51
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Worpenberg L, Paolantoni C, Longhi S, Mulorz MM, Lence T, Wessels HH, Dassi E, Aiello G, Sutandy FXR, Scheibe M, Edupuganti RR, Busch A, Möckel MM, Vermeulen M, Butter F, König J, Notarangelo M, Ohler U, Dieterich C, Quattrone A, Soldano A, Roignant JY. Ythdf is a N6-methyladenosine reader that modulates Fmr1 target mRNA selection and restricts axonal growth in Drosophila. EMBO J 2021; 40:e104975. [PMID: 33428246 PMCID: PMC7883056 DOI: 10.15252/embj.2020104975] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 11/18/2020] [Accepted: 11/30/2020] [Indexed: 12/19/2022] Open
Abstract
N6‐methyladenosine (m6A) regulates a variety of physiological processes through modulation of RNA metabolism. This modification is particularly enriched in the nervous system of several species, and its dysregulation has been associated with neurodevelopmental defects and neural dysfunctions. In Drosophila, loss of m6A alters fly behavior, albeit the underlying molecular mechanism and the role of m6A during nervous system development have remained elusive. Here we find that impairment of the m6A pathway leads to axonal overgrowth and misguidance at larval neuromuscular junctions as well as in the adult mushroom bodies. We identify Ythdf as the main m6A reader in the nervous system, being required to limit axonal growth. Mechanistically, we show that the m6A reader Ythdf directly interacts with Fmr1, the fly homolog of Fragile X mental retardation RNA binding protein (FMRP), to inhibit the translation of key transcripts involved in axonal growth regulation. Altogether, this study demonstrates that the m6A pathway controls development of the nervous system and modulates Fmr1 target transcript selection.
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Affiliation(s)
- Lina Worpenberg
- Center for Integrative Genomics, Génopode Building, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Chiara Paolantoni
- Center for Integrative Genomics, Génopode Building, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Sara Longhi
- Laboratory of Translational Genomics, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | | | - Tina Lence
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Hans-Hermann Wessels
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Berlin, Germany.,Department of Biology, Humboldt University Berlin, Berlin, Germany
| | - Erik Dassi
- Laboratory of RNA Regulatory Networks, Department CIBIO, University of Trento, Trento, Italy
| | - Giuseppe Aiello
- Armenise-Harvard Laboratory of Brain Disorders and Cancer, Department CIBIO, University of Trento, Trento, Italy
| | | | | | - Raghu R Edupuganti
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Oncode Institute, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Anke Busch
- Bioinformatics Core Facility, IMB, Mainz, Germany
| | | | - Michiel Vermeulen
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Oncode Institute, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Falk Butter
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Julian König
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Michela Notarangelo
- Laboratory of Translational Genomics, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Uwe Ohler
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Berlin, Germany.,Department of Biology, Humboldt University Berlin, Berlin, Germany
| | - Christoph Dieterich
- Klaus Tschira Institute for Integrative Computational Cardiology and Department of Internal Medicine III, University Hospital Heidelberg, Heidelberg, Germany.,German Center for Cardiovascular Research (DZHK), Partner site Heidelberg-Mannheim, Heidelberg, Germany
| | - Alessandro Quattrone
- Center for Integrative Genomics, Génopode Building, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.,Laboratory of Translational Genomics, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Alessia Soldano
- Laboratory of Translational Genomics, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Jean-Yves Roignant
- Center for Integrative Genomics, Génopode Building, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.,Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, Mainz, Germany
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52
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Casingal CR, Kikkawa T, Inada H, Sasaki Y, Osumi N. Identification of FMRP target mRNAs in the developmental brain: FMRP might coordinate Ras/MAPK, Wnt/β-catenin, and mTOR signaling during corticogenesis. Mol Brain 2020; 13:167. [PMID: 33323119 PMCID: PMC7739466 DOI: 10.1186/s13041-020-00706-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/23/2020] [Indexed: 01/18/2023] Open
Abstract
Corticogenesis is one of the most critical and complicated processes during embryonic brain development. Any slight impairment in corticogenesis could cause neurodevelopmental disorders such as Fragile X syndrome (FXS), of which symptoms contain intellectual disability (ID) and autism spectrum disorder (ASD). Fragile X mental retardation protein (FMRP), an RNA-binding protein responsible for FXS, shows strong expression in neural stem/precursor cells (NPCs) during corticogenesis, although its function during brain development remains largely unknown. In this study, we attempted to identify the FMRP target mRNAs in the cortical primordium using RNA immunoprecipitation sequencing analysis in the mouse embryonic brain. We identified 865 candidate genes as targets of FMRP involving 126 and 118 genes overlapped with ID and ASD-associated genes, respectively. These overlapped genes were enriched with those related to chromatin/chromosome organization and histone modifications, suggesting the involvement of FMRP in epigenetic regulation. We further identified a common set of 17 FMRP “core” target genes involved in neurogenesis/FXS/ID/ASD, containing factors associated with Ras/mitogen-activated protein kinase, Wnt/β-catenin, and mammalian target of rapamycin (mTOR) pathways. We indeed showed overactivation of mTOR signaling via an increase in mTOR phosphorylation in the Fmr1 knockout (Fmr1 KO) neocortex. Our results provide further insight into the critical roles of FMRP in the developing brain, where dysfunction of FMRP may influence the regulation of its mRNA targets affecting signaling pathways and epigenetic modifications.
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Affiliation(s)
- Cristine R Casingal
- Department of Developmental Neuroscience, United Center for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Takako Kikkawa
- Department of Developmental Neuroscience, United Center for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Hitoshi Inada
- Department of Developmental Neuroscience, United Center for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.,Laboratory of Health and Sports Sciences, Division of Biomedical Engineering for Health and Welfare, Tohoku University Graduate School of Biomedical Engineering, 6-6-12, Aramaki Aza Aoba Aoba-ku, Sendai, Miyagi, 980-8579, Japan
| | - Yukio Sasaki
- Functional Structure Biology Laboratory, Department of Medical Life Science, Yokohama City University Graduate School of Medical Life Science, 1-7-29 Suehiro-cho, Tsumuri-ku, Yokohama, 230-0045, Japan
| | - Noriko Osumi
- Department of Developmental Neuroscience, United Center for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
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53
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Charif SE, Luchelli L, Vila A, Blaustein M, Igaz LM. Cytoplasmic Expression of the ALS/FTD-Related Protein TDP-43 Decreases Global Translation Both in vitro and in vivo. Front Cell Neurosci 2020; 14:594561. [PMID: 33363456 PMCID: PMC7752804 DOI: 10.3389/fncel.2020.594561] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 11/18/2020] [Indexed: 12/13/2022] Open
Abstract
TDP-43 is a major component of cytoplasmic inclusions observed in neurodegenerative diseases like frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). To further understand the role of TDP-43 in mRNA/protein metabolism and proteostasis, we used a combined approach with cellular and animal models overexpressing a cytoplasmic form of human TDP-43 (TDP-43-ΔNLS), recapitulating ALS/FTD features. We applied in HEK293 cells a method for labeling de novo translation, surface sensing of translation (SUnSET), based on puromycin (PURO) incorporation. While control cells displayed robust puromycilation, TDP-43-ΔNLS transfected cells exhibited reduced ongoing protein synthesis. Next, by using a transgenic mouse overexpressing cytoplasmic TDP-43 in the forebrain (TDP-43-ΔNLS mice) we assessed whether cytoplasmic TDP-43 regulates global translation in vivo. Polysome profiling of brain cortices from transgenic mice showed a shift toward non-polysomal fractions as compared to wild-type littermates, indicating a decrease in global translation. Lastly, cellular level translational assessment by SUNSET was performed in TDP-43-ΔNLS mice brain slices. Control mice slices incubated with PURO exhibited robust cytoplasmic PURO signal in layer 5 neurons from motor cortex, and normal nuclear TDP-43 staining. Neurons in TDP-43-ΔNLS mice slices incubated with PURO exhibited high cytoplasmic expression of TDP-43 and reduced puromycilation respect to control mice. These in vitro and in vivo results indicate that cytoplasmic TDP-43 decreases global translation and potentially cause functional/cytotoxic effects as observed in ALS/FTD. Our study provide in vivo evidence (by two independent and complementary methods) for a role of mislocalized TDP-43 in the regulation of global mRNA translation, with implications for TDP-43 proteinopathies.
