold condensates, such that these condensates are clustered by binding of presynaptic teneurin and FLRT ligands to LPHN3. Moreover, neuronal activity promotes alternative splicing of the synaptogenic Gαs-coupled variant of LPHN3. Together, these data suggest that activity-dependent alternative splicing of a key synaptic adhesion molecule controls synapse formation by parallel activation of two convergent pathways: Gαs signalling and clustered phase separation of postsynaptic protein scaffolds.
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Affiliation(s)
- Shuai Wang
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA.
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA.
| | - Chelsea DeLeon
- Department of Pharmacology, UNC Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Wenfei Sun
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
- Department of Applied Physics, Stanford University, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Stephen R Quake
- Department of Applied Physics, Stanford University, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- The Chan Zuckerberg Initiative, Redwood City, CA, USA
| | - Bryan L Roth
- Department of Pharmacology, UNC Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA.
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA.
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4
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Chen Z, Dragan M, Sun P, Haensel D, Vu R, Cui L, Shi Y, Dai X. An AhR-Ovol1-Id1 regulatory axis in keratinocytes promotes skin homeostasis against atopic dermatitis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.29.577821. [PMID: 38352592 PMCID: PMC10862726 DOI: 10.1101/2024.01.29.577821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Skin is our outer permeability and immune defense barrier against myriad external assaults. Aryl hydrocarbon receptor (AhR) senses environmental factors and regulates barrier robustness and immune homeostasis. AhR agonist is in clinical trial for atopic dermatitis (AD) treatment, but the underlying mechanism of action remains ill-defined. Here we report OVOL1/Ovol1 as a conserved and direct transcriptional target of AhR in epidermal keratinocytes. We show that OVOL1/Ovol1 impacts AhR regulation of keratinocyte gene expression, and Ovol1 deletion in keratinocytes hampers AhR's barrier promotion function and worsens AD-like inflammation. Mechanistically, we identify Ovol1's direct downstream targets genome-wide, and provide in vivo evidence for Id1's critical role in barrier maintenance and disease suppression. Furthermore, our findings reveal an IL-1/dermal γδT cell axis exacerbating both type 2 and type 3 immune responses downstream of barrier perturbation in Ovol1 -deficient AD skin. Finally, we present data suggesting the clinical relevance of OVOL1 and ID1 function in human AD. Our study highlights a keratinocyte-intrinsic AhR-Ovol1-Id1 regulatory axis that promotes both epidermal and immune homeostasis against AD-like inflammation, implicating new therapeutic targets for AD.
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5
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Tsukahara T, Kethireddy S, Bonefas K, Chen A, Sutton BLM, Dou Y, Iwase S, Sutton MA. Division of labor among H3K4 Methyltransferases Defines Distinct Facets of Homeostatic Plasticity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.20.558734. [PMID: 37790395 PMCID: PMC10542164 DOI: 10.1101/2023.09.20.558734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Heterozygous mutations in any of the six H3K4 methyltransferases (KMT2s) result in monogenic neurodevelopmental disorders, indicating nonredundant yet poorly understood roles of this enzyme family in neurodevelopment. Recent evidence suggests that histone methyltransferase activity may not be central to KMT2 functions; however, the enzymatic activity is evolutionarily conserved, implicating the presence of selective pressure to maintain the catalytic activity. Here, we show that H3K4 methylation is dynamically regulated during prolonged alteration of neuronal activity. The perturbation of H3K4me by the H3.3K4M mutant blocks synaptic scaling, a form of homeostatic plasticity that buffers the impact of prolonged reductions or increases in network activity. Unexpectedly, we found that the six individual enzymes are all necessary for synaptic scaling and that the roles of KMT2 enzymes segregate into evolutionary-defined subfamilies: KMT2A and KMT2B (fly-Trx homologs) for synaptic downscaling, KMT2C and KMT2D (Trr homologs) for upscaling, and KMT2F and KMT2G (dSet homologs) for both directions. Selective blocking of KMT2A enzymatic activity by a small molecule and targeted disruption of the enzymatic domain both blocked the synaptic downscaling and interfered with the activity-dependent transcriptional program. Furthermore, our study revealed specific phases of synaptic downscaling, i.e., induction and maintenance, in which KMT2A and KMT2B play distinct roles. These results suggest that mammalian brains have co-opted intricate H3K4me installation to achieve stability of the expanding neuronal circuits.
