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Nowacka A, Getz AM, Bessa-Neto D, Choquet D. Activity-dependent diffusion trapping of AMPA receptors as a key step for expression of early LTP. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230220. [PMID: 38853553 DOI: 10.1098/rstb.2023.0220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 04/11/2024] [Indexed: 06/11/2024] Open
Abstract
This review focuses on the activity-dependent diffusion trapping of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) as a crucial mechanism for the expression of early long-term potentiation (LTP), a process central to learning and memory. Despite decades of research, the precise mechanisms by which LTP induction leads to an increase in AMPAR responses at synapses have been elusive. We review the different hypotheses that have been put forward to explain the increased AMPAR responsiveness during LTP. We discuss the dynamic nature of AMPAR complexes, including their constant turnover and activity-dependent modifications that affect their synaptic accumulation. We highlight a hypothesis suggesting that AMPARs are diffusively trapped at synapses through activity-dependent interactions with protein-based binding slots in the post-synaptic density (PSD), offering a potential explanation for the increased synaptic strength during LTP. Furthermore, we outline the challenges still to be addressed before we fully understand the functional roles and molecular mechanisms of AMPAR dynamic nanoscale organization in LTP. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.
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Affiliation(s)
- Agata Nowacka
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297 , Bordeaux F-33000, France
| | - Angela M Getz
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297 , Bordeaux F-33000, France
- University of Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4 , Bordeaux F-33000, France
| | - Diogo Bessa-Neto
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297 , Bordeaux F-33000, France
| | - Daniel Choquet
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297 , Bordeaux F-33000, France
- University of Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4 , Bordeaux F-33000, France
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2
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Kaizuka T, Takumi T. Alteration of synaptic protein composition during developmental synapse maturation. Eur J Neurosci 2024; 59:2894-2914. [PMID: 38571321 DOI: 10.1111/ejn.16304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 01/02/2024] [Accepted: 02/07/2024] [Indexed: 04/05/2024]
Abstract
The postsynaptic density (PSD) is a collection of specialized proteins assembled beneath the postsynaptic membrane of dendritic spines. The PSD proteome comprises ~1000 proteins, including neurotransmitter receptors, scaffolding proteins and signalling enzymes. Many of these proteins have essential roles in synaptic function and plasticity. During brain development, changes are observed in synapse density and in the stability and shape of spines, reflecting the underlying molecular maturation of synapses. Synaptic protein composition changes in terms of protein abundance and the assembly of protein complexes, supercomplexes and the physical organization of the PSD. Here, we summarize the developmental alterations of postsynaptic protein composition during synapse maturation. We describe major PSD proteins involved in postsynaptic signalling that regulates synaptic plasticity and discuss the effect of altered expression of these proteins during development. We consider the abnormality of synaptic profiles and synaptic protein composition in the brain in neurodevelopmental disorders such as autism spectrum disorders. We also explain differences in synapse development between rodents and primates in terms of synaptic profiles and protein composition. Finally, we introduce recent findings related to synaptic diversity and nanoarchitecture and discuss their impact on future research. Synaptic protein composition can be considered a major determinant and marker of synapse maturation in normality and disease.
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Affiliation(s)
- Takeshi Kaizuka
- Department of Physiology and Cell Biology, Kobe University School of Medicine, Kobe, Japan
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Toru Takumi
- Department of Physiology and Cell Biology, Kobe University School of Medicine, Kobe, Japan
- RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
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3
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Robinson K, Delhaye M, Craig AM. Mapping proteomic composition of excitatory postsynaptic sites in the cerebellar cortex. Front Mol Neurosci 2024; 17:1381534. [PMID: 38783902 PMCID: PMC11111907 DOI: 10.3389/fnmol.2024.1381534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Accepted: 04/24/2024] [Indexed: 05/25/2024] Open
Abstract
Functions of the cerebellar cortex, from motor learning to emotion and cognition, depend on the appropriate molecular composition at diverse synapse types. Glutamate receptor distributions have been partially mapped using immunogold electron microscopy. However, information is lacking on the distribution of many other components, such as Shank2, a postsynaptic scaffolding protein whose cerebellar dysfunction is associated with autism spectrum disorders. Here, we used an adapted Magnified Analysis of the Proteome, an expansion microscopy approach, to map multiple glutamate receptors, scaffolding and signaling proteins at single synapse resolution in the cerebellar cortex. Multiple distinct synapse-selective distribution patterns were observed. For example, AMPA receptors were most concentrated at synapses on molecular layer interneurons and at climbing fiber synapses, Shank1 was most concentrated at parallel fiber synapses on Purkinje cells, and Shank2 at both climbing fiber and parallel fiber synapses on Purkinje cells but little on molecular layer interneurons. Our results are consistent with gene expression data but also reveal input-selective targeting within Purkinje cells. In specialized glomerular structures of the granule cell layer, AMPA receptors as well as most other synaptic components preferentially targeted to synapses. However, NMDA receptors and the synaptic GTPase activating protein SynGAP preferentially targeted to extrasynaptic sites. Thus, glomeruli may be considered integrative signaling units through which mossy fibers differentially activate synaptic AMPA and extrasynaptic NMDA receptor complexes. Furthermore, we observed NMDA receptors and SynGAP at adherens junctions, suggesting a role in structural plasticity of glomeruli. Altogether, these data contribute to mapping the cerebellar 'synaptome'.
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Affiliation(s)
| | | | - Ann Marie Craig
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
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4
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Wiltrout K, Brimble E, Poduri A. Comprehensive phenotypes of patients with SYNGAP1-related disorder reveals high rates of epilepsy and autism. Epilepsia 2024; 65:1428-1438. [PMID: 38470175 DOI: 10.1111/epi.17913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 03/13/2024]
Abstract
OBJECTIVE To delineate the comprehensive phenotypic spectrum of SYNGAP1-related disorder in a large patient cohort aggregated through a digital registry. METHODS We obtained de-identified patient data from an online registry. Data were extracted from uploaded medical records. We reclassified all SYNGAP1 variants using American College of Medical Genetics criteria and included patients with pathogenic/likely pathogenic (P/LP) single nucleotide variants or microdeletions incorporating SYNGAP1. We analyzed neurodevelopmental phenotypes, including epilepsy, intellectual disability (ID), autism spectrum disorder (ASD), behavioral disorders, and gait dysfunction for all patients with respect to variant type and location within the SynGAP1 protein. RESULTS We identified 147 patients (50% male, median age 8 years) with P/LP SYNGAP1 variants from 151 individuals with data available through the database. One hundred nine were truncating variants and 22 were missense. All patients were diagnosed with global developmental delay (GDD) and/or ID, and 123 patients (84%) were diagnosed with epilepsy. Of those with epilepsy, 73% of patients had GDD diagnosed before epilepsy was diagnosed. Other prominent features included autistic traits (n = 100, 68%), behavioral problems (n = 100, 68%), sleep problems (n = 90, 61%), anxiety (n = 35, 24%), ataxia or abnormal gait (n = 69, 47%), sensory problems (n = 32, 22%), and feeding difficulties (n = 69, 47%). Behavioral problems were more likely in those patients diagnosed with anxiety (odds ratio [OR] 3.6, p = .014) and sleep problems (OR 2.41, p = .015) but not necessarily those with autistic traits. Patients with variants in exons 1-4 were more likely to have the ability to speak in phrases vs those with variants in exons 5-19, and epilepsy occurred less frequently in patients with variants in the SH3 binding motif. SIGNIFICANCE We demonstrate that the data obtained from a digital registry recapitulate earlier but smaller studies of SYNGAP1-related disorder and add additional genotype-phenotype relationships, validating the use of the digital registry. Access to data through digital registries broadens the possibilities for efficient data collection in rare diseases.
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Affiliation(s)
- Kimberly Wiltrout
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | | | - Annapurna Poduri
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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5
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Yuan Y, Lopez-Santiago L, Denomme N, Chen C, O'Malley HA, Hodges SL, Ji S, Han Z, Christiansen A, Isom LL. Antisense oligonucleotides restore excitability, GABA signalling and sodium current density in a Dravet syndrome model. Brain 2024; 147:1231-1246. [PMID: 37812817 PMCID: PMC10994531 DOI: 10.1093/brain/awad349] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/13/2023] [Accepted: 09/27/2023] [Indexed: 10/11/2023] Open
Abstract
Dravet syndrome is an intractable developmental and epileptic encephalopathy caused by de novo variants in SCN1A resulting in haploinsufficiency of the voltage-gated sodium channel Nav1.1. We showed previously that administration of the antisense oligonucleotide STK-001, also called ASO-22, generated using targeted augmentation of nuclear gene output technology to prevent inclusion of the nonsense-mediated decay, or poison, exon 20N in human SCN1A, increased productive Scn1a transcript and Nav1.1 expression and reduced the incidence of electrographic seizures and sudden unexpected death in epilepsy in a mouse model of Dravet syndrome. Here, we investigated the mechanism of action of ASO-84, a surrogate for ASO-22 that also targets splicing of SCN1A exon 20N, in Scn1a+/- Dravet syndrome mouse brain. Scn1a +/- Dravet syndrome and wild-type mice received a single intracerebroventricular injection of antisense oligonucleotide or vehicle at postnatal Day 2. We examined the electrophysiological properties of cortical pyramidal neurons and parvalbumin-positive fast-spiking interneurons in brain slices at postnatal Days 21-25 and measured sodium currents in parvalbumin-positive interneurons acutely dissociated from postnatal Day 21-25 brain slices. We show that, in untreated Dravet syndrome mice, intrinsic cortical pyramidal neuron excitability was unchanged while cortical parvalbumin-positive interneurons showed biphasic excitability with initial hyperexcitability followed by hypoexcitability and depolarization block. Dravet syndrome parvalbumin-positive interneuron sodium current density was decreased compared to wild-type. GABAergic signalling to cortical pyramidal neurons was reduced in Dravet syndrome mice, suggesting decreased GABA release from interneurons. ASO-84 treatment restored action potential firing, sodium current density and GABAergic signalling in Dravet syndrome parvalbumin-positive interneurons. Our work suggests that interneuron excitability is selectively affected by ASO-84. This new work provides critical insights into the mechanism of action of this antisense oligonucleotide and supports the potential of antisense oligonucleotide-mediated upregulation of Nav1.1 as a successful strategy to treat Dravet syndrome.
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Affiliation(s)
- Yukun Yuan
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Luis Lopez-Santiago
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Nicholas Denomme
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Chunling Chen
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Heather A O'Malley
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Samantha L Hodges
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sophina Ji
- Stoke Therapeutics, Inc., Bedford, MA 01730, USA
| | - Zhou Han
- Stoke Therapeutics, Inc., Bedford, MA 01730, USA
| | | | - Lori L Isom
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
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6
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Fenton TA, Haouchine OY, Hallam EL, Smith EM, Jackson KC, Rahbarian D, Canales C, Adhikari A, Nord AS, Ben-Shalom R, Silverman JL. Hyperexcitability and translational phenotypes in a preclinical mouse model of SYNGAP1-Related Intellectual Disability. RESEARCH SQUARE 2024:rs.3.rs-4067746. [PMID: 38562838 PMCID: PMC10984035 DOI: 10.21203/rs.3.rs-4067746/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Disruption of SYNGAP1 directly causes a genetically identifiable neurodevelopmental disorder (NDD) called SYNGAP1-related intellectual disability (SRID). Without functional SynGAP1 protein, individuals are developmentally delayed and have prominent features of intellectual disability, motor impairments, and epilepsy. Over the past two decades, there have been numerous discoveries indicting the critical role of Syngap1. Several rodent models with a loss of Syngap1 have been engineered identifying precise roles in neuronal structure and function, as well as key biochemical pathways key for synapse integrity. Homozygous loss of SYNGAP1/Syngap1 is lethal. Heterozygous mutations of Syngap1 result in a broad range of behavioral phenotypes. Our in vivo functional data, using the original mouse model from the Huganir laboratory, corroborated behaviors including robust hyperactivity and deficits in learning and memory in young adults. Furthermore, we described impairments in the domain of sleep, characterized using neurophysiological data collected with wireless, telemetric electroencephalography (EEG). Syngap1+/- mice exhibited elevated spiking events and spike trains, in addition to elevated power, most notably in the delta power frequency. For the first time, we illustrated primary neurons from Syngap1+/- mice displayed increased network firing activity, greater bursts, and shorter inter-burst intervals between peaks by employing high density microelectrode arrays (HD-MEA). Our work bridges in-vitro electrophysiological neuronal activity and function with in vivo neurophysiological brain activity and function. These data elucidate quantitative, translational biomarkers in vivo and in vitro that can be utilized for the development and efficacy assessment of targeted treatments for SRID.
