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Moss ND, Wells KL, Theis A, Kim YK, Spigelman AF, Liu X, MacDonald PE, Sussel L. Modulation of insulin secretion by RBFOX2-mediated alternative splicing. Nat Commun 2023; 14:7732. [PMID: 38007492 PMCID: PMC10676425 DOI: 10.1038/s41467-023-43605-4] [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: 01/31/2023] [Accepted: 11/15/2023] [Indexed: 11/27/2023] Open
Abstract
Insulin secretion is a tightly regulated process that is vital for maintaining blood glucose homeostasis. Although the molecular components of insulin granule trafficking and secretion are well established, how they are regulated to rapidly fine-tune secretion in response to changing environmental conditions is not well characterized. Recent studies have determined that dysregulation of RNA-binding proteins (RBPs) and aberrant mRNA splicing occurs at the onset of diabetes. We demonstrate that the RBP, RBFOX2, is a critical regulator of insulin secretion through the alternative splicing of genes required for insulin granule docking and exocytosis. Conditional mutation of Rbfox2 in the mouse pancreas results in decreased insulin secretion and impaired blood glucose homeostasis. Consistent with defects in secretion, we observe reduced insulin granule docking and corresponding splicing defects in the SNARE complex components. These findings identify an additional mechanism for modulating insulin secretion in both healthy and dysfunctional pancreatic β cells.
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Affiliation(s)
- Nicole D Moss
- Barbara Davis Center for Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kristen L Wells
- Barbara Davis Center for Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Alexandra Theis
- Barbara Davis Center for Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Yong-Kyung Kim
- Barbara Davis Center for Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Aliya F Spigelman
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Xiong Liu
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Patrick E MacDonald
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Lori Sussel
- Barbara Davis Center for Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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2
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Uzay B, Kavalali ET. Genetic disorders of neurotransmitter release machinery. Front Synaptic Neurosci 2023; 15:1148957. [PMID: 37066095 PMCID: PMC10102358 DOI: 10.3389/fnsyn.2023.1148957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/10/2023] [Indexed: 04/03/2023] Open
Abstract
Synaptic neurotransmitter release is an evolutionarily conserved process that mediates rapid information transfer between neurons as well as several peripheral tissues. Release of neurotransmitters are ensured by successive events such as synaptic vesicle docking and priming that prepare synaptic vesicles for rapid fusion. These events are orchestrated by interaction of different presynaptic proteins and are regulated by presynaptic calcium. Recent studies have identified various mutations in different components of neurotransmitter release machinery resulting in aberrant neurotransmitter release, which underlie a wide spectrum of psychiatric and neurological symptoms. Here, we review how these genetic alterations in different components of the core neurotransmitter release machinery affect the information transfer between neurons and how aberrant synaptic release affects nervous system function.
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Affiliation(s)
- Burak Uzay
- Vanderbilt Brain Institute, Nashville, TN, United States
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
| | - Ege T. Kavalali
- Vanderbilt Brain Institute, Nashville, TN, United States
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
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3
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Brocato ER, Wolstenholme JT. Adolescent binge ethanol impacts H3K36me3 regulation of synaptic genes. Front Mol Neurosci 2023; 16:1082104. [PMID: 36937047 PMCID: PMC10020663 DOI: 10.3389/fnmol.2023.1082104] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 02/10/2023] [Indexed: 03/06/2023] Open
Abstract
Adolescence is marked in part by the ongoing development of the prefrontal cortex (PFC). Binge ethanol use during this critical stage in neurodevelopment induces significant structural changes to the PFC, as well as cognitive and behavioral deficits that can last into adulthood. Previous studies showed that adolescent binge ethanol causes lasting deficits in working memory, decreases in the expression of chromatin remodeling genes responsible for the methylation of histone 3 lysine 36 (H3K36), and global decreases in H3K36 in the PFC. H3K36me3 is present within the coding region of actively-transcribed genes, and safeguards against aberrant, cryptic transcription by RNA Polymerase II. We hypothesize that altered methylation of H3K36 could play a role in adolescent binge ethanol-induced memory deficits. To investigate this at the molecular level, ethanol (4 g/kg, i.g.) or water was administered intermittently to adolescent mice. RNA-and ChIP-sequencing were then performed within the same tissue to determine gene expression changes and identify genes and loci where H3K36me3 was disrupted by ethanol. We further assessed ethanol-induced changes at the transcription level with differential exon-use and cryptic transcription analysis - a hallmark of decreased H3K36me3. Here, we found ethanol-induced changes to the gene expression and H3K36me3-regulation of synaptic-related genes in all our analyses. Notably, H3K36me3 was differentially trimethylated between ethanol and control conditions at synaptic-related genes, and Snap25 and Cplx1 showed evidence of cryptic transcription in males and females treated with ethanol during adolescence. Our results provide preliminary evidence that ethanol-induced changes to H3K36me3 during adolescent neurodevelopment may be linked to synaptic dysregulation at the transcriptional level, which may explain the reported ethanol-induced changes to PFC synaptic function.
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Affiliation(s)
- Emily R. Brocato
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Jennifer T. Wolstenholme
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
- VCU Alcohol Research Center, Virginia Commonwealth University, Richmond, VA, United States
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4
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Michetti C, Falace A, Benfenati F, Fassio A. Synaptic genes and neurodevelopmental disorders: From molecular mechanisms to developmental strategies of behavioral testing. Neurobiol Dis 2022; 173:105856. [PMID: 36070836 DOI: 10.1016/j.nbd.2022.105856] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 10/14/2022] Open
Abstract
Synaptopathies are a class of neurodevelopmental disorders caused by modification in genes coding for synaptic proteins. These proteins oversee the process of neurotransmission, mainly controlling the fusion and recycling of synaptic vesicles at the presynaptic terminal, the expression and localization of receptors at the postsynapse and the coupling between the pre- and the postsynaptic compartments. Murine models, with homozygous or heterozygous deletion for several synaptic genes or knock-in for specific pathogenic mutations, have been developed. They have proved to be extremely informative for understanding synaptic physiology, as well as for clarifying the patho-mechanisms leading to developmental delay, epilepsy and motor, cognitive and social impairments that are the most common clinical manifestations of neurodevelopmental disorders. However, the onset of these disorders emerges during infancy and adolescence while the behavioral phenotyping is often conducted in adult mice, missing important information about the impact of synaptic development and maturation on the manifestation of the behavioral phenotype. Here, we review the main achievements obtained by behavioral testing in murine models of synaptopathies and propose a battery of behavioral tests to improve classification, diagnosis and efficacy of potential therapeutic treatments. Our aim is to underlie the importance of studying behavioral development and better focusing on disease onset and phenotypes.
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Affiliation(s)
- Caterina Michetti
- Department of Experimental Medicine, University of Genoa, Genoa, Italy; Center for Synaptic Neuroscience, Istituto Italiano di Tecnologia, Genoa, Italy.
| | - Antonio Falace
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Children's Hospital A. Meyer-University of Florence, Florence, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience, Istituto Italiano di Tecnologia, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Anna Fassio
- Department of Experimental Medicine, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
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5
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Özdemir Ç, Şahin N, Edgünlü T. Vesicle trafficking with snares: a perspective for autism. Mol Biol Rep 2022; 49:12193-12202. [PMID: 36198849 DOI: 10.1007/s11033-022-07970-5] [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: 06/08/2022] [Accepted: 09/21/2022] [Indexed: 11/30/2022]
Abstract
Vesicle-mediated membrane traffic is the mechanism fundamental to many biological events, especially the release of neurotransmitters. The main proteins of the mechanism that mediates membrane fusion in vesicle-mediated membrane traffic are N-ethylmaleimide sensitive factor (NSF) supplemental protein (SNAP) receptor (SNAREs) proteins. SNAREs are classified into vesicle-associated SNAREs (vesicle-SNAREs/v-SNAREs) and target membrane-associated SNAREs (target-SNARE/t-SNAREs). Autism spectrum disorders (ASD) are neurodevelopmental disorders characterized by many symptoms, especially complications in social communication and stereotypical behaviours. Defects in synaptogenesis and neurotransmission, oxidative stress, and developmental defects in the early stages of development are defined in the pathogenesis of the disease. SNARE proteins are on the basis of synaptogenesis and neurotransmission. Although the formation mechanisms and underlying causes of the SNARE complex are not fully understood, expression differences, polymorphisms, abnormal expressions or dysfunctions of the proteins that make up the SNARE complex have been associated with many neurodevelopmental diseases, including autism. Further understanding of SNARE mechanisms is crucial both for understanding ASD and for developing new treatments. In this review, the formation mechanisms of the SNARE complex and the roles of various factors involved in this process are explained. In addition, a brief evaluation of clinical and basic studies on the SNARE complex in autism spectrum disorders was made.
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Affiliation(s)
- Çilem Özdemir
- Department of Medical Biology, Health Sciences Institution, Muğla Sıtkı Koçman University, Mugla, Turkey
| | - Nilfer Şahin
- Department of Child and Adolescent Mental Health Diseases School of Medicine, Muğla Sıtkı Koçman University, Mugla, Turkey
| | - Tuba Edgünlü
- Department of Medical Biology, School of Medicine, Muğla Sıtkı Koçman University, 48000, Mugla, Turkey.
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6
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Stein AN, Joglekar A, Poon CL, Tilgner HU. ScisorWiz: Visualizing Differential Isoform Expression in Single-Cell Long-Read Data. Bioinformatics 2022; 38:3474-3476. [PMID: 35604081 PMCID: PMC9237735 DOI: 10.1093/bioinformatics/btac340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 04/11/2022] [Accepted: 05/18/2022] [Indexed: 11/21/2022] Open
Abstract
Summary RNA isoforms contribute to the diverse functionality of the proteins they encode within the cell. Visualizing how isoform expression differs across cell types and brain regions can inform our understanding of disease and gain or loss of functionality caused by alternative splicing with potential negative impacts. However, the extent to which this occurs in specific cell types and brain regions is largely unknown. This is the kind of information that ScisorWiz plots can provide in an informative and easily communicable manner. ScisorWiz affords its user the opportunity to visualize specific genes across any number of cell types, and provides various sorting options for the user to gain different ways to understand their data. ScisorWiz provides a clear picture of differential isoform expression through various clustering methods and highlights features such as alternative exons and single-nucleotide variants. Tools like ScisorWiz are key for interpreting single-cell isoform sequencing data. This tool applies to any single-cell long-read RNA sequencing data in any cell type, tissue or species. Availability and implementation Source code is available at http://github.com/ans4013/ScisorWiz. No new data were generated for this publication. Data used to generate figures was sourced from GEO accession token GSE158450 and available on GitHub as example data.