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Affiliation(s)
- Santiago E Charif
- Instituto de Fisiología y Biofísica "Bernardo Houssay", (IFIBIO-Houssay), Grupo de Neurociencia de Sistemas, Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Luciana Luchelli
- Instituto de Fisiología y Biofísica "Bernardo Houssay", (IFIBIO-Houssay), Grupo de Neurociencia de Sistemas, Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Antonella Vila
- Instituto de Biociencias, Biotecnología y Biología Traslacional, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Matías Blaustein
- Instituto de Biociencias, Biotecnología y Biología Traslacional, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Lionel M Igaz
- Instituto de Fisiología y Biofísica "Bernardo Houssay", (IFIBIO-Houssay), Grupo de Neurociencia de Sistemas, Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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54
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Grozdanov PN, Masoumzadeh E, Kalscheuer VM, Bienvenu T, Billuart P, Delrue MA, Latham MP, MacDonald CC. A missense mutation in the CSTF2 gene that impairs the function of the RNA recognition motif and causes defects in 3' end processing is associated with intellectual disability in humans. Nucleic Acids Res 2020; 48:9804-9821. [PMID: 32816001 PMCID: PMC7515730 DOI: 10.1093/nar/gkaa689] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 08/03/2020] [Accepted: 08/18/2020] [Indexed: 11/25/2022] Open
Abstract
CSTF2 encodes an RNA-binding protein that is essential for mRNA cleavage and polyadenylation (C/P). No disease-associated mutations have been described for this gene. Here, we report a mutation in the RNA recognition motif (RRM) of CSTF2 that changes an aspartic acid at position 50 to alanine (p.D50A), resulting in intellectual disability in male patients. In mice, this mutation was sufficient to alter polyadenylation sites in over 1300 genes critical for brain development. Using a reporter gene assay, we demonstrated that C/P efficiency of CSTF2D50A was lower than wild type. To account for this, we determined that p.D50A changed locations of amino acid side chains altering RNA binding sites in the RRM. The changes modified the electrostatic potential of the RRM leading to a greater affinity for RNA. These results highlight the significance of 3′ end mRNA processing in expression of genes important for brain plasticity and neuronal development.
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Affiliation(s)
- Petar N Grozdanov
- Department of Cell Biology & Biochemistry, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6540, USA
| | - Elahe Masoumzadeh
- Department of Chemistry & Biochemistry, Texas Tech University, Lubbock, TX 79409-1061, USA
| | - Vera M Kalscheuer
- Max Planck Institute for Molecular Genetics, Research Group Development and Disease, Ihnestr. 63-73, D-14195 Berlin, Germany
| | - Thierry Bienvenu
- Institut de Psychiatrie et de Neurosciences de Paris, Inserm U1266, 102 rue de la Santé, 75014 Paris, France
| | - Pierre Billuart
- Institut de Psychiatrie et de Neurosciences de Paris, Inserm U1266, 102 rue de la Santé, 75014 Paris, France
| | - Marie-Ange Delrue
- Département de Génétique Médicale, CHU Sainte Justine, Montréal, Canada
| | - Michael P Latham
- Department of Chemistry & Biochemistry, Texas Tech University, Lubbock, TX 79409-1061, USA
| | - Clinton C MacDonald
- Department of Cell Biology & Biochemistry, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6540, USA
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55
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Sears JC, Broadie K. FMRP-PKA Activity Negative Feedback Regulates RNA Binding-Dependent Fibrillation in Brain Learning and Memory Circuitry. Cell Rep 2020; 33:108266. [PMID: 33053340 PMCID: PMC7590955 DOI: 10.1016/j.celrep.2020.108266] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 09/07/2020] [Accepted: 09/22/2020] [Indexed: 11/29/2022] Open
Abstract
Fragile X mental retardation protein (FMRP) promotes cyclic AMP (cAMP) signaling. Using an in vivo protein kinase A activity sensor (PKA-SPARK), we find that Drosophila FMRP (dFMRP) and human FMRP (hFMRP) enhance PKA activity in a central brain learning and memory center. Increasing neuronal PKA activity suppresses FMRP in Kenyon cells, demonstrating an FMRP-PKA negative feedback loop. A patient-derived R140Q FMRP point mutation mislocalizes PKA-SPARK activity, whereas deletion of the RNA-binding argi-nine-glycine-glycine (RGG) box (hFMRP-ΔRGG) produces fibrillar PKA-SPARK assemblies colocalizing with ribonucleoprotein (RNP) and aggregation (thioflavin T) markers, demonstrating fibrillar partitioning of cytosolic protein aggregates. hFMRP-ΔRGG reduces dFMRP levels, indicating RGG-independent regulation. Short-term hFMRP-ΔRGG induction produces activated PKA-SPARK puncta, whereas long induction drives fibrillar assembly. Elevated temperature disassociates hFMRP-ΔRGG aggregates and blocks activated PKA-SPARK localization. These results suggest that FMRP regulates compartmentalized signaling via complex assembly, directing PKA activity localization, with FMRP RGG box RNA binding restricting separation via low-complexity interactions. FMRP is required for brain cAMP induction and cAMP-dependent PKA activation, but the FMRP mechanism is uncharacterized. Sears and Broadie test FXS patient-derived and FMRP domain-deficient mutants to reveal conserved FMRP functions regulating PKA activation, subcellular localization, and reversible partitioning into elongated fibrillar assemblies in brain learning/ memory circuit neurons.
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Affiliation(s)
- James C Sears
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN 37235, USA; Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA.
| | - Kendal Broadie
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN 37235, USA; Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA; Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37235, USA; Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37235, USA.
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56
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Clifton NE, Thomas KL, Wilkinson LS, Hall J, Trent S. FMRP and CYFIP1 at the Synapse and Their Role in Psychiatric Vulnerability. Complex Psychiatry 2020; 6:5-19. [PMID: 34883502 PMCID: PMC7673588 DOI: 10.1159/000506858] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 02/27/2020] [Indexed: 12/23/2022] Open
Abstract
There is increasing awareness of the role genetic risk variants have in mediating vulnerability to psychiatric disorders such as schizophrenia and autism. Many of these risk variants encode synaptic proteins, influencing biological pathways of the postsynaptic density and, ultimately, synaptic plasticity. Fragile-X mental retardation 1 (FMR1) and cytoplasmic fragile-X mental retardation protein (FMRP)-interacting protein 1 (CYFIP1) contain 2 such examples of highly penetrant risk variants and encode synaptic proteins with shared functional significance. In this review, we discuss the biological actions of FMRP and CYFIP1, including their regulation of (i) protein synthesis and specifically FMRP targets, (ii) dendritic and spine morphology, and (iii) forms of synaptic plasticity such as long-term depression. We draw upon a range of preclinical studies that have used genetic dosage models of FMR1 and CYFIP1 to determine their biological function. In parallel, we discuss how clinical studies of fragile X syndrome or 15q11.2 deletion patients have informed our understanding of FMRP and CYFIP1, and highlight the latest psychiatric genomic findings that continue to implicate FMRP and CYFIP1. Lastly, we assess the current limitations in our understanding of FMRP and CYFIP1 biology and how they must be addressed before mechanism-led therapeutic strategies can be developed for psychiatric disorders.