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Affiliation(s)
- Timothy A Fenton
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA 95817
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA 95817
| | - Olivia Y Haouchine
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA 95817
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA 95817
| | - Elizabeth L Hallam
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA 95817
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA 95817
| | - Emily M Smith
- UC Davis Center for Neuroscience; Department of Psychiatry and Behavioral Sciences & Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, CA 95616
| | - Kiya C. Jackson
- UC Davis Center for Neuroscience; Department of Psychiatry and Behavioral Sciences & Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, CA 95616
| | - Darlene Rahbarian
- UC Davis Center for Neuroscience; Department of Psychiatry and Behavioral Sciences & Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, CA 95616
| | - Cesar Canales
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA 95817
- UC Davis Center for Neuroscience; Department of Psychiatry and Behavioral Sciences & Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, CA 95616
| | - Anna Adhikari
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA 95817
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA 95817
| | - Alexander S. Nord
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA 95817
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA 95817
- UC Davis Center for Neuroscience; Department of Psychiatry and Behavioral Sciences & Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, CA 95616
| | - Roy Ben-Shalom
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA 95817
- Department of Neurology, University of California Davis School of Medicine, Sacramento, CA 95817
| | - Jill L Silverman
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA 95817
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA 95817
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7
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Marotta N, Boland MJ, Prosser BL. Accelerating therapeutic development and clinical trial readiness for STXBP1 and SYNGAP1 disorders. Curr Probl Pediatr Adolesc Health Care 2024:101576. [PMID: 38472035 DOI: 10.1016/j.cppeds.2024.101576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
Gene-targeted therapies for genetic neurodevelopmental disorders (NDDs) are becoming a reality. The Center for Epilepsy and Neurodevelopmental Disorders (ENDD) is currently focused on the development of therapeutics for STXBP1 and SYNGAP1 disorders. Here we review the known clinical features of these disorders, highlight the biological role of STXBP1 and SYNGAP1, and discuss our current understanding of pathogenic mechanisms and therapeutic development. Finally, we provide our perspective as scientists and parents of children with NDDs, and comment on the current challenges for both clinical and basic science endeavors.
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Affiliation(s)
- Nicolas Marotta
- Department of Biochemistry and Molecular Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, USA; Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Michael J Boland
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, USA.
| | - Benjamin L Prosser
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, USA; Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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8
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Araki Y, Rajkovich KE, Gerber EE, Gamache TR, Johnson RC, Tran THN, Liu B, Zhu Q, Hong I, Kirkwood A, Huganir R. SynGAP regulates synaptic plasticity and cognition independently of its catalytic activity. Science 2024; 383:eadk1291. [PMID: 38422154 PMCID: PMC11188940 DOI: 10.1126/science.adk1291] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 12/28/2023] [Indexed: 03/02/2024]
Abstract
SynGAP is an abundant synaptic GTPase-activating protein (GAP) critical for synaptic plasticity, learning, memory, and cognition. Mutations in SYNGAP1 in humans result in intellectual disability, autistic-like behaviors, and epilepsy. Heterozygous Syngap1-knockout mice display deficits in synaptic plasticity, learning, and memory and exhibit seizures. It is unclear whether SynGAP imparts structural properties at synapses independently of its GAP activity. Here, we report that inactivating mutations within the GAP domain do not inhibit synaptic plasticity or cause behavioral deficits. Instead, SynGAP modulates synaptic strength by physically competing with the AMPA-receptor-TARP excitatory receptor complex in the formation of molecular condensates with synaptic scaffolding proteins. These results have major implications for developing therapeutic treatments for SYNGAP1-related neurodevelopmental disorders.
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Affiliation(s)
| | | | | | | | - Richard C. Johnson
- Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Thanh Hai N. Tran
- Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Bian Liu
- Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Qianwen Zhu
- Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ingie Hong
- Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alfredo Kirkwood
- Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Richard Huganir
- Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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9
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Choquet D. Shifting rules in a brain disorder. Science 2024; 383:950-951. [PMID: 38422158 DOI: 10.1126/science.adn8707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
The mode of action of a synaptic protein is challenged.
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Affiliation(s)
- Daniel Choquet
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, CNRS, UMR 5297, F-33000 Bordeaux, France
- Bordeaux Imaging Center, University of Bordeaux, CNRS, INSERM, US4, UAR 3420, F-33000 Bordeaux, France
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10
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Cherra SJ, Lamb R. Interactions between Ras and Rap signaling pathways during neurodevelopment in health and disease. Front Mol Neurosci 2024; 17:1352731. [PMID: 38463630 PMCID: PMC10920261 DOI: 10.3389/fnmol.2024.1352731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 02/08/2024] [Indexed: 03/12/2024] Open
Abstract
The Ras family of small GTPases coordinates tissue development by modulating cell proliferation, cell-cell adhesion, and cellular morphology. Perturbations of any of these key steps alter nervous system development and are associated with neurological disorders. While the underlying causes are not known, genetic mutations in Ras and Rap GTPase signaling pathways have been identified in numerous neurodevelopmental disorders, including autism spectrum, neurofibromatosis, intellectual disability, epilepsy, and schizophrenia. Despite diverse clinical presentations, intersections between these two signaling pathways may provide a better understanding of how deviations in neurodevelopment give rise to neurological disorders. In this review, we focus on presynaptic and postsynaptic functions of Ras and Rap GTPases. We highlight various roles of these small GTPases during synapse formation and plasticity. Based on genomic analyses, we discuss how disease-related mutations in Ras and Rap signaling proteins may underlie human disorders. Finally, we discuss how recent observations have identified molecular interactions between these pathways and how these findings may provide insights into the mechanisms that underlie neurodevelopmental disorders.
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Affiliation(s)
- Salvatore J. Cherra
- Department of Neuroscience, University of Kentucky College of Medicine, Lexington, KY, United States
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11
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Nguyen TTA, Mohanty V, Yan Y, Francis KR, Cologna SM. Comparative Hippocampal Proteome and Phosphoproteome in a Niemann-Pick, Type C1 Mouse Model Reveal Insights into Disease Mechanisms. J Proteome Res 2024; 23:84-94. [PMID: 37999680 DOI: 10.1021/acs.jproteome.3c00375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
Niemann-Pick disease, type C (NPC) is a neurodegenerative, lysosomal storage disorder in individuals carrying two mutated copies of either the NPC1 or NPC2 gene. Consequently, impaired cholesterol recycling and an array of downstream events occur. Interestingly, in NPC, the hippocampus displays lysosomal lipid storage but does not succumb to progressive neurodegeneration as significantly as other brain regions. Since defining the neurodegeneration mechanisms in this disease is still an active area of research, we use mass spectrometry to analyze the overall proteome and phosphorylation pattern changes in the hippocampal region of a murine model of NPC. Using 3 week old mice representing an early disease time point, we observed changes in the expression of 47 proteins, many of which are consistent with the previous literature. New to this study, changes in members of the SNARE complex, including STX7, VTI1B, and VAMP7, were identified. Furthermore, we identified that phosphorylation of T286 on CaMKIIα and S1303 on NR2B increased in mutant animals, even at the late stage of the disease. These phosphosites are crucial to learning and memory and can trigger neuronal death by altering protein-protein interactions.
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Affiliation(s)
- Thu T A Nguyen
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Varshasnata Mohanty
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Ying Yan
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Kevin R Francis
- Cellular Therapies and Stem Cell Biology Group, Sanford Research, Sioux Falls, South Dakota 57104, United States
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, South Dakota 57105, United States
| | - Stephanie M Cologna
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, United States
- Laboratory of Integrated Neuroscience, University of Illinois Chicago, Chicago, Illinois 60607, United States
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12
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Birtele M, Del Dosso A, Xu T, Nguyen T, Wilkinson B, Hosseini N, Nguyen S, Urenda JP, Knight G, Rojas C, Flores I, Atamian A, Moore R, Sharma R, Pirrotte P, Ashton RS, Huang EJ, Rumbaugh G, Coba MP, Quadrato G. Non-synaptic function of the autism spectrum disorder-associated gene SYNGAP1 in cortical neurogenesis. Nat Neurosci 2023; 26:2090-2103. [PMID: 37946050 DOI: 10.1038/s41593-023-01477-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 09/29/2023] [Indexed: 11/12/2023]
Abstract
Genes involved in synaptic function are enriched among those with autism spectrum disorder (ASD)-associated rare genetic variants. Dysregulated cortical neurogenesis has been implicated as a convergent mechanism in ASD pathophysiology, yet it remains unknown how 'synaptic' ASD risk genes contribute to these phenotypes, which arise before synaptogenesis. Here, we show that the synaptic Ras GTPase-activating (RASGAP) protein 1 (SYNGAP1, a top ASD risk gene) is expressed within the apical domain of human radial glia cells (hRGCs). In a human cortical organoid model of SYNGAP1 haploinsufficiency, we find dysregulated cytoskeletal dynamics that impair the scaffolding and division plane of hRGCs, resulting in disrupted lamination and accelerated maturation of cortical projection neurons. Additionally, we confirmed an imbalance in the ratio of progenitors to neurons in a mouse model of Syngap1 haploinsufficiency. Thus, SYNGAP1-related brain disorders may arise through non-synaptic mechanisms, highlighting the need to study genes associated with neurodevelopmental disorders (NDDs) in diverse human cell types and developmental stages.
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Affiliation(s)
- Marcella Birtele
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Ashley Del Dosso
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Tiantian Xu
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Xiangya Hospital, Central South University, Changsha, China
| | - Tuan Nguyen
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Brent Wilkinson
- Department of Psychiatry and Behavioral Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Negar Hosseini
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Sarah Nguyen
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Jean-Paul Urenda
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Gavin Knight
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA
| | - Camilo Rojas
- Departments of Neuroscience and Molecular Medicine, University of Florida Scripps Biomedical Research Institute, Jupiter, FL, USA
- Skaggs Graduate School of Chemical and Biological Sciences, Scripps Research, Jupiter, FL, USA
| | - Ilse Flores
- Department of Psychiatry and Behavioral Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Alexander Atamian
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Roger Moore
- Integrated Mass Spectrometry Shared Resource, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Ritin Sharma
- Integrated Mass Spectrometry Shared Resource, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
- Cancer and Cell Biology Division, Translational Genomics Research Institute, Phoenix, AZ, USA
| | - Patrick Pirrotte
- Integrated Mass Spectrometry Shared Resource, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
- Cancer and Cell Biology Division, Translational Genomics Research Institute, Phoenix, AZ, USA
| | - Randolph S Ashton
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA
| | - Eric J Huang
- Department of Pathology, University of California, San Francisco, CA, USA
- Eli and Edythe Broad Institute for Stem Cell Research and Regeneration Medicine, University of California, San Francisco, CA, USA
| | - Gavin Rumbaugh
- Departments of Neuroscience and Molecular Medicine, University of Florida Scripps Biomedical Research Institute, Jupiter, FL, USA
- Skaggs Graduate School of Chemical and Biological Sciences, Scripps Research, Jupiter, FL, USA
| | - Marcelo P Coba
- Department of Psychiatry and Behavioral Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Giorgia Quadrato
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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13
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Frederiksen SD, Wicki-Stordeur LE, Swayne LA. Overlap in synaptic neurological condition susceptibility pathways and the neural pannexin 1 interactome revealed by bioinformatics analyses. Channels (Austin) 2023; 17:2253102. [PMID: 37807670 PMCID: PMC10563626 DOI: 10.1080/19336950.2023.2253102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 08/22/2023] [Indexed: 10/10/2023] Open
Abstract
Many neurological conditions exhibit synaptic impairments, suggesting mechanistic convergence. Additionally, the pannexin 1 (PANX1) channel and signaling scaffold is linked to several of these neurological conditions and is an emerging regulator of synaptic development and plasticity; however, its synaptic pathogenic contributions are relatively unexplored. To this end, we explored connections between synaptic neurodevelopmental disorder and neurodegenerative disease susceptibility genes discovered by genome-wide association studies (GWASs), and the neural PANX1 interactome (483 proteins) identified from mouse Neuro2a (N2a) cells. To identify shared susceptibility genes, we compared synaptic suggestive GWAS candidate genes amongst autism spectrum disorders, schizophrenia, Parkinson's disease, and Alzheimer's disease. To further probe PANX1 signaling pathways at the synapse, we used bioinformatics tools to identify PANX1 interactome signaling pathways and protein-protein interaction clusters. To shed light on synaptic disease mechanisms potentially linking PANX1 and these four neurological conditions, we performed additional cross-analyses between gene ontologies enriched for the PANX1 synaptic and disease-susceptibility gene sets. Finally, to explore the regional specificity of synaptic PANX1-neurological condition connections, we identified brain region-specific elevations of synaptic PANX1 interactome and GWAS candidate gene set transcripts. Our results confirm considerable overlap in risk genes for autism spectrum disorders and schizophrenia and identify potential commonalities in genetic susceptibility for neurodevelopmental disorders and neurodegenerative diseases. Our findings also pinpointed novel putative PANX1 links to synaptic disease-associated pathways, such as regulation of vesicular trafficking and proteostasis, warranting further validation.
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Affiliation(s)
| | | | - Leigh Anne Swayne
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
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14
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Pedini G, Chen CL, Achsel T, Bagni C. Cancer drug repurposing in autism spectrum disorder. Trends Pharmacol Sci 2023; 44:963-977. [PMID: 37940430 DOI: 10.1016/j.tips.2023.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/20/2023] [Accepted: 09/20/2023] [Indexed: 11/10/2023]
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with uncertain origins. Understanding of the mechanisms underlying ASD remains limited, and treatments are lacking. Genetic diversity complicates drug development. Given the complexity and severity of ASD symptoms and the rising number of diagnoses, exploring novel therapeutic strategies is essential. Here, we focus on shared molecular pathways between ASD and cancer and highlight recent progress on the repurposing of cancer drugs for ASD treatment, such as mTOR inhibitors, histone deacetylase inhibitors, and anti-inflammatory agents. We discuss how to improve trial design considering drug dose and patient age. Lastly, the discussion explores the critical aspects of side effects, commercial factors, and the efficiency of drug-screening pipelines; all of which are essential considerations in the pursuit of repurposing cancer drugs for addressing core features of ASD.