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Affiliation(s)
- Alexander N Stein
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.,Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | - Anoushka Joglekar
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.,Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | - Chi-Lam Poon
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.,Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | - Hagen U Tilgner
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.,Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
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7
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SNAP25 mutation disrupts metabolic homeostasis, steroid hormone production and central neurobehavior. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166304. [PMID: 34826585 PMCID: PMC8759409 DOI: 10.1016/j.bbadis.2021.166304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 10/29/2021] [Accepted: 11/11/2021] [Indexed: 02/03/2023]
Abstract
OBJECTIVE SNAP-25 is one of the key proteins involved in formation of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes that are at the core of hormonal secretion and synaptic transmission. Altered expression or function of SNAP-25 can contribute to the development of neuropsychiatric and metabolic disease. A dominant negative (DN) I67T missense mutation in the b-isoform of SNAP-25 (DN-SNAP25mut) mice leads to abnormal interactions within the SNARE complex and impaired exocytotic vesicle recycling, yet the significance of this mutation to any association between the central nervous system and metabolic homeostasis is unknown. METHODS Here we explored aspects of metabolism, steroid hormone production and neurobehavior of DN-SNAP25mut mice. RESULTS DN-SNAP25mut mice displayed enhanced insulin function through increased Akt phosphorylation, alongside increased adrenal and gonadal hormone production. In addition, increased anxiety behavior and beigeing of white adipose tissue with increased energy expenditure were observed in mutants. CONCLUSIONS Our results show that SNAP25 plays an important role in bridging central neurological systems with peripheral metabolic homeostasis, and provide potential insights between metabolic disease and neuropsychiatric disorders in humans.
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8
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Takikawa K, Nishimune H. Similarity and Diversity of Presynaptic Molecules at Neuromuscular Junctions and Central Synapses. Biomolecules 2022; 12:biom12020179. [PMID: 35204679 PMCID: PMC8961632 DOI: 10.3390/biom12020179] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/17/2022] [Accepted: 01/19/2022] [Indexed: 12/04/2022] Open
Abstract
Synaptic transmission is essential for controlling motor functions and maintaining brain functions such as walking, breathing, cognition, learning, and memory. Neurotransmitter release is regulated by presynaptic molecules assembled in active zones of presynaptic terminals. The size of presynaptic terminals varies, but the size of a single active zone and the types of presynaptic molecules are highly conserved among neuromuscular junctions (NMJs) and central synapses. Three parameters play an important role in the determination of neurotransmitter release properties at NMJs and central excitatory/inhibitory synapses: the number of presynaptic molecular clusters, the protein families of the presynaptic molecules, and the distance between presynaptic molecules and voltage-gated calcium channels. In addition, dysfunction of presynaptic molecules causes clinical symptoms such as motor and cognitive decline in patients with various neurological disorders and during aging. This review focuses on the molecular mechanisms responsible for the functional similarities and differences between excitatory and inhibitory synapses in the peripheral and central nervous systems, and summarizes recent findings regarding presynaptic molecules assembled in the active zone. Furthermore, we discuss the relationship between functional alterations of presynaptic molecules and dysfunction of NMJs or central synapses in diseases and during aging.
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Affiliation(s)
- Kenji Takikawa
- Laboratory of Neurobiology of Aging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015, Japan;
| | - Hiroshi Nishimune
- Laboratory of Neurobiology of Aging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015, Japan;
- Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-8-1 Harumi-cho, Fuchu-shi, Tokyo 183-8538, Japan
- Correspondence: ; Tel.: +81-3-3964-3241
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9
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Adori C, Daraio T, Kuiper R, Barde S, Horvathova L, Yoshitake T, Ihnatko R, Valladolid-Acebes I, Vercruysse P, Wellendorf AM, Gramignoli R, Bozoky B, Kehr J, Theodorsson E, Cancelas JA, Mravec B, Jorns C, Ellis E, Mulder J, Uhlén M, Bark C, Hökfelt T. Disorganization and degeneration of liver sympathetic innervations in nonalcoholic fatty liver disease revealed by 3D imaging. SCIENCE ADVANCES 2021; 7:7/30/eabg5733. [PMID: 34290096 PMCID: PMC8294768 DOI: 10.1126/sciadv.abg5733] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 06/04/2021] [Indexed: 05/08/2023]
Abstract
Hepatic nerves have a complex role in synchronizing liver metabolism. Here, we used three-dimensional (3D) immunoimaging to explore the integrity of the hepatic nervous system in experimental and human nonalcoholic fatty liver disease (NAFLD). We demonstrate parallel signs of mild degeneration and axonal sprouting of sympathetic innervations in early stages of experimental NAFLD and a collapse of sympathetic arborization in steatohepatitis. Human fatty livers display a similar pattern of sympathetic nerve degeneration, correlating with the severity of NAFLD pathology. We show that chronic sympathetic hyperexcitation is a key factor in the axonal degeneration, here genetically phenocopied in mice deficient of the Rac-1 activator Vav3. In experimental steatohepatitis, 3D imaging reveals a severe portal vein contraction, spatially correlated with the extension of the remaining nerves around the portal vein, enlightening a potential intrahepatic neuronal mechanism of portal hypertension. These fundamental alterations in liver innervation and vasculature uncover previously unidentified neuronal components in NAFLD pathomechanisms.
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Affiliation(s)
- Csaba Adori
- Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
| | - Teresa Daraio
- The Rolf Luft Research Center for Diabetes and Endocrinology, Department of Molecular Medicine and Surgery, Karolinska Institutet, 17176 Stockholm, Sweden
| | - Raoul Kuiper
- Department of Laboratory Medicine, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Swapnali Barde
- Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Lubica Horvathova
- Biomedical Research Center, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Takashi Yoshitake
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Robert Ihnatko
- Department of Clinical Chemistry and Department of Clinical and Experimental Medicine, Linköping University, 58285 Linköping, Sweden
| | - Ismael Valladolid-Acebes
- The Rolf Luft Research Center for Diabetes and Endocrinology, Department of Molecular Medicine and Surgery, Karolinska Institutet, 17176 Stockholm, Sweden
| | - Pauline Vercruysse
- The Rolf Luft Research Center for Diabetes and Endocrinology, Department of Molecular Medicine and Surgery, Karolinska Institutet, 17176 Stockholm, Sweden
| | - Ashley M Wellendorf
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229-3039, USA
| | - Roberto Gramignoli
- Department of Laboratory Medicine, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Bela Bozoky
- Department of Clinical Pathology/Cytology, Karolinska University Hospital, Huddinge, Sweden
| | - Jan Kehr
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Elvar Theodorsson
- Department of Clinical Chemistry and Department of Clinical and Experimental Medicine, Linköping University, 58285 Linköping, Sweden
| | - Jose A Cancelas
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229-3039, USA
- Hoxworth Blood Center, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0055, USA
| | - Boris Mravec
- Biomedical Research Center, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovak Republic
- Institute of Physiology, Faculty of Medicine, Comenius University in Bratislava, Slovak Republic
| | - Carl Jorns
- PO Transplantation, Karolinska University Hospital Huddinge, 141 52 Stockholm, Sweden
| | - Ewa Ellis
- Department of Transplantation Surgery and Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska University Hospital, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Jan Mulder
- Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Mathias Uhlén
- Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden
- Science for Life Laboratory, Royal Institute of Technology, 10691 Stockholm, Sweden
| | - Christina Bark
- Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Tomas Hökfelt
- Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden
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10
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Sena RM, Twiss JL, Gardiner AS, Dell’Orco M, Linsenbardt DN, Perrone-Bizzozero NI. The RNA-Binding Protein HuD Regulates Alternative Splicing and Alternative Polyadenylation in the Mouse Neocortex. Molecules 2021; 26:2836. [PMID: 34064652 PMCID: PMC8151252 DOI: 10.3390/molecules26102836] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/03/2021] [Accepted: 05/05/2021] [Indexed: 11/18/2022] Open
Abstract
The neuronal Hu/ELAV-like proteins HuB, HuC and HuD are a class of RNA-binding proteins that are crucial for proper development and maintenance of the nervous system. These proteins bind to AU-rich elements (AREs) in the untranslated regions (3'-UTRs) of target mRNAs regulating mRNA stability, transport and translation. In addition to these cytoplasmic functions, Hu proteins have been implicated in alternative splicing and alternative polyadenylation in the nucleus. The purpose of this study was to identify transcriptome-wide effects of HuD deletion on both of these nuclear events using RNA sequencing data obtained from the neocortex of Elavl4-/- (HuD KO) mice. HuD KO affected alternative splicing of 310 genes, including 17 validated HuD targets such as Cbx3, Cspp1, Snap25 and Gria2. In addition, deletion of HuD affected polyadenylation of 53 genes, with the majority of significantly altered mRNAs shifting towards usage of proximal polyadenylation signals (PAS), resulting in shorter 3'-UTRs. None of these genes overlapped with those showing alternative splicing events. Overall, HuD KO had a greater effect on alternative splicing than polyadenylation, with many of the affected genes implicated in several neuronal functions and neuropsychiatric disorders.
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Affiliation(s)
- Rebecca M. Sena
- Department Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA; (R.M.S.); (A.S.G.); (M.D.)
| | - Jeffery L. Twiss
- Department Biological Sciences, University of South Carolina, Columbia, SC 29208, USA;
| | - Amy S. Gardiner
- Department Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA; (R.M.S.); (A.S.G.); (M.D.)
- Department Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA
| | - Michela Dell’Orco
- Department Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA; (R.M.S.); (A.S.G.); (M.D.)
| | - David N. Linsenbardt
- Department Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA; (R.M.S.); (A.S.G.); (M.D.)
| | - Nora I. Perrone-Bizzozero
- Department Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA; (R.M.S.); (A.S.G.); (M.D.)
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11
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Chen F, Chen H, Chen Y, Wei W, Sun Y, Zhang L, Cui L, Wang Y. Dysfunction of the SNARE complex in neurological and psychiatric disorders. Pharmacol Res 2021; 165:105469. [PMID: 33524541 DOI: 10.1016/j.phrs.2021.105469] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/30/2020] [Accepted: 01/24/2021] [Indexed: 02/07/2023]
Abstract
The communication between neurons constitutes the basis of all neural activities, and synaptic vesicle exocytosis is the fundamental biological event that mediates most communication between neurons in the central nervous system. The SNARE complex is the core component of the protein machinery that facilitates the fusion of synaptic vesicles with presynaptic terminals and thereby the release of neurotransmitters. In synapses, each release event is dependent on the assembly of the SNARE complex. In recent years, basic research on the SNARE complex has provided a clearer understanding of the mechanism underlying the formation of the SNARE complex and its role in vesicle formation. Emerging evidence indicates that abnormal expression or dysfunction of the SNARE complex in synapse physiology might contribute to abnormal neurotransmission and ultimately to synaptic dysfunction. Clinical research using postmortem tissues suggests that SNARE complex dysfunction is correlated with various neurological diseases, and some basic research has also confirmed the important role of the SNARE complex in the pathology of these diseases. Genetic and pharmacogenetic studies suggest that the SNARE complex and individual proteins might represent important molecular targets in neurological disease. In this review, we summarize the recent progress toward understanding the SNARE complex in regulating membrane fusion events and provide an update of the recent discoveries from clinical and basic research on the SNARE complex in neurodegenerative, neuropsychiatric, and neurodevelopmental diseases.