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Affiliation(s)
- Nicholas E. Clifton
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
- MRC Centre for Neuropsychiatric Genetics and Genomics, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Kerrie L. Thomas
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Lawrence S. Wilkinson
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
- School of Psychology, Cardiff University, Cardiff, United Kingdom
| | - Jeremy Hall
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
- MRC Centre for Neuropsychiatric Genetics and Genomics, School of Medicine, Cardiff University, Cardiff, United Kingdom
- Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Simon Trent
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
- School of Life Sciences, Faculty of Natural Sciences, Keele University, Keele, United Kingdom
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57
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Utami KH, Skotte NH, Colaço AR, Yusof NABM, Sim B, Yeo XY, Bae HG, Garcia-Miralles M, Radulescu CI, Chen Q, Chaldaiopoulou G, Liany H, Nama S, Peteri UKA, Sampath P, Castrén ML, Jung S, Mann M, Pouladi MA. Integrative Analysis Identifies Key Molecular Signatures Underlying Neurodevelopmental Deficits in Fragile X Syndrome. Biol Psychiatry 2020; 88:500-511. [PMID: 32653109 DOI: 10.1016/j.biopsych.2020.05.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 03/26/2020] [Accepted: 05/02/2020] [Indexed: 12/23/2022]
Abstract
BACKGROUND Fragile X syndrome (FXS) is a neurodevelopmental disorder caused by epigenetic silencing of FMR1 and loss of FMRP expression. Efforts to understand the molecular underpinnings of the disease have been largely performed in rodent or nonisogenic settings. A detailed examination of the impact of FMRP loss on cellular processes and neuronal properties in the context of isogenic human neurons remains lacking. METHODS Using CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 to introduce indels in exon 3 of FMR1, we generated an isogenic human pluripotent stem cell model of FXS that shows complete loss of FMRP expression. We generated neuronal cultures and performed genome-wide transcriptome and proteome profiling followed by functional validation of key dysregulated processes. We further analyzed neurodevelopmental and neuronal properties, including neurite length and neuronal activity, using multielectrode arrays and patch clamp electrophysiology. RESULTS We showed that the transcriptome and proteome profiles of isogenic FMRP-deficient neurons demonstrate perturbations in synaptic transmission, neuron differentiation, cell proliferation and ion transmembrane transporter activity pathways, and autism spectrum disorder-associated gene sets. We uncovered key deficits in FMRP-deficient cells demonstrating abnormal neural rosette formation and neural progenitor cell proliferation. We further showed that FMRP-deficient neurons exhibit a number of additional phenotypic abnormalities, including neurite outgrowth and branching deficits and impaired electrophysiological network activity. These FMRP-deficient related impairments have also been validated in additional FXS patient-derived human-induced pluripotent stem cell neural cells. CONCLUSIONS Using isogenic human pluripotent stem cells as a model to investigate the pathophysiology of FXS in human neurons, we reveal key neural abnormalities arising from the loss of FMRP.
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Affiliation(s)
- Kagistia Hana Utami
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Niels H Skotte
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen N, Denmark
| | - Ana R Colaço
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen N, Denmark
| | | | - Bernice Sim
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Xin Yi Yeo
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Han-Gyu Bae
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Marta Garcia-Miralles
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Carola I Radulescu
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore; UK Dementia Research Institute, Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Qiyu Chen
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Georgia Chaldaiopoulou
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Herty Liany
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Srikanth Nama
- Institute of Medical Biology, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Ulla-Kaisa A Peteri
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Prabha Sampath
- Institute of Medical Biology, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore
| | - Maija L Castrén
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Sangyong Jung
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Matthias Mann
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen N, Denmark
| | - Mahmoud A Pouladi
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore (A∗STAR), Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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58
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Wang X, Kohl A, Yu X, Zorio DAR, Klar A, Sela-Donenfeld D, Wang Y. Temporal-specific roles of fragile X mental retardation protein in the development of the hindbrain auditory circuit. Development 2020; 147:dev.188797. [PMID: 32747436 DOI: 10.1242/dev.188797] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 06/29/2020] [Indexed: 01/01/2023]
Abstract
Fragile X mental retardation protein (FMRP) is an RNA-binding protein abundant in the nervous system. Functional loss of FMRP leads to sensory dysfunction and severe intellectual disabilities. In the auditory system, FMRP deficiency alters neuronal function and synaptic connectivity and results in perturbed processing of sound information. Nevertheless, roles of FMRP in embryonic development of the auditory hindbrain have not been identified. Here, we developed high-specificity approaches to genetically track and manipulate throughout development of the Atoh1+ neuronal cell type, which is highly conserved in vertebrates, in the cochlear nucleus of chicken embryos. We identified distinct FMRP-containing granules in the growing axons of Atoh1+ neurons and post-migrating NM cells. FMRP downregulation induced by CRISPR/Cas9 and shRNA techniques resulted in perturbed axonal pathfinding, delay in midline crossing, excess branching of neurites, and axonal targeting errors during the period of circuit development. Together, these results provide the first in vivo identification of FMRP localization and actions in developing axons of auditory neurons, and demonstrate the importance of investigating early embryonic alterations toward understanding the pathogenesis of neurodevelopmental disorders.
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Affiliation(s)
- Xiaoyu Wang
- Department of Biomedical Sciences, Program in Neuroscience, Florida State University College of Medicine, Tallahassee, FL 32306, USA.,Division of Histology & Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University, Guangzhou 510632, China
| | - Ayelet Kohl
- Koret School of Veterinary Medicine, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Xiaoyan Yu
- Department of Biomedical Sciences, Program in Neuroscience, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Diego A R Zorio
- Department of Biomedical Sciences, Program in Neuroscience, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Avihu Klar
- Department of Medical Neurobiology IMRIC, Hebrew University Medical School, Jerusalem 91120, Israel
| | - Dalit Sela-Donenfeld
- Koret School of Veterinary Medicine, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Yuan Wang
- Department of Biomedical Sciences, Program in Neuroscience, Florida State University College of Medicine, Tallahassee, FL 32306, USA
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59
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Prieto M, Folci A, Martin S. Post-translational modifications of the Fragile X Mental Retardation Protein in neuronal function and dysfunction. Mol Psychiatry 2020; 25:1688-1703. [PMID: 31822816 DOI: 10.1038/s41380-019-0629-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/22/2019] [Accepted: 11/27/2019] [Indexed: 12/17/2022]
Abstract
The Fragile X Mental Retardation Protein (FMRP) is an RNA-binding protein essential to the regulation of local translation at synapses. In the mammalian brain, synapses are constantly formed and eliminated throughout development to achieve functional neuronal networks. At the molecular level, thousands of proteins cooperate to accomplish efficient neuronal communication. Therefore, synaptic protein levels and their functional interactions need to be tightly regulated. FMRP generally acts as a translational repressor of its mRNA targets. FMRP is the target of several post-translational modifications (PTMs) that dynamically regulate its function. Here we provide an overview of the PTMs controlling the FMRP function and discuss how their spatiotemporal interplay contributes to the physiological regulation of FMRP. Importantly, FMRP loss-of-function leads to Fragile X syndrome (FXS), a rare genetic developmental condition causing a range of neurological alterations including intellectual disability (ID), learning and memory impairments, autistic-like features and seizures. Here, we also explore the possibility that recently reported missense mutations in the FMR1 gene disrupt the PTM homoeostasis of FMRP, thus participating in the aetiology of FXS. This suggests that the pharmacological targeting of PTMs may be a promising strategy to develop innovative therapies for patients carrying such missense mutations.
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Affiliation(s)
- Marta Prieto
- Université Côte d'Azur, CNRS, IPMC, Valbonne, France
| | | | - Stéphane Martin
- Université Côte d'Azur, INSERM, CNRS, IPMC, Valbonne, France.
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60
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Brandalise F, Kalmbach BE, Mehta P, Thornton O, Johnston D, Zemelman BV, Brager DH. Fragile X Mental Retardation Protein Bidirectionally Controls Dendritic I h in a Cell Type-Specific Manner between Mouse Hippocampus and Prefrontal Cortex. J Neurosci 2020; 40:5327-5340. [PMID: 32467357 PMCID: PMC7329306 DOI: 10.1523/jneurosci.1670-19.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 04/06/2020] [Accepted: 04/15/2020] [Indexed: 11/21/2022] Open
Abstract
Channelopathies are implicated in Fragile X syndrome (FXS), yet the dysfunction of a particular ion channel varies with cell type. We previously showed that HCN channel function is elevated in CA1 dendrites of the fmr1-/y mouse model of FXS, but reduced in L5 PFC dendrites. Using male mice, we tested whether Fragile X Mental Retardation Protein (FMRPO), the protein whose absence causes FXS, differentially modulates HCN channels in CA1 versus L5 PFC dendrites. Using a combination of viral tools, intracellular peptide, and dendritic electrophysiology, we found that FMRP regulates HCN channels via a cell-autonomous protein-protein interaction. Virally expressed FMRP restored WT HCN channel-related dendritic properties in both CA1 and L5 neurons. Rapid intracellular perfusion of the non-mRNA binding N-terminal fragment, FMRP1-298, similarly restored dendritic function. In support of a protein-protein interaction, we found that FMRP associated with HCN-TRIP8b complexes in both hippocampus and PFC. Finally, voltage-clamp recordings showed that FMRP modulated Ih by regulating the number of functional dendritic HCN channels rather than individual channel properties. Together, these represent three novel findings as to the nature of the changes in dendritic function in CA1 and PFC neurons based on the presence or absence of FMRP. Moreover, our findings provide evidence that FMRP can regulate its targets in opposite directions depending upon the cellular milieu.SIGNIFICANCE STATEMENT Changes in dendritic function, and voltage-gated ion channels in particular, are increasingly the focus of neurological disorders. We, and others, previously identified cell type-specific channelopathies in a mouse of model of Fragile X syndrome. The present study shows that replacing Fragile X Mental Retardation Protein, which is absent in Fragile X syndrome, in adult CA1 and L5 PFC neurons regulates the number of functional dendritic HCN channels in a cell type-specific manner. These results suggest that Fragile X Mental Retardation Protein regulates dendritic HCN channels via a cell-autonomous protein--protein mechanism.