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Affiliation(s)
- Takao Tsukahara
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, Michigan
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Saini Kethireddy
- College of Literature, Science, and the Arts, University of Michigan, Ann Arbor, Michigan
| | - Katherine Bonefas
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan
| | - Alex Chen
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan
| | - Brendan LM Sutton
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan
| | - Yali Dou
- Department of Medicine and Department of Biochemistry and Molecular Medicine, Keck School of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Shigeki Iwase
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, Michigan
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan
| | - Michael A. Sutton
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, Michigan
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan
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6
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Cheung A, Konno K, Imamura Y, Matsui A, Abe M, Sakimura K, Sasaoka T, Uemura T, Watanabe M, Futai K. Neurexins in serotonergic neurons regulate neuronal survival, serotonin transmission, and complex mouse behaviors. eLife 2023; 12:85058. [PMID: 36695811 PMCID: PMC9876567 DOI: 10.7554/elife.85058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 01/13/2023] [Indexed: 01/26/2023] Open
Abstract
Extensive serotonin (5-hydroxytryptamine, 5-HT) innervation throughout the brain corroborates 5-HT's modulatory role in numerous cognitive activities. Volume transmission is the major mode for 5-HT transmission but mechanisms underlying 5-HT signaling are still largely unknown. Abnormal brain 5-HT levels and function have been implicated in autism spectrum disorder (ASD). Neurexin (Nrxn) genes encode presynaptic cell adhesion molecules important for the regulation of synaptic neurotransmitter release, notably glutamatergic and GABAergic transmission. Mutations in Nrxn genes are associated with neurodevelopmental disorders including ASD. However, the role of Nrxn genes in the 5-HT system is poorly understood. Here, we generated a mouse model with all three Nrxn genes disrupted specifically in 5-HT neurons to study how Nrxns affect 5-HT transmission. Loss of Nrxns in 5-HT neurons reduced the number of serotonin neurons in the early postnatal stage, impaired 5-HT release, and decreased 5-HT release sites and serotonin transporter expression. Furthermore, 5-HT neuron-specific Nrxn knockout reduced sociability and increased depressive-like behavior. Our results highlight functional roles for Nrxns in 5-HT neurotransmission, 5-HT neuron survival, and the execution of complex behaviors.
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Affiliation(s)
- Amy Cheung
- Department of Neurobiology, University of Massachusetts Chan Medical SchoolWorcesterUnited States
- Brudnick Neuropsychiatric Research Institute, University of MassachusettsWorcesterUnited States
- Medical Scientist Training Program, University of MassachusettsWorcesterUnited States
| | - Kotaro Konno
- Department of Anatomy, Faculty of Medicine, Hokkaido UniversitySapporoJapan
| | - Yuka Imamura
- Departments of Pharmacology and Biochemistry & Molecular Biology, Institute for Personalized Medicine, Pennsylvania State University College of Medicine, 500 University DriveHersheyUnited States
| | - Aya Matsui
- Vollum Institute, Oregon Health & Science UniversityPortlandUnited States
| | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Kenji Sakimura
- Department of Animal Model Development, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Toshikuni Sasaoka
- Department of Comparative and Experimental Medicine, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Takeshi Uemura
- Division of Gene Research, Research Center for Advanced Science, Shinshu UniversityNaganoJapan
- Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu UniversityNaganoJapan
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido UniversitySapporoJapan
| | - Kensuke Futai
- Department of Neurobiology, University of Massachusetts Chan Medical SchoolWorcesterUnited States
- Brudnick Neuropsychiatric Research Institute, University of MassachusettsWorcesterUnited States
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7
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Pumo GM, Kitazawa T, Rijli FM. Epigenetic and Transcriptional Regulation of Spontaneous and Sensory Activity Dependent Programs During Neuronal Circuit Development. Front Neural Circuits 2022; 16:911023. [PMID: 35664458 PMCID: PMC9158562 DOI: 10.3389/fncir.2022.911023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 04/28/2022] [Indexed: 11/13/2022] Open
Abstract
Spontaneous activity generated before the onset of sensory transduction has a key role in wiring developing sensory circuits. From axonal targeting, to synapse formation and elimination, to the balanced integration of neurons into developing circuits, this type of activity is implicated in a variety of cellular processes. However, little is known about its molecular mechanisms of action, especially at the level of genome regulation. Conversely, sensory experience-dependent activity implements well-characterized transcriptional and epigenetic chromatin programs that underlie heterogeneous but specific genomic responses that shape both postnatal circuit development and neuroplasticity in the adult. In this review, we focus on our knowledge of the developmental processes regulated by spontaneous activity and the underlying transcriptional mechanisms. We also review novel findings on how chromatin regulates the specificity and developmental induction of the experience-dependent program, and speculate their relevance for our understanding of how spontaneous activity may act at the genomic level to instruct circuit assembly and prepare developing neurons for sensory-dependent connectivity refinement and processing.