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Affiliation(s)
- Giorgia Pedini
- University of Rome Tor Vergata, Department of Biomedicine and Prevention, Via Montpellier 1, 00133, Rome, Italy
| | - Chin-Lin Chen
- University of Lausanne, Department of Fundamental Neurosciences, Rue du Bugnon 9, 1005, Lausanne, Switzerland
| | - Tilmann Achsel
- University of Lausanne, Department of Fundamental Neurosciences, Rue du Bugnon 9, 1005, Lausanne, Switzerland
| | - Claudia Bagni
- University of Rome Tor Vergata, Department of Biomedicine and Prevention, Via Montpellier 1, 00133, Rome, Italy; University of Lausanne, Department of Fundamental Neurosciences, Rue du Bugnon 9, 1005, Lausanne, Switzerland.
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15
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Nicoll RA, Schulman H. Synaptic memory and CaMKII. Physiol Rev 2023; 103:2877-2925. [PMID: 37290118 PMCID: PMC10642921 DOI: 10.1152/physrev.00034.2022] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 04/26/2023] [Accepted: 04/30/2023] [Indexed: 06/10/2023] Open
Abstract
Ca2+/calmodulin-dependent protein kinase II (CaMKII) and long-term potentiation (LTP) were discovered within a decade of each other and have been inextricably intertwined ever since. However, like many marriages, it has had its up and downs. Based on the unique biochemical properties of CaMKII, it was proposed as a memory molecule before any physiological linkage was made to LTP. However, as reviewed here, the convincing linkage of CaMKII to synaptic physiology and behavior took many decades. New technologies were critical in this journey, including in vitro brain slices, mouse genetics, single-cell molecular genetics, pharmacological reagents, protein structure, and two-photon microscopy, as were new investigators attracted by the exciting challenge. This review tracks this journey and assesses the state of this marriage 40 years on. The collective literature impels us to propose a relatively simple model for synaptic memory involving the following steps that drive the process: 1) Ca2+ entry through N-methyl-d-aspartate (NMDA) receptors activates CaMKII. 2) CaMKII undergoes autophosphorylation resulting in constitutive, Ca2+-independent activity and exposure of a binding site for the NMDA receptor subunit GluN2B. 3) Active CaMKII translocates to the postsynaptic density (PSD) and binds to the cytoplasmic C-tail of GluN2B. 4) The CaMKII-GluN2B complex initiates a structural rearrangement of the PSD that may involve liquid-liquid phase separation. 5) This rearrangement involves the PSD-95 scaffolding protein, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs), and their transmembrane AMPAR-regulatory protein (TARP) auxiliary subunits, resulting in an accumulation of AMPARs in the PSD that underlies synaptic potentiation. 6) The stability of the modified PSD is maintained by the stability of the CaMKII-GluN2B complex. 7) By a process of subunit exchange or interholoenzyme phosphorylation CaMKII maintains synaptic potentiation in the face of CaMKII protein turnover. There are many other important proteins that participate in enlargement of the synaptic spine or modulation of the steps that drive and maintain the potentiation. In this review we critically discuss the data underlying each of the steps. As will become clear, some of these steps are more firmly grounded than others, and we provide suggestions as to how the evidence supporting these steps can be strengthened or, based on the new data, be replaced. Although the journey has been a long one, the prospect of having a detailed cellular and molecular understanding of learning and memory is at hand.
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Affiliation(s)
- Roger A Nicoll
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California, United States
| | - Howard Schulman
- Department of Neurobiology, Stanford University School of Medicine, Stanford, California, United States
- Panorama Research Institute, Sunnyvale, California, United States
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16
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Sumathipala SH, Khan S, Kozol RA, Araki Y, Syed S, Huganir RL, Dallman JE. Context-dependent hyperactivity in syngap1a and syngap1b zebrafish autism models. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.20.557316. [PMID: 37786701 PMCID: PMC10541574 DOI: 10.1101/2023.09.20.557316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Background and Aims SYNGAP1 disorder is a prevalent genetic form of Autism Spectrum Disorder and Intellectual Disability (ASD/ID) and is caused by de novo or inherited mutations in one copy of the SYNGAP1 gene. In addition to ASD/ID, SYNGAP1 disorder is associated with comorbid symptoms including treatment-resistant-epilepsy, sleep disturbances, and gastrointestinal distress. Mechanistic links between these diverse symptoms and SYNGAP1 variants remain obscure, therefore, our goal was to generate a zebrafish model in which this range of symptoms can be studied. Methods We used CRISPR/Cas9 to introduce frameshift mutations in the syngap1a and syngap1b zebrafish duplicates (syngap1ab) and validated these stable models for Syngap1 loss-of-function. Because SYNGAP1 is extensively spliced, we mapped splice variants to the two zebrafish syngap1a and b genes and identified mammalian-like isoforms. We then quantified locomotory behaviors in zebrafish syngap1ab larvae under three conditions that normally evoke different arousal states in wild type larvae: aversive, high-arousal acoustic, medium-arousal dark, and low-arousal light stimuli. Results We show that CRISPR/Cas9 indels in zebrafish syngap1a and syngap1b produced loss-of-function alleles at RNA and protein levels. Our analyses of zebrafish Syngap1 isoforms showed that, as in mammals, zebrafish Syngap1 N- and C-termini are extensively spliced. We identified a zebrafish syngap1 α1-like variant that maps exclusively to the syngap1b gene. Quantifying locomotor behaviors showed that syngap1ab larvae are hyperactive compared to wild type but to differing degrees depending on the stimulus. Hyperactivity was most pronounced in low arousal settings, with overall movement increasing with the number of mutant syngap1 alleles. Conclusions Our data support mutations in zebrafish syngap1ab as causal for hyperactivity associated with elevated arousal that is especially pronounced in low-arousal environments.
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Affiliation(s)
- Sureni H. Sumathipala
- Department of Biology, University of Miami, Coral Gables, FL USA
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
| | - Suha Khan
- Department of Biology, University of Miami, Coral Gables, FL USA
| | - Robert A. Kozol
- Department of Biology, University of Miami, Coral Gables, FL USA
- Jupiter Life Science Initiative, Florida Atlantic University, Jupiter FL, USA
| | - Yoichi Araki
- Department of Neuroscience and Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD USA
| | - Sheyum Syed
- Department of Physics, University of Miami, Coral Gables, FL USA
| | - Richard L. Huganir
- Department of Neuroscience and Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD USA
| | - Julia E. Dallman
- Department of Biology, University of Miami, Coral Gables, FL USA
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17
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Silverman JL, Fenton T, Haouchine O, Hallam E, Smith E, Jackson K, Rahbarian D, Canales C, Adhikari A, Nord A, Ben-Shalom R. Hyperexcitability and translational phenotypes in a preclinical model of SYNGAP1 mutations. RESEARCH SQUARE 2023:rs.3.rs-3246655. [PMID: 37790402 PMCID: PMC10543290 DOI: 10.21203/rs.3.rs-3246655/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
SYNGAP1 is a critical gene for neuronal development, synaptic structure, and function. Although rare, the disruption of SYNGAP1 directly causes a genetically identifiable neurodevelopmental disorder (NDD) called SYNGAP1 -related intellectual disability. Without functional SynGAP1 protein, patients present with intellectual disability, motor impairments, and epilepsy. Previous work using mouse models with a variety of germline and conditional mutations has helped delineate SynGAP1's critical roles in neuronal structure and function, as well as key biochemical signaling pathways essential to synapse integrity. Homozygous loss of SYNGAP1 is embryonically lethal. Heterozygous mutations of SynGAP1 result in a broad range of phenotypes including increased locomotor activity, impaired working spatial memory, impaired cued fear memory, and increased stereotypic behavior. Our in vivo functional data, using the original germline mutation mouse line from the Huganir laboratory, corroborated robust hyperactivity and learning and memory deficits. Here, we describe impairments in the translational biomarker domain of sleep, characterized using neurophysiological data collected with wireless telemetric electroencephalography (EEG). We discovered Syngap1+/- mice exhibited elevated spike trains in both number and duration, in addition to elevated power, most notably in the delta power band. Primary neurons from Syngap1+/- mice displayed increased network firing activity, greater spikes per burst, and shorter inter-burst intervals between peaks using high density micro-electrode arrays (HD-MEA). This work is translational, innovative, and highly significant as it outlines functional impairments in Syngap1 mutant mice. Simultaneously, the work utilized untethered, wireless neurophysiology that can discover potential biomarkers of Syngap1 RI-D, for clinical trials, as it has done with other NDDs. Our work is substantial forward progress toward translational work for SynGAP1R-ID as it bridges in-vitro electrophysiological neuronal activity and function with in vivo neurophysiological brain activity and function. These data elucidate multiple quantitative, translational biomarkers in vivo and in vitro for the development of treatments for SYNGAP1-related intellectual disability.
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Affiliation(s)
- Jill L Silverman
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine
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18
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Srivastava A, Kumari A, Jagdale P, Ayanur A, Pant AB, Khanna VK. Potential of Quercetin to Protect Cadmium Induced Cognitive Deficits in Rats by Modulating NMDA-R Mediated Downstream Signaling and PI3K/AKT-Nrf2/ARE Signaling Pathways in Hippocampus. Neuromolecular Med 2023; 25:426-440. [PMID: 37460789 DOI: 10.1007/s12017-023-08747-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 04/14/2023] [Indexed: 09/22/2023]
Abstract
Exposure to cadmium, a heavy metal distributed in the environment is a cause of concern due to associated health effects in population around the world. Continuing with the leads demonstrating alterations in brain cholinergic signalling in cadmium induced cognitive deficits by us; the study is focussed to understand involvement of N-Methyl-D-aspartate receptor (NMDA-R) and its postsynaptic signalling and Nrf2-ARE pathways in hippocampus. Also, the protective potential of quercetin, a polyphenolic bioflavonoid, was assessed in cadmium induced alterations. Cadmium treatment (5 mg/kg, body weight, p.o., 28 days) decreased mRNA expression and protein levels of NMDA receptor subunits (NR1, NR2A) in rat hippocampus, compared to controls. Cadmium treated rats also exhibited decrease in levels of NMDA-R associated downstream signalling proteins (CaMKIIα, PSD-95, TrkB, BDNF, PI3K, AKT, Erk1/2, GSK3β, and CREB) and increase in levels of SynGap in hippocampus. Further, decrease in protein levels of Nrf2 and HO1 associated with increase in levels of Keap1 exhibits alterations in Nrf2/ARE signalling in hippocampus of cadmium treated rats. Degeneration of pyramidal neurons in hippocampus was also evident on cadmium treatment. Simultaneous treatment with quercetin (25 mg/kg body weight p.o., 28 days) was found to attenuate cadmium induced changes in hippocampus. The results provide novel evidence that cadmium exposure may disrupt integrity of NMDA receptors and its downstream signaling targets by affecting the Nrf2/ARE signaling pathway in hippocampus and these could contribute in cognitive deficits. It is further interesting that quercetin has the potential to protect cadmium induced changes by modulating Nrf2/ARE signaling which was effective to control NMDA-R and PI3K/AKT cell signaling pathways.
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Affiliation(s)
- Anugya Srivastava
- Developmental Toxicology Laboratory, Systems Toxicology & Health Risk Assessment Area, CSIR- Indian Institute of Toxicology Research, Vishvigyan Bhavan, 31 Mahatma Gandhi Marg, Lucknow, Uttar Pradesh, 226001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India
| | - Anima Kumari
- Developmental Toxicology Laboratory, Systems Toxicology & Health Risk Assessment Area, CSIR- Indian Institute of Toxicology Research, Vishvigyan Bhavan, 31 Mahatma Gandhi Marg, Lucknow, Uttar Pradesh, 226001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India
| | - Pankaj Jagdale
- Central Pathology Laboratory, Regulatory Toxicology Area, CSIR- Indian Institute of Toxicology Research, Vishvigyan Bhavan, 31 Mahatma Gandhi Marg, Lucknow, Uttar Pradesh, 226001, India
| | - Anjaneya Ayanur
- Central Pathology Laboratory, Regulatory Toxicology Area, CSIR- Indian Institute of Toxicology Research, Vishvigyan Bhavan, 31 Mahatma Gandhi Marg, Lucknow, Uttar Pradesh, 226001, India
| | - Aditya Bhushan Pant
- Developmental Toxicology Laboratory, Systems Toxicology & Health Risk Assessment Area, CSIR- Indian Institute of Toxicology Research, Vishvigyan Bhavan, 31 Mahatma Gandhi Marg, Lucknow, Uttar Pradesh, 226001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India
| | - Vinay Kumar Khanna
- Developmental Toxicology Laboratory, Systems Toxicology & Health Risk Assessment Area, CSIR- Indian Institute of Toxicology Research, Vishvigyan Bhavan, 31 Mahatma Gandhi Marg, Lucknow, Uttar Pradesh, 226001, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India.