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Affiliation(s)
- Feng Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Huiyi Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Yanting Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Wenyan Wei
- Department of Gerontology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Yuanhong Sun
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Lu Zhang
- The First Clinical College, Guangdong Medical University, Zhanjiang, China
| | - Lili Cui
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China.
| | - Yan Wang
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China; Key Laboratory of Biomedical Information Engineering of Ministry of Education, Biomedical Informatics & Genomics Center, School of Life Science and Technology, Xi'an Jiao tong University, Xi'an, China.
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12
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Ha KCH, Sterne-Weiler T, Morris Q, Weatheritt RJ, Blencowe BJ. Differential contribution of transcriptomic regulatory layers in the definition of neuronal identity. Nat Commun 2021; 12:335. [PMID: 33436550 PMCID: PMC7804943 DOI: 10.1038/s41467-020-20483-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 11/25/2020] [Indexed: 12/23/2022] Open
Abstract
Previous transcriptomic profiling studies have typically focused on separately analyzing mRNA expression, alternative splicing and alternative polyadenylation differences between cell and tissue types. However, the relative contribution of these three transcriptomic regulatory layers to cell type specification is poorly understood. This question is particularly relevant to neurons, given their extensive heterogeneity associated with brain location, morphology and function. In the present study, we generated profiles for the three regulatory layers from developmentally and regionally distinct subpopulations of neurons from the mouse hippocampus and broader nervous system. Multi-omics factor analyses revealed differing contributions of each transcriptomic layer in the discrimination of neurons based on their stage of development, region, and function. Importantly, profiles of differential alternative splicing and polyadenylation better discriminated specific neuronal subtype populations than gene expression patterns. These results provide evidence for differential relative contributions of coordinated gene regulatory layers in the specification of neuronal subtypes.
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Affiliation(s)
- Kevin C H Ha
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5A 1A8, Canada
- Vector Institute, Toronto, ON, M5G 1M1, Canada
- BioSymetrics, Inc., Huntington, New York, NY, USA
| | - Timothy Sterne-Weiler
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Quaid Morris
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5A 1A8, Canada
- Vector Institute, Toronto, ON, M5G 1M1, Canada
- Department of Computer Science, University of Toronto, Toronto, ON, M5S 4G4, Canada
| | - Robert J Weatheritt
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada.
- EMBL Australia, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia.
- St. Vincent Clinical School, University of New South Wales, Darlinghurst, NSW, 2010, Australia.
| | - Benjamin J Blencowe
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada.
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5A 1A8, Canada.
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13
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Zhang D, Yamaguchi S, Zhang X, Yang B, Kurooka N, Sugawara R, Albuayjan HHH, Nakatsuka A, Eguchi J, Hiyama TY, Kamiya A, Wada J. Upregulation of Mir342 in Diet-Induced Obesity Mouse and the Hypothalamic Appetite Control. Front Endocrinol (Lausanne) 2021; 12:727915. [PMID: 34526970 PMCID: PMC8437242 DOI: 10.3389/fendo.2021.727915] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 08/10/2021] [Indexed: 12/21/2022] Open
Abstract
In obesity and type 2 diabetes, numerous genes are differentially expressed, and microRNAs are involved in transcriptional regulation of target mRNAs, but miRNAs critically involved in the appetite control are not known. Here, we identified upregulation of miR-342-3p and its host gene Evl in brain and adipose tissues in C57BL/6 mice fed with high fat-high sucrose (HFHS) chow by RNA sequencing. Mir342 (-/-) mice fed with HFHS chow were protected from obesity and diabetes. The hypothalamic arcuate nucleus neurons co-express Mir342 and EVL. The percentage of activated NPY+pSTAT3+ neurons were reduced, while POMC+pSTAT3+ neurons increased in Mir342 (-/-) mice, and they demonstrated the reduction of food intake and amelioration of metabolic phenotypes. Snap25 was identified as a major target gene of miR-342-3p and the reduced expression of Snap25 may link to functional impairment hypothalamic neurons and excess of food intake. The inhibition of miR-342-3p may be a potential candidate for miRNA-based therapy.
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Affiliation(s)
- Dongxiao Zhang
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Satoshi Yamaguchi
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Xinhao Zhang
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Boxuan Yang
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Naoko Kurooka
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Ryosuke Sugawara
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Haya Hamed H. Albuayjan
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Atsuko Nakatsuka
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Jun Eguchi
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Takeshi Y. Hiyama
- Department of Cellular Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Atsunori Kamiya
- Department of Cellular Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Jun Wada
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
- *Correspondence: Jun Wada,
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14
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Tang BL. SNAREs and developmental disorders. J Cell Physiol 2020; 236:2482-2504. [PMID: 32959907 DOI: 10.1002/jcp.30067] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/20/2020] [Accepted: 09/09/2020] [Indexed: 12/12/2022]
Abstract
Members of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) family mediate membrane fusion processes associated with vesicular trafficking and autophagy. SNAREs mediate core membrane fusion processes essential for all cells, but some SNAREs serve cell/tissue type-specific exocytic/endocytic functions, and are therefore critical for various aspects of embryonic development. Mutations or variants of their encoding genes could give rise to developmental disorders, such as those affecting the nervous system and immune system in humans. Mutations to components in the canonical synaptic vesicle fusion SNARE complex (VAMP2, STX1A/B, and SNAP25) and a key regulator of SNARE complex formation MUNC18-1, produce variant phenotypes of autism, intellectual disability, movement disorders, and epilepsy. STX11 and MUNC18-2 mutations underlie 2 subtypes of familial hemophagocytic lymphohistiocytosis. STX3 mutations contribute to variant microvillus inclusion disease. Chromosomal microdeletions involving STX16 play a role in pseudohypoparathyroidism type IB associated with abnormal imprinting of the GNAS complex locus. In this short review, I discuss these and other SNARE gene mutations and variants that are known to be associated with a variety developmental disorders, with a focus on their underlying cellular and molecular pathological basis deciphered through disease modeling. Possible pathogenic potentials of other SNAREs whose variants could be disease predisposing are also speculated upon.
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Affiliation(s)
- Bor L Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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15
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Marcheva B, Perelis M, Weidemann BJ, Taguchi A, Lin H, Omura C, Kobayashi Y, Newman MV, Wyatt EJ, McNally EM, Fox JEM, Hong H, Shankar A, Wheeler EC, Ramsey KM, MacDonald PE, Yeo GW, Bass J. A role for alternative splicing in circadian control of exocytosis and glucose homeostasis. Genes Dev 2020; 34:1089-1105. [PMID: 32616519 PMCID: PMC7397853 DOI: 10.1101/gad.338178.120] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 06/10/2020] [Indexed: 11/24/2022]
Abstract
The circadian clock is encoded by a negative transcriptional feedback loop that coordinates physiology and behavior through molecular programs that remain incompletely understood. Here, we reveal rhythmic genome-wide alternative splicing (AS) of pre-mRNAs encoding regulators of peptidergic secretion within pancreatic β cells that are perturbed in Clock-/- and Bmal1-/- β-cell lines. We show that the RNA-binding protein THRAP3 (thyroid hormone receptor-associated protein 3) regulates circadian clock-dependent AS by binding to exons at coding sequences flanking exons that are more frequently skipped in clock mutant β cells, including transcripts encoding Cask (calcium/calmodulin-dependent serine protein kinase) and Madd (MAP kinase-activating death domain). Depletion of THRAP3 restores expression of the long isoforms of Cask and Madd, and mimicking exon skipping in these transcripts through antisense oligonucleotide delivery in wild-type islets reduces glucose-stimulated insulin secretion. Finally, we identify shared networks of alternatively spliced exocytic genes from islets of rodent models of diet-induced obesity that significantly overlap with clock mutants. Our results establish a role for pre-mRNA alternative splicing in β-cell function across the sleep/wake cycle.
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Affiliation(s)
- Biliana Marcheva
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Mark Perelis
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093, USA
| | - Benjamin J Weidemann
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Akihiko Taguchi
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Haopeng Lin
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Chiaki Omura
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Yumiko Kobayashi
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Marsha V Newman
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Eugene J Wyatt
- Center for Genetic Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Elizabeth M McNally
- Center for Genetic Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Jocelyn E Manning Fox
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Heekyung Hong
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Archana Shankar
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093, USA
| | - Emily C Wheeler
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093, USA
| | - Kathryn Moynihan Ramsey
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Patrick E MacDonald
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093, USA
| | - Joseph Bass
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
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16
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Bonnycastle K, Davenport EC, Cousin MA. Presynaptic dysfunction in neurodevelopmental disorders: Insights from the synaptic vesicle life cycle. J Neurochem 2020; 157:179-207. [PMID: 32378740 DOI: 10.1111/jnc.15035] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/14/2020] [Accepted: 04/22/2020] [Indexed: 12/11/2022]
Abstract
The activity-dependent fusion, retrieval and recycling of synaptic vesicles is essential for the maintenance of neurotransmission. Until relatively recently it was believed that most mutations in genes that were essential for this process would be incompatible with life, because of this fundamental role. However, an ever-expanding number of mutations in this very cohort of genes are being identified in individuals with neurodevelopmental disorders, including autism, intellectual disability and epilepsy. This article will summarize the current state of knowledge linking mutations in presynaptic genes to neurodevelopmental disorders by sequentially covering the various stages of the synaptic vesicle life cycle. It will also discuss how perturbations of specific stages within this recycling process could translate into human disease. Finally, it will also provide perspectives on the potential for future therapy that are targeted to presynaptic function.