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Affiliation(s)
- Gabriele M. Pumo
- Laboratory of Neurodevelopmental Epigenetics, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Department Biozentrum, University of Basel, Basel, Switzerland
| | - Taro Kitazawa
- Laboratory of Neurodevelopmental Epigenetics, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Filippo M. Rijli
- Laboratory of Neurodevelopmental Epigenetics, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Department Biozentrum, University of Basel, Basel, Switzerland
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8
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Wu CH, Tatavarty V, Jean Beltran PM, Guerrero AA, Keshishian H, Krug K, MacMullan MA, Li L, Carr SA, Cottrell JR, Turrigiano GG. A bidirectional switch in the Shank3 phosphorylation state biases synapses toward up- or downscaling. eLife 2022; 11:74277. [PMID: 35471151 PMCID: PMC9084893 DOI: 10.7554/elife.74277] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
Homeostatic synaptic plasticity requires widespread remodeling of synaptic signaling and scaffolding networks, but the role of post-translational modifications in this process has not been systematically studied. Using deep-scale quantitative analysis of the phosphoproteome in mouse neocortical neurons, we found widespread and temporally complex changes during synaptic scaling up and down. We observed 424 bidirectionally modulated phosphosites that were strongly enriched for synapse-associated proteins, including S1539 in the autism spectrum disorder-associated synaptic scaffold protein Shank3. Using a parallel proteomic analysis performed on Shank3 isolated from rat neocortical neurons by immunoaffinity, we identified two sites that were persistently hypophosphorylated during scaling up and transiently hyperphosphorylated during scaling down: one (rat S1615) that corresponded to S1539 in mouse, and a second highly conserved site, rat S1586. The phosphorylation status of these sites modified the synaptic localization of Shank3 during scaling protocols, and dephosphorylation of these sites via PP2A activity was essential for the maintenance of synaptic scaling up. Finally, phosphomimetic mutations at these sites prevented scaling up but not down, while phosphodeficient mutations prevented scaling down but not up. These mutations did not impact baseline synaptic strength, indicating that they gate, rather than drive, the induction of synaptic scaling. Thus, an activity-dependent switch between hypo- and hyperphosphorylation at S1586 and S1615 of Shank3 enables scaling up or down, respectively. Collectively, our data show that activity-dependent phosphoproteome dynamics are important for the functional reconfiguration of synaptic scaffolds and can bias synapses toward upward or downward homeostatic plasticity.
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Affiliation(s)
- Chi-Hong Wu
- Department of Biology, Brandeis UniversityWalthamUnited States
| | | | | | | | - Hasmik Keshishian
- Proteomics Platform, Broad Institute of MIT and HarvardCambridgeUnited States
| | - Karsten Krug
- Proteomics Platform, Broad Institute of MIT and HarvardCambridgeUnited States
| | - Melanie A MacMullan
- Proteomics Platform, Broad Institute of MIT and HarvardCambridgeUnited States
| | - Li Li
- Stanley Center for Psychiatric Research, Broad Institute of MIT and HarvardCambridgeUnited States
| | - Steven A Carr
- Proteomics Platform, Broad Institute of MIT and HarvardCambridgeUnited States
| | - Jeffrey R Cottrell
- Stanley Center for Psychiatric Research, Broad Institute of MIT and HarvardCambridgeUnited States
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9
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Garay PM, Chen A, Tsukahara T, Rodríguez Díaz JC, Kohen R, Althaus JC, Wallner MA, Giger RJ, Jones KS, Sutton MA, Iwase S. RAI1 Regulates Activity-Dependent Nascent Transcription and Synaptic Scaling. Cell Rep 2021; 32:108002. [PMID: 32783930 PMCID: PMC7418709 DOI: 10.1016/j.celrep.2020.108002] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 06/17/2020] [Accepted: 07/15/2020] [Indexed: 12/15/2022] Open
Abstract
Long-lasting forms of synaptic plasticity such as synaptic scaling are critically dependent on transcription. Activity-dependent transcriptional dynamics in neurons, however, remain incompletely characterized because most previous efforts relied on measurement of steady-state mRNAs. Here, we use nascent RNA sequencing to profile transcriptional dynamics of primary neuron cultures undergoing network activity shifts. We find pervasive transcriptional changes, in which ∼45% of expressed genes respond to network activity shifts. We further link retinoic acid-induced 1 (RAI1), the Smith-Magenis syndrome gene, to the transcriptional program driven by reduced network activity. Remarkable agreement among nascent transcriptomes, dynamic chromatin occupancy of RAI1, and electrophysiological properties of Rai1-deficient neurons demonstrates the essential roles of RAI1 in suppressing synaptic upscaling in the naive network, while promoting upscaling triggered by activity silencing. These results highlight the utility of bona fide transcription profiling to discover mechanisms of activity-dependent chromatin remodeling that underlie normal and pathological synaptic plasticity. BrU-seq reveals nascent transcription during synaptic up- or downscaling Smith-Magenis syndrome protein RAI1 regulates upscaling-associated transcription RAI1 departs chromatin in response to network activity shifts RAI1 blocks upscaling in naive networks and promotes inactivity-induced upscaling
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Affiliation(s)
- Patricia M Garay
- Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Alex Chen
- Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Takao Tsukahara
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Rafi Kohen
- Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - J Christian Althaus
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Margarete A Wallner
- College of Literature, Science, and the Arts, University of Michigan, Ann Arbor, MI 48109, USA
| | - Roman J Giger
- Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA; Cellular and Molecular Biology Graduate Program, University of Michigan Medical School, Ann Arbor, MI, 48109, USA; Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Kevin S Jones
- Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Michael A Sutton
- Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Shigeki Iwase
- Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA.
