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Severino L, Kim J, Nam MH, McHugh TJ. From synapses to circuits: What mouse models have taught us about how autism spectrum disorder impacts hippocampal function. Neurosci Biobehav Rev 2024; 158:105559. [PMID: 38246230 DOI: 10.1016/j.neubiorev.2024.105559] [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: 11/29/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 01/23/2024]
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that impacts a variety of cognitive and behavioral domains. While a genetic component of ASD has been well-established, none of the numerous syndromic genes identified in humans accounts for more than 1% of the clinical patients. Due to this large number of target genes, numerous mouse models of the disorder have been generated. However, the focus on distinct brain circuits, behavioral phenotypes and diverse experimental approaches has made it difficult to synthesize the overwhelming number of model animal studies into concrete throughlines that connect the data across levels of investigation. Here we chose to focus on one circuit, the hippocampus, and one hypothesis, a shift in excitatory/inhibitory balance, to examine, from the level of the tripartite synapse up to the level of in vivo circuit activity, the key commonalities across disparate models that can illustrate a path towards a better mechanistic understanding of ASD's impact on hippocampal circuit function.
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Affiliation(s)
- Leandra Severino
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea; Division of Bio-Medical Science & Technology, KIST-School, University of Science and Technology, Seoul, South Korea
| | - Jinhyun Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea; Division of Bio-Medical Science & Technology, KIST-School, University of Science and Technology, Seoul, South Korea
| | - Min-Ho Nam
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea; Division of Bio-Medical Science & Technology, KIST-School, University of Science and Technology, Seoul, South Korea.
| | - Thomas J McHugh
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea; Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi Saitama, Japan.
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2
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Benner O, Cast TP, Minamide LS, Lenninger Z, Bamburg JR, Chanda S. Multiple N-linked glycosylation sites critically modulate the synaptic abundance of neuroligin isoforms. J Biol Chem 2023; 299:105361. [PMID: 37865312 PMCID: PMC10679506 DOI: 10.1016/j.jbc.2023.105361] [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: 09/05/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 10/23/2023] Open
Abstract
In recent years, elegant glycomic and glycoproteomic approaches have revealed an intricate glycosylation profile of mammalian brain with enormous spatial and temporal diversities. Nevertheless, at a cellular level, it is unclear how these post-translational modifications affect various proteins to influence crucial neuronal properties. Here, we have investigated the impact of N-linked glycosylation on neuroligins (NLGNs), a class of cell-adhesion molecules that play instructive roles in synapse organization. We found that endogenous NLGN proteins are differentially glycosylated across several regions of murine brain in a sex-independent but isoform-dependent manner. In both rodent primary neurons derived from brain sections and human neurons differentiated from stem cells, all NLGN variants were highly enriched with multiple N-glycan subtypes, which cumulatively ensured their efficient trafficking to the cell surface. Removal of these N-glycosylation residues only had a moderate effect on NLGNs' stability or expression levels but particularly enhanced their retention at the endoplasmic reticulum. As a result, the glycosylation-deficient NLGNs exhibited considerable impairments in their dendritic distribution and postsynaptic accumulation, which in turn, virtually eliminated their ability to recruit presynaptic terminals and significantly reduced NLGN overexpression-induced assemblies of both glutamatergic and GABAergic synapse structures. Therefore, our results highlight an essential mechanistic contribution of N-linked glycosylations in facilitating the appropriate secretory transport of a major synaptic cell-adhesion molecule and promoting its cellular function in neurons.
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Affiliation(s)
- Orion Benner
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, USA
| | - Thomas P Cast
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, USA
| | - Laurie S Minamide
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, USA
| | - Zephyr Lenninger
- Molecular, Cellular & Integrated Neurosciences, Colorado State University, Fort Collins, Colorado, USA
| | - James R Bamburg
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, USA; Molecular, Cellular & Integrated Neurosciences, Colorado State University, Fort Collins, Colorado, USA; Cell & Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Soham Chanda
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, USA; Molecular, Cellular & Integrated Neurosciences, Colorado State University, Fort Collins, Colorado, USA; Cell & Molecular Biology, Colorado State University, Fort Collins, Colorado, USA.
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3
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Muellerleile J, Vnencak M, Sethi MVA, Jungenitz T, Schwarzacher SW, Jedlicka P. Increased Network Inhibition in the Dentate Gyrus of Adult Neuroligin-4 Knock-Out Mice. eNeuro 2023; 10:10/4/ENEURO.0471-22.2023. [PMID: 37080762 PMCID: PMC10121080 DOI: 10.1523/eneuro.0471-22.2023] [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: 11/18/2022] [Revised: 03/01/2023] [Accepted: 03/12/2023] [Indexed: 04/22/2023] Open
Abstract
Loss-of-function mutations in neuroligin-4 (Nlgn4), a member of the neuroligin family of postsynaptic adhesion proteins, cause autism spectrum disorder in humans. Nlgn4 knockout (KO) in mice leads to social behavior deficits and complex alterations of synaptic inhibition or excitation, depending on the brain region. In the present work, we comprehensively analyzed synaptic function and plasticity at the cellular and network levels in hippocampal dentate gyrus of Nlgn4 KO mice. Compared with wild-type littermates, adult Nlgn4 KO mice exhibited increased paired-pulse inhibition of dentate granule cell population spikes, but no impairments in excitatory synaptic transmission or short-term and long-term plasticity in vivo In vitro patch-clamp recordings in neonatal organotypic entorhino-hippocampal slice cultures from Nlgn4 KO and wild-type littermates revealed no significant differences in excitatory or inhibitory synaptic transmission, homeostatic synaptic plasticity, and passive electrotonic properties in dentate granule cells, suggesting that the increased inhibition in vivo is the result of altered network activity in the adult Nlgn4 KO. A comparison with prior studies on Nlgn 1-3 knock-out mice reveals that each of the four neuroligins exerts a characteristic effect on both intrinsic cellular and network activity in the dentate gyrus in vivo.
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Affiliation(s)
- Julia Muellerleile
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
- Faculty of Biosciences, Goethe University Frankfurt, 60439 Frankfurt am Main, Germany
| | - Matej Vnencak
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Mohammad Valeed Ahmed Sethi
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Tassilo Jungenitz
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Stephan W Schwarzacher
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Peter Jedlicka
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
- Faculty of Medicine, Justus-Liebig-University Giessen, 35392 Giessen, Germany
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4
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Nabavi M, Hiesinger PR. Turnover of synaptic adhesion molecules. Mol Cell Neurosci 2023; 124:103816. [PMID: 36649812 DOI: 10.1016/j.mcn.2023.103816] [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: 09/30/2022] [Revised: 12/15/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Molecular interactions between pre- and postsynaptic membranes play critical roles during the development, function and maintenance of synapses. Synaptic interactions are mediated by cell surface receptors that may be held in place by trans-synaptic adhesion or intracellular binding to membrane-associated scaffolding and signaling complexes. Despite their role in stabilizing synaptic contacts, synaptic adhesion molecules undergo turnover and degradation during all stages of a neuron's life. Here we review current knowledge about membrane trafficking mechanisms that regulate turnover of synaptic adhesion molecules and the functional significance of turnover for synapse development and function. Based on recent proteomics, genetics and imaging studies, synaptic adhesion molecules exhibit remarkably high turnover rates compared to other synaptic proteins. Degradation occurs predominantly via endolysosomal mechanisms, with little evidence for roles of proteasomal or autophagic degradation. Basal turnover occurs both during synaptic development and maintenance. Neuronal activity typically stabilizes synaptic adhesion molecules while downregulating neurotransmitter receptors based on turnover. In conclusion, constitutive turnover of synaptic adhesion molecules is not a necessarily destabilizing factor, but a basis for the dynamic regulation of trans-synaptic interactions during synapse formation and maintenance.
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Affiliation(s)
- Melinda Nabavi
- Institute for Biology, Division of Neurobiology, Freie Universität Berlin, Germany
| | - P Robin Hiesinger
- Institute for Biology, Division of Neurobiology, Freie Universität Berlin, Germany.
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Wang L, Wang B, Wu C, Wang J, Sun M. Autism Spectrum Disorder: Neurodevelopmental Risk Factors, Biological Mechanism, and Precision Therapy. Int J Mol Sci 2023; 24:ijms24031819. [PMID: 36768153 PMCID: PMC9915249 DOI: 10.3390/ijms24031819] [Citation(s) in RCA: 33] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/19/2023] Open
Abstract
Autism spectrum disorder (ASD) is a heterogeneous, behaviorally defined neurodevelopmental disorder. Over the past two decades, the prevalence of autism spectrum disorders has progressively increased, however, no clear diagnostic markers and specifically targeted medications for autism have emerged. As a result, neurobehavioral abnormalities, neurobiological alterations in ASD, and the development of novel ASD pharmacological therapy necessitate multidisciplinary collaboration. In this review, we discuss the development of multiple animal models of ASD to contribute to the disease mechanisms of ASD, as well as new studies from multiple disciplines to assess the behavioral pathology of ASD. In addition, we summarize and highlight the mechanistic advances regarding gene transcription, RNA and non-coding RNA translation, abnormal synaptic signaling pathways, epigenetic post-translational modifications, brain-gut axis, immune inflammation and neural loop abnormalities in autism to provide a theoretical basis for the next step of precision therapy. Furthermore, we review existing autism therapy tactics and limits and present challenges and opportunities for translating multidisciplinary knowledge of ASD into clinical practice.
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English J, McSweeney D, Ribbe F, Howell E, Pak C. Generation and Co-culture of Cortical Glutamatergic and GABAergic-Induced Neuronal Cells. Methods Mol Biol 2023; 2683:21-37. [PMID: 37300764 DOI: 10.1007/978-1-0716-3287-1_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] [Indexed: 06/12/2023]
Abstract
The study of neurological disorders requires experimentation on human neurons throughout their development. Primary neurons can be difficult to obtain, and animal models may not fully recapitulate phenotypes observed in human neurons. Human neuronal culturing schemes which contain a balanced mixture of excitatory and inhibitory neurons that resemble physiological ratios seen in vivo will be useful to probe the neurological basis of excitation-inhibition (E-I) balance. Here, we describe a method for directly inducing a homogenous population of cortical excitatory neurons and cortical interneurons from human pluripotent stem cells, as well as the generation of mixed cultures using these induced neurons. The obtained cells display robust neuronal synchronous network activity as well as complex morphologies that are amenable to studies probing the molecular and cellular basis of disease mutations or other aspects of neuronal and synaptic development.
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Affiliation(s)
- Jay English
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts Amherst, Amherst, MA, USA
| | - Danny McSweeney
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts Amherst, Amherst, MA, USA
| | - Fumiko Ribbe
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Ethan Howell
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - ChangHui Pak
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA.