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Affiliation(s)
- Federico Brandalise
- Center for Learning and Memory, University of Texas at Austin, Austin, Texas 78712
- Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712
| | - Brian E Kalmbach
- Center for Learning and Memory, University of Texas at Austin, Austin, Texas 78712
- Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712
| | - Preeti Mehta
- Center for Learning and Memory, University of Texas at Austin, Austin, Texas 78712
- Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712
| | - Olivia Thornton
- Center for Learning and Memory, University of Texas at Austin, Austin, Texas 78712
- Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712
| | - Daniel Johnston
- Center for Learning and Memory, University of Texas at Austin, Austin, Texas 78712
- Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712
| | - Boris V Zemelman
- Center for Learning and Memory, University of Texas at Austin, Austin, Texas 78712
- Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712
| | - Darrin H Brager
- Center for Learning and Memory, University of Texas at Austin, Austin, Texas 78712
- Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712
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Abstract
Flaviviruses are a genus of mostly arthropod-borne RNA viruses that cause a range of pathologies in humans. Basic knowledge on flaviviruses is rapidly expanding, partly due to their status as frequent emerging or re-emerging pathogens. Flaviviruses include the dengue, Zika, West Nile, tick-borne encephalitis and yellow fever viruses (DENV, ZIKV, WNV, TBEV and YFV, respectively). As is the case with other families of viruses, the success of productive infection of human cells by flaviviruses depends in part on the antiviral activity of a heterogeneous group of cellular antiviral proteins called restriction factors. Restriction factors are the effector proteins of the cell-autonomous innate response against viruses, an immune pathway that also includes virus sensors as well as intracellular and extracellular signal mediators such as type I interferons (IFN-I). In this review, I summarize recent progress toward the identification and characterization of flavivirus restriction factors. In particular, I focus on IFI6, Schlafen 11, FMRP, OAS-RNase L, RyDEN, members of the TRIM family of proteins (TRIM5α, TRIM19, TRIM56, TRIM69 and TRIM79α) and a new mechanism of action proposed for viperin. Recent and future studies on this topic will lead to a more complete picture of the flavivirus restrictome, defined as the ensemble of cellular factors with demonstrated anti-flaviviral activity.
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Hu J, Chen L, Yin J, Yin H, Huang Y, Tian J. Hyperactivity, Memory Defects, and Craniofacial Abnormalities in Zebrafish fmr1 Mutant Larvae. Behav Genet 2020; 50:152-160. [PMID: 32048109 DOI: 10.1007/s10519-020-09995-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Accepted: 02/04/2020] [Indexed: 01/05/2023]
Abstract
Fragile X syndrome (FXS) is a heritable mental retardation disease caused by unstable trinucleotide repeat sequences in FMR1. FXS is characterized by delayed development, hyperactivity, and autism behavior. Zebrafish is an excellent model to study FXS and the underlying function of fmr1. However, at present, fmr1 function is mainly studied via morpholinos or generated mutants using targeting induced local lesions in genomes. However, both of these methods generate off-target effects, making them suboptimal techniques for studying FXS. In this study, CRISPR/Cas9 technology was used to generate two zebrafish fmr1 mutant lines. High-throughput behavior analysis, qRT-PCR, and alcian blue staining experiments were employed to investigate fmr1 function. The fmr1 mutant line showed abnormal behavior, learning memory defects, and impaired craniofacial cartilage development. These features are similar to the human FXS phenotype, indicating that the fmr1 mutant generated in this study can be used as a new model for studying the molecular pathology of FXS. It also provides a suitable model for high-throughput screening of small molecule drugs for FXS therapeutics.
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Affiliation(s)
- Jia Hu
- School of Biology & Basic Medical Sciences, Medical College, Soochow University, Suzhou, 215123, Jiangsu, People's Republic of China
| | - Lei Chen
- Department of Medical Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, 215000, Jiangsu, People's Republic of China
| | - Jian Yin
- CAS Key Lab of Bio-medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, 215163, Jiangsu, People's Republic of China
| | - Huancai Yin
- CAS Key Lab of Bio-medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, 215163, Jiangsu, People's Republic of China
| | - Yinong Huang
- Shaanxi Institute of Pediatric Diseases, Xi'an Children's Hospital, Xi'an, 710003, Shaanxi, People's Republic of China.
| | - Jingjing Tian
- CAS Key Lab of Bio-medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, 215163, Jiangsu, People's Republic of China.
- Academy for Engineering & Technology, Fudan University, Shanghai, 200433, People's Republic of China.
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McCullagh EA, Rotschafer SE, Auerbach BD, Klug A, Kaczmarek LK, Cramer KS, Kulesza RJ, Razak KA, Lovelace JW, Lu Y, Koch U, Wang Y. Mechanisms underlying auditory processing deficits in Fragile X syndrome. FASEB J 2020; 34:3501-3518. [PMID: 32039504 DOI: 10.1096/fj.201902435r] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 12/31/2019] [Accepted: 01/18/2020] [Indexed: 01/14/2023]
Abstract
Autism spectrum disorders (ASD) are strongly associated with auditory hypersensitivity or hyperacusis (difficulty tolerating sounds). Fragile X syndrome (FXS), the most common monogenetic cause of ASD, has emerged as a powerful gateway for exploring underlying mechanisms of hyperacusis and auditory dysfunction in ASD. This review discusses examples of disruption of the auditory pathways in FXS at molecular, synaptic, and circuit levels in animal models as well as in FXS individuals. These examples highlight the involvement of multiple mechanisms, from aberrant synaptic development and ion channel deregulation of auditory brainstem circuits, to impaired neuronal plasticity and network hyperexcitability in the auditory cortex. Though a relatively new area of research, recent discoveries have increased interest in auditory dysfunction and mechanisms underlying hyperacusis in this disorder. This rapidly growing body of data has yielded novel research directions addressing critical questions regarding the timing and possible outcomes of human therapies for auditory dysfunction in ASD.
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Affiliation(s)
- Elizabeth A McCullagh
- Department of Physiology and Biophysics, University of Colorado Anschutz, Aurora, CO, USA.,Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA
| | - Sarah E Rotschafer
- Department of Neurobiology and Behavior, University of California, Irvine, CA, USA.,Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, GA, USA
| | - Benjamin D Auerbach
- Center for Hearing and Deafness, Department of Communicative Disorders & Sciences, SUNY at Buffalo, Buffalo, NY, USA
| | - Achim Klug
- Department of Physiology and Biophysics, University of Colorado Anschutz, Aurora, CO, USA
| | - Leonard K Kaczmarek
- Departments of Pharmacology and Cellular and Molecular Physiology, Yale University, New Haven, CT, USA
| | - Karina S Cramer
- Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - Randy J Kulesza
- Department of Anatomy, Lake Erie College of Osteopathic Medicine, Erie, PA, USA
| | - Khaleel A Razak
- Department of Psychology, University of California, Riverside, CA, USA
| | | | - Yong Lu
- Department of Anatomy and Neurobiology, College of Medicine, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Ursula Koch
- Institute of Biology, Neurophysiology, Freie Universität Berlin, Berlin, Germany
| | - Yuan Wang
- Department of Biomedical Sciences, Program in Neuroscience, Florida State University, Tallahassee, FL, USA
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64
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Novel Approaches for Identifying the Molecular Background of Schizophrenia. Cells 2020; 9:cells9010246. [PMID: 31963710 PMCID: PMC7017322 DOI: 10.3390/cells9010246] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/06/2020] [Accepted: 01/16/2020] [Indexed: 12/20/2022] Open
Abstract
Recent advances in psychiatric genetics have led to the discovery of dozens of genomic loci associated with schizophrenia. However, a gap exists between the detection of genetic associations and understanding the underlying molecular mechanisms. This review describes the basic approaches used in the so-called post-GWAS studies to generate biological interpretation of the existing population genetic data, including both molecular (creation and analysis of knockout animals, exploration of the transcriptional effects of common variants in human brain cells) and computational (fine-mapping of causal variability, gene set enrichment analysis, partitioned heritability analysis) methods. The results of the crucial studies, in which these approaches were used to uncover the molecular and neurobiological basis of the disease, are also reported.