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Affiliation(s)
- Katherine Bonnycastle
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Elizabeth C Davenport
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
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17
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Disabling Gβγ-SNAP-25 interaction in gene-targeted mice results in enhancement of long-term potentiation at Schaffer collateral-CA1 synapses in the hippocampus. Neuroreport 2020; 30:695-699. [PMID: 31095110 DOI: 10.1097/wnr.0000000000001258] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Three SNARE proteins, SNAP-25, syntaxin 1A, and VAMP2 or synaptobrevin 2, constitute the minimal functional machinery needed for the regulated secretion of neurotransmitters. Dynamic changes in the regulated release of neurotransmitters are associated with the induction of long-term plasticity at central synapses. In-vitro studies have validated the C-terminus of SNAP-25 as a target for inhibitory Gi/o-coupled G-protein coupled receptors at a number of synapses. The physiological consequences of the interaction between Gi/o proteins and SNAP-25 in the context of activity-dependent long-term synaptic plasticity are not well understood. Here, we report direct ex-vivo evidence of the involvement of the C-terminus of SNAP-25 in inducing long-term potentiation of synaptic strength at Schaffer collateral-CA1 synapses using a gene-targeted mouse model with truncated C-terminus (carboxyl terminus) of SNAP-25. It has been shown previously that truncation of the three extreme C-terminal residues in SNAP-25[INCREMENT]3 homozygote mice reduces its interaction with the inhibitory Gβγ subunits two-fold. In in-vitro hippocampal slices, we show that these SNAP-25[INCREMENT]3 mice express significantly larger magnitude of long-term potentiation at hippocampal Schaffer collateral-CA1 synapses.
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18
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Gopaul KR, Irfan M, Miry O, Vose LR, Moghadam A, Subah G, Hökfelt T, Bark C, Stanton PK. Developmental Time Course of SNAP-25 Isoforms Regulate Hippocampal Long-Term Synaptic Plasticity and Hippocampus-Dependent Learning. Int J Mol Sci 2020; 21:ijms21041448. [PMID: 32093363 PMCID: PMC7073020 DOI: 10.3390/ijms21041448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/12/2020] [Accepted: 02/18/2020] [Indexed: 12/28/2022] Open
Abstract
SNAP-25 is essential to activity-dependent vesicle fusion and neurotransmitter release in the nervous system. During early development and adulthood, SNAP-25 appears to have differential influences on short- and long-term synaptic plasticity. The involvement of SNAP-25 in these processes may be different at hippocampal and neocortical synapses because of the presence of two different splice variants, which are developmentally regulated. We show here that the isoform SNAP-25a, which is expressed first developmentally in rodent brain, contributes to developmental regulation of the expression of both long-term depression (LTD) and long-term potentiation (LTP) at Schaffer collateral-CA1 synapses in the hippocampus. In one month old mice lacking the developmentally later expressed isoform SNAP-25b, Schaffer collateral-CA1 synapses showed faster release kinetics, decreased LTP and enhanced LTD. By four months of age, SNAP-25b-deficient mice appeared to have compensated for the lack of the adult SNAP-25b isoform, now exhibiting larger LTP and no differences in LTD compared to wild type mice. Interestingly, learning a hippocampus-dependent task reversed the reductions in LTP, but not LTD, seen at one month of age. In four month old adult mice, learning prevented the compensatory up-regulation of LTD that we observed prior to training. These findings support the hypothesis that SNAP-25b promotes stronger LTP and weakens LTD at Schaffer collateral-CA1 synapses in young mice, and suggest that compensatory mechanisms can reverse alterations in synaptic plasticity associated with a lack of SNAP-25b, once mice reach adulthood.
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Affiliation(s)
- Katisha R. Gopaul
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY 10595, USA; (K.R.G.); (M.I.); (O.M.); (L.R.V.); (A.M.); (G.S.)
| | - Muhammad Irfan
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY 10595, USA; (K.R.G.); (M.I.); (O.M.); (L.R.V.); (A.M.); (G.S.)
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden;
| | - Omid Miry
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY 10595, USA; (K.R.G.); (M.I.); (O.M.); (L.R.V.); (A.M.); (G.S.)
| | - Linnea R. Vose
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY 10595, USA; (K.R.G.); (M.I.); (O.M.); (L.R.V.); (A.M.); (G.S.)
| | - Alexander Moghadam
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY 10595, USA; (K.R.G.); (M.I.); (O.M.); (L.R.V.); (A.M.); (G.S.)
| | - Galadu Subah
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY 10595, USA; (K.R.G.); (M.I.); (O.M.); (L.R.V.); (A.M.); (G.S.)
| | - Tomas Hökfelt
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden;
| | - Christina Bark
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden;
- Correspondence: (C.B.); (P.K.S.); Tel. +46-085-248-6984 (C.B.); +1-914-594-4883 (P.K.S.)
| | - Patric K. Stanton
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY 10595, USA; (K.R.G.); (M.I.); (O.M.); (L.R.V.); (A.M.); (G.S.)
- Correspondence: (C.B.); (P.K.S.); Tel. +46-085-248-6984 (C.B.); +1-914-594-4883 (P.K.S.)
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19
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SNAP-25 Puts SNAREs at Center Stage in Metabolic Disease. Neuroscience 2019; 420:86-96. [DOI: 10.1016/j.neuroscience.2018.07.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 07/12/2018] [Accepted: 07/19/2018] [Indexed: 12/20/2022]
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20
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The SNAP-25 Protein Family. Neuroscience 2019; 420:50-71. [DOI: 10.1016/j.neuroscience.2018.09.020] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 08/31/2018] [Accepted: 09/14/2018] [Indexed: 01/04/2023]
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21
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SNAP-25 isoforms differentially regulate synaptic transmission and long-term synaptic plasticity at central synapses. Sci Rep 2019; 9:6403. [PMID: 31024034 PMCID: PMC6484009 DOI: 10.1038/s41598-019-42833-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 04/09/2019] [Indexed: 01/08/2023] Open
Abstract
SNAP-25 exists as two developmentally regulated alternatively spliced isoforms, SNAP-25a and SNAP-25b. We explored the function of SNAP-25a and SNAP-25b at Schaffer collateral-CA1 synapses in hippocampus using 4-week-old wild-type (WT) and SNAP-25b-deficient (MT) mice. Characterizing the protein expression of individual SNAP-25 isoforms revealed that WT females had higher levels of SNAP-25a than WT males, suggesting a sex-dependent delay of the alternative splicing switch from SNAP-25a to SNAP-25b. MT mice expressed normal levels of total SNAP-25, Syntaxin 1A and SNAP-47 in the hippocampus, but females expressed lower levels of VAMP2. Electrophysiological recordings in in vitro hippocampal slices revealed significantly reduced magnitude of LTP in MT mice. We also found reduction in paired-pulse facilitation after induction of LTP in WT males, but not in WT females, possibly related to the difference in SNAP-25a/SNAP-25b ratios, suggesting that the splicing switch may play a sex-specific role in LTP-associated increases in presynaptic release probability. Basal synaptic transmission measured in input-output relations revealed that the ability to discriminate between the intensity of presynaptic stimuli was affected in SNAP-25b-deficient mice. Learning in a behavioural paradigm of active-avoidance was impaired in MT mice, strengthening the conclusion that SNAP-25b is important for cognitive performance by altering activity-dependent synaptic plasticity.
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22
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Zurawski Z, Thompson Gray AD, Brady LJ, Page B, Church E, Harris NA, Dohn MR, Yim YY, Hyde K, Mortlock DP, Jones CK, Winder DG, Alford S, Hamm HE. Disabling the Gβγ-SNARE interaction disrupts GPCR-mediated presynaptic inhibition, leading to physiological and behavioral phenotypes. Sci Signal 2019; 12:12/569/eaat8595. [PMID: 30783011 DOI: 10.1126/scisignal.aat8595] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
G protein-coupled receptors (GPCRs) that couple to Gi/o proteins modulate neurotransmission presynaptically by inhibiting exocytosis. Release of Gβγ subunits from activated G proteins decreases the activity of voltage-gated Ca2+ channels (VGCCs), decreasing excitability. A less understood Gβγ-mediated mechanism downstream of Ca2+ entry is the binding of Gβγ to SNARE complexes, which facilitate the fusion of vesicles with the cell plasma membrane in exocytosis. Here, we generated mice expressing a form of the SNARE protein SNAP25 with premature truncation of the C terminus and that were therefore partially deficient in this interaction. SNAP25Δ3 homozygote mice exhibited normal presynaptic inhibition by GABAB receptors, which inhibit VGCCs, but defective presynaptic inhibition by receptors that work directly on the SNARE complex, such as 5-hydroxytryptamine (serotonin) 5-HT1b receptors and adrenergic α2a receptors. Simultaneously stimulating receptors that act through both mechanisms showed synergistic inhibitory effects. SNAP25Δ3 homozygote mice had various behavioral phenotypes, including increased stress-induced hyperthermia, defective spatial learning, impaired gait, and supraspinal nociception. These data suggest that the inhibition of exocytosis by Gi/o-coupled GPCRs through the Gβγ-SNARE interaction is a crucial component of numerous physiological and behavioral processes.
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Affiliation(s)
- Zack Zurawski
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612, USA
| | | | - Lillian J Brady
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Brian Page
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Emily Church
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Nicholas A Harris
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Michael R Dohn
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Yun Young Yim
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Karren Hyde
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Douglas P Mortlock
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Carrie K Jones
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Danny G Winder
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Simon Alford
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Heidi E Hamm
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.
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23
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SNAP-25 in Major Psychiatric Disorders: A Review. Neuroscience 2019; 420:79-85. [PMID: 30790667 DOI: 10.1016/j.neuroscience.2019.02.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 01/10/2019] [Accepted: 02/07/2019] [Indexed: 02/07/2023]
Abstract
Synaptosomal Associated Protein-25 kilodaltons (SNAP-25) is an integral member of the SNARE complex. This complex is essential for calcium-triggered synaptic vesicular fusion and release of neurotransmitters into the synaptic cleft. In addition to neurotransmission, SNAP-25 is associated with insulin release, the regulation of intracellular calcium, and neuroplasticity. Because of SNAP-25's varied and crucial biological roles, the consequences of changes in this protein can be seen in both the central nervous system and the periphery. In this review, we will look at the published literature from human genetic, postmortem, and animal studies involving SNAP-25. The accumulated data indicate that SNAP-25 may be linked with some symptoms associated with a variety of psychiatric disorders. These disorders include bipolar disorder, schizophrenia, major depressive disorder, attention deficit hyperactivity disorder, autism, alcohol use disorder, and dementia. There are also data suggesting SNAP-25 may be involved with non-psychiatric seizures and metabolic disorders. We believe investigation of SNAP-25 is important for understanding both normal behavior and some aspects of the pathophysiology of behavior seen with psychiatric disorders. The wealth of information from both animal and human studies on SNAP-25 offers an excellent opportunity to use a bi-directional research approach. Hypotheses generated from genetically manipulated mice can be directly tested in human postmortem tissue, and, conversely, human genetic and postmortem findings can improve and validate animal models for psychiatric disorders.