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Granerud G, Elvsåshagen T, Arntzen E, Juhasz K, Emilsen NM, Sønderby IE, Nærland T, Malt EA. A family study of symbolic learning and synaptic plasticity in autism spectrum disorder. Front Hum Neurosci 2022; 16:950922. [PMID: 36504626 PMCID: PMC9730282 DOI: 10.3389/fnhum.2022.950922] [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: 10/26/2022] [Accepted: 05/23/2022] [Indexed: 11/25/2022] Open
Abstract
The current study presents a male with autism spectrum disorder (ASD) and a 3q29 deletion, and three healthy first-degree relatives. Our magnetic resonance imaging (MRI) dataset included a healthy control subset. We describe a comprehensive multimodal approach, including equivalence class formation, neurocognitive testing, MRI, and electroencephalography (EEG)-based cortical plasticity, which can provide new insights into socio-communicative and learning impairments and neural underpinnings in ASD. On neurocognitive testing, the proband showed reduced processing speed, attending behavior, and executive function. He required more training trials in equivalence class training compared with family members and exhibited impaired priming of words compared with priming with images. The proband had smaller intracranial volume and surface area and a larger visual evoked potential (VEP) C1 amplitude than family members and intact long-term potentiation (LTP)-like visual cortex plasticity. Together, these results suggest that 3q29 deletion-related ASD is associated with impaired problem-solving strategies in complex socio-communicative and learning tasks, smaller intracranial and surface area, altered VEP amplitude, and normal LTP-like visual cortex plasticity. Further studies are needed to clarify whether this multimodal approach can be used to identify ASD subgroups with distinct neurobiological alterations and to uncover mechanisms underlying socio-communicative and learning impairments. Lay Summary: We studied learning, brain activity, and brain structure in a person with autism and a genetic aberration, and his close relatives. Compared with relatives, the person with autism required more training for learning, and visual learning was better than verbal learning. This person had some changes in the activity of the visual cortex, and the size and the surface area of the brain were reduced. Knowledge about learning and brain mechanisms is valuable for the development of training programs for individuals with autism.
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Affiliation(s)
- Guro Granerud
- Department of Adult Habilitation, Akershus University Hospital, Oslo, Norway,Department of Behavioral Science, Oslo Metropolitan University, Oslo, Norway,KG Jebsen Centre for Neurodevelopmental Disorders, University of Oslo, Oslo, Norway,*Correspondence: Guro Granerud
| | - Torbjørn Elvsåshagen
- Norwegian Centre for Mental Disorders Research, Oslo University Hospital, Oslo, Norway,Department of Neurology, Oslo University Hospital, Oslo, Norway,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Erik Arntzen
- Department of Behavioral Science, Oslo Metropolitan University, Oslo, Norway
| | - Katalin Juhasz
- Department of Adult Habilitation, Akershus University Hospital, Oslo, Norway
| | - Nina Merete Emilsen
- Department of Adult Habilitation, Akershus University Hospital, Oslo, Norway
| | - Ida Elken Sønderby
- KG Jebsen Centre for Neurodevelopmental Disorders, University of Oslo, Oslo, Norway,Norwegian Centre for Mental Disorders Research, Oslo University Hospital, Oslo, Norway,Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Terje Nærland
- KG Jebsen Centre for Neurodevelopmental Disorders, University of Oslo, Oslo, Norway,NevSom Department of Rare Disorders and Disabilities, Oslo University Hospital, Oslo, Norway
| | - Eva Albertsen Malt
- Department of Adult Habilitation, Akershus University Hospital, Oslo, Norway,Institute of Clinical Medicine, Campus Ahus, University of Oslo, Oslo, Norway
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Liu X, Hua F, Yang D, Lin Y, Zhang L, Ying J, Sheng H, Wang X. Roles of neuroligins in central nervous system development: focus on glial neuroligins and neuron neuroligins. Lab Invest 2022; 20:418. [PMID: 36088343 PMCID: PMC9463862 DOI: 10.1186/s12967-022-03625-y] [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: 07/25/2022] [Accepted: 09/01/2022] [Indexed: 11/10/2022]
Abstract
Neuroligins are postsynaptic cell adhesion molecules that are relevant to many neurodevelopmental disorders. They are differentially enriched at the postsynapse and interact with their presynaptic ligands, neurexins, whose differential binding to neuroligins has been shown to regulate synaptogenesis, transmission, and other synaptic properties. The proper functioning of functional networks in the brain depends on the proper connection between neuronal synapses. Impaired synaptogenesis or synaptic transmission results in synaptic dysfunction, and these synaptic pathologies are the basis for many neurodevelopmental disorders. Deletions or mutations in the neuroligins genes have been found in patients with both autism and schizophrenia. It is because of the important role of neuroligins in synaptic connectivity and synaptic dysfunction that studies on neuroligins in the past have mainly focused on their expression in neurons. As studies on the expression of genes specific to various cells of the central nervous system deepened, neuroligins were found to be expressed in non-neuronal cells as well. In the central nervous system, glial cells are the most representative non-neuronal cells, which can also express neuroligins in large amounts, especially astrocytes and oligodendrocytes, and they are involved in the regulation of synaptic function, as are neuronal neuroligins. This review examines the mechanisms of neuron neuroligins and non-neuronal neuroligins in the central nervous system and also discusses the important role of neuroligins in the development of the central nervous system and neurodevelopmental disorders from the perspective of neuronal neuroligins and glial neuroligins.
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9
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Lim D, Kim D, Um JW, Ko J. Reassessing synaptic adhesion pathways. Trends Neurosci 2022; 45:517-528. [DOI: 10.1016/j.tins.2022.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 04/12/2022] [Accepted: 04/19/2022] [Indexed: 01/19/2023]
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10
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Gatford NJF, Deans PJM, Duarte RRR, Chennell G, Sellers KJ, Raval P, Srivastava DP. Neuroligin-3 and neuroligin-4X form nanoscopic clusters and regulate growth cone organization and size. Hum Mol Genet 2022; 31:674-691. [PMID: 34542148 PMCID: PMC8895740 DOI: 10.1093/hmg/ddab277] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/25/2021] [Accepted: 09/13/2021] [Indexed: 12/01/2022] Open
Abstract
The cell-adhesion proteins neuroligin-3 and neuroligin-4X (NLGN3/4X) have well described roles in synapse formation. NLGN3/4X are also expressed highly during neurodevelopment. However, the role these proteins play during this period is unknown. Here we show that NLGN3/4X localized to the leading edge of growth cones where it promoted neuritogenesis in immature human neurons. Super-resolution microscopy revealed that NLGN3/4X clustering induced growth cone enlargement and influenced actin filament organization. Critically, these morphological effects were not induced by autism spectrum disorder (ASD)-associated NLGN3/4X variants. Finally, actin regulators p21-activated kinase 1 and cofilin were found to be activated by NLGN3/4X and involved in mediating the effects of these adhesion proteins on actin filaments, growth cones and neuritogenesis. These data reveal a novel role for NLGN3 and NLGN4X in the development of neuronal architecture, which may be altered in the presence of ASD-associated variants.
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Affiliation(s)
- Nicholas J F Gatford
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, UK
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - P J Michael Deans
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, UK
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Rodrigo R R Duarte
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, UK
| | - George Chennell
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, UK
| | - Katherine J Sellers
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, UK
| | - Pooja Raval
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, UK
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Deepak P Srivastava
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, UK
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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Neuroligin-3 Regulates Excitatory Synaptic Transmission and EPSP-Spike Coupling in the Dentate Gyrus In Vivo. Mol Neurobiol 2021; 59:1098-1111. [PMID: 34845591 PMCID: PMC8857112 DOI: 10.1007/s12035-021-02663-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 11/22/2021] [Indexed: 11/27/2022]
Abstract
Neuroligin-3 (Nlgn3), a neuronal adhesion protein implicated in autism spectrum disorder (ASD), is expressed at excitatory and inhibitory postsynapses and hence may regulate neuronal excitation/inhibition balance. To test this hypothesis, we recorded field excitatory postsynaptic potentials (fEPSPs) in the dentate gyrus of Nlgn3 knockout (KO) and wild-type mice. Synaptic transmission evoked by perforant path stimulation was reduced in KO mice, but coupling of the fEPSP to the population spike was increased, suggesting a compensatory change in granule cell excitability. These findings closely resemble those in neuroligin-1 (Nlgn1) KO mice and could be partially explained by the reduction in Nlgn1 levels we observed in hippocampal synaptosomes from Nlgn3 KO mice. However, unlike Nlgn1, Nlgn3 is not necessary for long-term potentiation. We conclude that while Nlgn1 and Nlgn3 have distinct functions, both are required for intact synaptic transmission in the mouse dentate gyrus. Our results indicate that interactions between neuroligins may play an important role in regulating synaptic transmission and that ASD-related neuroligin mutations may also affect the synaptic availability of other neuroligins.
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12
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Ali H, Marth L, Krueger-Burg D. Neuroligin-2 as a central organizer of inhibitory synapses in health and disease. Sci Signal 2020; 13:13/663/eabd8379. [DOI: 10.1126/scisignal.abd8379] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Postsynaptic organizational protein complexes play central roles both in orchestrating synapse formation and in defining the functional properties of synaptic transmission that together shape the flow of information through neuronal networks. A key component of these organizational protein complexes is the family of synaptic adhesion proteins called neuroligins. Neuroligins form transsynaptic bridges with presynaptic neurexins to regulate various aspects of excitatory and inhibitory synaptic transmission. Neuroligin-2 (NLGN2) is the only member that acts exclusively at GABAergic inhibitory synapses. Altered expression and mutations in NLGN2 and several of its interacting partners are linked to cognitive and psychiatric disorders, including schizophrenia, autism, and anxiety. Research on NLGN2 has fundamentally shaped our understanding of the molecular architecture of inhibitory synapses. Here, we discuss the current knowledge on the molecular and cellular functions of mammalian NLGN2 and its role in the neuronal circuitry that regulates behavior in rodents and humans.
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Affiliation(s)
- Heba Ali
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
- Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, University of Göttingen, 37077 Göttingen, Germany
| | - Lena Marth
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Dilja Krueger-Burg
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, 37075 Göttingen, Germany
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An Autism-Associated Mutation Impairs Neuroligin-4 Glycosylation and Enhances Excitatory Synaptic Transmission in Human Neurons. J Neurosci 2020; 41:392-407. [PMID: 33268543 DOI: 10.1523/jneurosci.0404-20.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 11/18/2020] [Accepted: 11/20/2020] [Indexed: 02/06/2023] Open
Abstract
Neuroligins (NLGNs) are a class of postsynaptic cell adhesion molecules that interact with presynaptic neurexins (NRXNs) and regulate synapse function. NLGN4 is a member of the NLGN family and consists of a unique amino acid sequence in humans that is not evolutionarily well conserved in rodents. The human-specific NLGN4 gene has been reported to be mutated in many patients with autism and other neurodevelopmental disorders. However, it remained unclear how these mutations might alter the molecular properties of NLGN4 and affect synaptic transmission in human neurons. Here, we describe a severely autistic male patient carrying a single amino acid substitution (R101Q) in the NLGN4 gene. When expressed in HEK293 cells, the R101Q mutation in NLGN4 did not affect its binding affinity for NRXNs or its capacity to form homodimers. This mutation, however, impaired the maturation of NLGN4 protein by inhibiting N-linked glycosylation at an adjacent residue (N102), which is conserved in all NLGNs. As a result, the R101Q substitution significantly decreased the surface trafficking of NLGN4 and increased its retention in the endoplasmic reticulum and Golgi apparatus. In human neurons derived from male stem cell lines, the R101Q mutation also similarly reduced the synaptic localization of NLGN4, resulting in a loss-of-function phenotype. This mutation-induced trafficking defect substantially diminished the ability of NLGN4 to form excitatory synapses and modulate their functional properties. Viewed together, our findings suggest that the R101Q mutation is pathogenic for NLGN4 and can lead to synaptic dysfunction in autism.