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65
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ICAM5 as a Novel Target for Treating Cognitive Impairment in Fragile X Syndrome. J Neurosci 2019; 40:1355-1365. [PMID: 31882402 PMCID: PMC7002157 DOI: 10.1523/jneurosci.2626-18.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/12/2019] [Accepted: 12/15/2019] [Indexed: 12/11/2022] Open
Abstract
Fragile X syndrome (FXS) is the most common inherited form of intellectual disability, resulted from the silencing of the Fmr1 gene and the subsequent loss of fragile X mental retardation protein (FMRP). Spine dysgenesis and cognitive impairment have been extensively characterized in FXS; however, the underlying mechanism remains poorly understood. Fragile X syndrome (FXS) is the most common inherited form of intellectual disability, resulted from the silencing of the Fmr1 gene and the subsequent loss of fragile X mental retardation protein (FMRP). Spine dysgenesis and cognitive impairment have been extensively characterized in FXS; however, the underlying mechanism remains poorly understood. As an important regulator of spine maturation, intercellular adhesion molecule 5 (ICAM5) mRNA may be one of the targets of FMRP and involved in cognitive impairment in FXS. Here we show that in Fmr1 KO male mice, ICAM5 was excessively expressed during the late developmental stage, and its expression was negatively correlated with the expression of FMRP and positively related with the morphological abnormalities of dendritic spines. While in vitro reduction of ICAM5 normalized dendritic spine abnormalities in Fmr1 KO neurons, and in vivo knockdown of ICAM5 in the dentate gyrus rescued the impaired spatial and fear memory and anxiety-like behaviors in Fmr1 KO mice, through both granule cell and mossy cell with a relative rate of 1.32 ± 0.15. Furthermore, biochemical analyses showed direct binding of FMRP with ICAM5 mRNA, to the coding sequence of ICAM5 mRNA. Together, our study suggests that ICAM5 is one of the targets of FMRP and is implicated in the molecular pathogenesis of FXS. ICAM5 could be a therapeutic target for treating cognitive impairment in FXS. SIGNIFICANCE STATEMENT Fragile X syndrome (FXS) is characterized by dendritic spine dysgenesis and cognitive dysfunctions, while one of the FMRP latent targets, ICAM5, is well established for contributing both spine maturation and learning performance. In this study, we examined the potential link between ICAM5 mRNA and FMRP in FXS, and further investigated the molecular details and pathological consequences of ICAM5 overexpression. Our results indicate a critical role of ICAM5 in spine maturation and cognitive impairment in FXS and suggest that ICAM5 is a potential molecular target for the development of medication against FXS.
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66
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Trent S, Hall J, Connelly WM, Errington AC. Cyfip1 Haploinsufficiency Does Not Alter GABA A Receptor δ-Subunit Expression and Tonic Inhibition in Dentate Gyrus PV + Interneurons and Granule Cells. eNeuro 2019; 6:ENEURO.0364-18.2019. [PMID: 31209152 PMCID: PMC6635810 DOI: 10.1523/eneuro.0364-18.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 05/28/2019] [Accepted: 05/31/2019] [Indexed: 12/01/2022] Open
Abstract
Copy number variation (CNV) at chromosomal region 15q11.2 is linked to increased risk of neurodevelopmental disorders including autism and schizophrenia. A significant gene at this locus is cytoplasmic fragile X mental retardation protein (FMRP) interacting protein 1 (CYFIP1). CYFIP1 protein interacts with FMRP, whose monogenic absence causes fragile X syndrome (FXS). Fmrp knock-out has been shown to reduce tonic GABAergic inhibition by interacting with the δ-subunit of the GABAA receptor (GABAAR). Using in situ hybridization (ISH), qPCR, Western blotting techniques, and patch clamp electrophysiology in brain slices from a Cyfip1 haploinsufficient mouse, we examined δ-subunit mediated tonic inhibition in the dentate gyrus (DG). In wild-type (WT) mice, DG granule cells (DGGCs) responded to the δ-subunit-selective agonist THIP with significantly increased tonic currents. In heterozygous mice, no significant difference was observed in THIP-evoked currents in DGGCs. Phasic GABAergic inhibition in DGGC was also unaltered with no difference in properties of spontaneous IPSCs (sIPSCs). Additionally, we demonstrate that DG granule cell layer (GCL) parvalbumin-positive interneurons (PV+-INs) have functional δ-subunit-mediated tonic GABAergic currents which, unlike DGGC, are also modulated by the α1-selective drug zolpidem. Similar to DGGC, both IPSCs and THIP-evoked currents in PV+-INs were not different between Cyfip1 heterozygous and WT mice. Supporting our electrophysiological data, we found no significant change in hippocampal δ-subunit mRNA expression or protein level and no change in α1/α4-subunit mRNA expression. Thus, Cyfip1 haploinsufficiency, mimicking human 15q11.2 microdeletion syndrome, does not alter hippocampal phasic or tonic GABAergic inhibition, substantially differing from the Fmrp knock-out mouse model.
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Affiliation(s)
- Simon Trent
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, CF24 4HQ, United Kingdom
| | - Jeremy Hall
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, CF24 4HQ, United Kingdom
| | - William M Connelly
- School of Medicine, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Adam C Errington
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, CF24 4HQ, United Kingdom
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67
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Bodaleo F, Tapia-Monsalves C, Cea-Del Rio C, Gonzalez-Billault C, Nunez-Parra A. Structural and Functional Abnormalities in the Olfactory System of Fragile X Syndrome Models. Front Mol Neurosci 2019; 12:135. [PMID: 31191246 PMCID: PMC6548058 DOI: 10.3389/fnmol.2019.00135] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/09/2019] [Indexed: 12/18/2022] Open
Abstract
Fragile X Syndrome (FXS) is the most common inherited form of intellectual disability. It is produced by mutation of the Fmr1 gene that encodes for the Fragile Mental Retardation Protein (FMRP), an important RNA-binding protein that regulates the expression of multiple proteins located in neuronal synapses. Individuals with FXS exhibit abnormal sensory information processing frequently leading to hypersensitivity across sensory modalities and consequently a wide array of behavioral symptoms. Insects and mammals engage primarily their sense of smell to create proper representations of the external world and guide adequate decision-making processes. This feature in combination with the exquisitely organized neuronal circuits found throughout the olfactory system (OS) and the wide expression of FMRP in brain regions that process olfactory information makes it an ideal model to study sensory alterations in FXS models. In the last decade several groups have taken advantage of these features and have used the OS of fruit fly and rodents to understand neuronal alteration giving rise to sensory perception issues. In this review article, we will discuss molecular, morphological and physiological aspects of the olfactory information processing in FXS models. We will highlight the decreased inhibitory/excitatory synaptic balance and the diminished synaptic plasticity found in this system resulting in behavioral alteration of individuals in the presence of odorant stimuli.
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Affiliation(s)
- Felipe Bodaleo
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | | | - Christian Cea-Del Rio
- Laboratory of Neurophysiopathology, Centro de Investigacion Biomedica y Aplicada (CIBAP), School of Medicine, Universidad de Santiago de Chile, Santiago, Chile
| | - Christian Gonzalez-Billault
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile.,The Buck Institute for Research on Aging, Novato, CA, United States
| | - Alexia Nunez-Parra
- Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Cell Physiology Center, Universidad de Chile, Santiago, Chile
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68
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Kang H, Zhao J, Jiang X, Li G, Huang W, Cheng H, Duan R. Drosophila Netrin-B controls mushroom body axon extension and regulates courtship-associated learning and memory of a Drosophila fragile X syndrome model. Mol Brain 2019; 12:52. [PMID: 31138234 PMCID: PMC6540430 DOI: 10.1186/s13041-019-0472-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 05/06/2019] [Indexed: 01/29/2023] Open
Abstract
Mushroom body (MB) is a prominent structure essential for olfactory learning and memory in the Drosophila brain. The development of the MB involves the appropriate guidance of axon lobes and sister axon branches. Appropriate guidance that accurately shapes MB development requires the integration of various guidance cues provided by a series of cell types, which guide axons to reach their final positions within the MB neuropils. Netrins are axonal guidance molecules that are conserved regulators of embryonic nerve cord patterning. However, whether they contribute to MB morphogenesis has not yet been evaluated. Here, we find that Netrin-B (NetB) is highly expressed in the MB lobes, regulating lobe length through genetic interactions with the receptors Frazzled and Uncoordinated-5 from 24 h after pupal formation onwards. We observe that overexpression of NetB causes severe β lobe fusion in the MB, which is similar to the MB defects seen in the Drosophila model of fragile X syndrome (FXS). Our results further show that fragile-X mental retardation protein FMRP inhibits the translational activity of human ortholog Netrin-1 (NTN1). Knock-down of NetB significantly rescues the MB defects and ameliorates deficits in the learning and memory in FXS model Drosophila. These results indicate a critical role for NetB in MB lobe extension and identify NetB as a novel target of FMRP which contributes to learning and memory.