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24
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Dark C, Homman-Ludiye J, Bryson-Richardson RJ. The role of ADHD associated genes in neurodevelopment. Dev Biol 2018; 438:69-83. [DOI: 10.1016/j.ydbio.2018.03.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 03/04/2018] [Accepted: 03/27/2018] [Indexed: 12/19/2022]
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25
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Blue RE, Curry EG, Engels NM, Lee EY, Giudice J. How alternative splicing affects membrane-trafficking dynamics. J Cell Sci 2018; 131:jcs216465. [PMID: 29769303 PMCID: PMC6031328 DOI: 10.1242/jcs.216465] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The cell biology field has outstanding working knowledge of the fundamentals of membrane-trafficking pathways, which are of critical importance in health and disease. Current challenges include understanding how trafficking pathways are fine-tuned for specialized tissue functions in vivo and during development. In parallel, the ENCODE project and numerous genetic studies have revealed that alternative splicing regulates gene expression in tissues and throughout development at a post-transcriptional level. This Review summarizes recent discoveries demonstrating that alternative splicing affects tissue specialization and membrane-trafficking proteins during development, and examines how this regulation is altered in human disease. We first discuss how alternative splicing of clathrin, SNAREs and BAR-domain proteins influences endocytosis, secretion and membrane dynamics, respectively. We then focus on the role of RNA-binding proteins in the regulation of splicing of membrane-trafficking proteins in health and disease. Overall, our aim is to comprehensively summarize how trafficking is molecularly influenced by alternative splicing and identify future directions centered on its physiological relevance.
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Affiliation(s)
- R Eric Blue
- Department of Cell Biology & Physiology, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ennessa G Curry
- Department of Cell Biology & Physiology, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nichlas M Engels
- Department of Cell Biology & Physiology, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Eunice Y Lee
- Department of Cell Biology & Physiology, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jimena Giudice
- Department of Cell Biology & Physiology, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- McAllister Heart Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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26
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Daraio T, Valladolid-Acebes I, Brismar K, Bark C. SNAP-25a and SNAP-25b differently mediate interactions with Munc18-1 and Gβγ subunits. Neurosci Lett 2018; 674:75-80. [PMID: 29548989 DOI: 10.1016/j.neulet.2018.03.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 03/09/2018] [Accepted: 03/12/2018] [Indexed: 02/06/2023]
Abstract
SNAP-25 is a protein involved in regulated membrane fusion and part of the SNARE complex. It exists as two splicing variants, SNAP-25a and SNAP-25b, which differ in 9 out of 206 amino acids. SNAP-25 together with Syntaxin 1 and VAMP-2 forms the ternary SNARE complex essential for mediating activity-dependent release of hormones and neurotransmitters. The functional difference between SNAP-25a and SNAP-25b is poorly understood as both can participate in SNARE complexes and mediate membrane fusion. However, we recently demonstrated that SNAP-25b-deficiency results in metabolic disease and increased insulin secretion. Here we investigated if SNAP-25a and SNAP-25b differently affect interactions with other SNAREs and SNARE-interacting proteins in mouse hippocampus. Adult mice almost exclusively express the SNAP-25b protein in hippocampus whereas SNAP-25b-deficient mice only express SNAP-25a. Immunoprecipitation studies showed no significant differences in amount of Syntaxin 1 and VAMP-2 co-precipitated with the different SNAP-25 isoforms. In contrast, Munc18-1, that preferentially interacts with SNAP-25 via Syntaxin 1 and/or the trimeric SNARE complex, demonstrated an increased ability to bind protein-complexes containing SNAP-25b. Moreover, we found that both SNAP-25 isoforms co-precipitated the Gβγ subunits of the heterotrimeric G proteins, an interaction known to play a role in presynaptic inhibition. We have identified Gβ1 and Gβ2 as the interacting partners of both SNAP-25 isoforms in mouse hippocampus, but Gβ2 was less efficiently captured by SNAP-25a. These results implicate that the two SNAP-25 isoforms could differently mediate protein interactions outside the ternary SNARE core complex and thereby contribute to modulate neurotransmission.
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Affiliation(s)
- Teresa Daraio
- Department of Molecular Medicine and Surgery, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Ismael Valladolid-Acebes
- Department of Molecular Medicine and Surgery, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Kerstin Brismar
- Department of Molecular Medicine and Surgery, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Christina Bark
- Department of Molecular Medicine and Surgery, Karolinska Institutet, SE-171 76 Stockholm, Sweden.
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27
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Abe T, Minowa Y, Kudo H. Molecular characterization and gene expression of synaptosome-associated protein-25 (SNAP-25) in the brain during both seaward and homeward migrations of chum salmon Oncorhynchus keta. Comp Biochem Physiol A Mol Integr Physiol 2018; 217:17-25. [DOI: 10.1016/j.cbpa.2017.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 12/07/2017] [Accepted: 12/08/2017] [Indexed: 01/12/2023]
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28
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Fukuda H, Imagawa E, Hamanaka K, Fujita A, Mitsuhashi S, Miyatake S, Mizuguchi T, Takata A, Miyake N, Kramer U, Matsumoto N, Fattal-Valevski A. A novel missense SNAP25b mutation in two affected siblings from an Israeli family showing seizures and cerebellar ataxia. J Hum Genet 2018; 63:673-676. [DOI: 10.1038/s10038-018-0421-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/17/2018] [Accepted: 01/28/2018] [Indexed: 12/11/2022]
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29
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Small-molecule flunarizine increases SMN protein in nuclear Cajal bodies and motor function in a mouse model of spinal muscular atrophy. Sci Rep 2018; 8:2075. [PMID: 29391529 PMCID: PMC5794986 DOI: 10.1038/s41598-018-20219-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 01/16/2018] [Indexed: 02/07/2023] Open
Abstract
The hereditary neurodegenerative disorder spinal muscular atrophy (SMA) is characterized by the loss of spinal cord motor neurons and skeletal muscle atrophy. SMA is caused by mutations of the survival motor neuron (SMN) gene leading to a decrease in SMN protein levels. The SMN deficiency alters nuclear body formation and whether it can contribute to the disease remains unclear. Here we screen a series of small-molecules on SMA patient fibroblasts and identify flunarizine that accumulates SMN into Cajal bodies, the nuclear bodies important for the spliceosomal small nuclear RNA (snRNA)-ribonucleoprotein biogenesis. Using histochemistry, real-time RT-PCR and behavioural analyses in a mouse model of SMA, we show that along with the accumulation of SMN into Cajal bodies of spinal cord motor neurons, flunarizine treatment modulates the relative abundance of specific spliceosomal snRNAs in a tissue-dependent manner and can improve the synaptic connections and survival of spinal cord motor neurons. The treatment also protects skeletal muscles from cell death and atrophy, raises the neuromuscular junction maturation and prolongs life span by as much as 40 percent (p < 0.001). Our findings provide a functional link between flunarizine and SMA pathology, highlighting the potential benefits of flunarizine in a novel therapeutic perspective against neurodegenerative diseases.
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30
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Hippocampal Pathophysiology: Commonality Shared by Temporal Lobe Epilepsy and Psychiatric Disorders. NEUROSCIENCE JOURNAL 2018; 2018:4852359. [PMID: 29610762 PMCID: PMC5828345 DOI: 10.1155/2018/4852359] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 12/02/2017] [Accepted: 12/20/2017] [Indexed: 11/18/2022]
Abstract
Accumulating evidence points to the association of epilepsy, particularly, temporal lobe epilepsy (TLE), with psychiatric disorders, such as schizophrenia. Among these illnesses, the hippocampus is considered the regional focal point of the brain, playing an important role in cognition, psychosis, and seizure activity and potentially suggesting common etiologies and pathophysiology of TLE and schizophrenia. In the present review, we overview abnormal network connectivity between the dentate gyrus (DG) and the Cornus Ammonis area 3 (CA3) subregions of the hippocampus relative to the induction of epilepsy and schizophrenia. In light of our recent finding on the misguidance of hippocampal mossy fiber projection in the rodent model of schizophrenia, we discuss whether ectopic mossy fiber projection is a commonality in order to evoke TLE as well as symptoms related to schizophrenia.
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31
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Hatje K, Rahman RU, Vidal RO, Simm D, Hammesfahr B, Bansal V, Rajput A, Mickael ME, Sun T, Bonn S, Kollmar M. The landscape of human mutually exclusive splicing. Mol Syst Biol 2017; 13:959. [PMID: 29242366 PMCID: PMC5740500 DOI: 10.15252/msb.20177728] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Mutually exclusive splicing of exons is a mechanism of functional gene and protein diversification with pivotal roles in organismal development and diseases such as Timothy syndrome, cardiomyopathy and cancer in humans. In order to obtain a first genomewide estimate of the extent and biological role of mutually exclusive splicing in humans, we predicted and subsequently validated mutually exclusive exons (MXEs) using 515 publically available RNA‐Seq datasets. Here, we provide evidence for the expression of over 855 MXEs, 42% of which represent novel exons, increasing the annotated human mutually exclusive exome more than fivefold. The data provide strong evidence for the existence of large and multi‐cluster MXEs in higher vertebrates and offer new insights into MXE evolution. More than 82% of the MXE clusters are conserved in mammals, and five clusters have homologous clusters in Drosophila. Finally, MXEs are significantly enriched in pathogenic mutations and their spatio‐temporal expression might predict human disease pathology.