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Tien CW, Yu B, Huang M, Stepien KP, Sugita K, Xie X, Han L, Monnier PP, Zhen M, Rizo J, Gao S, Sugita S. Open syntaxin overcomes exocytosis defects of diverse mutants in C. elegans. Nat Commun 2020; 11:5516. [PMID: 33139696 PMCID: PMC7606450 DOI: 10.1038/s41467-020-19178-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 10/01/2020] [Indexed: 11/09/2022] Open
Abstract
Assembly of SNARE complexes that mediate neurotransmitter release requires opening of a ‘closed’ conformation of UNC-64/syntaxin. Rescue of unc-13/Munc13 mutant phenotypes by overexpressed open UNC-64/syntaxin suggested a specific function of UNC-13/Munc13 in opening UNC-64/ syntaxin. Here, we revisit the effects of open unc-64/syntaxin by generating knockin (KI) worms. The KI animals exhibit enhanced spontaneous and evoked exocytosis compared to WT animals. Unexpectedly, the open syntaxin KI partially suppresses exocytosis defects of various mutants, including snt-1/synaptotagmin, unc-2/P/Q/N-type Ca2+ channel alpha-subunit and unc-31/CAPS, in addition to unc-13/Munc13 and unc-10/RIM, and enhanced exocytosis in tom-1/Tomosyn mutants. However, open syntaxin aggravates the defects of unc-18/Munc18 mutants. Correspondingly, open syntaxin partially bypasses the requirement of Munc13 but not Munc18 for liposome fusion. Our results show that facilitating opening of syntaxin enhances exocytosis in a wide range of genetic backgrounds, and may provide a general means to enhance synaptic transmission in normal and disease states. Opening of the UNC-64/syntaxin closed conformation by UNC-13/Munc13 to form the neuronal SNARE complex is critical for neurotransmitter release. Here the authors show that facilitating the opening of syntaxin enhances exocytosis not only in unc-13 nulls as well as in diverse C. elegans mutants.
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Affiliation(s)
- Chi-Wei Tien
- Division of Fundamental Neurobiology, Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada, M5T 2S8.,Faculty of Medicine, Department of Physiology, University of Toronto, Toronto, Ontario, Canada, M5S 1A8
| | - Bin Yu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Mengjia Huang
- Division of Fundamental Neurobiology, Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada, M5T 2S8.,Faculty of Medicine, Department of Physiology, University of Toronto, Toronto, Ontario, Canada, M5S 1A8
| | - Karolina P Stepien
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kyoko Sugita
- Division of Genetics and Development, Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada, M5T 2S8
| | - Xiaoyu Xie
- Division of Fundamental Neurobiology, Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada, M5T 2S8.,Department of Anesthesiology, Dalian Medical University, Dalian, Liaoning, China
| | - Liping Han
- Department of Anesthesiology, Dalian Medical University, Dalian, Liaoning, China.,Department of Anesthesiology, Dalian Municipal Friendship Hospital, Dalian Medical University, Dalian, Liaoning, China
| | - Philippe P Monnier
- Faculty of Medicine, Department of Physiology, University of Toronto, Toronto, Ontario, Canada, M5S 1A8.,Division of Genetics and Development, Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada, M5T 2S8.,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada, M5S 1A8
| | - Mei Zhen
- Faculty of Medicine, Department of Physiology, University of Toronto, Toronto, Ontario, Canada, M5S 1A8.,Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada, M5G 1X5.,Faculty of Medicine, Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada, M5S 1A8
| | - Josep Rizo
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA. .,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA. .,Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
| | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Shuzo Sugita
- Division of Fundamental Neurobiology, Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada, M5T 2S8. .,Faculty of Medicine, Department of Physiology, University of Toronto, Toronto, Ontario, Canada, M5S 1A8.
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15
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Nguyen TA, Lehr AW, Roche KW. Neuroligins and Neurodevelopmental Disorders: X-Linked Genetics. Front Synaptic Neurosci 2020; 12:33. [PMID: 32848696 PMCID: PMC7431521 DOI: 10.3389/fnsyn.2020.00033] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/22/2020] [Indexed: 12/24/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder that results in social-communication impairments, as well as restricted and repetitive behaviors. Moreover, ASD is more prevalent in males, with a male to female ratio of 4 to 1. Although the underlying etiology of ASD is generally unknown, recent advances in genome sequencing have facilitated the identification of a host of associated genes. Among these, synaptic proteins such as cell adhesion molecules have been strongly linked with ASD. Interestingly, many large genome sequencing studies exclude sex chromosomes, which leads to a shift in focus toward autosomal genes as targets for ASD research. However, there are many genes on the X chromosome that encode synaptic proteins, including strong candidate genes. Here, we review findings regarding two members of the neuroligin (NLGN) family of postsynaptic adhesion molecules, NLGN3 and NLGN4. Neuroligins have multiple isoforms (NLGN1-4), which are both autosomal and sex-linked. The sex-linked genes, NLGN3 and NLGN4, are both on the X chromosome and were among the first few genes to be linked with ASD and intellectual disability (ID). In addition, there is a less studied human neuroligin on the Y chromosome, NLGN4Y, which forms an X-Y pair with NLGN4X. We will discuss recent findings of these neuroligin isoforms regarding function at the synapse in both rodent models and human-derived differentiated neurons, and highlight the exciting challenges moving forward to a better understanding of ASD/ID.
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Affiliation(s)
- Thien A. Nguyen
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
- Department of Pharmacology and Physiology, Georgetown University, Washington, DC, United States
| | - Alexander W. Lehr
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Katherine W. Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
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16
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Keable R, Leshchyns'ka I, Sytnyk V. Trafficking and Activity of Glutamate and GABA Receptors: Regulation by Cell Adhesion Molecules. Neuroscientist 2020; 26:415-437. [PMID: 32449484 DOI: 10.1177/1073858420921117] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The efficient targeting of ionotropic receptors to postsynaptic sites is essential for the function of chemical excitatory and inhibitory synapses, constituting the majority of synapses in the brain. A growing body of evidence indicates that cell adhesion molecules (CAMs), which accumulate at synapses at the earliest stages of synaptogenesis, are critical for this process. A diverse variety of CAMs assemble into complexes with glutamate and GABA receptors and regulate the targeting of these receptors to the cell surface and synapses. Presynaptically localized CAMs provide an additional level of regulation, sending a trans-synaptic signal that can regulate synaptic strength at the level of receptor trafficking. Apart from controlling the numbers of receptors present at postsynaptic sites, CAMs can also influence synaptic strength by modulating the conductivity of single receptor channels. CAMs thus act to maintain basal synaptic transmission and are essential for many forms of activity dependent synaptic plasticity. These activities of CAMs may underlie the association between CAM gene mutations and synaptic pathology and represent fundamental mechanisms by which synaptic strength is dynamically tuned at both excitatory and inhibitory synapses.
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Affiliation(s)
- Ryan Keable
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Iryna Leshchyns'ka
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Vladimir Sytnyk
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia
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17
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Nguyen TA, Wu K, Pandey S, Lehr AW, Li Y, Bemben MA, Badger JD, Lauzon JL, Wang T, Zaghloul KA, Thurm A, Jain M, Lu W, Roche KW. A Cluster of Autism-Associated Variants on X-Linked NLGN4X Functionally Resemble NLGN4Y. Neuron 2020; 106:759-768.e7. [PMID: 32243781 DOI: 10.1016/j.neuron.2020.03.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 02/12/2020] [Accepted: 03/11/2020] [Indexed: 12/20/2022]
Abstract
Autism spectrum disorder (ASD) is more prevalent in males; however, the etiology for this sex bias is not well understood. Many mutations on X-linked cell adhesion molecule NLGN4X result in ASD or intellectual disability. NLGN4X is part of an X-Y pair, with NLGN4Y sharing ∼97% sequence homology. Using biochemistry, electrophysiology, and imaging, we show that NLGN4Y displays severe deficits in maturation, surface expression, and synaptogenesis regulated by one amino acid difference with NLGN4X. Furthermore, we identify a cluster of ASD-associated mutations surrounding the critical amino acid in NLGN4X, and these mutations phenocopy NLGN4Y. We show that NLGN4Y cannot compensate for the functional deficits observed in ASD-associated NLGN4X mutations. Altogether, our data reveal a potential pathogenic mechanism for male bias in NLGN4X-associated ASD.
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Affiliation(s)
- Thien A Nguyen
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA; Department of Pharmacology and Physiology, Georgetown University, Washington DC 20057, USA
| | - Kunwei Wu
- Synapse and Neural Circuit Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Saurabh Pandey
- Synapse and Neural Circuit Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alexander W Lehr
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yan Li
- Protein/Peptide Sequencing Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael A Bemben
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - John D Badger
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Julie L Lauzon
- Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Tongguang Wang
- Translational Neuroscience Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kareem A Zaghloul
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Audrey Thurm
- National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mahim Jain
- Department of Bone and OI, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Wei Lu
- Synapse and Neural Circuit Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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18
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McDiarmid TA, Belmadani M, Liang J, Meili F, Mathews EA, Mullen GP, Hendi A, Wong WR, Rand JB, Mizumoto K, Haas K, Pavlidis P, Rankin CH. Systematic phenomics analysis of autism-associated genes reveals parallel networks underlying reversible impairments in habituation. Proc Natl Acad Sci U S A 2020; 117:656-667. [PMID: 31754030 PMCID: PMC6968627 DOI: 10.1073/pnas.1912049116] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
A major challenge facing the genetics of autism spectrum disorders (ASDs) is the large and growing number of candidate risk genes and gene variants of unknown functional significance. Here, we used Caenorhabditis elegans to systematically functionally characterize ASD-associated genes in vivo. Using our custom machine vision system, we quantified 26 phenotypes spanning morphology, locomotion, tactile sensitivity, and habituation learning in 135 strains each carrying a mutation in an ortholog of an ASD-associated gene. We identified hundreds of genotype-phenotype relationships ranging from severe developmental delays and uncoordinated movement to subtle deficits in sensory and learning behaviors. We clustered genes by similarity in phenomic profiles and used epistasis analysis to discover parallel networks centered on CHD8•chd-7 and NLGN3•nlg-1 that underlie mechanosensory hyperresponsivity and impaired habituation learning. We then leveraged our data for in vivo functional assays to gauge missense variant effect. Expression of wild-type NLG-1 in nlg-1 mutant C. elegans rescued their sensory and learning impairments. Testing the rescuing ability of conserved ASD-associated neuroligin variants revealed varied partial loss of function despite proper subcellular localization. Finally, we used CRISPR-Cas9 auxin-inducible degradation to determine that phenotypic abnormalities caused by developmental loss of NLG-1 can be reversed by adult expression. This work charts the phenotypic landscape of ASD-associated genes, offers in vivo variant functional assays, and potential therapeutic targets for ASD.