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19
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Wang Y, Yang X, Zhang H, Liu N, Liu Y, Gai Z, Liu Y, Lv Y. Generation of a transgene-free iPS cell line (SDQLCHi053-A) from a young girl carrying a heterozygous mutation (c.427C > T) in SYNGAP1 gene. Stem Cell Res 2023; 71:103132. [PMID: 37385133 DOI: 10.1016/j.scr.2023.103132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 05/03/2023] [Accepted: 06/02/2023] [Indexed: 07/01/2023] Open
Abstract
The pathogenic mutations of Synaptic Ras GTPase-activating protein 1 (SYNGAP1) gene (OMIM #603384) have been tightly associated with a neurodevelopmental disease, also called autosomal dominant mental retardation type 5 (MRD5, OMIM #612621). We generated a human iPS cell line from a 34-month-old young girl bearing a recurrent heterozygous mutation (c.427C > T) of SYNGAP1. This cell line has great performance in pluripotency and shows differentiation potential towards three germ layers in vitro.
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Affiliation(s)
- Yanxin Wang
- Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China
| | - Xiaomeng Yang
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China
| | - Haiyan Zhang
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China
| | - Ning Liu
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China
| | - Yong Liu
- Epilepsy Center, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China
| | - Zhongtao Gai
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China.
| | - Yi Liu
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China.
| | - Yuqiang Lv
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China.
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20
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Meccariello R. Molecular Advances on Cannabinoid and Endocannabinoid Research. Int J Mol Sci 2023; 24:12760. [PMID: 37628940 PMCID: PMC10454180 DOI: 10.3390/ijms241612760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 08/27/2023] Open
Abstract
Since ancient times, cannabis has been used for recreational and medical purposes [...].
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Affiliation(s)
- Rosaria Meccariello
- Department of Movement and Wellness Sciences, Parthenope University of Naples, 80133 Naples, Italy
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21
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Cho H, Yoo T, Moon H, Kang H, Yang Y, Kang M, Yang E, Lee D, Hwang D, Kim H, Kim D, Kim JY, Kim E. Adnp-mutant mice with cognitive inflexibility, CaMKIIα hyperactivity, and synaptic plasticity deficits. Mol Psychiatry 2023; 28:3548-3562. [PMID: 37365244 PMCID: PMC10618100 DOI: 10.1038/s41380-023-02129-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 05/14/2023] [Accepted: 06/13/2023] [Indexed: 06/28/2023]
Abstract
ADNP syndrome, involving the ADNP transcription factor of the SWI/SNF chromatin-remodeling complex, is characterized by developmental delay, intellectual disability, and autism spectrum disorders (ASD). Although Adnp-haploinsufficient (Adnp-HT) mice display various phenotypic deficits, whether these mice display abnormal synaptic functions remain poorly understood. Here, we report synaptic plasticity deficits associated with cognitive inflexibility and CaMKIIα hyperactivity in Adnp-HT mice. These mice show impaired and inflexible contextual learning and memory, additional to social deficits, long after the juvenile-stage decrease of ADNP protein levels to ~10% of the newborn level. The adult Adnp-HT hippocampus shows hyperphosphorylated CaMKIIα and its substrates, including SynGAP1, and excessive long-term potentiation that is normalized by CaMKIIα inhibition. Therefore, Adnp haploinsufficiency in mice leads to cognitive inflexibility involving CaMKIIα hyperphosphorylation and excessive LTP in adults long after its marked expressional decrease in juveniles.
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Affiliation(s)
- Heejin Cho
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, 34141, Korea
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141, Korea
| | - Taesun Yoo
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141, Korea
| | - Heera Moon
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Hyojin Kang
- Division of National Supercomputing, Korea Institute of Science and Technology Information, Daejeon, 34141, Korea
| | - Yeji Yang
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, 34141, Korea
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, 162 Yeongudanjiro, Ochang, Cheongju, Chungbuk, 28119, Korea
| | - MinSoung Kang
- Therapeutics & Biotechnology Division, Drug discovery platform research center, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Korea
| | - Esther Yang
- Department of Anatomy and BK21 Graduate Program, Biomedical Sciences, College of Medicine, Korea University, Seoul, 02841, Korea
| | - Dowoon Lee
- School of Biological Sciences, Seoul National University, Seoul, 08826, Korea
| | - Daehee Hwang
- School of Biological Sciences, Seoul National University, Seoul, 08826, Korea
| | - Hyun Kim
- Department of Anatomy and BK21 Graduate Program, Biomedical Sciences, College of Medicine, Korea University, Seoul, 02841, Korea
| | - Doyoun Kim
- Therapeutics & Biotechnology Division, Drug discovery platform research center, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Korea
- Medicinal Chemistry and Pharmacology, Korea University of Science and Technology (UST), Daejeon, 34113, Korea
| | - Jin Young Kim
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, 162 Yeongudanjiro, Ochang, Cheongju, Chungbuk, 28119, Korea
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, 34141, Korea.
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141, Korea.
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22
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Fenton TA, Haouchine OY, Hallam EL, Smith EM, Jackson KC, Rahbarian D, Canales C, Adhikari A, Nord AS, Ben-Shalom R, Silverman JL. Hyperexcitability and translational phenotypes in a preclinical model of SYNGAP1 mutations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.24.550093. [PMID: 37546838 PMCID: PMC10402099 DOI: 10.1101/2023.07.24.550093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
SYNGAP1 is a critical gene for neuronal development, synaptic structure, and function. Although rare, the disruption of SYNGAP1 directly causes a genetically identifiable neurodevelopmental disorder (NDD) called SYNGAP1-related intellectual disability. Without functional SynGAP1 protein, patients present with intellectual disability, motor impairments, and epilepsy. Previous work using mouse models with a variety of germline and conditional mutations has helped delineate SynGAP1's critical roles in neuronal structure and function, as well as key biochemical signaling pathways essential to synapse integrity. Homozygous loss of SYNGAP1 is embryonically lethal. Heterozygous mutations of SynGAP1 result in a broad range of phenotypes including increased locomotor activity, impaired working spatial memory, impaired cued fear memory, and increased stereotypic behavior. Our in vivo functional data, using the original germline mutation mouse line from the Huganir laboratory, corroborated robust hyperactivity and learning and memory deficits. Here, we describe impairments in the translational biomarker domain of sleep, characterized using neurophysiological data collected with wireless telemetric electroencephalography (EEG). We discovered Syngap1 +/- mice exhibited elevated spike trains in both number and duration, in addition to elevated power, most notably in the delta power band. Primary neurons from Syngap1 +/- mice displayed increased network firing activity, greater spikes per burst, and shorter inter-burst intervals between peaks using high density micro-electrode arrays (HD-MEA). This work is translational, innovative, and highly significant as it outlines functional impairments in Syngap1 mutant mice. Simultaneously, the work utilized untethered, wireless neurophysiology that can discover potential biomarkers of Syngap1R-ID, for clinical trials, as it has done with other NDDs. Our work is substantial forward progress toward translational work for SynGAP1R-ID as it bridges in-vitro electrophysiological neuronal activity and function with in vivo neurophysiological brain activity and function. These data elucidate multiple quantitative, translational biomarkers in vivo and in vitro for the development of treatments for SYNGAP1-related intellectual disability.
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Daniel JA, Elizarova S, Shaib AH, Chouaib AA, Magnussen HM, Wang J, Brose N, Rhee J, Tirard M. An intellectual-disability-associated mutation of the transcriptional regulator NACC1 impairs glutamatergic neurotransmission. Front Mol Neurosci 2023; 16:1115880. [PMID: 37533751 PMCID: PMC10393139 DOI: 10.3389/fnmol.2023.1115880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 06/14/2023] [Indexed: 08/04/2023] Open
Abstract
Advances in genome sequencing technologies have favored the identification of rare de novo mutations linked to neurological disorders in humans. Recently, a de novo autosomal dominant mutation in NACC1 was identified (NM_052876.3: c.892C > T, NP_443108.1; p.Arg298Trp), associated with severe neurological symptoms including intellectual disability, microcephaly, and epilepsy. As NACC1 had never before been associated with neurological diseases, we investigated how this mutation might lead to altered brain function. We examined neurotransmission in autaptic glutamatergic mouse neurons expressing the murine homolog of the human mutant NACC1, i.e., Nacc1-R284W. We observed that expression of Nacc1-R284W impaired glutamatergic neurotransmission in a cell-autonomous manner, likely through a dominant negative mechanism. Furthermore, by screening for Nacc1 interaction targets in the brain, we identified SynGAP1, GluK2A, and several SUMO E3 ligases as novel Nacc1 interaction partners. At a biochemical level, Nacc1-R284W exhibited reduced binding to SynGAP1 and GluK2A, and also showed greatly increased SUMOylation. Ablating the SUMOylation of Nacc1-R284W partially restored its interaction with SynGAP1 but did not restore binding to GluK2A. Overall, these data indicate a role for Nacc1 in regulating glutamatergic neurotransmission, which is substantially impaired by the expression of a disease-associated Nacc1 mutant. This study provides the first functional insights into potential deficits in neuronal function in patients expressing the de novo mutant NACC1 protein.
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Affiliation(s)
- James A. Daniel
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Sofia Elizarova
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Ali H. Shaib
- Institute for Neuro- and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany
| | - Abed A. Chouaib
- Department of Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
| | - Helge M. Magnussen
- MRC Protein Phosphorylation and Ubiquitination Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Jianlong Wang
- Department of Medicine, Columbia Center for Human Development and Stem Cell Therapies, Columbia University Irving Medical Center, New York, NY, United States
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - JeongSeop Rhee
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Marilyn Tirard
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
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Aria F, Pandey K, Alberini CM. Excessive Protein Accumulation and Impaired Autophagy in the Hippocampus of Angelman Syndrome Modeled in Mice. Biol Psychiatry 2023; 94:68-83. [PMID: 36764852 PMCID: PMC10276539 DOI: 10.1016/j.biopsych.2022.11.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 11/03/2022] [Accepted: 11/18/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Angelman syndrome (AS), a neurodevelopmental disorder caused by abnormalities of the 15q11.2-q13.1 chromosome region, is characterized by impairment of cognitive and motor functions, sleep problems, and seizures. How the genetic defects of AS produce these neurological symptoms is unclear. Mice modeling AS (AS mice) accumulate activity-regulated cytoskeleton-associated protein (ARC/ARG3.1), a neuronal immediate early gene (IEG) critical for synaptic plasticity. This accumulation suggests an altered protein metabolism. METHODS Focusing on the dorsal hippocampus (dHC), a brain region critical for memory formation and cognitive functions, we assessed levels and tissue distribution of IEGs, de novo protein synthesis, and markers of protein synthesis, endosomes, autophagy, and synaptic functions in AS mice at baseline and following learning. We also tested autophagic flux and memory retention following autophagy-promoting treatment. RESULTS AS dHC exhibited accumulation of IEGs ARC, FOS, and EGR1; autophagy proteins MLP3B, SQSTM1, and LAMP1; and reduction of the endosomal protein RAB5A. AS dHC also had increased levels of de novo protein synthesis, impaired autophagic flux with accumulation of autophagosome, and altered synaptic protein levels. Contextual fear conditioning significantly increased levels of IEGs and autophagy proteins, de novo protein synthesis, and autophagic flux in the dHC of normal mice, but not in AS mice. Enhancing autophagy in the dHC alleviated AS-related memory and autophagic flux impairments. CONCLUSIONS A major biological deficit of AS brain is a defective protein metabolism, particularly that dynamically regulated by learning, resulting in stalled autophagy and accumulation of neuronal proteins. Activating autophagy ameliorates AS cognitive impairments and dHC protein accumulation.
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Affiliation(s)
- Francesca Aria
- Center for Neural Science, New York University, New York, New York
| | - Kiran Pandey
- Center for Neural Science, New York University, New York, New York
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25
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王 晓, 田 亚, 陈 晨, 彭 镜. [Autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations: a report of 8 cases and literature review]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2023; 25:489-496. [PMID: 37272175 PMCID: PMC10247193 DOI: 10.7499/j.issn.1008-8830.2301054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 03/29/2023] [Indexed: 06/06/2023]
Abstract
OBJECTIVES To summarize the clinical phenotype and genetic characteristics of children with autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations. METHODS A retrospective analysis was performed on the medical data of 8 children with autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations who were diagnosed and treated in the Department of Pediatrics, Xiangya Hospital of Central South University. RESULTS The mean age of onset was 9 months for the 8 children. All children had moderate-to-severe developmental delay (especially delayed language development), among whom 7 children also had seizures. Among these 8 children, 7 had novel heterozygous mutations (3 with frameshift mutations, 2 with nonsense mutations, and 2 with missense mutations) and 1 had 6p21.3 microdeletion. According to the literature review, there were 48 Chinese children with mental retardation caused by SYNGAP1 gene mutations (including the children in this study), among whom 40 had seizures, and the mean age of onset of seizures was 31.4 months. Frameshift mutations (15/48, 31%) and nonsense mutations (19/48, 40%) were relatively common in these children. In terms of treatment, among the 33 children with a history of epileptic medication, 28 (28/33, 85%) showed response to valproic acid antiepileptic treatment and 16 (16/33, 48%) achieved complete seizure control after valproic acid monotherapy or combined therapy. CONCLUSIONS Children with autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations tend to have an early age of onset, and most of them are accompanied by seizures. These children mainly have frameshift and nonsense mutations. Valproic acid is effective for the treatment of seizures in most children.