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Affiliation(s)
- Klas Hatje
- Group Systems Biology of Motor Proteins Department of NMR-Based Structural Biology Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.,Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany
| | - Raza-Ur Rahman
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany.,Center for Molecular Neurobiology, Institute of Medical Systems Biology University Clinic Hamburg-Eppendorf, Hamburg, Germany
| | - Ramon O Vidal
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany
| | - Dominic Simm
- Group Systems Biology of Motor Proteins Department of NMR-Based Structural Biology Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.,Theoretical Computer Science and Algorithmic Methods, Institute of Computer Science Georg-August-University, Göttingen, Germany
| | - Björn Hammesfahr
- Group Systems Biology of Motor Proteins Department of NMR-Based Structural Biology Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Vikas Bansal
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany.,Center for Molecular Neurobiology, Institute of Medical Systems Biology University Clinic Hamburg-Eppendorf, Hamburg, Germany
| | - Ashish Rajput
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany.,Center for Molecular Neurobiology, Institute of Medical Systems Biology University Clinic Hamburg-Eppendorf, Hamburg, Germany
| | - Michel Edwar Mickael
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany.,Center for Molecular Neurobiology, Institute of Medical Systems Biology University Clinic Hamburg-Eppendorf, Hamburg, Germany
| | - Ting Sun
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany.,Center for Molecular Neurobiology, Institute of Medical Systems Biology University Clinic Hamburg-Eppendorf, Hamburg, Germany
| | - Stefan Bonn
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany .,Center for Molecular Neurobiology, Institute of Medical Systems Biology University Clinic Hamburg-Eppendorf, Hamburg, Germany.,German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Martin Kollmar
- Group Systems Biology of Motor Proteins Department of NMR-Based Structural Biology Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
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32
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Daraio T, Bombek LK, Gosak M, Valladolid-Acebes I, Klemen MS, Refai E, Berggren PO, Brismar K, Rupnik MS, Bark C. SNAP-25b-deficiency increases insulin secretion and changes spatiotemporal profile of Ca 2+oscillations in β cell networks. Sci Rep 2017; 7:7744. [PMID: 28798351 PMCID: PMC5552776 DOI: 10.1038/s41598-017-08082-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/04/2017] [Indexed: 01/02/2023] Open
Abstract
SNAP-25 is a protein of the core SNARE complex mediating stimulus-dependent release of insulin from pancreatic β cells. The protein exists as two alternatively spliced isoforms, SNAP-25a and SNAP-25b, differing in 9 out of 206 amino acids, yet their specific roles in pancreatic β cells remain unclear. We explored the effect of SNAP-25b-deficiency on glucose-stimulated insulin release in islets and found increased secretion both in vivo and in vitro. However, slow photo-release of caged Ca2+ in β cells within pancreatic slices showed no significant differences in Ca2+-sensitivity, amplitude or rate of exocytosis between SNAP-25b-deficient and wild-type littermates. Therefore, we next investigated if Ca2+ handling was affected in glucose-stimulated β cells using intracellular Ca2+-imaging and found premature activation and delayed termination of [Ca2+]i elevations. These findings were accompanied by less synchronized Ca2+-oscillations and hence more segregated functional β cell networks in SNAP-25b-deficient mice. Islet gross morphology and architecture were maintained in mutant mice, although sex specific compensatory changes were observed. Thus, our study proposes that SNAP-25b in pancreatic β cells, except for participating in the core SNARE complex, is necessary for accurate regulation of Ca2+-dynamics.
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Affiliation(s)
- Teresa Daraio
- The Rolf Luft Research Center for Diabetes and Endocrinology, Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 76, Stockholm, Sweden
| | - Lidija Križančić Bombek
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000, Maribor, Slovenia
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000, Maribor, Slovenia.,Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000, Maribor, Slovenia
| | - Ismael Valladolid-Acebes
- The Rolf Luft Research Center for Diabetes and Endocrinology, Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 76, Stockholm, Sweden
| | - Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000, Maribor, Slovenia
| | - Essam Refai
- The Rolf Luft Research Center for Diabetes and Endocrinology, Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 76, Stockholm, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 76, Stockholm, Sweden
| | - Kerstin Brismar
- The Rolf Luft Research Center for Diabetes and Endocrinology, Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 76, Stockholm, Sweden
| | - Marjan Slak Rupnik
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000, Maribor, Slovenia. .,Center for Physiology and Pharmacology, Medical University of Vienna, A-1090, Vienna, Austria.
| | - Christina Bark
- The Rolf Luft Research Center for Diabetes and Endocrinology, Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 76, Stockholm, Sweden.
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33
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Epilepsy and synaptic proteins. Curr Opin Neurobiol 2017; 45:1-8. [DOI: 10.1016/j.conb.2017.02.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 01/25/2017] [Accepted: 02/01/2017] [Indexed: 12/22/2022]
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34
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Song Y, Botvinnik OB, Lovci MT, Kakaradov B, Liu P, Xu JL, Yeo GW. Single-Cell Alternative Splicing Analysis with Expedition Reveals Splicing Dynamics during Neuron Differentiation. Mol Cell 2017; 67:148-161.e5. [PMID: 28673540 DOI: 10.1016/j.molcel.2017.06.003] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 03/29/2017] [Accepted: 06/02/2017] [Indexed: 12/28/2022]
Abstract
Alternative splicing (AS) generates isoform diversity for cellular identity and homeostasis in multicellular life. Although AS variation has been observed among single cells, little is known about the biological or evolutionary significance of such variation. We developed Expedition, a computational framework consisting of outrigger, a de novo splice graph transversal algorithm to detect AS; anchor, a Bayesian approach to assign modalities; and bonvoyage, a visualization tool using non-negative matrix factorization to display modality changes. Applying Expedition to single pluripotent stem cells undergoing neuronal differentiation, we discover that up to 20% of AS exons exhibit bimodality. Bimodal exons are flanked by more conserved intronic sequences harboring distinct cis-regulatory motifs, constitute much of cell-type-specific splicing, are highly dynamic during cellular transitions, preserve reading frame, and reveal intricacy of cell states invisible to conventional gene expression analysis. Systematic AS characterization in single cells redefines our understanding of AS complexity in cell biology.
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Affiliation(s)
- Yan Song
- Department of Cellular and Molecular Medicine, Stem Cell Program and Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Olga B Botvinnik
- Department of Cellular and Molecular Medicine, Stem Cell Program and Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michael T Lovci
- Department of Cellular and Molecular Medicine, Stem Cell Program and Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Boyko Kakaradov
- Department of Cellular and Molecular Medicine, Stem Cell Program and Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Patrick Liu
- Department of Cellular and Molecular Medicine, Stem Cell Program and Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jia L Xu
- Department of Cellular and Molecular Medicine, Stem Cell Program and Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, Stem Cell Program and Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore; Molecular Engineering Laboratory, A(∗)STAR, Singapore 138632, Singapore.
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35
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van Deijk ALF, Camargo N, Timmerman J, Heistek T, Brouwers JF, Mogavero F, Mansvelder HD, Smit AB, Verheijen MHG. Astrocyte lipid metabolism is critical for synapse development and function in vivo. Glia 2017; 65:670-682. [PMID: 28168742 DOI: 10.1002/glia.23120] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 01/08/2017] [Accepted: 01/10/2017] [Indexed: 12/21/2022]
Abstract
The brain is considered to be autonomous in lipid synthesis with astrocytes producing lipids far more efficiently than neurons. Accordingly, it is generally assumed that astrocyte-derived lipids are taken up by neurons to support synapse formation and function. Initial confirmation of this assumption has been obtained in cell cultures, but whether astrocyte-derived lipids support synapses in vivo is not known. Here, we address this issue and determined the role of astrocyte lipid metabolism in hippocampal synapse formation and function in vivo. Hippocampal protein expression for the sterol regulatory element-binding protein (SREBP) and its target gene fatty acid synthase (Fasn) was found in astrocytes but not in neurons. Diminishing SREBP activity in astrocytes using mice in which the SREBP cleavage-activating protein (SCAP) was deleted from GFAP-expressing cells resulted in decreased cholesterol and phospholipid secretion by astrocytes. Interestingly, SCAP mutant mice showed more immature synapses, lower presynaptic protein SNAP-25 levels as well as reduced numbers of synaptic vesicles, indicating impaired development of the presynaptic terminal. Accordingly, hippocampal short-term and long-term synaptic plasticity were defective in mutant mice. These findings establish a critical role for astrocyte lipid metabolism in presynaptic terminal development and function in vivo. GLIA 2017;65:670-682.
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Affiliation(s)
- Anne-Lieke F van Deijk
- Department of Molecular & Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - Nutabi Camargo
- Department of Molecular & Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - Jaap Timmerman
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - Tim Heistek
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - Jos F Brouwers
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Yalelaan 1, 3584 CL Utrecht University, Utrecht, The Netherlands
| | - Floriana Mogavero
- Department of Molecular & Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - Huibert D Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - August B Smit
- Department of Molecular & Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - Mark H G Verheijen
- Department of Molecular & Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
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36
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Damianov A, Ying Y, Lin CH, Lee JA, Tran D, Vashisht AA, Bahrami-Samani E, Xing Y, Martin KC, Wohlschlegel JA, Black DL. Rbfox Proteins Regulate Splicing as Part of a Large Multiprotein Complex LASR. Cell 2016; 165:606-19. [PMID: 27104978 DOI: 10.1016/j.cell.2016.03.040] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 12/18/2015] [Accepted: 03/22/2016] [Indexed: 12/11/2022]
Abstract
Rbfox proteins control alternative splicing and posttranscriptional regulation in mammalian brain and are implicated in neurological disease. These proteins recognize the RNA sequence (U)GCAUG, but their structures and diverse roles imply a variety of protein-protein interactions. We find that nuclear Rbfox proteins are bound within a large assembly of splicing regulators (LASR), a multimeric complex containing the proteins hnRNP M, hnRNP H, hnRNP C, Matrin3, NF110/NFAR-2, NF45, and DDX5, all approximately equimolar to Rbfox. We show that splicing repression mediated by hnRNP M is stimulated by Rbfox. Virtually all the intron-bound Rbfox is associated with LASR, and hnRNP M motifs are enriched adjacent to Rbfox crosslinking sites in vivo. These findings demonstrate that Rbfox proteins bind RNA with a defined set of cofactors and affect a broader set of exons than previously recognized. The function of this multimeric LASR complex has implications for deciphering the regulatory codes controlling splicing networks.
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Affiliation(s)
- Andrey Damianov
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yi Ying
- Molecular Biology Interdepartmental Ph.D. Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Chia-Ho Lin
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ji-Ann Lee
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Diana Tran
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ajay A Vashisht
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Emad Bahrami-Samani
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yi Xing
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Kelsey C Martin
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - James A Wohlschlegel
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Douglas L Black
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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37
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Barakauskas VE, Moradian A, Barr AM, Beasley CL, Rosoklija G, Mann JJ, Ilievski B, Stankov A, Dwork AJ, Falkai P, Morin GB, Honer WG. Quantitative mass spectrometry reveals changes in SNAP-25 isoforms in schizophrenia. Schizophr Res 2016; 177:44-51. [PMID: 26971072 PMCID: PMC5017887 DOI: 10.1016/j.schres.2016.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/02/2016] [Accepted: 03/04/2016] [Indexed: 11/24/2022]
Abstract
SNAP-25 and syntaxin are presynaptic terminal SNARE proteins altered in amount and function in schizophrenia. In the ventral caudate, we observed 32% lower SNAP-25 and 26% lower syntaxin, but greater interaction between the two proteins using an in vitro assay. SNAP-25 has two isoforms, SNAP-25A and B, differing by only 9 amino acids, but with different effects on neurotransmission. A quantitative mass spectrometry assay was developed to measure total SNAP-25, and proportions of SNAP-25A and B. The assay had a good linear range (50- to 150-fold) and coefficient of variation (4.5%). We studied ventral caudate samples from patients with schizophrenia (n=15) previously reported to have lower total SNAP-25 than controls (n=13). We confirmed 27% lower total SNAP-25 in schizophrenia, and observed 31% lower SNAP-25A (P=0.002) with 20% lower SNAP-25B amounts (P=0.10). Lower SNAP-25A amount correlated with greater SNAP-25-syntaxin protein-protein interactions (r=-0.41, P=0.03); the level of SNAP-25B did not. Administration of haloperidol or clozapine to rats did not mimic the changes found in schizophrenia. The findings suggest that lower levels of SNAP-25 in schizophrenia may represent a greater effect of the illness on the SNAP-25A isoform. This in turn could contribute to the greater interaction between SNAP25 and syntaxin, and possibly disturb neurotransmission in the illness.