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10
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Wang Y, Fu AKY, Ip NY. Instructive roles of astrocytes in hippocampal synaptic plasticity: neuronal activity-dependent regulatory mechanisms. FEBS J 2021; 289:2202-2218. [PMID: 33864430 PMCID: PMC9290076 DOI: 10.1111/febs.15878] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 03/02/2021] [Accepted: 04/12/2021] [Indexed: 12/22/2022]
Abstract
In the adult hippocampus, synaptic plasticity is important for information processing, learning, and memory encoding. Astrocytes, the most common glial cells, play a pivotal role in the regulation of hippocampal synaptic plasticity. While astrocytes were initially described as a homogenous cell population, emerging evidence indicates that in the adult hippocampus, astrocytes are highly heterogeneous and can differentially respond to changes in neuronal activity in a subregion‐dependent manner to actively modulate synaptic plasticity. In this review, we summarize how local neuronal activity changes regulate the interactions between astrocytes and synapses, either by modulating the secretion of gliotransmitters and synaptogenic proteins or via contact‐mediated signaling pathways. In turn, these specific responses induced in astrocytes mediate the interactions between astrocytes and neurons, thus shaping synaptic communication in the adult hippocampus. Importantly, the activation of astrocytic signaling is required for memory performance including memory acquisition and recall. Meanwhile, the dysregulation of this signaling can cause hippocampal circuit dysfunction in pathological conditions, resulting in cognitive impairment and neurodegeneration. Indeed, reactive astrocytes, which have dysregulated signaling associated with memory, are induced in the brains of patients with Alzheimer's disease (AD) and transgenic mouse model of AD. Emerging technologies that can precisely manipulate and monitor astrocytic signaling in vivo enable the examination of the specific actions of astrocytes in response to neuronal activity changes as well as how they modulate synaptic connections and circuit activity. Such findings will clarify the roles of astrocytes in hippocampal synaptic plasticity and memory in health and disease.
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Affiliation(s)
- Ye Wang
- Division of Life Science, The Hong Kong University of Science and Technology, China.,Molecular Neuroscience Center, The Hong Kong University of Science and Technology, China.,State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, China.,Hong Kong Center for Neurodegenerative Diseases, China
| | - Amy K Y Fu
- Division of Life Science, The Hong Kong University of Science and Technology, China.,Molecular Neuroscience Center, The Hong Kong University of Science and Technology, China.,State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, China.,Hong Kong Center for Neurodegenerative Diseases, China.,Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen, China
| | - Nancy Y Ip
- Division of Life Science, The Hong Kong University of Science and Technology, China.,Molecular Neuroscience Center, The Hong Kong University of Science and Technology, China.,State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, China.,Hong Kong Center for Neurodegenerative Diseases, China.,Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen, China
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11
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Uchigashima M, Konno K, Demchak E, Cheung A, Watanabe T, Keener DG, Abe M, Le T, Sakimura K, Sasaoka T, Uemura T, Imamura Kawasawa Y, Watanabe M, Futai K. Specific Neuroligin3-αNeurexin1 signaling regulates GABAergic synaptic function in mouse hippocampus. eLife 2020; 9:e59545. [PMID: 33355091 PMCID: PMC7758064 DOI: 10.7554/elife.59545] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 12/08/2020] [Indexed: 12/11/2022] Open
Abstract
Synapse formation and regulation require signaling interactions between pre- and postsynaptic proteins, notably cell adhesion molecules (CAMs). It has been proposed that the functions of neuroligins (Nlgns), postsynaptic CAMs, rely on the formation of trans-synaptic complexes with neurexins (Nrxns), presynaptic CAMs. Nlgn3 is a unique Nlgn isoform that localizes at both excitatory and inhibitory synapses. However, Nlgn3 function mediated via Nrxn interactions is unknown. Here we demonstrate that Nlgn3 localizes at postsynaptic sites apposing vesicular glutamate transporter 3-expressing (VGT3+) inhibitory terminals and regulates VGT3+ inhibitory interneuron-mediated synaptic transmission in mouse organotypic slice cultures. Gene expression analysis of interneurons revealed that the αNrxn1+AS4 splice isoform is highly expressed in VGT3+ interneurons as compared with other interneurons. Most importantly, postsynaptic Nlgn3 requires presynaptic αNrxn1+AS4 expressed in VGT3+ interneurons to regulate inhibitory synaptic transmission. Our results indicate that specific Nlgn-Nrxn signaling generates distinct functional properties at synapses.