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26
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Li X, Du Y, Chen X, Liu C. Emerging roles of O-glycosylation in regulating protein aggregation, phase separation, and functions. Curr Opin Chem Biol 2023; 75:102314. [PMID: 37156204 DOI: 10.1016/j.cbpa.2023.102314] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/28/2023] [Accepted: 04/02/2023] [Indexed: 05/10/2023]
Abstract
Protein O-glycosylation is widely identified in various proteins involved in diverse biological processes. Recent studies have demonstrated that O-glycosylation plays crucial and multifaceted roles in modulating protein amyloid aggregation and liquid-liquid phase separation (LLPS) under physiological conditions. Dysregulation of these processes is closely associated with human diseases such as neurodegenerative diseases (NDs) and cancers. In this review, we first summarize the distinct roles of O-glycosylation in regulating pathological aggregation of different amyloid proteins related to NDs and elaborate the underlying mechanisms of how O-glycosylation modulates protein aggregation kinetics, induces new aggregated structures, and mediates the pathogenesis of amyloid aggregates under diseased conditions. Furthermore, we introduce recent discoveries on O-GlcNAc-mediated regulation of synaptic LLPS and phase separation potency of low-complexity domain-enriched proteins. Finally, we identify challenges in future research and highlight the potential for developing new therapeutic strategies of NDs by targeting protein O-glycosylation.
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Affiliation(s)
- Xiang Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Yifei Du
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China; Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Xing Chen
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China; Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China; Synthetic and Functional Biomolecules Center, Peking University, Beijing, China; Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Peking University, Beijing, China.
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China; State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China.
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27
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Dawicki-McKenna JM, Felix AJ, Waxman EA, Cheng C, Amado DA, Ranum PT, Bogush A, Dungan LV, Maguire JA, Gagne AL, Heller EA, French DL, Davidson BL, Prosser BL. Mapping PTBP2 binding in human brain identifies SYNGAP1 as a target for therapeutic splice switching. Nat Commun 2023; 14:2628. [PMID: 37149717 PMCID: PMC10164156 DOI: 10.1038/s41467-023-38273-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 04/22/2023] [Indexed: 05/08/2023] Open
Abstract
Alternative splicing of neuronal genes is controlled partly by the coordinated action of polypyrimidine tract binding proteins (PTBPs). While PTBP1 is ubiquitously expressed, PTBP2 is predominantly neuronal. Here, we define the PTBP2 footprint in the human transcriptome using brain tissue and human induced pluripotent stem cell-derived neurons (iPSC-neurons). We map PTBP2 binding sites, characterize PTBP2-dependent alternative splicing events, and identify novel PTBP2 targets including SYNGAP1, a synaptic gene whose loss-of-function leads to a complex neurodevelopmental disorder. We find that PTBP2 binding to SYNGAP1 mRNA promotes alternative splicing and nonsense-mediated decay, and that antisense oligonucleotides (ASOs) that disrupt PTBP binding redirect splicing and increase SYNGAP1 mRNA and protein expression. In SYNGAP1 haploinsufficient iPSC-neurons generated from two patients, we show that PTBP2-targeting ASOs partially restore SYNGAP1 expression. Our data comprehensively map PTBP2-dependent alternative splicing in human neurons and cerebral cortex, guiding development of novel therapeutic tools to benefit neurodevelopmental disorders.
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Affiliation(s)
- Jennine M Dawicki-McKenna
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Alex J Felix
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Elisa A Waxman
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Congsheng Cheng
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Defne A Amado
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Paul T Ranum
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Alexey Bogush
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Lea V Dungan
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Jean Ann Maguire
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Alyssa L Gagne
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Elizabeth A Heller
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Deborah L French
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Beverly L Davidson
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
- Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
| | - Benjamin L Prosser
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
- Center for Epilepsy and Neurodevelopmental Disorders (ENDD), University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
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Chalkiadaki K, Hooshmandi M, Lach G, Statoulla E, Simbriger K, Amorim IS, Kouloulia S, Zafeiri M, Pothos P, Bonneil É, Gantois I, Popic J, Kim SH, Wong C, Cao R, Komiyama NH, Atlasi Y, Jafarnejad SM, Khoutorsky A, Gkogkas CG. Mnk1/2 kinases regulate memory and autism-related behaviours via Syngap1. Brain 2023; 146:2175-2190. [PMID: 36315645 PMCID: PMC10411928 DOI: 10.1093/brain/awac398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 09/03/2022] [Accepted: 10/01/2022] [Indexed: 11/14/2022] Open
Abstract
MAPK interacting protein kinases 1 and 2 (Mnk1/2) regulate a plethora of functions, presumably via phosphorylation of their best characterized substrate, eukaryotic translation initiation factor 4E (eIF4E) on Ser209. Here, we show that, whereas deletion of Mnk1/2 (Mnk double knockout) impairs synaptic plasticity and memory in mice, ablation of phospho-eIF4E (Ser209) does not affect these processes, suggesting that Mnk1/2 possess additional downstream effectors in the brain. Translational profiling revealed only a small overlap between the Mnk1/2- and phospho-eIF4E(Ser209)-regulated translatome. We identified the synaptic Ras GTPase activating protein 1 (Syngap1), encoded by a syndromic autism gene, as a downstream target of Mnk1 because Syngap1 immunoprecipitated with Mnk1 and showed reduced phosphorylation (S788) in Mnk double knockout mice. Knockdown of Syngap1 reversed memory deficits in Mnk double knockout mice and pharmacological inhibition of Mnks rescued autism-related phenotypes in Syngap1+/- mice. Thus, Syngap1 is a downstream effector of Mnk1, and the Mnks-Syngap1 axis regulates memory formation and autism-related behaviours.
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Affiliation(s)
- Kleanthi Chalkiadaki
- Biomedical Research Institute, Foundation for Research and Technology-Hellas, University Campus, 45110 Ioannina, Greece
- Centre for Discovery Brain Sciences and The Patrick Wild Centre, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Mehdi Hooshmandi
- Department of Anesthesia and Alan Edwards Centre for Research on Pain, McGill University, Montréal H3A 0G1, Canada
| | - Gilliard Lach
- Centre for Discovery Brain Sciences and The Patrick Wild Centre, University of Edinburgh, Edinburgh EH8 9XD, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Elpida Statoulla
- Biomedical Research Institute, Foundation for Research and Technology-Hellas, University Campus, 45110 Ioannina, Greece
| | - Konstanze Simbriger
- Centre for Discovery Brain Sciences and The Patrick Wild Centre, University of Edinburgh, Edinburgh EH8 9XD, UK
- Department of Pharmacology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Ines S Amorim
- Centre for Discovery Brain Sciences and The Patrick Wild Centre, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Stella Kouloulia
- Centre for Discovery Brain Sciences and The Patrick Wild Centre, University of Edinburgh, Edinburgh EH8 9XD, UK
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Maria Zafeiri
- Biomedical Research Institute, Foundation for Research and Technology-Hellas, University Campus, 45110 Ioannina, Greece
| | - Panagiotis Pothos
- Biomedical Research Institute, Foundation for Research and Technology-Hellas, University Campus, 45110 Ioannina, Greece
| | - Éric Bonneil
- Institute for Research in Immunology and Cancer, Université de Montréal, Station Centreville, Montréal H3C 3J7, Canada
| | - Ilse Gantois
- Goodman Cancer Institute and Biochemistry Department, McGill University, Montréal H3A 1A3, Canada
| | - Jelena Popic
- Goodman Cancer Institute and Biochemistry Department, McGill University, Montréal H3A 1A3, Canada
| | - Sung-Hoon Kim
- Goodman Cancer Institute and Biochemistry Department, McGill University, Montréal H3A 1A3, Canada
| | - Calvin Wong
- Department of Anesthesia and Alan Edwards Centre for Research on Pain, McGill University, Montréal H3A 0G1, Canada
| | - Ruifeng Cao
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, USA
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Noboru H Komiyama
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Yaser Atlasi
- Patrick G. Johnston Centre for Cancer Research, Queen's University of Belfast, Belfast BT9 7AE, Northern Ireland, UK
| | - Seyed Mehdi Jafarnejad
- Patrick G. Johnston Centre for Cancer Research, Queen's University of Belfast, Belfast BT9 7AE, Northern Ireland, UK
| | - Arkady Khoutorsky
- Department of Anesthesia and Alan Edwards Centre for Research on Pain, McGill University, Montréal H3A 0G1, Canada
| | - Christos G Gkogkas
- Biomedical Research Institute, Foundation for Research and Technology-Hellas, University Campus, 45110 Ioannina, Greece
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Li Z. The ALS-Related SynGAP1 Pathogenic Variant Causes Dendritic Spine Loss: Potential Mechanisms of Early-Stage ALS Progression. J Neurosci 2023; 43:2819-2821. [PMID: 37076290 PMCID: PMC10124941 DOI: 10.1523/jneurosci.0099-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/27/2023] [Accepted: 02/27/2023] [Indexed: 04/21/2023] Open
Affiliation(s)
- Zhanxu Li
- Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
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30
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Zeng X, Chen Y, Yu X, Che Y, Chen H, Yi Z, Qin J, Zhong J. Novel variants of SYNGAP1 associated epileptic encephalopathy: two cases report and literature review. ACTA EPILEPTOLOGICA 2023. [DOI: 10.1186/s42494-022-00114-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
Abstract
Background
SYNGAP1 is a significant genetic risk factor for global developmental delay, autism spectrum disorder, and epileptic encephalopathy. De novo loss-of-function variants in this gene cause a neurodevelopmental disorder, for example, early-onset and drug-refractory seizures. We report two children with global developmental delay and epileptic encephalopathy, which are caused by SYNGAP1 gene novel mutations, and drug treatment is effective.
Case presentation
We report a boy and a girl presented with global developmental delay when they were young babies; as they grew up, cognitive impairment and social-communication disorder became more and more prominent; unfortunately, the patients developed into various seizure types, including eyelid myoclonia, myoclonic and absences when the boy was 1 year 8 mouths old and the girl was 3 years old. The two patients were found two previously unknown mutations by high throughput sequencing [c.3271_ c.3272insT; (p.L1091L fs*62), c.2515A > T (p.K839*)] in exon 15 of the SYNGAP in the proband. Sanger sequencing confirmed the heterozygous nature, and neither of their parents carried the same mutation. The girl treated with valproic acid and prednisone became seizure-free, and valproic acid and levetiracetam combined with clonazepam were influential in the other.
Conclusions
The global developmental delay and epileptic encephalopathy of the children were probably due to the pathogenic mutation of the SYNGAP1 gene, and prednisone and clonazepam may be effective in achieving seizure-free.
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Abstract
O-linked β-N-acetylglucosamine (O-GlcNAc) is a ubiquitous post-translational modification in mammals, decorating thousands of intracellular proteins. O-GlcNAc cycling is an essential regulator of myriad aspects of cell physiology and is dysregulated in numerous human diseases. Notably, O-GlcNAcylation is abundant in the brain and numerous studies have linked aberrant O-GlcNAc signaling to various neurological conditions. However, the complexity of the nervous system and the dynamic nature of protein O-GlcNAcylation have presented challenges for studying of neuronal O-GlcNAcylation. In this context, chemical approaches have been a particularly valuable complement to conventional cellular, biochemical, and genetic methods to understand O-GlcNAc signaling and to develop future therapeutics. Here we review selected recent examples of how chemical tools have empowered efforts to understand and rationally manipulate O-GlcNAcylation in mammalian neurobiology.
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Affiliation(s)
- Duc Tan Huynh
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Michael Boyce
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
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32
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Kong W, Huang S, Chen Z, Li X, Liu S, Zhang Z, Yang Y, Wang Z, Zhu X, Ni X, Lu H, Zhang M, Li Z, Wen Y, Shang D. Proteomics and weighted gene correlated network analysis reveal glutamatergic synapse signaling in diazepam treatment of alcohol withdrawal. Front Pharmacol 2023; 13:1111758. [PMID: 36712652 PMCID: PMC9873974 DOI: 10.3389/fphar.2022.1111758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 12/28/2022] [Indexed: 01/12/2023] Open
Abstract
Background: Alcohol use disorder (AUD) is characterized by chronic excessive alcohol consumption, often alternating with periods of abstinence known as alcohol withdrawal syndrome (AWS). Diazepam is the preferred benzodiazepine for treatment of alcohol withdrawal syndrome under most circumstances, but the specific mechanism underlying the treatment needs further research. Methods: We constructed an animal model of two-bottle choices and chronic intermittent ethanol exposure. LC-MS/MS proteomic analysis based on the label-free and intensity-based quantification approach was used to detect the protein profile of the whole brain. Weighted gene correlated network analysis was applied for scale-free network topology analysis. We established a protein-protein interaction network based on the Search Tool for the Retrieval of Interacting Genes (STRING) database and Cytoscape software and identified hub proteins by CytoHubba and MCODE plugins of Cytoscape. The online tool Targetscan identified miRNA-mRNA pair interactions. Results: Seven hub proteins (Dlg3, Dlg4, Shank3, Grin2b, Camk2b, Camk2a and Syngap1) were implicated in alcohol withdrawal syndrome or diazepam treatment. In enrichment analysis, glutamatergic synapses were considered the most important pathway related to alcohol use disorder. Decreased glutamatergic synapses were observed in the late stage of withdrawal, as a protective mechanism that attenuated withdrawal-induced excitotoxicity. Diazepam treatment during withdrawal increased glutamatergic synapses, alleviating withdrawal-induced synapse inhibition. Conclusion: Glutamatergic synapses are considered the most important pathway related to alcohol use disorder that may be a potential molecular target for new interventional strategies.