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Affiliation(s)
- Vilte E Barakauskas
- BC Mental Health and Addictions Research Institute, Vancouver, BC,Department of Psychiatry, University of British Columbia, Vancouver, BC
| | - Annie Moradian
- Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, BC
| | - Alasdair M. Barr
- BC Mental Health and Addictions Research Institute, Vancouver, BC,Department of Anesthesiology, Pharmacology & Therapeutics, University of British Columbia, Vancouver, BC
| | - Clare L Beasley
- BC Mental Health and Addictions Research Institute, Vancouver, BC,Department of Psychiatry, University of British Columbia, Vancouver, BC
| | - Gorazd Rosoklija
- Department of Molecular Imaging and Neuropathology, New York State Psychiatric Institute; and Department of Psychiatry, Columbia University, New York, NY, USA,Macedonian Academy of Sciences and Arts, University “SS. Cyril and Methodius,” Skopje, Macedonia
| | - J John Mann
- Department of Molecular Imaging and Neuropathology, New York State Psychiatric Institute; and Department of Psychiatry, Columbia University, New York, NY, USA
| | - Boro Ilievski
- Department of Molecular Imaging and Neuropathology, New York State Psychiatric Institute; and Department of Psychiatry, Columbia University, New York, NY, USA,Institute for Pathology, University “SS. Cyril and Methodius,” Skopje, Macedonia
| | - Aleksandar Stankov
- Institute of Forensic Medicine, Criminology and Medical Deontology, University “SS. Cyril and Methodius,” Skopje, Macedonia
| | - Andrew J Dwork
- Department of Molecular Imaging and Neuropathology, New York State Psychiatric Institute; and Department of Psychiatry, Columbia University, New York, NY, USA,Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Peter Falkai
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Germany
| | - Gregg B Morin
- Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, BC, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.
| | - William G Honer
- BC Mental Health and Addictions Research Institute, Vancouver, BC, Canada; Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
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38
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Abstract
Alternative precursor-mRNA splicing is a key mechanism for regulating gene expression in mammals and is controlled by specialized RNA-binding proteins. The misregulation of splicing is implicated in multiple neurological disorders. We describe recent mouse genetic studies of alternative splicing that reveal its critical role in both neuronal development and the function of mature neurons. We discuss the challenges in understanding the extensive genetic programmes controlled by proteins that regulate splicing, both during development and in the adult brain.
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Affiliation(s)
- Celine K Vuong
- Molecular Biology Interdepartmental Graduate Program, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Douglas L Black
- Department of Microbiology, Immunology, and Molecular Genetics, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Sika Zheng
- Division of Biomedical Sciences, University of California at Riverside, Riverside, California 92521, USA
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39
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Valladolid-Acebes I, Daraio T, Brismar K, Hökfelt T, Bark C. Minor differences in the molecular machinery mediating regulated membrane fusion has major impact on metabolic health. Adipocyte 2016; 5:318-25. [PMID: 27617177 DOI: 10.1080/21623945.2015.1137689] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 12/21/2015] [Accepted: 12/24/2015] [Indexed: 12/16/2022] Open
Abstract
The exocytosis of signaling molecules from neuronal, neuroendocrine and endocrine cells is regulated by membrane fusion involving SNAP-25 and associated SNARE proteins. The importance of this process for metabolic control recently became evident by studies of mouse mutants genetically engineered to only express one of 2 closely related, alternatively-spliced variants of SNAP-25. The results showed that even minor differences in the function of proteins regulating exocytosis are sufficient to provoke metabolic disease, including hyperglycaemia, liver steatosis, adipocyte hypertrophy and obesity. Thus, an imbalance in the dynamics of hormonal and/or neurotransmitter release can cause obesity and type 2 diabetes. This recent discovery highlights the fact that metabolic health requires a perfectly operating interplay between the SNARE protein machinery in excitable cells and the organs responding to these messengers.
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40
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Yang L, Ke XX, Xuan F, Tan J, Hou J, Wang M, Cui H, Zhang Y. PHOX2B Is Associated with Neuroblastoma Cell Differentiation. Cancer Biother Radiopharm 2016; 31:44-51. [PMID: 26910576 DOI: 10.1089/cbr.2015.1952] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Neuroblastoma is a common pediatric malignancy that accounts for ∼15% of tumor-related deaths in children. The tumor is generally believed to originate from neural crest cells during early sympathetic neurogenesis. As the degree of neuroblastoma differentiation has been correlated with clinical outcome, clarifying the molecular mechanisms that drive neuroblastoma progression and differentiation is important for increasing the survival of these patients. In a previous study, the authors identified paired-like homeobox 2b (PHOX2B) as a key mediator of neuroblastoma pathogenesis in a TH-MYCN mouse model. In the present study, they aimed to define whether PHOX2B is also associated with proliferation and differentiation of human neuroblastoma cells. PHOX2B expression in neuroblastoma cells was evaluated by immunoblot analyses, and the effects of PHOX2B on the proliferation of neuroblastoma cells in vitro were determined using clonogenic and sphere formation assays. Xenograft experiments in NOD/SCID mice were used to examine the in vivo response to PHOX2B knockdown. Their data demonstrated that PHOX2B acts as a prognostic marker in neuroblastoma and that retinoic acid-induced neuronal differentiation downregulates PHOX2B expression, thereby suppressing the self-renewal capacity of neuroblastoma cells and inhibiting tumorigenicity. These findings confirmed that PHOX2B is a key regulator of neuroblastoma differentiation and stemness maintenance and indicated that PHOX2B might serve as a potential therapeutic target in neuroblastoma patients.
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Affiliation(s)
- Liqun Yang
- 1 Cell Biology Laboratory, State Key Laboratory of Silkworm Genome Biology, Southwest University , Chongqing, P.R. China
| | - Xiao-Xue Ke
- 1 Cell Biology Laboratory, State Key Laboratory of Silkworm Genome Biology, Southwest University , Chongqing, P.R. China
| | - Fan Xuan
- 1 Cell Biology Laboratory, State Key Laboratory of Silkworm Genome Biology, Southwest University , Chongqing, P.R. China
| | - Juan Tan
- 1 Cell Biology Laboratory, State Key Laboratory of Silkworm Genome Biology, Southwest University , Chongqing, P.R. China
| | - Jianbing Hou
- 1 Cell Biology Laboratory, State Key Laboratory of Silkworm Genome Biology, Southwest University , Chongqing, P.R. China
| | - Mei Wang
- 1 Cell Biology Laboratory, State Key Laboratory of Silkworm Genome Biology, Southwest University , Chongqing, P.R. China
| | - Hongjuan Cui
- 1 Cell Biology Laboratory, State Key Laboratory of Silkworm Genome Biology, Southwest University , Chongqing, P.R. China
| | - Yundong Zhang
- 2 Department of Neurosurgery, Research Institute of Surgery, Daping Hospital, Third Military Medical University , Chongqing, P.R. China
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41
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Cupertino RB, Kappel DB, Bandeira CE, Schuch JB, da Silva BS, Müller D, Bau CHD, Mota NR. SNARE complex in developmental psychiatry: neurotransmitter exocytosis and beyond. J Neural Transm (Vienna) 2016; 123:867-83. [DOI: 10.1007/s00702-016-1514-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 01/20/2016] [Indexed: 12/31/2022]
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42
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Watanabe S, Yamamori S, Otsuka S, Saito M, Suzuki E, Kataoka M, Miyaoka H, Takahashi M. Epileptogenesis and epileptic maturation in phosphorylation site-specific SNAP-25 mutant mice. Epilepsy Res 2015. [DOI: 10.1016/j.eplepsyres.2015.05.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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43
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Abstract
Synaptosomal-associated protein of 25 kDa (SNAP-25) is a key molecule in the soluble N-ethylmaleimide-sensitive factor attachment protein (SNARE) complex mediating fast Ca(2+)-triggered release of hormones and neurotransmitters, and both splice variants, SNAP-25a and SNAP-25b, can participate in this process. Here we explore the hypothesis that minor alterations in the machinery mediating regulated membrane fusion can increase the susceptibility for metabolic disease and precede obesity and type 2 diabetes. Thus, we used a mouse mutant engineered to express normal levels of SNAP-25 but only SNAP-25a. These SNAP-25b-deficient mice were exposed to either a control or a high-fat/high-sucrose diet. Monitoring of food intake, body weight, hypothalamic function, and lipid and glucose homeostases showed that SNAP-25b-deficient mice fed with control diet developed hyperglycemia, liver steatosis, and adipocyte hypertrophy, conditions dramatically exacerbated when combined with the high-fat/high-sucrose diet. Thus, modified SNARE function regulating stimulus-dependent exocytosis can increase the vulnerability to and even provoke metabolic disease. When combined with a high-fat/high-sucrose diet, this vulnerability resulted in diabesity. Our SNAP-25b-deficient mouse may represent a diabesity model.
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44
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SNAREs Controlling Vesicular Release of BDNF and Development of Callosal Axons. Cell Rep 2015; 11:1054-66. [PMID: 25959820 DOI: 10.1016/j.celrep.2015.04.032] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 03/11/2015] [Accepted: 04/14/2015] [Indexed: 11/22/2022] Open
Abstract
At presynaptic active zones, exocytosis of neurotransmitter vesicles (SVs) is driven by SNARE complexes that recruit Syb2 and SNAP25. However, it remains unknown which SNAREs promote the secretion of neuronal proteins, including those essential for circuit development and experience-dependent plasticity. Here we demonstrate that Syb2 and SNAP25 mediate the vesicular release of BDNF in axons and dendrites of cortical neurons, suggesting these SNAREs act in multiple spatially segregated secretory pathways. Remarkably, axonal secretion of BDNF is also strongly regulated by SNAP47, which interacts with SNAP25 but appears to be dispensable for exocytosis of SVs. Cell-autonomous ablation of SNAP47 disrupts the layer-specific branching of callosal axons of projection cortical neurons in vivo, and this phenotype is recapitulated by ablation of BDNF or its receptor, TrkB. Our results provide insights into the molecular mechanisms of protein secretion, and they define the functions of SNAREs in BDNF signaling and regulation of neuronal connectivity.