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Affiliation(s)
- Motokazu Uchigashima
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
- Department of Cellular Neuropathology, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Kohtarou Konno
- Department of Anatomy, Faculty of Medicine, Hokkaido UniversitySapporoJapan
| | - Emily Demchak
- Department of Biochemistry and Molecular Biology and Institute for Personalized Medicine, Pennsylvania State University College of MedicineHersheyUnited States
| | - Amy Cheung
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Takuya Watanabe
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - David G Keener
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Timmy Le
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Kenji Sakimura
- Department of Animal Model Development, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Toshikuni Sasaoka
- Department of Comparative and Experimental Medicine, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Takeshi Uemura
- Division of Gene Research, Research Center for Supports to Advanced Science, Shinshu UniversityNaganoJapan
- Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu UniversityNaganoJapan
| | - Yuka Imamura Kawasawa
- Department of Biochemistry and Molecular Biology and Institute for Personalized Medicine, Pennsylvania State University College of MedicineHersheyUnited States
- Department of Pharmacology Pennsylvania State University College of MedicineHersheyUnited States
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido UniversitySapporoJapan
| | - Kensuke Futai
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
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12
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Hermann J, Bender M, Schumacher D, Woo MS, Shaposhnykov A, Rosenkranz SC, Kuryshev V, Meier C, Guse AH, Friese MA, Freichel M, Tsvilovskyy V. Contribution of NAADP to Glutamate-Evoked Changes in Ca 2+ Homeostasis in Mouse Hippocampal Neurons. Front Cell Dev Biol 2020; 8:496. [PMID: 32676502 PMCID: PMC7333232 DOI: 10.3389/fcell.2020.00496] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 05/25/2020] [Indexed: 12/20/2022] Open
Abstract
Nicotinic acid adenine dinucleotide phosphate (NAADP) is a second messenger that evokes calcium release from intracellular organelles by the engagement of calcium release channels, including members of the Transient Receptor Potential (TRP) family, such as TRPML1, the (structurally) related Two Pore Channel type 1 (TPC1) and TPC2 channels as well as Ryanodine Receptors type 1 (RYR1; Guse, 2012). NAADP evokes calcium release from acidic calcium stores of many cell types (Guse, 2012), and NAADP-sensitive Ca2+ stores have been described in hippocampal neurons of the rat (Bak et al., 1999; McGuinness et al., 2007). Glutamate triggers Ca2+-mediated neuronal excitotoxicity in inflammation-induced neurodegenerative pathologies such as Multiple Sclerosis (MS; Friese et al., 2014), and when applied extracellularly to neurons glutamate can elevate NAADP levels in these cells. Accordingly, glutamate-evoked Ca2+ signals from intracellular organelles were inhibited by preventing organelle acidification (Pandey et al., 2009). Analysis of reported RNA sequencing experiments of cultured hippocampal neurons revealed the abundance of Mcoln1 (encoding TRPML1), Tpcn1, and Tpcn2 (encoding TPC1 and TPC2, respectively) as potential NAADP target channels in these cells. Transcripts encoding Ryr1 were not found in contrast to Ryr2 and Ryr3. To study the contribution of NAADP signaling to glutamate-evoked calcium transients in murine hippocampal neurons we used the NAADP antagonists Ned-19 (Naylor et al., 2009) and BZ194 (Dammermann et al., 2009). Our results show that both NAADP antagonists significantly reduce glutamate-evoked calcium transients. In addition to extracellular glutamate application, we studied synchronized calcium oscillations in the cells of the neuronal cultures evoked by addition of the GABAA receptor antagonist bicuculline. Pretreatment with Ned-19 (50 μM) or BZ194 (100 μM) led to an increase in the frequency of bicuculline-induced calcium oscillations at the cost of calcium transient amplitudes. Interestingly, Ned-19 triggered a rise in intracellular calcium concentrations 25 min after bicuculline stimulation, leading to the question whether NAADP acts as a neuroprotective messenger in hippocampal neurons. Taken together, our results are in agreement with the concept that NAADP signaling significantly contributes to glutamate evoked Ca2+ rise in hippocampal neurons and to the amplitude and frequency of synchronized Ca2+ oscillations triggered by spontaneous glutamate release events.