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Affiliation(s)
- Troy A McDiarmid
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Manuel Belmadani
- Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2A1, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Joseph Liang
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Fabian Meili
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Eleanor A Mathews
- Genetic Models of Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Gregory P Mullen
- Biology Program, Oklahoma City University, Oklahoma City, OK 73106
| | - Ardalan Hendi
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Wan-Rong Wong
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | - James B Rand
- Genetic Models of Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Kota Mizumoto
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Kurt Haas
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Paul Pavlidis
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 2B5, Canada
- Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2A1, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Catharine H Rankin
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 2B5, Canada;
- Department of Psychology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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19
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Al-Ayadhi LY, Qasem HY, Alghamdi HAM, Elamin NE. Elevated Plasma X-Linked Neuroligin 4 Expression Is Associated with Autism Spectrum Disorder. Med Princ Pract 2020; 29:480-485. [PMID: 32155636 PMCID: PMC7511674 DOI: 10.1159/000507081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 03/09/2020] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES In this study, we compared plasma levels of neuroligin 4 (NLGN4) in children with autism versus matched healthy controls to examine a possible correlation between plasma NLGN4 and degree of autism severity as well as social impairment in autistic patients. SUBJECTS AND METHODS 88 autistic patients aged 3-12 years and 33 age- and sex-matched controls aged 3-9 years were recruited. Plasma levels of NLGN4 were determined using a commercial enzyme-linked immunoassay (ELISA). The Childhood Autism Rating Scale (CARS) and the Social Responsiveness Scale (SRS) were used to assess cognitive dysfunction and social impairment in autistic patients. RESULTS Plasma levels of NLGN4 were significantly higher (p = 0.001) in autistic children than in healthy controls. Despite alterations in the levels of NLGN4 in the subgroups of the autistic children, no correlation between plasma concentration of NLGN4 and cognitive problems or social impairment was observed (p> 0.05). CONCLUSION Increased plasma concentrations of NLGN4 may play a role in the pathogenesis of autism, and it could be a valuable biomarker for autism. Further studies with larger sample sizes are warranted to validate this finding and also to explore the potential links between NLGN4 and the features of autism.
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Affiliation(s)
- Laila Y Al-Ayadhi
- Autism Research and Treatment Center, Faculty of Medicine, King Saud University, Riyadh, Saudi Arabia,
- Department of Physiology, Faculty of Medicine, King Saud University, Riyadh, Saudi Arabia,
| | - Hanan Y Qasem
- Autism Research and Treatment Center, Faculty of Medicine, King Saud University, Riyadh, Saudi Arabia
| | | | - Nadra E Elamin
- Autism Research and Treatment Center, Faculty of Medicine, King Saud University, Riyadh, Saudi Arabia
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20
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Bin NR, Huang M, Sugita S. Investigating the Role of SNARE Proteins in Trafficking of Postsynaptic Receptors using Conditional Knockouts. Neuroscience 2019; 420:22-31. [DOI: 10.1016/j.neuroscience.2018.11.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 11/15/2018] [Accepted: 11/16/2018] [Indexed: 11/30/2022]
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21
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Marro SG, Chanda S, Yang N, Janas JA, Valperga G, Trotter J, Zhou B, Merrill S, Yousif I, Shelby H, Vogel H, Kalani MYS, Südhof TC, Wernig M. Neuroligin-4 Regulates Excitatory Synaptic Transmission in Human Neurons. Neuron 2019; 103:617-626.e6. [PMID: 31257103 DOI: 10.1016/j.neuron.2019.05.043] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 04/17/2019] [Accepted: 05/28/2019] [Indexed: 12/26/2022]
Abstract
The autism-associated synaptic-adhesion gene Neuroligin-4 (NLGN4) is poorly conserved evolutionarily, limiting conclusions from Nlgn4 mouse models for human cells. Here, we show that the cellular and subcellular expression of human and murine Neuroligin-4 differ, with human Neuroligin-4 primarily expressed in cerebral cortex and localized to excitatory synapses. Overexpression of NLGN4 in human embryonic stem cell-derived neurons resulted in an increase in excitatory synapse numbers but a remarkable decrease in synaptic strength. Human neurons carrying the syndromic autism mutation NLGN4-R704C also formed more excitatory synapses but with increased functional synaptic transmission due to a postsynaptic mechanism, while genetic loss of NLGN4 did not significantly affect synapses in the human neurons analyzed. Thus, the NLGN4-R704C mutation represents a change-of-function mutation. Our work reveals contrasting roles of NLGN4 in human and mouse neurons, suggesting that human evolution has impacted even fundamental cell biological processes generally assumed to be highly conserved.
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Affiliation(s)
- Samuele G Marro
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Soham Chanda
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nan Yang
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Justyna A Janas
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Giulio Valperga
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Justin Trotter
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Bo Zhou
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sean Merrill
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Issa Yousif
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Hannah Shelby
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Hannes Vogel
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - M Yashar S Kalani
- Departments of Neurosurgery and Neuroscience, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Marius Wernig
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
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22
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Martucci LL, Amar M, Chaussenot R, Benet G, Bauer O, de Zélicourt A, Nosjean A, Launay JM, Callebert J, Sebrié C, Galione A, Edeline JM, de la Porte S, Fossier P, Granon S, Vaillend C, Cancela JM. A multiscale analysis in CD38 -/- mice unveils major prefrontal cortex dysfunctions. FASEB J 2019; 33:5823-5835. [PMID: 30844310 DOI: 10.1096/fj.201800489r] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Autism spectrum disorder (ASD) is characterized by early onset of behavioral and cognitive alterations. Low plasma levels of oxytocin (OT) have also been found in ASD patients; recently, a critical role for the enzyme CD38 in the regulation of OT release was demonstrated. CD38 is important in regulating several Ca2+-dependent pathways, but beyond its role in regulating OT secretion, it is not known whether a deficit in CD38 expression leads to functional modifications of the prefrontal cortex (PFC), a structure involved in social behavior. Here, we report that CD38-/- male mice show an abnormal cortex development, an excitation-inhibition balance shifted toward a higher excitation, and impaired synaptic plasticity in the PFC such as those observed in various mouse models of ASD. We also show that a lack of CD38 alters social behavior and emotional responses. Finally, examining neuromodulators known to control behavioral flexibility, we found elevated monoamine levels in the PFC of CD38-/- adult mice. Overall, our study unveiled major changes in PFC physiologic mechanisms and provides new evidence that the CD38-/- mouse could be a relevant model to study pathophysiological brain mechanisms of mental disorders such as ASD.-Martucci, L. L., Amar, M., Chaussenot, R., Benet, G., Bauer, O., de Zélicourt, A., Nosjean, A., Launay, J.-M., Callebert, J., Sebrié, C., Galione, A., Edeline, J.-M., de la Porte, S., Fossier, P., Granon, S., Vaillend, C., Cancela, J.-M., A multiscale analysis in CD38-/- mice unveils major prefrontal cortex dysfunctions.
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Affiliation(s)
- Lora L Martucci
- Neuroscience Paris-Saclay Institute (Neuro-PSI), Unité Mixte de Recherche (UMR) 9197, Paris-Sud University, Paris-Saclay University, Orsay, France.,INSERM Unité 1179, Handicap Neuromusculaire: Physiologie, Biothérapie et Pharmacologie Appliquées, Unité de Formation et de Recherche (UFR) des Sciences de la Santé Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Montigny-le-Bretonneux, France
| | - Muriel Amar
- Neuroscience Paris-Saclay Institute (Neuro-PSI), Unité Mixte de Recherche (UMR) 9197, Paris-Sud University, Paris-Saclay University, Orsay, France
| | - Remi Chaussenot
- Neuroscience Paris-Saclay Institute (Neuro-PSI), Unité Mixte de Recherche (UMR) 9197, Paris-Sud University, Paris-Saclay University, Orsay, France
| | - Gabriel Benet
- Neuroscience Paris-Saclay Institute (Neuro-PSI), Unité Mixte de Recherche (UMR) 9197, Paris-Sud University, Paris-Saclay University, Orsay, France
| | - Oscar Bauer
- Neuroscience Paris-Saclay Institute (Neuro-PSI), Unité Mixte de Recherche (UMR) 9197, Paris-Sud University, Paris-Saclay University, Orsay, France.,Génétique Humaine et Fonctions Cognitives, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 3571, Gènes, Synapses et Cognition, CNRS, Institut Pasteur, Paris, France
| | - Antoine de Zélicourt
- Neuroscience Paris-Saclay Institute (Neuro-PSI), Unité Mixte de Recherche (UMR) 9197, Paris-Sud University, Paris-Saclay University, Orsay, France.,INSERM Unité 1179, Handicap Neuromusculaire: Physiologie, Biothérapie et Pharmacologie Appliquées, Unité de Formation et de Recherche (UFR) des Sciences de la Santé Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Montigny-le-Bretonneux, France
| | - Anne Nosjean
- Neuroscience Paris-Saclay Institute (Neuro-PSI), Unité Mixte de Recherche (UMR) 9197, Paris-Sud University, Paris-Saclay University, Orsay, France
| | | | | | - Catherine Sebrié
- Imagerie par Résonance Magnétique Médicale et Multimodalité (IR4M) Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 8081, Paris-Sud University, Paris-Saclay University, CNRS, Orsay, France
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Jean-Marc Edeline
- Neuroscience Paris-Saclay Institute (Neuro-PSI), Unité Mixte de Recherche (UMR) 9197, Paris-Sud University, Paris-Saclay University, Orsay, France
| | - Sabine de la Porte
- INSERM Unité 1179, Handicap Neuromusculaire: Physiologie, Biothérapie et Pharmacologie Appliquées, Unité de Formation et de Recherche (UFR) des Sciences de la Santé Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Montigny-le-Bretonneux, France
| | - Philippe Fossier
- Neuroscience Paris-Saclay Institute (Neuro-PSI), Unité Mixte de Recherche (UMR) 9197, Paris-Sud University, Paris-Saclay University, Orsay, France
| | - Sylvie Granon
- Neuroscience Paris-Saclay Institute (Neuro-PSI), Unité Mixte de Recherche (UMR) 9197, Paris-Sud University, Paris-Saclay University, Orsay, France
| | - Cyrille Vaillend
- Neuroscience Paris-Saclay Institute (Neuro-PSI), Unité Mixte de Recherche (UMR) 9197, Paris-Sud University, Paris-Saclay University, Orsay, France
| | - José-Manuel Cancela
- Neuroscience Paris-Saclay Institute (Neuro-PSI), Unité Mixte de Recherche (UMR) 9197, Paris-Sud University, Paris-Saclay University, Orsay, France
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Zhang XC, Shu LQ, Zhao XS, Li XK. Autism spectrum disorders: autistic phenotypes and complicated mechanisms. World J Pediatr 2019; 15:17-25. [PMID: 30607884 DOI: 10.1007/s12519-018-0210-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 11/12/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Autism spectrum disorder (ASD), a pervasive developmental neurological disorder, is characterized by impairments in social interaction and communication, and stereotyped, repetitive patterns of interests or behaviors. The mechanism of ASDs is complex, and genetic components and epigenetic modifications play important roles. In this review, we summarized the recent progresses of ASDs focusing on the genetic and epigenetic mechanisms. We also briefly discussed current animal models of ASD and the application of high-throughput sequencing technologies in studying ASD. DATA SOURCES Original research articles and literature reviews published in PubMed-indexed journals. RESULTS Individuals with ASDs exhibit a set of phenotypes including neurological alteration. Genetic components including gene mutation, copy-number variations, and epigenetic modifications play important and diverse roles in ASDs. The establishment of animal models and development of new-generation sequencing technologies have contributed to reveal the complicated mechanisms underlying autistic phenotypes. CONCLUSIONS Dramatic progress has been made for understanding the roles of genetic and epigenetic components in ASD. Future basic and translational studies should be carried out towards those candidate therapeutic targets.