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45
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Glazova MV, Nikitina LS, Hudik KA, Kirillova OD, Dorofeeva NA, Korotkov AA, Chernigovskaya EV. Inhibition of ERK1/2 signaling prevents epileptiform behavior in rats prone to audiogenic seizures. J Neurochem 2014; 132:218-29. [PMID: 25351927 DOI: 10.1111/jnc.12982] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 10/14/2014] [Accepted: 10/22/2014] [Indexed: 01/24/2023]
Abstract
It has recently been proposed that extracellular signal-regulated kinases 1 and 2 (ERK1/2) are one of the factors mediating seizure development. We hypothesized that inhibition of ERK1/2 activity could prevent audiogenic seizures by altering GABA and glutamate release mechanisms. Krushinsky-Molodkina rats, genetically prone to audiogenic seizure, were recruited in the experiments. Animals were i.p. injected with an inhibitor of ERK1/2 SL 327 at different doses 60 min before audio stimulation. We demonstrated for the first time that inhibition of ERK1/2 activity by SL 327 injections prevented seizure behavior and this effect was dose-dependent and correlated with ERK1/2 activity. The obtained data also demonstrated unchanged levels of GABA production, and an increase in the level of vesicular glutamate transporter 2. The study of exocytosis protein expression showed that SL 327 treatment leads to downregulation of vesicle-associated membrane protein 2 and synapsin I, and accumulation of synaptosomal-associated protein 25 (SNAP-25). The obtained data indicate that the inhibition of ERK1/2 blocks seizure behavior presumably by altering the exocytosis machinery, and identifies ERK1/2 as a potential target for the development of new strategies for seizure treatment. Extracellular signal-regulated kinases 1 and 2 (ERK1/2) are one of the factors mediating seizure development. Here we report that inhibition of ERK1/2 by SL 327 prevented seizure behavior and this effect was dose-dependent and correlated with ERK1/2 activity. Accumulation of VGLUT2 was associated with differential changing of synaptic proteins VAMP2, SNAP-25 and synapsin I. The obtained data indicate that the inhibition of ERK1/2 alters neurotransmitter release by changing the exocytosis machinery, thus preventing seizures.
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Affiliation(s)
- Margarita V Glazova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Saint-Petersburg, Russia
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46
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Xie J. Differential evolution of signal-responsive RNA elements and upstream factors that control alternative splicing. Cell Mol Life Sci 2014; 71:4347-60. [PMID: 25064062 PMCID: PMC11113106 DOI: 10.1007/s00018-014-1688-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 07/13/2014] [Accepted: 07/17/2014] [Indexed: 12/17/2022]
Abstract
Cell signal-regulated alternative splicing occurs for many genes but the evolutionary origin of the regulatory components and their relationship remain unclear. This review focuses on the alternative splicing components of several systems based on the available bioinformatics data. Eight mammalian RNA elements for signal-regulated splicing were aligned among corresponding sequences from dozens of representative vertebrate species to allow for assessment of the trends in evolutionary changes. Four distinct trends were observed. Four of the elements are highly conserved in bird, reptile and fish species examined (i); two elements can be found in fish but the sequences have been changing till in marsupials or higher mammals (ii); one element is almost exclusively found in mammals with mostly the same sequence (iii); and one element can be found in birds or lower vertebrates but expanded abruptly to have variable numbers of copies in mammals (iv). All examined prototype trans-acting factors and protein kinases emerged earlier than the RNA elements but additional (paralog) factors emerged in the same or later species. Thus, after their emergence mainly in fish or mammals with pre-existing prototype trans-acting factors/kinases, half of the elements have been highly conserved from fish to humans but the other half have evolved differentially with additional trans-acting factors. Their differential evolution likely contributes to the exon- and species/class-specific control of alternative splicing and its regulation by cell signals. The evolvement of a group of mammal-specific components would help relay signals from extracellular stimuli to the splicing machinery and thus contribute to higher proteomic diversity.
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Affiliation(s)
- Jiuyong Xie
- Departments of Physiology, Biochemistry and Medical Genetics, Faculty of Medicine, University of Manitoba, Winnipeg, MB, R3E 0J9, Canada,
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47
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Lovci MT, Ghanem D, Marr H, Arnold J, Gee S, Parra M, Liang TY, Stark TJ, Gehman LT, Hoon S, Massirer KB, Pratt GA, Black DL, Gray JW, Conboy JG, Yeo GW. Rbfox proteins regulate alternative mRNA splicing through evolutionarily conserved RNA bridges. Nat Struct Mol Biol 2013; 20:1434-42. [PMID: 24213538 DOI: 10.1038/nsmb.2699] [Citation(s) in RCA: 248] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 09/19/2013] [Indexed: 02/08/2023]
Abstract
Alternative splicing (AS) enables programmed diversity of gene expression across tissues and development. We show here that binding in distal intronic regions (>500 nucleotides (nt) from any exon) by Rbfox splicing factors important in development is extensive and is an active mode of splicing regulation. Similarly to exon-proximal sites, distal sites contain evolutionarily conserved GCATG sequences and are associated with AS activation and repression upon modulation of Rbfox abundance in human and mouse experimental systems. As a proof of principle, we validated the activity of two specific Rbfox enhancers in KIF21A and ENAH distal introns and showed that a conserved long-range RNA-RNA base-pairing interaction (an RNA bridge) is necessary for Rbfox-mediated exon inclusion in the ENAH gene. Thus we demonstrate a previously unknown RNA-mediated mechanism for AS control by distally bound RNA-binding proteins.
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Affiliation(s)
- Michael T Lovci
- 1] Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California, USA. [2] Stem Cell Program, University of California, San Diego, La Jolla, California, USA. [3] Institute for Genomic Medicine, University of California, San Diego, La Jolla, California, USA
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48
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Németh N, Kerékgyártó M, Sasvári-Székely M, Rónai Z, Guttman A. Rapid identification of human SNAP-25 transcript variants by a miniaturized capillary electrophoresis system. Electrophoresis 2013; 35:379-84. [DOI: 10.1002/elps.201300221] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 05/28/2013] [Accepted: 05/29/2013] [Indexed: 12/25/2022]
Affiliation(s)
- Nóra Németh
- Department of Medical Chemistry; Molecular Biology and Pathobiochemistry, Semmelweis University; Budapest Hungary
| | - Márta Kerékgyártó
- Horváth Laboratory of Bioseparation Sciences; University of Debrecen; Debrecen Hungary
| | - Mária Sasvári-Székely
- Department of Medical Chemistry; Molecular Biology and Pathobiochemistry, Semmelweis University; Budapest Hungary
| | - Zsolt Rónai
- Department of Medical Chemistry; Molecular Biology and Pathobiochemistry, Semmelweis University; Budapest Hungary
| | - András Guttman
- Horváth Laboratory of Bioseparation Sciences; University of Debrecen; Debrecen Hungary
- MTA-PE Translational Glycomics Group; University of Pannonia; Veszprém Hungary
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49
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Rohena L, Neidich J, Truitt Cho M, Gonzalez KD, Tang S, Devinsky O, Chung WK. Mutation in SNAP25 as a novel genetic cause of epilepsy and intellectual disability. Rare Dis 2013; 1:e26314. [PMID: 25003006 PMCID: PMC3932847 DOI: 10.4161/rdis.26314] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 08/26/2013] [Accepted: 08/29/2013] [Indexed: 12/23/2022] Open
Abstract
Whole exome sequencing using a parent-child trio design to identify de novo mutations provides an efficient method to identify novel genes for rare diseases with low reproductive fitness that are difficult to study by more classical genetic methods of linkage analysis. We describe a 15 y old female with severe static encephalopathy, intellectual disability, and generalized epilepsy. After extensive metabolic and genetic testing, whole exome sequencing identified a novel de novo variant in Synaptosomal-associated protein-25 (SNAP25), c.142G > T p.Phe48Val alteration. This variant is predicted to be damaging by all prediction algorithms. SNAP25 is part of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein complex which is involved in exocytotic release of neurotransmitters. Genetic alterations in Snap25 in animal models can cause anxiety-related behavior, ataxia and seizures. We suggest that SNAP25 mutations in humans are a novel genetic cause of intellectual disability and epilepsy.
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Affiliation(s)
- Luis Rohena
- Children's Hospital of New York; New York City, NY USA
| | | | | | | | - Sha Tang
- Ambry Genetics; Aliso Viejo, CA USA
| | | | - Wendy K Chung
- Columbia University Medical Center; New York City, NY USA
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50
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Dong Y, Gu Y, Huan Y, Wang Y, Liu Y, Liu M, Ding F, Gu X, Wang Y. HMGB1 protein does not mediate the inflammatory response in spontaneous spinal cord regeneration: a hint for CNS regeneration. J Biol Chem 2013; 288:18204-18. [PMID: 23649623 DOI: 10.1074/jbc.m113.463810] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Uncontrolled, excessive inflammation contributes to the secondary tissue damage of traumatic spinal cord, and HMGB1 is highlighted for initiation of a vicious self-propagating inflammatory circle by release from necrotic cells or immune cells. Several regenerative-competent vertebrates have evolved to circumvent the second damages during the spontaneous spinal cord regeneration with an unknown HMGB1 regulatory mechanism. By genomic surveys, we have revealed that two paralogs of HMGB1 are broadly retained from fish in the phylogeny. However, their spatial-temporal expression and effects, as shown in lowest amniote gecko, were tightly controlled in order that limited inflammation was produced in spontaneous regeneration. Two paralogs from gecko HMGB1 (gHMGB1) yielded distinct injury and infectious responses, with gHMGB1b significantly up-regulated in the injured cord. The intracellular gHMGB1b induced less release of inflammatory cytokines than gHMGB1a in macrophages, and the effects could be shifted by exchanging one amino acid in the inflammatory domain. Both intracellular proteins were able to mediate neuronal programmed apoptosis, which has been indicated to produce negligible inflammatory responses. In vivo studies demonstrated that the extracellular proteins could not trigger a cascade of the inflammatory cytokines in the injured spinal cord. Signal transduction analysis found that gHMGB1 proteins could not bind with cell surface receptors TLR2 and TLR4 to activate inflammatory signaling pathway. However, they were able to interact with the receptor for advanced glycation end products to potentiate oligodendrocyte migration by activation of both NFκB and Rac1/Cdc42 signaling. Our results reveal that HMGB1 does not mediate the inflammatory response in spontaneous spinal cord regeneration, but it promotes CNS regeneration.
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Affiliation(s)
- Yingying Dong
- Key Laboratory of Neuroregeneration, Nantong University, Nantong 226007, China
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