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Affiliation(s)
- Julia Hermann
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Melanie Bender
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Dagmar Schumacher
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Marcel S Woo
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Artem Shaposhnykov
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Sina C Rosenkranz
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Vladimir Kuryshev
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Chris Meier
- Organic Chemistry, Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Andreas H Guse
- The Calcium Signaling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Manuel A Friese
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Marc Freichel
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Volodymyr Tsvilovskyy
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
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13
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Uchigashima M, Leung M, Watanabe T, Cheung A, Le T, Pallat S, Dinis ALM, Watanabe M, Kawasawa YI, Futai K. Neuroligin3 splice isoforms shape inhibitory synaptic function in the mouse hippocampus. J Biol Chem 2020; 295:8589-8595. [PMID: 32381505 DOI: 10.1074/jbc.ac120.012571] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 05/01/2020] [Indexed: 01/15/2023] Open
Abstract
Synapse formation is a dynamic process essential for the development and maturation of the neuronal circuitry in the brain. At the synaptic cleft, trans-synaptic protein-protein interactions are major biological determinants of proper synapse efficacy. The balance of excitatory and inhibitory synaptic transmission (E-I balance) stabilizes synaptic activity, and dysregulation of the E-I balance has been implicated in neurodevelopmental disorders, including autism spectrum disorders. However, the molecular mechanisms underlying the E-I balance remain to be elucidated. Here, using single-cell transcriptomics, immunohistochemistry, and electrophysiology approaches to murine CA1 pyramidal neurons obtained from organotypic hippocampal slice cultures, we investigate neuroligin (Nlgn) genes that encode a family of postsynaptic adhesion molecules known to shape excitatory and inhibitory synaptic function. We demonstrate that the NLGN3 protein differentially regulates inhibitory synaptic transmission in a splice isoform-dependent manner at hippocampal CA1 synapses. We also found that distinct subcellular localizations of the NLGN3 isoforms contribute to the functional differences observed among these isoforms. Finally, results from single-cell RNA-Seq analyses revealed that Nlgn1 and Nlgn3 are the major murine Nlgn genes and that the expression levels of the Nlgn splice isoforms are highly diverse in CA1 pyramidal neurons. Our results delineate isoform-specific effects of Nlgn genes on the E-I balance in the murine hippocampus.
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Affiliation(s)
- Motokazu Uchigashima
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Ming Leung
- Department of Biochemistry and Molecular Biology and Institute for Personalized Medicine, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| | - Takuya Watanabe
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Amy Cheung
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Timmy Le
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Sabine Pallat
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Alexandre Luis Marques Dinis
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Yuka Imamura Kawasawa
- Department of Biochemistry and Molecular Biology and Institute for Personalized Medicine, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA .,Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| | - Kensuke Futai
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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14
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Keener DG, Cheung A, Futai K. A highly efficient method for single-cell electroporation in mouse organotypic hippocampal slice culture. J Neurosci Methods 2020; 337:108632. [PMID: 32126275 DOI: 10.1016/j.jneumeth.2020.108632] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 01/19/2020] [Accepted: 02/10/2020] [Indexed: 01/06/2023]
Abstract
BACKGROUND Exogenous gene introduction by transfection is one of the most important approaches for understanding the function of specific genes at the cellular level. Electroporation has a long-standing history as a versatile gene delivery technique in vitro and in vivo. However, it has been underutilized in vitro because of technical difficulty and insufficient transfection efficiency. NEW METHOD We have developed an electroporation technique that combines the use of large glass electrodes, tetrodotoxin-containing artificial cerebrospinal fluid and mild electrical pulses. Here, we describe the technique and compare it with existing methods. RESULTS Our method achieves a high transfection efficiency (∼80 %) in both excitatory and inhibitory neurons with no detectable side effects on their function. We demonstrate this method is capable of transferring at least three different genes into a single neuron. In addition, we demonstrate the ability to transfect different genes into neighboring cells. COMPARISON WITH EXISTING METHODS The majority of existing methods use fine-tipped glass electrodes (i.e. > 10 MΩ) and apply high voltage (10 V) pulses with high frequency (100 Hz) for 1 s. These parameters contribute to practical difficulties thus lowering the transfection efficiency. Our unique method minimizes electrode clogging and therefore procedure duration, increasing transfection efficiency and cellular viability. CONCLUSIONS Our modifications, relative to current methods, optimize electroporation efficiency and cell survival. Our approach offers distinct research strategies not only in elucidating cell-autonomous functions of genes but also for assessing genes contributing to intercellular functions, such as trans-synaptic interactions.