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Affiliation(s)
- Wan Kong
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Shanqing Huang
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zikai Chen
- Department of Administration, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xiaolin Li
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Shujing Liu
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zi Zhang
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Ye Yang
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zhanzhang Wang
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xiuqing Zhu
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xiaojia Ni
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Haoyang Lu
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Ming Zhang
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zezhi Li
- Department of Adult Psychiatry, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China,*Correspondence: Zezhi Li, ; Yuguan Wen, ; Dewei Shang,
| | - Yuguan Wen
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China,*Correspondence: Zezhi Li, ; Yuguan Wen, ; Dewei Shang,
| | - Dewei Shang
- Department of Pharmacy, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China,*Correspondence: Zezhi Li, ; Yuguan Wen, ; Dewei Shang,
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Synaptoproteomic Analysis of the Prefrontal Cortex Reveals Spatio-Temporal Changes in SYNGAP1 Following Cannabinoid Exposure in Rat Adolescence. Int J Mol Sci 2022; 24:ijms24010698. [PMID: 36614142 PMCID: PMC9820805 DOI: 10.3390/ijms24010698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 12/19/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023] Open
Abstract
The regular use of cannabis during adolescence has been associated with a number of negative life outcomes, including psychopathology and cognitive impairments. However, the exact molecular mechanisms that underlie these outcomes are just beginning to be understood. Moreover, very little is known about the spatio-temporal molecular changes that occur following cannabinoid exposure in adolescence. To understand these changes, we exposed mid-adolescent male rats to a synthetic cannabinoid (WIN 55,212-2 mesylate; WIN) and, following drug abstinence through late adolescence, we subjected the synaptosomal fractions of the prefrontal cortex (PFC) to proteomic analyses. A total of N = 487 differentially expressed proteins were found in WIN-exposed animals compared to controls. Gene ontology analyses revealed enrichment of terms related to the gamma-aminobutyric acid (GABA)-ergic neurotransmitter system. Among the top differentially expressed proteins was the synaptic Ras GTPase-activating protein 1 (SYNGAP1). Using Western blotting experiments, we found that the WIN-induced upregulation of SYNGAP1 was spatio-temporal in nature, arising only in the synaptosomal fractions (not in the cytosol) and only following prolonged drug abstinence (not on abstinence day 1). Moreover, the SYNGAP1 changes were found to be specific to WIN-exposure in adolescence and not adulthood. Adolescent animals exposed to a natural cannabinoid (Δ9-tetrahydrocannabinol; THC) were also found to have increased levels of SYNGAP1 in the PFC. THC exposure also led to a pronounced upregulation of SYNGAP1 in the amygdala, but without any changes in the dorsal striatum, hippocampus, or nucleus accumbens. To our knowledge, this is the first study to uncover a link between cannabinoid exposure and changes in SYNGAP1 that are spatio-temporal and developmental in nature. Future studies are needed to investigate the putative role of SYNGAP1 in the negative behavioral consequences of cannabis use in adolescence.
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Wang Y, Lv Y, Li Z, Gao M, Yang X, Li Y, Shi J, Gao Z, Liu Y, Gai Z. Phenotype and genotype analyses of Chinese patients with autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations. Front Genet 2022; 13:957915. [PMID: 36583017 PMCID: PMC9792850 DOI: 10.3389/fgene.2022.957915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 11/09/2022] [Indexed: 12/15/2022] Open
Abstract
Background: Autosomal dominant mental retardation type 5 (MRD5), a rare neurodevelopmental disorder (NDD) characterized by intellectual disability (ID), developmental delay (DD), and epilepsy predominantly, is caused by a heterozygous mutation in the SYNGAP1 gene. SYNGAP1 mutations have been rarely reported in the Chinese population. Here, we present an investigation of SYNGAP1 mutations in a clinical cohort with ID and DD in Shandong, a northern province in China, to further explore the genotype and phenotype correlations. Methods: A retrospective study was conducted on 10 children with SYNGAP1 mutations presenting ID, DD, and epilepsy who were diagnosed between January 2014 and May 2022. Clinical data and genetic tests were collected. Treatment and regular follow-ups were carried out to pay close attention to the prognosis of the patients. Results: We described 10 unrelated affected individuals with SYNGAP1 mutations, displaying ID, DD, epilepsy, or seizures. All mutations of SYNGAP1 in the 10 patients were de novo, except patient 3 whose father was unavailable, including five nonsense mutations, two frameshift mutations, two splicing mutations, and one codon deletion. Among these mutations, five were novel and the other five were previously reported. Significantly, all patients with epilepsy were sensitive to anti-seizure drugs, especially sodium valproate. Furthermore, rehabilitation training seemed to exert a more improved effect on motor development than language development for the patients. Conclusion The 10 patients carrying SYNGAP1 mutations were diagnosed as MRD5. Five novel genetic mutations were found, which expanded the mutational spectrum of the SYNGAP1 gene. The identification of these mutations in this study helps explore the relationship between genotypes and phenotypes and contributes to genetic counseling and therapeutic intervention for patients with MRD5.
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Affiliation(s)
- Yanxin Wang
- Department of Pediatrics, Children’s Hospital Affiliated to Shandong University, Ji’nan, China
| | - Yuqiang Lv
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Ji’nan, China,Shandong Provincial Clinical Research Center for Children’s Health and Disease, Ji’nan, China
| | - Zilong Li
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Ji’nan, China,Shandong Provincial Clinical Research Center for Children’s Health and Disease, Ji’nan, China
| | - Min Gao
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Ji’nan, China,Shandong Provincial Clinical Research Center for Children’s Health and Disease, Ji’nan, China
| | - Xiaomeng Yang
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Ji’nan, China,Shandong Provincial Clinical Research Center for Children’s Health and Disease, Ji’nan, China
| | - Yue Li
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Ji’nan, China,Shandong Provincial Clinical Research Center for Children’s Health and Disease, Ji’nan, China
| | - Jianguo Shi
- Shandong Provincial Clinical Research Center for Children’s Health and Disease, Ji’nan, China,Epilepsy Center, Children’s Hospital Affiliated to Shandong University, Ji’nan, China
| | - Zaifen Gao
- Shandong Provincial Clinical Research Center for Children’s Health and Disease, Ji’nan, China,Epilepsy Center, Children’s Hospital Affiliated to Shandong University, Ji’nan, China
| | - Yi Liu
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Ji’nan, China,Shandong Provincial Clinical Research Center for Children’s Health and Disease, Ji’nan, China,*Correspondence: Yi Liu, ; Zhongtao Gai,
| | - Zhongtao Gai
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Ji’nan, China,Shandong Provincial Clinical Research Center for Children’s Health and Disease, Ji’nan, China,Epilepsy Center, Children’s Hospital Affiliated to Shandong University, Ji’nan, China,*Correspondence: Yi Liu, ; Zhongtao Gai,
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Megagiannis P, Suresh R, Rouleau GA, Zhou Y. Reversibility and therapeutic development for neurodevelopmental disorders, insights from genetic animal models. Adv Drug Deliv Rev 2022; 191:114562. [PMID: 36183904 DOI: 10.1016/j.addr.2022.114562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/30/2022] [Accepted: 09/24/2022] [Indexed: 01/24/2023]
Abstract
Neurodevelopmental Disorders (NDDs) encompass a broad spectrum of conditions resulting from atypical brain development. Over the past decades, we have had the fortune to witness enormous progress in diagnosis, etiology discovery, modeling, and mechanistic understanding of NDDs from both fundamental and clinical research. Here, we review recent neurobiological advances from experimental models of NDDs. We introduce several examples and highlight breakthroughs in reversal studies of phenotypes using genetically engineered models of NDDs. The in-depth understanding of brain pathophysiology underlying NDDs and evaluations of reversibility in animal models paves the foundation for discovering novel treatment options. We discuss how the expanding property of cutting-edge technologies, such as gene editing and AAV-mediated gene delivery, are leveraged in animal models for the therapeutic development of NDDs. We envision opportunities and challenges toward faithful modeling and fruitful clinical translation.
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Affiliation(s)
- Platon Megagiannis
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital; Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Rahul Suresh
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital; Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Guy A Rouleau
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital; Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Yang Zhou
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital; Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec H3A 2B4, Canada.
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Schiapparelli LM, Xie Y, Sharma P, McClatchy DB, Ma Y, Yates JR, Maximov A, Cline HT. Activity-Induced Cortical Glutamatergic Neuron Nascent Proteins. J Neurosci 2022; 42:7900-7920. [PMID: 36261270 PMCID: PMC9617616 DOI: 10.1523/jneurosci.0707-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 11/21/2022] Open
Abstract
Neuronal activity initiates signaling cascades that culminate in diverse outcomes including structural and functional neuronal plasticity, and metabolic changes. While studies have revealed activity-dependent neuronal cell type-specific transcriptional changes, unbiased quantitative analysis of cell-specific activity-induced dynamics in newly synthesized proteins (NSPs) synthesis in vivo has been complicated by cellular heterogeneity and a relatively low abundance of NSPs within the proteome in the brain. Here we combined targeted expression of mutant MetRS (methionine tRNA synthetase) in genetically defined cortical glutamatergic neurons with tight temporal control of treatment with the noncanonical amino acid, azidonorleucine, to biotinylate NSPs within a short period after pharmacologically induced seizure in male and female mice. By purifying peptides tagged with heavy or light biotin-alkynes and using direct tandem mass spectrometry detection of biotinylated peptides, we quantified activity-induced changes in cortical glutamatergic neuron NSPs. Seizure triggered significant changes in ∼300 NSPs, 33% of which were decreased by seizure. Proteins mediating excitatory and inhibitory synaptic plasticity, including SynGAP1, Pak3, GEPH1, Copine-6, and collybistin, and DNA and chromatin remodeling proteins, including Rad21, Smarca2, and Ddb1, are differentially synthesized in response to activity. Proteins likely to play homeostatic roles in response to activity, such as regulators of proteastasis, intracellular ion control, and cytoskeleton remodeling proteins, are activity induced. Conversely, seizure decreased newly synthetized NCAM, among others, suggesting that seizure induced degradation. Overall, we identified quantitative changes in the activity-induced nascent proteome from genetically defined cortical glutamatergic neurons as a strategy to discover downstream mediators of neuronal plasticity and generate hypotheses regarding their function.SIGNIFICANCE STATEMENT Activity-induced neuronal and synaptic plasticity are mediated by changes in the protein landscape, including changes in the activity-induced newly synthesized proteins; however, identifying neuronal cell type-specific nascent proteome dynamics in the intact brain has been technically challenging. We conducted an unbiased proteomic screen from which we identified significant activity-induced changes in ∼300 newly synthesized proteins in genetically defined cortical glutamatergic neurons within 20 h after pharmacologically induced seizure. Bioinformatic analysis of the dynamic nascent proteome indicates that the newly synthesized proteins play diverse roles in excitatory and inhibitory synaptic plasticity, chromatin remodeling, homeostatic mechanisms, and proteasomal and metabolic functions, extending our understanding of the diversity of plasticity mechanisms.
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Affiliation(s)
- Lucio M Schiapparelli
- Neuroscience Department and Dorris Neuroscience Center, Scripps Research Institute, La Jolla, California 92037
| | - Yi Xie
- Neuroscience Department and Dorris Neuroscience Center, Scripps Research Institute, La Jolla, California 92037
- Skaggs Graduate School, Scripps Research Institute, La Jolla, California 92037
| | - Pranav Sharma
- Neuroscience Department and Dorris Neuroscience Center, Scripps Research Institute, La Jolla, California 92037
- Xosomix, San Diego, California 92121
| | - Daniel B McClatchy
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, California 92037
| | - Yuanhui Ma
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, California 92037
| | - John R Yates
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, California 92037
| | - Anton Maximov
- Neuroscience Department and Dorris Neuroscience Center, Scripps Research Institute, La Jolla, California 92037
| | - Hollis T Cline
- Neuroscience Department and Dorris Neuroscience Center, Scripps Research Institute, La Jolla, California 92037
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Wang Y, Lv Y, Yang X, Li Y, Li Z, Gao Z, Gai Z, Liu Y. Generation of an induced pluripotent stem cell line (SDQLCHi044-A) from a patient with autosomal dominant mental retardation type 5 harboring heterozygous mutation in SYNGAP1 gene. Stem Cell Res 2022; 64:102922. [PMID: 36183676 DOI: 10.1016/j.scr.2022.102922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 11/24/2022] Open
Abstract
Autosomal dominant mental retardation type 5 (MRD5) is a rare neurodevelopmental disorder caused by mutations in the SYNGAP1 gene. Here, we established an induced pluripotent stem cell (iPSC) line from peripheral blood mononuclear cells (PBMCs) of a 30-month-old boy carrying a heterozygous mutation (c.2059C > T) in the SYNGAP1 gene. The iPSCs exhibited a normal karyotype, expressed pluripotency markers, and displayed differentiation potential in vitro.