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Affiliation(s)
- Xi-Cheng Zhang
- Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
- Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou, 310029, China
| | - Li-Qi Shu
- School of Medicine and Health Sciences, George Washington University, Washington, DC, USA
| | - Xing-Sen Zhao
- Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
- Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou, 310029, China
| | - Xue-Kun Li
- Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.
- Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou, 310029, China.
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24
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Ha HTT, Leal-Ortiz S, Lalwani K, Kiyonaka S, Hamachi I, Mysore SP, Montgomery JM, Garner CC, Huguenard JR, Kim SA. Shank and Zinc Mediate an AMPA Receptor Subunit Switch in Developing Neurons. Front Mol Neurosci 2018; 11:405. [PMID: 30524232 PMCID: PMC6256285 DOI: 10.3389/fnmol.2018.00405] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/15/2018] [Indexed: 11/18/2022] Open
Abstract
During development, pyramidal neurons undergo dynamic regulation of AMPA receptor (AMPAR) subunit composition and density to help drive synaptic plasticity and maturation. These normal developmental changes in AMPARs are particularly vulnerable to risk factors for Autism Spectrum Disorders (ASDs), which include loss or mutations of synaptic proteins and environmental insults, such as dietary zinc deficiency. Here, we show how Shank2 and Shank3 mediate a zinc-dependent regulation of AMPAR function and subunit switch from GluA2-lacking to GluA2-containing AMPARs. Over development, we found a concomitant increase in Shank2 and Shank3 with GluA2 at synapses, implicating these molecules as potential players in AMPAR maturation. Since Shank activation and function require zinc, we next studied whether neuronal activity regulated postsynaptic zinc at glutamatergic synapses. Zinc was found to increase transiently and reversibly with neuronal depolarization at synapses, which could affect Shank and AMPAR localization and activity. Elevated zinc induced multiple functional changes in AMPAR, indicative of a subunit switch. Specifically, zinc lengthened the decay time of AMPAR-mediated synaptic currents and reduced their inward rectification in young hippocampal neurons. Mechanistically, both Shank2 and Shank3 were necessary for the zinc-sensitive enhancement of AMPAR-mediated synaptic transmission and act in concert to promote removal of GluA1 while enhancing recruitment of GluA2 at pre-existing Shank puncta. These findings highlight a cooperative local dynamic regulation of AMPAR subunit switch controlled by zinc signaling through Shank2 and Shank3 to shape the biophysical properties of developing glutamatergic synapses. Given the zinc sensitivity of young neurons and its dependence on Shank2 and Shank3, genetic mutations and/or environmental insults during early development could impair synaptic maturation and circuit formation that underlie ASD etiology.
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Affiliation(s)
- Huong T T Ha
- Department of Neurology & Neurological Sciences, School of Medicine, Stanford University, Stanford, CA, United States.,Neurosciences Graduate Program, School of Medicine, Stanford University, Stanford, CA, United States
| | - Sergio Leal-Ortiz
- Department of Material Science & Engineering, School of Engineering, Stanford University, Stanford, CA, United States
| | - Kriti Lalwani
- Department of Neurology & Neurological Sciences, School of Medicine, Stanford University, Stanford, CA, United States
| | - Shigeki Kiyonaka
- Department of Synthetic Chemistry & Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Itaru Hamachi
- Department of Synthetic Chemistry & Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Shreesh P Mysore
- Department of Psychological & Brain Sciences, Johns Hopkins University, Baltimore, MD, United States
| | - Johanna M Montgomery
- Department of Physiology and Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - Craig C Garner
- German Center for Neurodegenerative Diseases (DZNE), Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - John R Huguenard
- Department of Neurology & Neurological Sciences, School of Medicine, Stanford University, Stanford, CA, United States
| | - Sally A Kim
- Department of Neurology & Neurological Sciences, School of Medicine, Stanford University, Stanford, CA, United States
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25
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Groeneweg FL, Trattnig C, Kuhse J, Nawrotzki RA, Kirsch J. Gephyrin: a key regulatory protein of inhibitory synapses and beyond. Histochem Cell Biol 2018; 150:489-508. [DOI: 10.1007/s00418-018-1725-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2018] [Indexed: 12/26/2022]
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26
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Neuroligin 1, 2, and 3 Regulation at the Synapse: FMRP-Dependent Translation and Activity-Induced Proteolytic Cleavage. Mol Neurobiol 2018; 56:2741-2759. [PMID: 30056576 PMCID: PMC6459971 DOI: 10.1007/s12035-018-1243-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 07/15/2018] [Indexed: 12/19/2022]
Abstract
Neuroligins (NLGNs) are cell adhesion molecules located on the postsynaptic side of the synapse that interact with their presynaptic partners neurexins to maintain trans-synaptic connection. Fragile X syndrome (FXS) is a common neurodevelopmental disease that often co-occurs with autism and is caused by the lack of fragile X mental retardation protein (FMRP) expression. To gain an insight into the molecular interactions between the autism-related genes, we sought to determine whether FMRP controls the synaptic levels of NLGNs. We show evidences that FMRP associates with Nlgn1, Nlgn2, and Nlgn3 mRNAs in vitro in both synaptoneurosomes and neuronal cultures. Next, we confirm local translation of Nlgn1, Nlgn2, and Nlgn3 mRNAs to be synaptically regulated by FMRP. As a consequence of elevated Nlgns mRNA translation Fmr1 KO mice exhibit increased incorporation of NLGN1 and NLGN3 into the postsynaptic membrane. Finally, we show that neuroligins synaptic level is precisely and dynamically regulated by their rapid proteolytic cleavage upon NMDA receptor stimulation in both wild type and Fmr1 KO mice. In aggregate, our study provides a novel approach to understand the molecular basis of FXS by linking the dysregulated synaptic expression of NLGNs with FMRP.
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27
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Wang X, Kery R, Xiong Q. Synaptopathology in autism spectrum disorders: Complex effects of synaptic genes on neural circuits. Prog Neuropsychopharmacol Biol Psychiatry 2018; 84:398-415. [PMID: 28986278 DOI: 10.1016/j.pnpbp.2017.09.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 09/05/2017] [Accepted: 09/26/2017] [Indexed: 01/03/2023]
Affiliation(s)
- Xinxing Wang
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY 11794, USA
| | - Rachel Kery
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY 11794, USA; Medical Scientist Training Program (MSTP), Stony Brook University, Stony Brook, NY 11794, USA
| | - Qiaojie Xiong
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY 11794, USA.
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28
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Zhang B, Gokce O, Hale WD, Brose N, Südhof TC. Autism-associated neuroligin-4 mutation selectively impairs glycinergic synaptic transmission in mouse brainstem synapses. J Exp Med 2018; 215:1543-1553. [PMID: 29724786 PMCID: PMC5987923 DOI: 10.1084/jem.20172162] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 03/25/2018] [Accepted: 04/24/2018] [Indexed: 01/01/2023] Open
Abstract
Loss-of-function mutations of the human postsynaptic cell-adhesion protein neuroligin-4 have been repeatedly associated with autism, but the precise synaptic function of neuroligin-4 that may account for its role in autism remains unclear. Here, we show in murine brainstem synapses that neuroligin-4 is selectively required for glycinergic synaptic transmission in mice. In human patients, loss-of-function mutations of the postsynaptic cell-adhesion molecule neuroligin-4 were repeatedly identified as monogenetic causes of autism. In mice, neuroligin-4 deletions caused autism-related behavioral impairments and subtle changes in synaptic transmission, and neuroligin-4 was found, at least in part, at glycinergic synapses. However, low expression levels precluded a comprehensive analysis of neuroligin-4 localization, and overexpression of neuroligin-4 puzzlingly impaired excitatory but not inhibitory synaptic function. As a result, the function of neuroligin-4 remains unclear, as does its relation to other neuroligins. To clarify these issues, we systematically examined the function of neuroligin-4, focusing on excitatory and inhibitory inputs to defined projection neurons of the mouse brainstem as central model synapses. We show that loss of neuroligin-4 causes a profound impairment of glycinergic but not glutamatergic synaptic transmission and a decrease in glycinergic synapse numbers. Thus, neuroligin-4 is essential for the organization and/or maintenance of glycinergic synapses.
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Affiliation(s)
- Bo Zhang
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
| | - Ozgun Gokce
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
| | - W Dylan Hale
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
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29
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Südhof TC. Synaptic Neurexin Complexes: A Molecular Code for the Logic of Neural Circuits. Cell 2017; 171:745-769. [PMID: 29100073 DOI: 10.1016/j.cell.2017.10.024] [Citation(s) in RCA: 485] [Impact Index Per Article: 69.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 10/04/2017] [Accepted: 10/15/2017] [Indexed: 10/18/2022]
Abstract
Synapses are specialized junctions between neurons in brain that transmit and compute information, thereby connecting neurons into millions of overlapping and interdigitated neural circuits. Here, we posit that the establishment, properties, and dynamics of synapses are governed by a molecular logic that is controlled by diverse trans-synaptic signaling molecules. Neurexins, expressed in thousands of alternatively spliced isoforms, are central components of this dynamic code. Presynaptic neurexins regulate synapse properties via differential binding to multifarious postsynaptic ligands, such as neuroligins, cerebellin/GluD complexes, and latrophilins, thereby shaping the input/output relations of their resident neural circuits. Mutations in genes encoding neurexins and their ligands are associated with diverse neuropsychiatric disorders, especially schizophrenia, autism, and Tourette syndrome. Thus, neurexins nucleate an overall trans-synaptic signaling network that controls synapse properties, which thereby determines the precise responses of synapses to spike patterns in a neuron and circuit and which is vulnerable to impairments in neuropsychiatric disorders.