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Affiliation(s)
- David G Keener
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, LRB-706, Worcester, MA, 01605-2324, USA; Graduate Program in Neuroscience, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Amy Cheung
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, LRB-706, Worcester, MA, 01605-2324, USA; UMMS MD/PhD Program, University of Massachusetts Medical School, Worcester, Massachusetts, 01604, USA
| | - Kensuke Futai
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, LRB-706, Worcester, MA, 01605-2324, USA.
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15
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Tyssowski KM, Letai KC, Rendall SD, Tan C, Nizhnik A, Kaeser PS, Gray JM. Firing Rate Homeostasis Can Occur in the Absence of Neuronal Activity-Regulated Transcription. J Neurosci 2019; 39:9885-9899. [PMID: 31672790 PMCID: PMC6978944 DOI: 10.1523/jneurosci.1108-19.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 09/27/2019] [Accepted: 10/18/2019] [Indexed: 01/06/2023] Open
Abstract
Despite dynamic inputs, neuronal circuits maintain relatively stable firing rates over long periods. This maintenance of firing rate, or firing rate homeostasis, is likely mediated by homeostatic mechanisms such as synaptic scaling and regulation of intrinsic excitability. Because some of these homeostatic mechanisms depend on transcription of activity-regulated genes, including Arc and Homer1a, we hypothesized that activity-regulated transcription would be required for firing rate homeostasis. Surprisingly, however, we found that cultured mouse cortical neurons from both sexes grown on multi-electrode arrays homeostatically adapt their firing rates to persistent pharmacological stimulation even when activity-regulated transcription is disrupted. Specifically, we observed firing rate homeostasis in Arc knock-out neurons, as well as knock-out neurons lacking the activity-regulated transcription factors AP1 and SRF. Firing rate homeostasis also occurred normally during acute pharmacological blockade of transcription. Thus, firing rate homeostasis in response to increased neuronal activity can occur in the absence of neuronal-activity-regulated transcription.SIGNIFICANCE STATEMENT Neuronal circuits maintain relatively stable firing rates even in the face of dynamic circuit inputs. Understanding the molecular mechanisms that enable this firing rate homeostasis could potentially provide insight into neuronal diseases that present with an imbalance of excitation and inhibition. It has long been proposed that activity-regulated transcription could underlie firing rate homeostasis because activity-regulated genes turn on when neurons are above their target firing rates and include many genes that could regulate firing rate. Surprisingly, despite this prediction, we found that cortical neurons can undergo firing rate homeostasis in the absence of activity-regulated transcription, indicating that firing rate homeostasis can be controlled by non-transcriptional mechanisms.
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Affiliation(s)
| | | | | | - Chao Tan
- Neurobiology, Harvard Medical School, Boston, Massachusetts 02115
| | | | - Pascal S Kaeser
- Neurobiology, Harvard Medical School, Boston, Massachusetts 02115
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16
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Tyssowski KM, Gray JM. The neuronal stimulation-transcription coupling map. Curr Opin Neurobiol 2019; 59:87-94. [PMID: 31163285 PMCID: PMC6885097 DOI: 10.1016/j.conb.2019.05.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/06/2019] [Indexed: 12/17/2022]
Abstract
Neurons transcribe different genes in response to different extracellular stimuli, and these genes regulate neuronal plasticity. Thus, understanding how different stimuli regulate different stimulus-dependent gene modules would deepen our understanding of plasticity. To systematically dissect the coupling between stimulation and transcription, we propose creating a 'stimulation-transcription coupling map' that describes the transcription response to each possible extracellular stimulus. While we are currently far from having a complete map, recent genomic experiments have begun to facilitate its creation. Here, we describe the current state of the stimulation-transcription coupling map as well as the transcriptional regulation that enables this coupling.
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Affiliation(s)
- Kelsey M Tyssowski
- Harvard Medical School, Department of Genetics, 77 Ave Louis Pasteur, Boston, MA 02115, United States
| | - Jesse M Gray
- Harvard Medical School, Department of Genetics, 77 Ave Louis Pasteur, Boston, MA 02115, United States.