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Affiliation(s)
- Yanxin Wang
- Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China
| | - Yuqiang Lv
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China
| | - Xiaomeng Yang
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China
| | - Yue Li
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China
| | - Zilong Li
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China
| | - Zaifen Gao
- Epilepsy Center, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China
| | - Zhongtao Gai
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China; Epilepsy Center, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China.
| | - Yi Liu
- Pediatric Research Institute, Children's Hospital Affiliated to Shandong University, Ji'nan 250022, China.
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Chakraborty S, Parayil R, Mishra S, Nongthomba U, Clement JP. Epilepsy Characteristics in Neurodevelopmental Disorders: Research from Patient Cohorts and Animal Models Focusing on Autism Spectrum Disorder. Int J Mol Sci 2022; 23:ijms231810807. [PMID: 36142719 PMCID: PMC9501968 DOI: 10.3390/ijms231810807] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/24/2022] Open
Abstract
Epilepsy, a heterogeneous group of brain-related diseases, has continued to significantly burden society and families. Epilepsy comorbid with neurodevelopmental disorders (NDDs) is believed to occur due to multifaceted pathophysiological mechanisms involving disruptions in the excitation and inhibition (E/I) balance impeding widespread functional neuronal circuitry. Although the field has received much attention from the scientific community recently, the research has not yet translated into actionable therapeutics to completely cure epilepsy, particularly those comorbid with NDDs. In this review, we sought to elucidate the basic causes underlying epilepsy as well as those contributing to the association of epilepsy with NDDs. Comprehensive emphasis is put on some key neurodevelopmental genes implicated in epilepsy, such as MeCP2, SYNGAP1, FMR1, SHANK1-3 and TSC1, along with a few others, and the main electrophysiological and behavioral deficits are highlighted. For these genes, the progress made in developing appropriate and valid rodent models to accelerate basic research is also detailed. Further, we discuss the recent development in the therapeutic management of epilepsy and provide a briefing on the challenges and caveats in identifying and testing species-specific epilepsy models.
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Affiliation(s)
- Sukanya Chakraborty
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
| | - Rrejusha Parayil
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
| | - Shefali Mishra
- Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bengaluru 560012, India
| | - Upendra Nongthomba
- Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bengaluru 560012, India
| | - James P. Clement
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
- Correspondence: ; Tel.: +91-08-2208-2613
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Qi C, Luo LD, Feng I, Ma S. Molecular mechanisms of synaptogenesis. Front Synaptic Neurosci 2022; 14:939793. [PMID: 36176941 PMCID: PMC9513053 DOI: 10.3389/fnsyn.2022.939793] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 07/27/2022] [Indexed: 11/29/2022] Open
Abstract
Synapses are the basic units for information processing and storage in the nervous system. It is only when the synaptic connection is established, that it becomes meaningful to discuss the structure and function of a circuit. In humans, our unparalleled cognitive abilities are correlated with an increase in the number of synapses. Additionally, genes involved in synaptogenesis are also frequently associated with neurological or psychiatric disorders, suggesting a relationship between synaptogenesis and brain physiology and pathology. Thus, understanding the molecular mechanisms of synaptogenesis is the key to the mystery of circuit assembly and neural computation. Furthermore, it would provide therapeutic insights for the treatment of neurological and psychiatric disorders. Multiple molecular events must be precisely coordinated to generate a synapse. To understand the molecular mechanisms underlying synaptogenesis, we need to know the molecular components of synapses, how these molecular components are held together, and how the molecular networks are refined in response to neural activity to generate new synapses. Thanks to the intensive investigations in this field, our understanding of the process of synaptogenesis has progressed significantly. Here, we will review the molecular mechanisms of synaptogenesis by going over the studies on the identification of molecular components in synapses and their functions in synaptogenesis, how cell adhesion molecules connect these synaptic molecules together, and how neural activity mobilizes these molecules to generate new synapses. Finally, we will summarize the human-specific regulatory mechanisms in synaptogenesis and results from human genetics studies on synaptogenesis and brain disorders.
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Affiliation(s)
- Cai Qi
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
- *Correspondence: Cai Qi,
| | - Li-Da Luo
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
- Department of Cellular and Molecular Physiology, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT, United States
| | - Irena Feng
- Boston University School of Medicine, Boston, MA, United States
| | - Shaojie Ma
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
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Nowakowski TJ, Salama SR. Cerebral Organoids as an Experimental Platform for Human Neurogenomics. Cells 2022; 11:2803. [PMID: 36139380 PMCID: PMC9496777 DOI: 10.3390/cells11182803] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/06/2022] [Accepted: 09/07/2022] [Indexed: 01/25/2023] Open
Abstract
The cerebral cortex forms early in development according to a series of heritable neurodevelopmental instructions. Despite deep evolutionary conservation of the cerebral cortex and its foundational six-layered architecture, significant variations in cortical size and folding can be found across mammals, including a disproportionate expansion of the prefrontal cortex in humans. Yet our mechanistic understanding of neurodevelopmental processes is derived overwhelmingly from rodent models, which fail to capture many human-enriched features of cortical development. With the advent of pluripotent stem cells and technologies for differentiating three-dimensional cultures of neural tissue in vitro, cerebral organoids have emerged as an experimental platform that recapitulates several hallmarks of human brain development. In this review, we discuss the merits and limitations of cerebral organoids as experimental models of the developing human brain. We highlight innovations in technology development that seek to increase its fidelity to brain development in vivo and discuss recent efforts to use cerebral organoids to study regeneration and brain evolution as well as to develop neurological and neuropsychiatric disease models.
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Affiliation(s)
- Tomasz J. Nowakowski
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94158, USA
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94158, USA
- Department of Psychiatry and Behavioral Sciences, University of California San Francisco, San Francisco, CA 94158, USA
- Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA 94158, USA
- Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA 94158, USA
| | - Sofie R. Salama
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
- UC Santa Cruz Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95060, USA
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Early postnatal serotonin modulation prevents adult-stage deficits in Arid1b-deficient mice through synaptic transcriptional reprogramming. Nat Commun 2022; 13:5051. [PMID: 36030255 PMCID: PMC9420115 DOI: 10.1038/s41467-022-32748-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 08/12/2022] [Indexed: 11/19/2022] Open
Abstract
Autism spectrum disorder is characterized by early postnatal symptoms, although little is known about the mechanistic deviations that produce them and whether correcting them has long-lasting preventive effects on adult-stage deficits. ARID1B, a chromatin remodeler implicated in neurodevelopmental disorders, including autism spectrum disorder, exhibits strong embryonic- and early postnatal-stage expression. We report here that Arid1b-happloinsufficient (Arid1b+/–) mice display autistic-like behaviors at juvenile and adult stages accompanied by persistent decreases in excitatory synaptic density and transmission. Chronic treatment of Arid1b+/– mice with fluoxetine, a selective serotonin-reuptake inhibitor, during the first three postnatal weeks prevents synaptic and behavioral deficits in adults. Mechanistically, these rescues accompany transcriptomic changes, including upregulation of FMRP targets and normalization of HDAC4/MEF2A-related transcriptional regulation of the synaptic proteins, SynGAP1 and Arc. These results suggest that chronic modulation of serotonergic receptors during critical early postnatal periods prevents synaptic and behavioral deficits in adult Arid1b+/– mice through transcriptional reprogramming. ARID1B is a chromatin remodeler associated with autism spectrum disorders. Here the authors demonstrate that early postnatal serotonin modulation prevents adult stage deficits in Arid1b-deficient mice through synaptic transcriptional reprogramming.
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Gross C. Some (Syn)Gaps are Worse than Others: Deciphering The Role of Syngap Isoforms in Excitatory Synaptic Function. Epilepsy Curr 2022; 22:312-314. [PMID: 36285208 PMCID: PMC9549232 DOI: 10.1177/15357597221111686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Endogenous Syngap Alpha Splice Forms Promote Cognitive Function and Seizure
Protection M Kilinc, V Arora, TK Creson, et al. eLife. 2022;11:e75707.
doi:10.7554/eLife.75707. Loss-of-function variants in SYNGAP cause a developmental encephalopathy defined by
cognitive impairment, autistic features, and epilepsy. SYNGAP splicing leads to
expression of distinct functional protein isoforms. Splicing imparts multiple cellular
functions of SynGAP proteins through coding of distinct C-terminal motifs. However, it
remains unknown how these different splice sequences function in vivo to regulate
neuronal function and behavior. Reduced expression of SynGAP-α1/2 C-terminal splice
variants in mice caused severe phenotypes, including reduced survival, impaired
learning, and reduced seizure latency. In contrast, upregulation of α1/2 expression
improved learning and increased seizure latency. Mice expressing α1-specific
mutations, which disrupted SynGAP cellular functions without altering protein
expression, promoted seizure, disrupted synapse plasticity, and impaired learning.
These findings demonstrate that endogenous SynGAP isoforms with α1/2 spliced sequences
promote cognitive function and impart seizure protection. Regulation of
SynGAP-αexpression or function may be a viable therapeutic strategy to broadly improve
cognitive function and mitigate seizure.
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Mohanan AG, Gunasekaran S, Jacob RS, Omkumar RV. Role of Ca2+/Calmodulin-Dependent Protein Kinase Type II in Mediating Function and Dysfunction at Glutamatergic Synapses. Front Mol Neurosci 2022; 15:855752. [PMID: 35795689 PMCID: PMC9252440 DOI: 10.3389/fnmol.2022.855752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 03/21/2022] [Indexed: 01/25/2023] Open
Abstract
Glutamatergic synapses harbor abundant amounts of the multifunctional Ca2+/calmodulin-dependent protein kinase type II (CaMKII). Both in the postsynaptic density as well as in the cytosolic compartment of postsynaptic terminals, CaMKII plays major roles. In addition to its Ca2+-stimulated kinase activity, it can also bind to a variety of membrane proteins at the synapse and thus exert spatially restricted activity. The abundance of CaMKII in glutamatergic synapse is akin to scaffolding proteins although its prominent function still appears to be that of a kinase. The multimeric structure of CaMKII also confers several functional capabilities on the enzyme. The versatility of the enzyme has prompted hypotheses proposing several roles for the enzyme such as Ca2+ signal transduction, memory molecule function and scaffolding. The article will review the multiple roles played by CaMKII in glutamatergic synapses and how they are affected in disease conditions.
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Affiliation(s)
- Archana G. Mohanan
- Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
| | - Sowmya Gunasekaran
- Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
- Research Scholar, Manipal Academy of Higher Education, Manipal, India
| | - Reena Sarah Jacob
- Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
- Research Scholar, Manipal Academy of Higher Education, Manipal, India
| | - R. V. Omkumar
- Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
- *Correspondence: R. V. Omkumar,
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Chaudry S, Vasudevan N. mTOR-Dependent Spine Dynamics in Autism. Front Mol Neurosci 2022; 15:877609. [PMID: 35782388 PMCID: PMC9241970 DOI: 10.3389/fnmol.2022.877609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/25/2022] [Indexed: 12/12/2022] Open
Abstract
Autism Spectrum Conditions (ASC) are a group of neurodevelopmental disorders characterized by deficits in social communication and interaction as well as repetitive behaviors and restricted range of interests. ASC are complex genetic disorders with moderate to high heritability, and associated with atypical patterns of neural connectivity. Many of the genes implicated in ASC are involved in dendritic spine pruning and spine development, both of which can be mediated by the mammalian target of rapamycin (mTOR) signaling pathway. Consistent with this idea, human postmortem studies have shown increased spine density in ASC compared to controls suggesting that the balance between autophagy and spinogenesis is altered in ASC. However, murine models of ASC have shown inconsistent results for spine morphology, which may underlie functional connectivity. This review seeks to establish the relevance of changes in dendritic spines in ASC using data gathered from rodent models. Using a literature survey, we identify 20 genes that are linked to dendritic spine pruning or development in rodents that are also strongly implicated in ASC in humans. Furthermore, we show that all 20 genes are linked to the mTOR pathway and propose that the mTOR pathway regulating spine dynamics is a potential mechanism underlying the ASC signaling pathway in ASC. We show here that the direction of change in spine density was mostly correlated to the upstream positive or negative regulation of the mTOR pathway and most rodent models of mutant mTOR regulators show increases in immature spines, based on morphological analyses. We further explore the idea that these mutations in these genes result in aberrant social behavior in rodent models that is due to these altered spine dynamics. This review should therefore pave the way for further research on the specific genes outlined, their effect on spine morphology or density with an emphasis on understanding the functional role of these changes in ASC.