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Affiliation(s)
- Thomas C Südhof
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University Medical School, 265 Campus Drive, CA 94305-5453, USA.
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30
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Varghese M, Keshav N, Jacot-Descombes S, Warda T, Wicinski B, Dickstein DL, Harony-Nicolas H, De Rubeis S, Drapeau E, Buxbaum JD, Hof PR. Autism spectrum disorder: neuropathology and animal models. Acta Neuropathol 2017; 134:537-566. [PMID: 28584888 PMCID: PMC5693718 DOI: 10.1007/s00401-017-1736-4] [Citation(s) in RCA: 301] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/30/2017] [Accepted: 05/31/2017] [Indexed: 12/13/2022]
Abstract
Autism spectrum disorder (ASD) has a major impact on the development and social integration of affected individuals and is the most heritable of psychiatric disorders. An increase in the incidence of ASD cases has prompted a surge in research efforts on the underlying neuropathologic processes. We present an overview of current findings in neuropathology studies of ASD using two investigational approaches, postmortem human brains and ASD animal models, and discuss the overlap, limitations, and significance of each. Postmortem examination of ASD brains has revealed global changes including disorganized gray and white matter, increased number of neurons, decreased volume of neuronal soma, and increased neuropil, the last reflecting changes in densities of dendritic spines, cerebral vasculature and glia. Both cortical and non-cortical areas show region-specific abnormalities in neuronal morphology and cytoarchitectural organization, with consistent findings reported from the prefrontal cortex, fusiform gyrus, frontoinsular cortex, cingulate cortex, hippocampus, amygdala, cerebellum and brainstem. The paucity of postmortem human studies linking neuropathology to the underlying etiology has been partly addressed using animal models to explore the impact of genetic and non-genetic factors clinically relevant for the ASD phenotype. Genetically modified models include those based on well-studied monogenic ASD genes (NLGN3, NLGN4, NRXN1, CNTNAP2, SHANK3, MECP2, FMR1, TSC1/2), emerging risk genes (CHD8, SCN2A, SYNGAP1, ARID1B, GRIN2B, DSCAM, TBR1), and copy number variants (15q11-q13 deletion, 15q13.3 microdeletion, 15q11-13 duplication, 16p11.2 deletion and duplication, 22q11.2 deletion). Models of idiopathic ASD include inbred rodent strains that mimic ASD behaviors as well as models developed by environmental interventions such as prenatal exposure to sodium valproate, maternal autoantibodies, and maternal immune activation. In addition to replicating some of the neuropathologic features seen in postmortem studies, a common finding in several animal models of ASD is altered density of dendritic spines, with the direction of the change depending on the specific genetic modification, age and brain region. Overall, postmortem neuropathologic studies with larger sample sizes representative of the various ASD risk genes and diverse clinical phenotypes are warranted to clarify putative etiopathogenic pathways further and to promote the emergence of clinically relevant diagnostic and therapeutic tools. In addition, as genetic alterations may render certain individuals more vulnerable to developing the pathological changes at the synapse underlying the behavioral manifestations of ASD, neuropathologic investigation using genetically modified animal models will help to improve our understanding of the disease mechanisms and enhance the development of targeted treatments.
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Affiliation(s)
- Merina Varghese
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Neha Keshav
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Sarah Jacot-Descombes
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Unit of Psychiatry, Department of Children and Teenagers, University Hospitals and School of Medicine, Geneva, CH-1205, Switzerland
| | - Tahia Warda
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Bridget Wicinski
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Dara L Dickstein
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Hala Harony-Nicolas
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Silvia De Rubeis
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Elodie Drapeau
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Joseph D Buxbaum
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Patrick R Hof
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA.
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
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Developmental plasticity shapes synaptic phenotypes of autism-associated neuroligin-3 mutations in the calyx of Held. Mol Psychiatry 2017; 22:1483-1491. [PMID: 27725662 PMCID: PMC5687809 DOI: 10.1038/mp.2016.157] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 07/08/2016] [Accepted: 07/27/2016] [Indexed: 01/21/2023]
Abstract
Neuroligins are postsynaptic cell-adhesion molecules that bind to presynaptic neurexins. Mutations in neuroligin-3 predispose to autism, but how such mutations affect synaptic function remains incompletely understood. Here we systematically examined the effect of three autism-associated mutations, the neuroligin-3 knockout, the R451C knockin, and the R704C knockin, on synaptic transmission in the calyx of Held, a central synapse ideally suited for high-resolution analyses of synaptic transmission. Surprisingly, germline knockout of neuroligin-3 did not alter synaptic transmission, whereas the neuroligin-3 R451C and R704C knockins decreased and increased, respectively, synaptic transmission. These puzzling results prompted us to ask whether neuroligin-3 mutant phenotypes may be reshaped by developmental plasticity. Indeed, conditional knockout of neuroligin-3 during late development produced a marked synaptic phenotype, whereas conditional knockout of neuroligin-3 during early development caused no detectable effect, mimicking the germline knockout. In canvassing potentially redundant candidate genes, we identified developmentally early expression of another synaptic neurexin ligand, cerebellin-1. Strikingly, developmentally early conditional knockout of cerebellin-1 only modestly impaired synaptic transmission, whereas in contrast to the individual single knockouts, developmentally early conditional double knockout of both cerebellin-1 and neuroligin-3 severely decreased synaptic transmission. Our data suggest an unanticipated mechanism of developmental compensation whereby cerebellin-1 and neuroligin-3 functionally occlude each other during development of calyx synapses. Thus, although acute manipulations more likely reveal basic gene functions, developmental plasticity can be a major factor in shaping the overall phenotypes of genetic neuropsychiatric disorders.
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32
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Wall MJ, Corrêa SAL. The mechanistic link between Arc/Arg3.1 expression and AMPA receptor endocytosis. Semin Cell Dev Biol 2017; 77:17-24. [PMID: 28890421 DOI: 10.1016/j.semcdb.2017.09.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/06/2017] [Accepted: 09/06/2017] [Indexed: 02/06/2023]
Abstract
The activity-regulated cytoskeleton associated protein (Arc/Arg3.1) plays a key role in determining synaptic strength through facilitation of AMPA receptor (AMPAR) endocytosis. Although there is considerable data on the mechanism by which Arc induction controls synaptic plasticity and learning behaviours, several key mechanistic questions remain. Here we review data on the link between Arc expression and the clathrin-mediated endocytic pathway which internalises AMPARs and discuss the significance of Arc binding to the clathrin adaptor protein 2 (AP-2) and to endophilin/dynamin. We consider which AMPAR subunits are selected for Arc-mediated internalisation, implications for synaptic function and consider Arc as a therapeutic target.
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Affiliation(s)
- Mark J Wall
- School of Life Sciences, University of Warwick, United Kingdom.
| | - Sonia A L Corrêa
- School of Pharmacy and Medical Sciences, Faculty of Life Sciences, University of Bradford, United Kingdom.
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33
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Functional significance of rare neuroligin 1 variants found in autism. PLoS Genet 2017; 13:e1006940. [PMID: 28841651 PMCID: PMC5571902 DOI: 10.1371/journal.pgen.1006940] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 07/21/2017] [Indexed: 12/14/2022] Open
Abstract
Genetic mutations contribute to the etiology of autism spectrum disorder (ASD), a common, heterogeneous neurodevelopmental disorder characterized by impairments in social interaction, communication, and repetitive and restricted patterns of behavior. Since neuroligin3 (NLGN3), a cell adhesion molecule at the neuronal synapse, was first identified as a risk gene for ASD, several additional variants in NLGN3 and NLGN4 were found in ASD patients. Moreover, synaptopathies are now known to cause several neuropsychiatric disorders including ASD. In humans, NLGNs consist of five family members, and neuroligin1 (NLGN1) is a major component forming a complex on excitatory glutamatergic synapses. However, the significance of NLGN1 in neuropsychiatric disorders remains unknown. Here, we systematically examine five missense variants of NLGN1 that were detected in ASD patients, and show molecular and cellular alterations caused by these variants. We show that a novel NLGN1 Pro89Leu (P89L) missense variant found in two ASD siblings leads to changes in cellular localization, protein degradation, and to the impairment of spine formation. Furthermore, we generated the knock-in P89L mice, and we show that the P89L heterozygote mice display abnormal social behavior, a core feature of ASD. These results, for the first time, implicate rare variants in NLGN1 as functionally significant and support that the NLGN synaptic pathway is of importance in the etiology of neuropsychiatric disorders. Autism spectrum disorder (ASD) is a childhood disorder manifested by abnormal social behavior, interests, and activities. The genetic contribution to ASD is higher than in other psychiatric disorders such as schizophrenia and mood disorders. Here, we found a novel mutation in NLGN1, a gene encoding a synaptic protein, in patients with ASD. We also developed a mouse model with this mutation, and showed that the model mouse exhibits abnormal social behavior. These results suggest that a rare variant in NLGN1 is functionally significant and support that the NLGN synaptic pathway may be important in the etiology of neuropsychiatric disorders. This humanized mouse model recapitulates some of the symptoms of patients with ASD and will serve as a valuable tool for therapeutic development.