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Affiliation(s)
- Huaixing Kang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Juan Zhao
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Xuan Jiang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Guangxu Li
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Wen Huang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Huili Cheng
- Changchun Children' Hospital, Changchun, 130000, Jilin, China.
| | - Ranhui Duan
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, 410078, Hunan, China. .,Hunan Key Laboratory of Medical Genetics, Central South University, Changsha, 410078, Hunan, China. .,Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, 410078, Hunan, China.
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69
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Brookes E, Riccio A. Location, location, location: nuclear structure regulates gene expression in neurons. Curr Opin Neurobiol 2019; 59:16-25. [PMID: 31005709 DOI: 10.1016/j.conb.2019.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/27/2019] [Accepted: 03/18/2019] [Indexed: 12/27/2022]
Abstract
Genome architecture plays a critical role in regulating the expression of genes that are essential for nervous system development. During neuronal differentiation, spatially and temporally regulated transcription allows neuronal migration, the growth of dendrites and axons, and at later stages, synaptic formation and the establishment of neuronal circuitry. Genome topology and relocation of gene loci within the nucleus are now regarded as key factors that contribute to transcriptional regulation. Here, we review recent work supporting the hypothesis that the dynamic organization of chromatin within the nucleus impacts gene activation in response to extrinsic signalling and during neuronal differentiation. The consequences of disruption of the genome architecture on neuronal health will be also discussed.
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Affiliation(s)
- Emily Brookes
- MRC Laboratory of Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Antonella Riccio
- MRC Laboratory of Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK.
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70
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Abnormal repetitive behaviors in zebrafish and their relevance to human brain disorders. Behav Brain Res 2019; 367:101-110. [PMID: 30926483 DOI: 10.1016/j.bbr.2019.03.044] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 03/22/2019] [Accepted: 03/25/2019] [Indexed: 02/01/2023]
Abstract
Abnormal repetitive behaviors (ARBs) are a prominent symptom of numerous human brain disorders and are commonly seen in rodent models as well. While rodent studies of ARBs continue to dominate the field, mounting evidence suggests that zebrafish (Danio rerio) also display ARB-like phenotypes and may therefore be a novel model organism for ARB research. In addition to clear practical research advantages as a model species, zebrafish share high genetic and physiological homology to humans and rodents, including multiple ARB-related genes and robust behaviors relevant to ARB. Here, we discuss a wide spectrum of stereotypic repetitive behaviors in zebrafish, data on their genetic and pharmacological modulation, and the overall translational relevance of fish ARBs to modeling human brain disorders. Overall, the zebrafish is rapidly emerging as a new promising model to study ARBs and their underlying mechanisms.
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71
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Sears JC, Choi WJ, Broadie K. Fragile X Mental Retardation Protein positively regulates PKA anchor Rugose and PKA activity to control actin assembly in learning/memory circuitry. Neurobiol Dis 2019; 127:53-64. [PMID: 30771457 DOI: 10.1016/j.nbd.2019.02.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 02/04/2019] [Indexed: 01/09/2023] Open
Abstract
Recent work shows Fragile X Mental Retardation Protein (FMRP) drives the translation of very large proteins (>2000 aa) mediating neurodevelopment. Loss of function results in Fragile X syndrome (FXS), the leading heritable cause of intellectual disability (ID) and autism spectrum disorder (ASD). Using the Drosophila FXS disease model, we discover FMRP positively regulates the translation of the very large A-Kinase Anchor Protein (AKAP) Rugose (>3000 aa), homolog of ASD-associated human Neurobeachin (NBEA). In the central brain Mushroom Body (MB) circuit, where Protein Kinase A (PKA) signaling is necessary for learning/memory, FMRP loss reduces Rugose levels and targeted FMRP overexpression elevates Rugose levels. Using a new in vivo transgenic PKA activity reporter (PKA-SPARK), we find FMRP loss reduces PKA activity in MB Kenyon cells whereas FMRP overexpression elevates PKA activity. Consistently, loss of Rugose reduces PKA activity, but Rugose overexpression has no independent effect. A well-established PKA output is regulation of F-actin cytoskeleton dynamics. In the FXS disease model, F-actin is aberrantly accumulated in MB lobes and single MB Kenyon cells. Consistently, Rugose loss results in similar F-actin accumulation. Moreover, targeted FMRP, Rugose and PKA overexpression all result in increased F-actin accumulation in the MB circuit. These findings uncover a FMRP-Rugose-PKA mechanism regulating actin cytoskeleton. This study reveals a novel FMRP mechanism controlling neuronal PKA activity, and demonstrates a shared mechanistic connection between FXS and NBEA associated ASD disease states, with a common link to PKA and F-actin misregulation in brain neural circuits. SIGNIFICANCE STATEMENT: Autism spectrum disorder (ASD) arises from a wide array of genetic lesions, and it is therefore critical to identify common underlying molecular mechanisms. Here, we link two ASD states; Neurobeachin (NBEA) associated ASD and Fragile X syndrome (FXS), the most common inherited ASD. Using established Drosophila disease models, we find Fragile X Mental Retardation Protein (FMRP) positively regulates translation of NBEA homolog Rugose, consistent with a recent advance showing FMRP promotes translation of very large proteins associated with ASD. FXS exhibits reduced cAMP induction, a potent activator of PKA, and Rugose/NBEA is a PKA anchor. Consistently, we find brain PKA activity strikingly reduced in both ASD models. We discover this pathway regulation controls actin cytoskeleton dynamics in brain neural circuits.
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Affiliation(s)
- James C Sears
- Vanderbilt Brain Institute, Departments of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Woong Jae Choi
- Departments of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Kendal Broadie
- Vanderbilt Brain Institute, Departments of Biological Sciences, Cell and Developmental Biology, and Pharmacology, Vanderbilt University and Medical Center, Nashville, TN 37235, USA.
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72
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Rosina E, Battan B, Siracusano M, Di Criscio L, Hollis F, Pacini L, Curatolo P, Bagni C. Disruption of mTOR and MAPK pathways correlates with severity in idiopathic autism. Transl Psychiatry 2019; 9:50. [PMID: 30705255 PMCID: PMC6355879 DOI: 10.1038/s41398-018-0335-z] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 11/04/2018] [Accepted: 11/13/2018] [Indexed: 12/15/2022] Open
Abstract
The molecular signature underlying autism spectrum disorder remains largely unknown. This study identifies differential expression of mTOR and MAPK pathways in patients affected by mild and severe idiopathic autism. A total of 55 subjects were enrolled, of which 22 were typically developing individuals and 33 were patients aged between 3 and 11 years, with autism spectrum disorder. A detailed history, including physical examination, developmental evaluation, mental health history and autism diagnostic observation schedule were performed for each patient. Components of the mTOR and MAPK signalling pathways were analysed from peripheral blood at the protein level. Patients were then stratified according to their clinical phenotypes, and the molecular profiling was analysed in relation to the degree of autism severity. In this cohort of patients, we identified increased activity of mTOR and the MAPK pathways, key regulators of synaptogenesis and protein synthesis. Specifically, rpS6, p-eIF4E, TSC1 and p-MNK1 expression discriminated patients according to their clinical diagnosis, suggesting that components of protein synthesis signalling pathways might constitute a molecular signature of clinical severity in autism spectrum disorder.