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17
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Hegde AN, Smith SG. Recent developments in transcriptional and translational regulation underlying long-term synaptic plasticity and memory. ACTA ACUST UNITED AC 2019; 26:307-317. [PMID: 31416904 PMCID: PMC6699410 DOI: 10.1101/lm.048769.118] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 06/20/2019] [Indexed: 12/16/2022]
Abstract
Formation of long-term synaptic plasticity that underlies long-term memory requires new protein synthesis. Years of research has elucidated some of the transcriptional and translational mechanisms that contribute to the production of new proteins. Early research on transcription focused on the transcription factor cAMP-responsive element binding protein. Since then, other transcription factors, such as the Nuclear Receptor 4 family of proteins that play a role in memory formation and maintenance have been identified. In addition, several studies have revealed details of epigenetic mechanisms consisting of new types of chemical alterations of DNA such as hydroxymethylation, and various histone modifications in long-term synaptic plasticity and memory. Our understanding of translational control critical for memory formation began with the identification of molecules that impinge on the 5′ and 3′ untranslated regions of mRNAs and continued with the appreciation for local translation near synaptic sites. Lately, a role for noncoding RNAs such as microRNAs in regulating translation factors and other molecules critical for memory has been found. This review describes the past research in brief and mainly focuses on the recent work on molecular mechanisms of transcriptional and translational regulation that form the underpinnings of long-term synaptic plasticity and memory.
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Affiliation(s)
- Ashok N Hegde
- Department of Biological and Environmental Sciences, Georgia College and State University, Milledgeville, Georgia 31061, USA
| | - Spencer G Smith
- Department of Biological and Environmental Sciences, Georgia College and State University, Milledgeville, Georgia 31061, USA
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18
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Herre M, Korb E. The chromatin landscape of neuronal plasticity. Curr Opin Neurobiol 2019; 59:79-86. [PMID: 31174107 DOI: 10.1016/j.conb.2019.04.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 04/18/2019] [Indexed: 01/27/2023]
Abstract
Examining the links between neuronal activity, transcriptional output, and synaptic function offers unique insights into how neurons adapt to changing environments and form memories. Epigenetic markers, such as DNA methylation and histone modifications, have been implicated in the formation of not only cellular memories such as cell fate, but also memories of experience at the organismal level. Here, we review recent advances in chromatin regulation that contribute to synaptic plasticity and drive adaptive behaviors through dynamic and precise regulation of transcription output in neurons. We discuss chromatin-associated proteins, histone variant proteins, the contribution of cis-regulatory elements and their interaction with histone modifications, and how these mechanisms are integrated into distinct behavior and environmental response paradigms.
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Affiliation(s)
- Margaret Herre
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Erica Korb
- Department of Genetics, Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA.
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19
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Uchigashima M, Cheung A, Suh J, Watanabe M, Futai K. Differential expression of neurexin genes in the mouse brain. J Comp Neurol 2019; 527:1940-1965. [PMID: 30761534 DOI: 10.1002/cne.24664] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 01/04/2019] [Accepted: 02/01/2019] [Indexed: 01/22/2023]
Abstract
Synapses, highly specialized membrane junctions between neurons, connect presynaptic neurotransmitter release sites and postsynaptic ligand-gated channels. Neurexins (Nrxns), a family of presynaptic adhesion molecules, have been characterized as major regulators of synapse development and function. Via their extracellular domains, Nrxns bind to different postsynaptic proteins, generating highly diverse functional readouts through their postsynaptic binding partners. Not surprisingly given these versatile protein interactions, mutations and deletions of Nrxn genes have been identified in patients with autism spectrum disorders, intellectual disabilities, and schizophrenia. Therefore, elucidating the expression profiles of Nrxns in the brain is of high significance. Here, using chromogenic and fluorescent in situ hybridization, we characterize the expression patterns of Nrxn isoforms throughout the brain. We found that each Nrxn isoform displays a unique expression profile in a region-, cell type-, and sensory system-specific manner. Interestingly, we also found that αNrxn1 and αNrxn2 mRNAs are expressed in non-neuronal cells, including astrocytes and oligodendrocytes. Lastly, we found diverse expression patterns of genes that encode Nrxn binding proteins, such as Neuroligins (Nlgns), Leucine-rich repeat transmembrane neuronal protein (Lrrtms) and Latrophilins (Adgrls), suggesting that Nrxn proteins can mediate numerous combinations of trans-synaptic interactions. Together, our anatomical profiling of Nrxn gene expression reflects the diverse roles of Nrxn molecules.
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Affiliation(s)
- Motokazu Uchigashima
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts.,Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Amy Cheung
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Julie Suh
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Kensuke Futai
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts
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