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Krueger-Burg D, Papadopoulos T, Brose N. Organizers of inhibitory synapses come of age. Curr Opin Neurobiol 2017; 45:66-77. [DOI: 10.1016/j.conb.2017.04.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/05/2017] [Indexed: 12/14/2022]
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35
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Jang S, Lee H, Kim E. Synaptic adhesion molecules and excitatory synaptic transmission. Curr Opin Neurobiol 2017; 45:45-50. [DOI: 10.1016/j.conb.2017.03.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/04/2017] [Accepted: 03/15/2017] [Indexed: 10/19/2022]
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36
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Wu HF, Chen PS, Hsu YT, Lee CW, Wang TF, Chen YJ, Lin HC. D-Cycloserine Ameliorates Autism-Like Deficits by Removing GluA2-Containing AMPA Receptors in a Valproic Acid-Induced Rat Model. Mol Neurobiol 2017; 55:4811-4824. [PMID: 28733898 DOI: 10.1007/s12035-017-0685-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/10/2017] [Indexed: 12/15/2022]
Abstract
Valproic acid (VPA)-exposed rat offspring have demonstrated autism spectrum disorder (ASD) phenotypes and impaired N-methyl-D-aspartate receptor (NMDAR)-dependent long-term depression (LTD) in the lateral nucleus of the amygdala. NMDAR partial agonist D-cycloserine (DCS) has been reported to act as a cognitive enhancer by increasing the NMDAR response to improve autistic-like phenotypes in animals. However, the mechanism of DCS in alleviating the ASD is still unknown. Using combined behavioral, electrophysiological, and molecular approaches, we found that DCS administration rescued social interaction deficits and anxiety/repetitive-like behaviors observed in VPA-exposed offspring. In the amygdala synapses, DCS treatment reversed the decreased paired pulse ratio (PPR) and the impaired NMDAR-dependent LTD, increased the frequency and amplitude of miniature excitatory post-synaptic currents (mEPSCs), and resulted in a higher dendritic spine density at the amygdala synapses in the VPA-exposed offspring. Moreover, we found that DCS facilitated the removal of GluA2-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (GluA2/AMPARs) by inducing NMDAR-dependent LTD in the VPA-exposed offspring. We further established that the effects of DCS treatment, including increased GluA2/AMPAR removal and rescues of impaired social behavior, were blocked by Tat-GluA23Y, a GluA2-derived peptide that disrupted regulation of AMPAR endocytosis. These results provided the first evidence that rescue of the ASD-like phenotype by DCS is mediated by the mechanism of GluA2/AMPAR removal in VPA-exposed rat offspring.
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Affiliation(s)
- Han-Fang Wu
- Department and Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Po See Chen
- Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
- Addiction Research Center, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Ya-Ting Hsu
- Department and Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Chi-Wei Lee
- Department and Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Tzu-Feng Wang
- Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
- Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Cheng Kung University and Academia Sinica, Taipei, Taiwan
| | - Yi-Ju Chen
- Department and Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Hui-Ching Lin
- Department and Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan.
- Brain Research Center, National Yang-Ming University, Taipei, 11221, Taiwan.
- Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, 11031, Taiwan.
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37
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Unique versus Redundant Functions of Neuroligin Genes in Shaping Excitatory and Inhibitory Synapse Properties. J Neurosci 2017; 37:6816-6836. [PMID: 28607166 DOI: 10.1523/jneurosci.0125-17.2017] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 05/10/2017] [Accepted: 05/31/2017] [Indexed: 11/21/2022] Open
Abstract
Neuroligins are evolutionarily conserved postsynaptic cell adhesion molecules that interact with presynaptic neurexins. Neurons express multiple neuroligin isoforms that are targeted to specific synapses, but their synaptic functions and mechanistic redundancy are not completely understood. Overexpression or RNAi-mediated knockdown of neuroligins, respectively, causes a dramatic increase or decrease in synapse density, whereas genetic deletions of neuroligins impair synapse function with only minor effects on synapse numbers, raising fundamental questions about the overall physiological role of neuroligins. Here, we have systematically analyzed the effects of conditional genetic deletions of all major neuroligin isoforms (i.e., NL1, NL2, and NL3), either individually or in combinations, in cultured mouse hippocampal and cortical neurons. We found that conditional genetic deletions of neuroligins caused no change or only a small change in synapses numbers, but strongly impaired synapse function. This impairment was isoform specific, suggesting that neuroligins are not functionally redundant. Sparse neuroligin deletions produced phenotypes comparable to those of global deletions, indicating that neuroligins function in a cell-autonomous manner. Mechanistically, neuroligin deletions decreased the synaptic levels of neurotransmitter receptors and had no effect on presynaptic release probabilities. Overexpression of neuroligin-1 in control or neuroligin-deficient neurons increased synaptic transmission and synapse density but not spine numbers, suggesting that these effects reflect a gain-of-function mechanism; whereas overexpression of neuroligin-3, which, like neuroligin-1 is also targeted to excitatory synapses, had no comparable effect. Our data demonstrate that neuroligins are required for the physiological organization of neurotransmitter receptors in postsynaptic specializations and suggest that they do not play a major role in synapse formation.SIGNIFICANCE STATEMENT Human neuroligin genes have been associated with autism, but the cellular functions of different neuroligins and their molecular mechanisms remain incompletely understood. Here, we performed comparative analyses in cultured mouse neurons of all major neuroligin isoforms, either individually or in combinations, using conditional knockouts. We found that neuroligin deletions did not affect synapse numbers but differentially impaired excitatory or inhibitory synaptic functions in an isoform-specific manner. These impairments were due, at least in part, to a decrease in synaptic distribution of neurotransmitter receptors upon deletion of neuroligins. Conversely, the overexpression of neuroligin-1 increased synapse numbers but not spine numbers. Our results suggest that various neuroligin isoforms perform unique postsynaptic functions in organizing synapses but are not essential for synapse formation or maintenance.
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Torper O, Götz M. Brain repair from intrinsic cell sources: Turning reactive glia into neurons. PROGRESS IN BRAIN RESEARCH 2017; 230:69-97. [PMID: 28552236 DOI: 10.1016/bs.pbr.2016.12.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The replacement of lost neurons in the brain due to injury or disease holds great promise for the treatment of neurological disorders. However, logistical and ethical hurdles in obtaining and maintaining viable cells for transplantation have proven difficult to overcome. In vivo reprogramming offers an alternative, to bypass many of the restrictions associated with an exogenous cell source as it relies on a source of cells already present in the brain. Recent studies have demonstrated the possibility to target and reprogram glial cells into functional neurons with high efficiency in the murine brain, using virally delivered transcription factors. In this chapter, we explore the different populations of glial cells, how they react to injury and how they can be exploited for reprogramming purposes. Further, we review the most significant publications and how they have contributed to the understanding of key aspects in direct reprogramming needed to take into consideration, like timing, cell type targeted, and regional differences. Finally, we discuss future challenges and what remains to be explored in order to determine the potential of in vivo reprogramming for future brain repair.
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Affiliation(s)
- Olof Torper
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians University Munich, Planegg, Germany; Institute of Stem Cell Research, Helmholtz Center Munich, Munich, Germany; SYNERGY, Excellence Cluster of Systems Neurology, Biomedical Center, Ludwig-Maximilians University Munich, Planegg, Germany
| | - Magdalena Götz
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians University Munich, Planegg, Germany; Institute of Stem Cell Research, Helmholtz Center Munich, Munich, Germany; SYNERGY, Excellence Cluster of Systems Neurology, Biomedical Center, Ludwig-Maximilians University Munich, Planegg, Germany.
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39
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Baig DN, Yanagawa T, Tabuchi K. Distortion of the normal function of synaptic cell adhesion molecules by genetic variants as a risk for autism spectrum disorders. Brain Res Bull 2016; 129:82-90. [PMID: 27743928 DOI: 10.1016/j.brainresbull.2016.10.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 10/08/2016] [Accepted: 10/10/2016] [Indexed: 12/15/2022]
Abstract
Synaptic cell adhesion molecules (SCAMs) are a functional category of cell adhesion molecules that connect pre- and postsynapses by the protein-protein interaction via their extracellular cell adhesion domains. Countless numbers of common genetic variants and rare mutations in SCAMs have been identified in the patients with autism spectrum disorders (ASDs). Among these, NRXN and NLGN family proteins cooperatively function at synaptic terminals both of which genes are strongly implicated as risk genes for ASDs. Knock-in mice carrying a single rare point mutation of NLGN3 (NLGN3 R451C) discovered in the patients with ASDs display a deficit in social interaction and an enhancement of spatial learning and memory ability reminiscent of the clinical phenotype of ASDs. NLGN4 knockout (KO) and NRXN2α KO mice also show a deficit in sociability as well as some specific neuropsychiatric behaviors. In this review, we selected NRXNs/NLGNs, CNTNAP2/CNTNAP4, CNTN4, ITGB3, and KIRREL3 as strong ASD risk genes based on SFARI score and summarize the protein structures, functions at synapses, representative discoveries in human genetic studies, and phenotypes of the mutant model mice in light of the pathophysiology of ASDs.
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Affiliation(s)
- Deeba Noreen Baig
- Department of Biological Sciences, Forman Christian College, Zahoor Elahi Rd, Lahore, 54600, Pakistan
| | - Toru Yanagawa
- Department of Oral and Maxillofacial Surgery, Faculty of Medicine, University of Tsukuba, Ibaraki, 305-8575, Japan
| | - Katsuhiko Tabuchi
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan; Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto, 390-8621, Japan; PRESTO, JST, Saitama, 332-0012, Japan.
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40
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Cao X, Tabuchi K. Functions of synapse adhesion molecules neurexin/neuroligins and neurodevelopmental disorders. Neurosci Res 2016; 116:3-9. [PMID: 27664583 DOI: 10.1016/j.neures.2016.09.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 09/02/2016] [Accepted: 09/02/2016] [Indexed: 12/15/2022]
Abstract
Neurexins and neuroligins are two distinct families of single-pass transmembrane proteins localized at pre- and postsynapses, respectively. They trans-synaptically interact with each other and induce synapse formation and maturation. Common variants and rare mutations, including copy number variations, short deletions, and single or small nucleotide changes in neurexin and neuroligin genes have been linked to the neurodevelopmental disorders, such as autism spectrum disorders (ASDs). In this review, we summarize the structure and basic synaptic function of neurexins and neuroligins, followed by behaviors and synaptic phenotypes of knock-in and knock-out mouse of these family genes. From the studies of these mice, it turns out that the effects of neurexins and neuroligins are amazingly neural circuit dependent, even within the same brain region. In addition, neurexins and neuroligins are commonly involved in the endocannabinoid signaling. These finding may provide not only insight into understanding the pathophysiology, but also the concept for strategy of therapeutic intervention for ASDs.
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Affiliation(s)
- Xueshan Cao
- Department of Molecular & Cellular Physiology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Katsuhiko Tabuchi
- Department of Molecular & Cellular Physiology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan; Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto 390-8621, Japan.
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41
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Patak J, Zhang-James Y, Faraone SV. Endosomal system genetics and autism spectrum disorders: A literature review. Neurosci Biobehav Rev 2016; 65:95-112. [PMID: 27048963 PMCID: PMC4866511 DOI: 10.1016/j.neubiorev.2016.03.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 03/25/2016] [Accepted: 03/27/2016] [Indexed: 01/01/2023]
Abstract
Autism spectrum disorders (ASDs) are a group of debilitating neurodevelopmental disorders thought to have genetic etiology, due to their high heritability. The endosomal system has become increasingly implicated in ASD pathophysiology. In an attempt to summarize the association between endosomal system genes and ASDs we performed a systematic review of the literature. We searched PubMed for relevant articles. Simons Foundation Autism Research Initiative (SFARI) gene database was used to exclude articles regarding genes with less than minimal evidence for association with ASDs. Our search retained 55 articles reviewed in two categories: genes that regulate and genes that are regulated by the endosomal system. Our review shows that the endosomal system is a novel pathway implicated in ASDs as well as other neuropsychiatric disorders. It plays a central role in aspects of cellular physiology on which neurons and glial cells are particularly reliant, due to their unique metabolic and functional demands. The system shows potential for biomarkers and pharmacological intervention and thus more research into this pathway is warranted.