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Affiliation(s)
- Eleonora Rosina
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Barbara Battan
- Department of Systems Medicine, Division of Child Neurology and Psychiatry, University Hospital of Tor Vergata, Rome, Italy
| | - Martina Siracusano
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | - Lorena Di Criscio
- Department of Systems Medicine, Division of Child Neurology and Psychiatry, University Hospital of Tor Vergata, Rome, Italy
| | - Fiona Hollis
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Laura Pacini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Paolo Curatolo
- Department of Systems Medicine, Division of Child Neurology and Psychiatry, University Hospital of Tor Vergata, Rome, Italy
| | - Claudia Bagni
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland.
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73
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Wang Z, Khemani P, Schmitt LM, Lui S, Mosconi MW. Static and dynamic postural control deficits in aging fragile X mental retardation 1 (FMR1) gene premutation carriers. J Neurodev Disord 2019; 11:2. [PMID: 30665341 PMCID: PMC6341725 DOI: 10.1186/s11689-018-9261-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 12/26/2018] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Individuals with premutation alleles of the fragile X mental retardation 1 (FMR1) gene are at risk of developing fragile X-associated tremor/ataxia syndrome (FXTAS) during aging. Characterization of motor issues associated with aging in FMR1 premutation carriers is needed to determine neurodegenerative processes and establish new biobehavioral indicators to help identify individuals at greatest risk of developing FXTAS. METHODS We examined postural stability in 18 premutation carriers ages 46-77 years and 14 age-matched healthy controls. Participants completed a test of static stance and two tests of dynamic postural sway on a force platform to quantify postural variability and complexity. CGG repeat length was measured for each premutation carrier, and MRI and neurological evaluations were conducted to identify carriers who currently met criteria for FXTAS. Of the 18 premutation carriers, seven met criteria for definite/probable FXTAS (FXTAS+), seven showed no MRI or neurological signs of FXTAS (FXTAS-), and four were inconclusive due to insufficient data. RESULTS Compared to controls, premutation carriers showed increased center of pressure (COP) variability in the mediolateral (COPML) direction during static stance and reduced COP variability in the anterior-posterior (COPAP) direction during dynamic AP sway. They also showed reductions in COPML complexity during each postural condition. FXTAS+ individuals showed reduced COPAP variability compared to FXTAS- carriers and healthy controls during dynamic AP sway. Across all carriers, increased sway variability during static stance and decreased sway variability in target directions during dynamic sways were associated with greater CGG repeat length and more severe neurologically rated posture and gait abnormalities. CONCLUSION Our findings indicate that aging FMR1 premutation carriers show static and dynamic postural control deficits relative to healthy controls implicating degenerative processes of spinocerebellar and cerebellar-brainstem circuits that may be independent of or precede the onset of FXTAS. Our finding that FXTAS+ and FXTAS- premutation carriers differed on their level of intentional AP sway suggests that neural mechanisms of dynamic postural control may be differentially impacted in patients with FXTAS, and its measurement may be useful for rapidly and precisely identifying disease presence and onset.
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Affiliation(s)
- Zheng Wang
- Department of Occupational Therapy, University of Florida, Gainesville, FL, 32611, USA. .,University of Florida, 1225 Center Drive, PO Box 100164, Gainesville, FL, 326100164, USA.
| | - Pravin Khemani
- Department of Neurology, Swedish Neuroscience Institute, Seattle, WA, 98121, USA
| | - Lauren M Schmitt
- Division of Developmental and Behavioral Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Su Lui
- Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, 610041, Sichuan, China
| | - Matthew W Mosconi
- Schiefelbusch Institute for Life Span Studies, University of Kansas, Lawrence, KS, 66045, USA.,Clinical Child Psychology Program, University of Kansas, Lawrence, KS, 66045, USA.,Kansas Center for Autism Research and Training (K-CART), University of Kansas, Lawrence, KS, 66045, USA
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74
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Keil KP, Sethi S, Wilson MD, Silverman JL, Pessah IN, Lein PJ. Genetic mutations in Ca 2+ signaling alter dendrite morphology and social approach in juvenile mice. GENES, BRAIN, AND BEHAVIOR 2019; 18:e12526. [PMID: 30311737 PMCID: PMC6540090 DOI: 10.1111/gbb.12526] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/05/2018] [Accepted: 10/09/2018] [Indexed: 01/28/2023]
Abstract
Dendritic morphology is a critical determinant of neuronal connectivity, and calcium signaling plays a predominant role in shaping dendrites. Altered dendritic morphology and genetic mutations in calcium signaling are both associated with neurodevelopmental disorders (NDDs). In this study we tested the hypothesis that dendritic arborization and NDD-relevant behavioral phenotypes are altered by human mutations that modulate calcium-dependent signaling pathways implicated in NDDs. The dendritic morphology of pyramidal neurons in CA1 hippocampus and somatosensory cortex was quantified in Golgi-stained brain sections from juvenile mice of both sexes expressing either a human gain-of-function mutation in ryanodine receptor 1 (T4826I-RYR1), a human CGG repeat expansion (170-200 CGG repeats) in the fragile X mental retardation gene 1 (FMR1 premutation), both mutations (double mutation; DM), or wildtype mice. In hippocampal neurons, increased dendritic arborization was observed in male T4826I-RYR1 and, to a lesser extent, male FMR1 premutation neurons. Dendritic morphology of cortical neurons was altered in both sexes of FMR1 premutation and DM animals with the most pronounced differences seen in DM females. Genotype also impaired behavior, as assessed using the three-chambered social approach test. The most striking lack of sociability was observed in DM male and female mice. In conclusion, mutations that alter the fidelity of calcium signaling enhance dendritic arborization in a brain region- and sex-specific manner and impair social behavior in juvenile mice. The phenotypic outcomes of these mutations likely provide a susceptible biological substrate for additional environmental stressors that converge on calcium signaling to determine individual NDD risk.
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Affiliation(s)
- Kimberly P. Keil
- Department of Molecular Biosciences, University of California-Davis, School of Veterinary Medicine, Davis, California
| | - Sunjay Sethi
- Department of Molecular Biosciences, University of California-Davis, School of Veterinary Medicine, Davis, California
| | - Machelle D. Wilson
- Clinical and Translational Science Center, Department of Public Health Sciences, Division of Biostatistics, University of California-Davis, School of Medicine, Davis, California
| | - Jill L. Silverman
- Department of Psychiatry and Behavioral Sciences, University of California-Davis School of Medicine, Sacramento, California
- MIND Institute, University of California-Davis, School of Medicine, Sacramento, California
| | - Isaac N. Pessah
- Department of Molecular Biosciences, University of California-Davis, School of Veterinary Medicine, Davis, California
- MIND Institute, University of California-Davis, School of Medicine, Sacramento, California
| | - Pamela J. Lein
- Department of Molecular Biosciences, University of California-Davis, School of Veterinary Medicine, Davis, California
- MIND Institute, University of California-Davis, School of Medicine, Sacramento, California
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75
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Tran SS, Jun HI, Bahn JH, Azghadi A, Ramaswami G, Van Nostrand EL, Nguyen TB, Hsiao YHE, Lee C, Pratt GA, Martínez-Cerdeño V, Hagerman RJ, Yeo GW, Geschwind DH, Xiao X. Widespread RNA editing dysregulation in brains from autistic individuals. Nat Neurosci 2019; 22:25-36. [PMID: 30559470 PMCID: PMC6375307 DOI: 10.1038/s41593-018-0287-x] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 11/08/2018] [Indexed: 12/29/2022]
Abstract
Transcriptomic analyses of postmortem brains have begun to elucidate molecular abnormalities in autism spectrum disorder (ASD). However, a crucial pathway involved in synaptic development, RNA editing, has not yet been studied on a genome-wide scale. Here we profiled global patterns of adenosine-to-inosine (A-to-I) editing in a large cohort of postmortem brains of people with ASD. We observed a global bias for hypoediting in ASD brains, which was shared across brain regions and involved many synaptic genes. We show that the Fragile X proteins FMRP and FXR1P interact with RNA-editing enzymes (ADAR proteins) and modulate A-to-I editing. Furthermore, we observed convergent patterns of RNA-editing alterations in ASD and Fragile X syndrome, establishing this as a molecular link between these related diseases. Our findings, which are corroborated across multiple data sets, including dup15q (genomic duplication of 15q11.2-13.1) cases associated with intellectual disability, highlight RNA-editing dysregulation in ASD and reveal new mechanisms underlying this disorder.