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Malone TJ, Kaczmarek LK. The role of altered translation in intellectual disability and epilepsy. Prog Neurobiol 2022; 213:102267. [PMID: 35364140 PMCID: PMC10583652 DOI: 10.1016/j.pneurobio.2022.102267] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 02/18/2022] [Accepted: 03/24/2022] [Indexed: 11/29/2022]
Abstract
A very high proportion of cases of intellectual disability are genetic in origin and are associated with the occurrence of epileptic seizures during childhood. These two disorders together effect more than 5% of the world's population. One feature linking the two diseases is that learning and memory require the synthesis of new synaptic components and ion channels, while maintenance of overall excitability also requires synthesis of similar proteins in response to altered neuronal stimulation. Many of these disorders result from mutations in proteins that regulate mRNA processing, translation initiation, translation elongation, mRNA stability or upstream translation modulators. One theme that emerges on reviewing this field is that mutations in proteins that regulate changes in translation following neuronal stimulation are more likely to result in epilepsy with intellectual disability than general translation regulators with no known role in activity-dependent changes. This is consistent with the notion that activity-dependent translation in neurons differs from that in other cells types in that the changes in local cellular composition, morphology and connectivity that occur generally in response to stimuli are directly coupled to local synaptic activity and persist for months or years after the original stimulus.
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Affiliation(s)
- Taylor J Malone
- Departments of Pharmacology, and of Cellular & Molecular Physiology, Yale University, 333 Cedar Street B-309, New Haven, CT 06520, USA
| | - Leonard K Kaczmarek
- Departments of Pharmacology, and of Cellular & Molecular Physiology, Yale University, 333 Cedar Street B-309, New Haven, CT 06520, USA.
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Chung C, Shin W, Kim E. Early and Late Corrections in Mouse Models of Autism Spectrum Disorder. Biol Psychiatry 2022; 91:934-944. [PMID: 34556257 DOI: 10.1016/j.biopsych.2021.07.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 06/18/2021] [Accepted: 07/21/2021] [Indexed: 12/18/2022]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social and repetitive symptoms. A key feature of ASD is early-life manifestations of symptoms, indicative of early pathophysiological mechanisms. In mouse models of ASD, increasing evidence indicates that there are early pathophysiological mechanisms that can be corrected early to prevent phenotypic defects in adults, overcoming the disadvantage of the short-lasting effects that characterize adult-initiated treatments. In addition, the results from gene restorations indicate that ASD-related phenotypes can be rescued in some cases even after the brain has fully matured. These results suggest that we need to consider both temporal and mechanistic aspects in studies of ASD models and carefully compare genetic and nongenetic corrections. Here, we summarize the early and late corrections in mouse models of ASD by genetic and pharmacological interventions and discuss how to better integrate these results to ensure efficient and long-lasting corrections for eventual clinical translation.
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Affiliation(s)
- Changuk Chung
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon, South Korea; Department of Neurosciences, University of California San Diego, La Jolla, California
| | - Wangyong Shin
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon, South Korea
| | - Eunjoon Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon, South Korea; Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
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O-GlcNAcylation modulates liquid–liquid phase separation of SynGAP/PSD-95. Nat Chem 2022; 14:831-840. [DOI: 10.1038/s41557-022-00946-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 04/07/2022] [Indexed: 12/13/2022]
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Kilinc M, Arora V, Creson TK, Rojas C, Le AA, Lauterborn J, Wilkinson B, Hartel N, Graham N, Reich A, Gou G, Araki Y, Bayés À, Coba M, Lynch G, Miller CA, Rumbaugh G. Endogenous Syngap1 alpha splice forms promote cognitive function and seizure protection. eLife 2022; 11:e75707. [PMID: 35394425 PMCID: PMC9064290 DOI: 10.7554/elife.75707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 04/08/2022] [Indexed: 11/13/2022] Open
Abstract
Loss-of-function variants in SYNGAP1 cause a developmental encephalopathy defined by cognitive impairment, autistic features, and epilepsy. SYNGAP1 splicing leads to expression of distinct functional protein isoforms. Splicing imparts multiple cellular functions of SynGAP proteins through coding of distinct C-terminal motifs. However, it remains unknown how these different splice sequences function in vivo to regulate neuronal function and behavior. Reduced expression of SynGAP-α1/2 C-terminal splice variants in mice caused severe phenotypes, including reduced survival, impaired learning, and reduced seizure latency. In contrast, upregulation of α1/2 expression improved learning and increased seizure latency. Mice expressing α1-specific mutations, which disrupted SynGAP cellular functions without altering protein expression, promoted seizure, disrupted synapse plasticity, and impaired learning. These findings demonstrate that endogenous SynGAP isoforms with α1/2 spliced sequences promote cognitive function and impart seizure protection. Regulation of SynGAP-αexpression or function may be a viable therapeutic strategy to broadly improve cognitive function and mitigate seizure.
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Affiliation(s)
- Murat Kilinc
- Graduate School of Chemical and Biological Sciences, The Scripps Research InstituteJupiterUnited States
- Departments of Neuroscience and Molecular Medicine, The Scripps Research InstituteJupiterUnited States
| | - Vineet Arora
- Departments of Neuroscience and Molecular Medicine, The Scripps Research InstituteJupiterUnited States
| | - Thomas K Creson
- Departments of Neuroscience and Molecular Medicine, The Scripps Research InstituteJupiterUnited States
| | - Camilo Rojas
- Departments of Neuroscience and Molecular Medicine, The Scripps Research InstituteJupiterUnited States
| | - Aliza A Le
- Department of Anatomy and Neurobiology, The University of CaliforniaIrvineUnited States
| | - Julie Lauterborn
- Department of Anatomy and Neurobiology, The University of CaliforniaIrvineUnited States
| | - Brent Wilkinson
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern CaliforniaLos AngelesUnited States
| | - Nicolas Hartel
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern CaliforniaLos AngelesUnited States
| | - Nicholas Graham
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern CaliforniaLos AngelesUnited States
| | - Adrian Reich
- Bioinformatics and Statistics Core, The Scripps Research InstituteJupiterUnited States
| | - Gemma Gou
- Molecular Physiology of the Synapse Laboratory, Institut d'Investigació Biomèdica Sant PauBarcelonaSpain
- Universitat Autònoma de BarcelonaBellaterraSpain
| | - Yoichi Araki
- Department of Neuroscience, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Àlex Bayés
- Molecular Physiology of the Synapse Laboratory, Institut d'Investigació Biomèdica Sant PauBarcelonaSpain
| | - Marcelo Coba
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern CaliforniaLos AngelesUnited States
| | - Gary Lynch
- Department of Anatomy and Neurobiology, The University of CaliforniaIrvineUnited States
| | - Courtney A Miller
- Graduate School of Chemical and Biological Sciences, The Scripps Research InstituteJupiterUnited States
- Departments of Neuroscience and Molecular Medicine, The Scripps Research InstituteJupiterUnited States
| | - Gavin Rumbaugh
- Graduate School of Chemical and Biological Sciences, The Scripps Research InstituteJupiterUnited States
- Departments of Neuroscience and Molecular Medicine, The Scripps Research InstituteJupiterUnited States
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FMRP Sustains Presynaptic Function via Control of Activity-Dependent Bulk Endocytosis. J Neurosci 2022; 42:1618-1628. [PMID: 34996816 PMCID: PMC8883869 DOI: 10.1523/jneurosci.0852-21.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 12/22/2021] [Accepted: 12/23/2021] [Indexed: 11/21/2022] Open
Abstract
Synaptic vesicle (SV) recycling is essential for the maintenance of neurotransmission, with a number of neurodevelopmental disorders linked to defects in this process. Fragile X syndrome (FXS) results from a loss of fragile X mental retardation protein (FMRP) encoded by the FMR1 gene. Hyperexcitability of neuronal circuits is a key feature of FXS, therefore we investigated whether SV recycling was affected by the absence of FMRP during increased neuronal activity. We revealed that primary neuronal cultures from male Fmr1 knock-out (KO) rats display a specific defect in activity-dependent bulk endocytosis (ADBE). ADBE is dominant during intense neuronal activity, and this defect resulted in an inability of Fmr1 KO neurons to sustain SV recycling during trains of high-frequency stimulation. Using a molecular replacement strategy, we also revealed that a human FMRP mutant that cannot bind BK channels failed to correct ADBE dysfunction in KO neurons, however this dysfunction was corrected by BK channel agonists. Therefore, FMRP performs a key role in sustaining neurotransmitter release via selective control of ADBE, suggesting intervention via this endocytosis mode may correct the hyperexcitability observed in FXS.SIGNIFICANCE STATEMENT Loss of fragile X mental retardation protein (FMRP) results in fragile X syndrome (FXS), however whether its loss has a direct role in neurotransmitter release remains a matter of debate. We demonstrate that neurons lacking FMRP display a specific defect in a mechanism that sustains neurotransmitter release during intense neuronal firing, called activity-dependent bulk endocytosis (ADBE). This discovery provides key insights into mechanisms of brain communication that occur because of loss of FMRP function. Importantly it also reveals ADBE as a potential therapeutic target to correct the circuit hyperexcitability observed in FXS.
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Buller-Peralta I, Maicas-Royo J, Lu Z, Till SM, Wood ER, Kind PC, Escudero J, Gonzalez-Sulser A. Abnormal brain state distribution and network connectivity in a SYNGAP1 rat model. Brain Commun 2022; 4:fcac263. [PMID: 36349120 PMCID: PMC9638780 DOI: 10.1093/braincomms/fcac263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 07/09/2022] [Accepted: 10/13/2022] [Indexed: 11/09/2022] Open
Abstract
Mutations in the SYNGAP1 gene are one of the common predictors of neurodevelopmental disorders, commonly resulting in individuals developing autism, intellectual disability, epilepsy, and sleep deficits. EEG recordings in neurodevelopmental disorders show potential to identify clinically translatable biomarkers to both diagnose and track the progress of novel therapeutic strategies, as well as providing insight into underlying pathological mechanisms. In a rat model of SYNGAP1 haploinsufficiency in which the exons encoding the calcium/lipid binding and GTPase-activating protein domains have been deleted (Syngap+/Δ-GAP ), we analysed the duration and occurrence of wake, non-rapid eye movement and rapid eye movement brain states during 6 h multi-electrode EEG recordings. We find that although Syngap+/Δ-GAP animals spend an equivalent percent time in wake and sleep states, they have an abnormal brain state distribution as the number of wake and non-rapid eye movement bouts are reduced and there is an increase in the average duration of both wake and non-rapid eye movement epochs. We perform connectivity analysis by calculating the average imaginary coherence between electrode pairs at varying distance thresholds during these states. In group averages from pairs of electrodes at short distances from each other, a clear reduction in connectivity during non-rapid eye movement is present between 11.5 Hz and 29.5 Hz, a frequency range that overlaps with sleep spindles, oscillatory phenomena thought to be important for normal brain function and memory consolidation. Sleep abnormalities were mostly uncorrelated to the electrophysiological signature of absence seizures, spike and wave discharges, as was the imaginary coherence deficit. Sleep spindles occurrence, amplitude, power and spread across multiple electrodes were not reduced in Syngap+/Δ-GAP rats, with only a small decrease in duration detected. Nonetheless, by analysing the dynamic imaginary coherence during sleep spindles, we found a reduction in high-connectivity instances between short-distance electrode pairs. Finally comparing the dynamic imaginary coherence during sleep spindles between individual electrode pairs, we identified a group of channels over the right somatosensory, association and visual cortices that have a significant reduction in connectivity during sleep spindles in mutant animals. This matched a significant reduction in connectivity during spindles when averaged regional comparisons were made. These data suggest that Syngap+/Δ-GAP rats have altered brain state dynamics and EEG connectivity, which may have clinical relevance for SYNGAP1 haploinsufficiency in humans.
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Affiliation(s)
- Ingrid Buller-Peralta
- Simons Initiative for the Developing Brain, Patrick Wild Centre, Centre for Discovery Brain Sciences, University of Edinburgh, EH8 9XD Edinburgh, United Kingdom
| | - Jorge Maicas-Royo
- Simons Initiative for the Developing Brain, Patrick Wild Centre, Centre for Discovery Brain Sciences, University of Edinburgh, EH8 9XD Edinburgh, United Kingdom
| | - Zhuoen Lu
- School of Engineering, Institute for Digital Communications, University of Edinburgh, EH9 3JL Edinburgh, United Kingdom
| | - Sally M Till
- Simons Initiative for the Developing Brain, Patrick Wild Centre, Centre for Discovery Brain Sciences, University of Edinburgh, EH8 9XD Edinburgh, United Kingdom
| | - Emma R Wood
- Simons Initiative for the Developing Brain, Patrick Wild Centre, Centre for Discovery Brain Sciences, University of Edinburgh, EH8 9XD Edinburgh, United Kingdom
| | - Peter C Kind
- Simons Initiative for the Developing Brain, Patrick Wild Centre, Centre for Discovery Brain Sciences, University of Edinburgh, EH8 9XD Edinburgh, United Kingdom
| | - Javier Escudero
- School of Engineering, Institute for Digital Communications, University of Edinburgh, EH9 3JL Edinburgh, United Kingdom
| | - Alfredo Gonzalez-Sulser
- Simons Initiative for the Developing Brain, Patrick Wild Centre, Centre for Discovery Brain Sciences, University of Edinburgh, EH8 9XD Edinburgh, United Kingdom
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