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Affiliation(s)
- Jameson Patak
- Dept. of Neuroscience and Physiology, Upstate Medical University, Syracuse, NY, United States.
| | - Yanli Zhang-James
- Dept of Psychiatry, Upstate Medical University, Syracuse, NY, United States.
| | - Stephen V Faraone
- Dept. of Neuroscience and Physiology, Upstate Medical University, Syracuse, NY, United States; Dept of Psychiatry, Upstate Medical University, Syracuse, NY, United States; K.G. Jebsen Centre for Neuropsychiatric Disorders, Department of Biomedicine, University of Bergen, Bergen, Norway.
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42
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Wang H. Endocannabinoid Mediates Excitatory Synaptic Function of β-Neurexins. Commentary: β-Neurexins Control Neural Circuits by Regulating Synaptic Endocannabinoid Signaling. Front Neurosci 2016; 10:203. [PMID: 27242408 PMCID: PMC4873487 DOI: 10.3389/fnins.2016.00203] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 04/25/2016] [Indexed: 11/13/2022] Open
Affiliation(s)
- Hansen Wang
- Faculty of Medicine, University of Toronto Toronto, ON, Canada
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43
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Panchision DM. Concise Review: Progress and Challenges in Using Human Stem Cells for Biological and Therapeutics Discovery: Neuropsychiatric Disorders. Stem Cells 2016; 34:523-36. [PMID: 26840228 DOI: 10.1002/stem.2295] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 11/29/2015] [Accepted: 12/09/2015] [Indexed: 12/12/2022]
Abstract
In facing the daunting challenge of using human embryonic and induced pluripotent stem cells to study complex neural circuit disorders such as schizophrenia, mood and anxiety disorders, and autism spectrum disorders, a 2012 National Institute of Mental Health workshop produced a set of recommendations to advance basic research and engage industry in cell-based studies of neuropsychiatric disorders. This review describes progress in meeting these recommendations, including the development of novel tools, strides in recapitulating relevant cell and tissue types, insights into the genetic basis of these disorders that permit integration of risk-associated gene regulatory networks with cell/circuit phenotypes, and promising findings of patient-control differences using cell-based assays. However, numerous challenges are still being addressed, requiring further technological development, approaches to resolve disease heterogeneity, and collaborative structures for investigators of different disciplines. Additionally, since data obtained so far is on small sample sizes, replication in larger sample sets is needed. A number of individual success stories point to a path forward in developing assays to translate discovery science to therapeutics development.
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Affiliation(s)
- David M Panchision
- Division of Neuroscience and Basic Behavioral Science, National Institute of Mental Health, Bethesda, Maryland, USA
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44
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Hammer M, Krueger-Burg D, Tuffy LP, Cooper BH, Taschenberger H, Goswami SP, Ehrenreich H, Jonas P, Varoqueaux F, Rhee JS, Brose N. Perturbed Hippocampal Synaptic Inhibition and γ-Oscillations in a Neuroligin-4 Knockout Mouse Model of Autism. Cell Rep 2015; 13:516-523. [PMID: 26456829 PMCID: PMC5862414 DOI: 10.1016/j.celrep.2015.09.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 08/23/2015] [Accepted: 09/02/2015] [Indexed: 12/02/2022] Open
Abstract
Loss-of-function mutations in the synaptic adhesion protein Neuroligin-4 are among the most common genetic abnormalities associated with autism spectrum disorders, but little is known about the function of Neuroligin-4 and the consequences of its loss. We assessed synaptic and network characteristics in Neuroligin-4 knockout mice, focusing on the hippocampus as a model brain region with a critical role in cognition and memory, and found that Neuroligin-4 deletion causes subtle defects of the protein composition and function of GABAergic synapses in the hippocampal CA3 region. Interestingly, these subtle synaptic changes are accompanied by pronounced perturbations of γ-oscillatory network activity, which has been implicated in cognitive function and is altered in multiple psychiatric and neurodevelopmental disorders. Our data provide important insights into the mechanisms by which Neuroligin-4-dependent GABAergic synapses may contribute to autism phenotypes and indicate new strategies for therapeutic approaches.
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Affiliation(s)
- Matthieu Hammer
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Dilja Krueger-Burg
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Liam Patrick Tuffy
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Benjamin Hillman Cooper
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Holger Taschenberger
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Sarit Pati Goswami
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Hannelore Ehrenreich
- Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Peter Jonas
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Frederique Varoqueaux
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Jeong-Seop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany.
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany.
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45
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Savas JN, Ribeiro LF, Wierda KD, Wright R, DeNardo-Wilke LA, Rice HC, Chamma I, Wang YZ, Zemla R, Lavallée-Adam M, Vennekens KM, O'Sullivan ML, Antonios JK, Hall EA, Thoumine O, Attie AD, Yates JR, Ghosh A, de Wit J. The Sorting Receptor SorCS1 Regulates Trafficking of Neurexin and AMPA Receptors. Neuron 2015; 87:764-80. [PMID: 26291160 PMCID: PMC4692362 DOI: 10.1016/j.neuron.2015.08.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 06/16/2015] [Accepted: 08/03/2015] [Indexed: 01/01/2023]
Abstract
The formation, function, and plasticity of synapses require dynamic changes in synaptic receptor composition. Here, we identify the sorting receptor SorCS1 as a key regulator of synaptic receptor trafficking. Four independent proteomic analyses identify the synaptic adhesion molecule neurexin and the AMPA glutamate receptor (AMPAR) as major proteins sorted by SorCS1. SorCS1 localizes to early and recycling endosomes and regulates neurexin and AMPAR surface trafficking. Surface proteome analysis of SorCS1-deficient neurons shows decreased surface levels of these, and additional, receptors. Quantitative in vivo analysis of SorCS1-knockout synaptic proteomes identifies SorCS1 as a global trafficking regulator and reveals decreased levels of receptors regulating adhesion and neurotransmission, including neurexins and AMPARs. Consequently, glutamatergic transmission at SorCS1-deficient synapses is reduced due to impaired AMPAR surface expression. SORCS1 mutations have been associated with autism and Alzheimer disease, suggesting that perturbed receptor trafficking contributes to synaptic-composition and -function defects underlying synaptopathies.
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Affiliation(s)
- Jeffrey N Savas
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Luís F Ribeiro
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium
| | - Keimpe D Wierda
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium
| | - Rebecca Wright
- Neurobiology Section, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Laura A DeNardo-Wilke
- Neurobiology Section, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Heather C Rice
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium
| | - Ingrid Chamma
- UMR 5297, Interdisciplinary Institute for Neuroscience, University of Bordeaux and Centre National de la Recherche Scientifique, 33000 Bordeaux, France
| | - Yi-Zhi Wang
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Roland Zemla
- School of Medicine, New York University, New York, New York 10016, USA
| | - Mathieu Lavallée-Adam
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Kristel M Vennekens
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium
| | - Matthew L O'Sullivan
- Neurobiology Section, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Joseph K Antonios
- Neurobiology Section, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Elizabeth A Hall
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Olivier Thoumine
- UMR 5297, Interdisciplinary Institute for Neuroscience, University of Bordeaux and Centre National de la Recherche Scientifique, 33000 Bordeaux, France
| | - Alan D Attie
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA.
| | - Anirvan Ghosh
- Neurobiology Section, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA; Neuroscience Discovery, F. Hoffman-La Roche, 4070 Basel, Switzerland
| | - Joris de Wit
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium.
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46
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Mottron L, Duret P, Mueller S, Moore RD, Forgeot d'Arc B, Jacquemont S, Xiong L. Sex differences in brain plasticity: a new hypothesis for sex ratio bias in autism. Mol Autism 2015; 6:33. [PMID: 26052415 PMCID: PMC4456778 DOI: 10.1186/s13229-015-0024-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 04/27/2015] [Indexed: 01/13/2023] Open
Abstract
Several observations support the hypothesis that differences in synaptic and regional cerebral plasticity between the sexes account for the high ratio of males to females in autism. First, males are more susceptible than females to perturbations in genes involved in synaptic plasticity. Second, sex-related differences in non-autistic brain structure and function are observed in highly variable regions, namely, the heteromodal associative cortices, and overlap with structural particularities and enhanced activity of perceptual associative regions in autistic individuals. Finally, functional cortical reallocations following brain lesions in non-autistic adults (for example, traumatic brain injury, multiple sclerosis) are sex-dependent. Interactions between genetic sex and hormones may therefore result in higher synaptic and consecutively regional plasticity in perceptual brain areas in males than in females. The onset of autism may largely involve mutations altering synaptic plasticity that create a plastic reaction affecting the most variable and sexually dimorphic brain regions. The sex ratio bias in autism may arise because males have a lower threshold than females for the development of this plastic reaction following a genetic or environmental event.
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Affiliation(s)
- Laurent Mottron
- Centre d'excellence en Troubles envahissants du dévelopement de l'Université de Montréal (CETEDUM), Montréal, Canada.,Hôpital Rivière-des-Prairies, Département de Psychiatrie, Montréal, Canada.,Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Québec, Canada.,Department of Psychiatry, University of Montreal, Québec, Canada
| | - Pauline Duret
- Centre d'excellence en Troubles envahissants du dévelopement de l'Université de Montréal (CETEDUM), Montréal, Canada.,Hôpital Rivière-des-Prairies, Département de Psychiatrie, Montréal, Canada.,Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Québec, Canada.,Department of Psychiatry, University of Montreal, Québec, Canada.,Département de Biologie, École Normale Supérieure de Lyon, Lyon, CEDEX 07 France
| | - Sophia Mueller
- Institute of Clinical Radiology, University Hospitals, Munich, Germany.,Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129 USA.,Harvard University, Center for Brain Science, Cambridge, MA 02138 USA
| | - Robert D Moore
- Department of Psychiatry, University of Montreal, Québec, Canada.,Department of Health Sciences, University of Montreal, Montreal, Canada.,College of Applied Health Sciences, University of Illinois, Urbana-Champaign, USA
| | - Baudouin Forgeot d'Arc
- Centre d'excellence en Troubles envahissants du dévelopement de l'Université de Montréal (CETEDUM), Montréal, Canada.,Hôpital Rivière-des-Prairies, Département de Psychiatrie, Montréal, Canada.,Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Québec, Canada.,Department of Psychiatry, University of Montreal, Québec, Canada
| | - Sebastien Jacquemont
- Department of Psychiatry, University of Montreal, Québec, Canada.,Centre de recherche, Centre Hospitalier Universitaire Sainte Justine, Montréal, Canada.,Service of Medical Genetics, University Hospital of Lausanne, University of Lausanne, Lausanne, 1011 Switzerland
| | - Lan Xiong
- Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Québec, Canada.,Department of Psychiatry, University of Montreal, Québec, Canada
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