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Affiliation(s)
- Stephen S Tran
- Bioinformatics Interdepartmental Program, UCLA, Los Angeles, CA, USA
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, CA, USA
| | - Hyun-Ik Jun
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, CA, USA
| | - Jae Hoon Bahn
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, CA, USA
| | - Adel Azghadi
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, CA, USA
| | - Gokul Ramaswami
- Department of Neurology, Center for Autism Research and Treatment, Semel Institute, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Eric L Van Nostrand
- Department of Cellular and Molecular Medicine, UCSD, La Jolla, CA, USA
- Stem Cell Program, UCSD, La Jolla, CA, USA
- Institute for Genomic Medicine, UCSD, La Jolla, CA, USA
| | - Thai B Nguyen
- Department of Cellular and Molecular Medicine, UCSD, La Jolla, CA, USA
- Stem Cell Program, UCSD, La Jolla, CA, USA
- Institute for Genomic Medicine, UCSD, La Jolla, CA, USA
| | | | - Changhoon Lee
- Department of Neurology, Center for Autism Research and Treatment, Semel Institute, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Gabriel A Pratt
- Department of Cellular and Molecular Medicine, UCSD, La Jolla, CA, USA
- Stem Cell Program, UCSD, La Jolla, CA, USA
- Institute for Genomic Medicine, UCSD, La Jolla, CA, USA
- Bioinformatics and Systems Biology Graduate Program, UCSD, La Jolla, CA, USA
| | | | - Randi J Hagerman
- The MIND Institute, Department of Pediatrics, UC Davis School of Medicine, Sacramento, CA, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, UCSD, La Jolla, CA, USA
- Stem Cell Program, UCSD, La Jolla, CA, USA
- Institute for Genomic Medicine, UCSD, La Jolla, CA, USA
- Bioinformatics and Systems Biology Graduate Program, UCSD, La Jolla, CA, USA
| | - Daniel H Geschwind
- Department of Neurology, Center for Autism Research and Treatment, Semel Institute, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.
- Program in Neurobehavioral Genetics, Semel Institute, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.
- Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.
| | - Xinshu Xiao
- Bioinformatics Interdepartmental Program, UCLA, Los Angeles, CA, USA.
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, CA, USA.
- Molecular Biology Institute, UCLA, Los Angeles, CA, USA.
- Institute for Quantitative and Computational Biology, UCLA, Los Angeles, CA, USA.
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76
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Guang S, Pang N, Deng X, Yang L, He F, Wu L, Chen C, Yin F, Peng J. Synaptopathology Involved in Autism Spectrum Disorder. Front Cell Neurosci 2018; 12:470. [PMID: 30627085 PMCID: PMC6309163 DOI: 10.3389/fncel.2018.00470] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/19/2018] [Indexed: 12/24/2022] Open
Abstract
Autism spectrum disorder (ASD) encompasses a group of multifactorial neurodevelopmental disorders characterized by impaired social communication, social interaction and repetitive behaviors. ASD affects 1 in 59 children, and is about 4 times more common among boys than among girls. Strong genetic components, together with environmental factors in the early stage of development, contribute to the pathogenesis of ASD. Multiple studies have revealed that mutations in genes like NRXN, NLGN, SHANK, TSC1/2, FMR1, and MECP2 converge on common cellular pathways that intersect at synapses. These genes encode cell adhesion molecules, scaffolding proteins and proteins involved in synaptic transcription, protein synthesis and degradation, affecting various aspects of synapses including synapse formation and elimination, synaptic transmission and plasticity. This suggests that the pathogenesis of ASD may, at least in part, be attributed to synaptic dysfunction. In this article, we will review major genes and signaling pathways implicated in synaptic abnormalities underlying ASD, and discuss molecular, cellular and functional studies of ASD experimental models.
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Affiliation(s)
- Shiqi Guang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Nan Pang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Xiaolu Deng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Liwen Wu
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Chen Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
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77
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Readhead B, Hartley BJ, Eastwood BJ, Collier DA, Evans D, Farias R, He C, Hoffman G, Sklar P, Dudley JT, Schadt EE, Savić R, Brennand KJ. Expression-based drug screening of neural progenitor cells from individuals with schizophrenia. Nat Commun 2018; 9:4412. [PMID: 30356048 PMCID: PMC6200740 DOI: 10.1038/s41467-018-06515-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 09/07/2018] [Indexed: 12/11/2022] Open
Abstract
A lack of biologically relevant screening models hinders the discovery of better treatments for schizophrenia (SZ) and other neuropsychiatric disorders. Here we compare the transcriptional responses of 8 commonly used cancer cell lines (CCLs) directly with that of human induced pluripotent stem cell (hiPSC)-derived neural progenitor cells (NPCs) from 12 individuals with SZ and 12 controls across 135 drugs, generating 4320 unique drug-response transcriptional signatures. We identify those drugs that reverse post-mortem SZ-associated transcriptomic signatures, several of which also differentially regulate neuropsychiatric disease-associated genes in a cell type (hiPSC NPC vs. CCL) and/or a diagnosis (SZ vs. control)-dependent manner. Overall, we describe a proof-of-concept application of transcriptomic drug screening to hiPSC-based models, demonstrating that the drug-induced gene expression differences observed with patient-derived hiPSC NPCs are enriched for SZ biology, thereby revealing a major advantage of incorporating cell type and patient-specific platforms in drug discovery. Unbiased large scale screening of small molecules for drug discovery in psychiatric disease is technically challenging and financially costly. Here, Readhead and colleagues integrate in silico and in vitro approaches to design and conduct transcriptomic drug screening in schizophrenia patient-derived neural cells, in order to survey novel pathologies and points of intervention.
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Affiliation(s)
- Benjamin Readhead
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Institute for Next Generation Healthcare, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,ASU-Banner Neurodegenerative Disease Research Center, Arizona State University, Tempe, AZ, 85287-5001, USA
| | - Brigham J Hartley
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | | | - David A Collier
- Eli Lilly and Company Ltd, Erl Wood Manor, Surrey, UK.,Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK
| | - David Evans
- Eli Lilly and Company Ltd, Erl Wood Manor, Surrey, UK
| | - Richard Farias
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Ching He
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Gabriel Hoffman
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Pamela Sklar
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Joel T Dudley
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.,Institute for Next Generation Healthcare, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Eric E Schadt
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. .,Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. .,Sema4, a Mount Sinai venture, Stamford, Connecticut, USA.
| | - Radoslav Savić
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. .,Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. .,Sema4, a Mount Sinai venture, Stamford, Connecticut, USA.
| | - Kristen J Brennand
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. .,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. .,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. .,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
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78
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Mably AJ, Colgin LL. Gamma oscillations in cognitive disorders. Curr Opin Neurobiol 2018; 52:182-187. [PMID: 30121451 DOI: 10.1016/j.conb.2018.07.009] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/18/2018] [Accepted: 07/31/2018] [Indexed: 02/06/2023]
Abstract
Gamma oscillations (∼25-100 Hz) are believed to play a role in cognition. Accordingly, aberrant gamma oscillations have been observed in several cognitive disorders, including Alzheimer's disease and Fragile X syndrome. Here, we review how recent results showing abnormal gamma rhythms in Alzheimer's disease and Fragile X syndrome help reveal links between cellular disturbances and cognitive impairments. We also discuss how gamma results from rodent models of Alzheimer's disease and Fragile X syndrome may provide insights about unique functions of distinct slow (∼25-50 Hz) and fast gamma (∼55-100 Hz) subtypes. Finally, we consider studies employing brain stimulation paradigms in Alzheimer's disease and discuss how such studies may reveal causal relationships between gamma impairments and memory disturbances.
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Affiliation(s)
- Alexandra J Mably
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, 1 University Station Stop C7000, Austin, TX 78712, USA
| | - Laura Lee Colgin
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, 1 University Station Stop C7000, Austin, TX 78712, USA.
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79
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Ferro D, Yao S, Zarnescu DC. Dynamic duo - FMRP and TDP-43: Regulating common targets, causing different diseases. Brain Res 2018; 1693:37-42. [PMID: 29715444 PMCID: PMC5997554 DOI: 10.1016/j.brainres.2018.04.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 10/17/2022]
Abstract
RNA binding proteins play essential roles during development and aging, and are also involved in disease pathomechanisms. RNA sequencing and omics analyses have provided a window into systems level alterations in neurological disease, and have identified RNA processing defects among notable disease mechanisms. This review focuses on two seemingly distinct neurological disorders, the RNA binding proteins they are linked to, and their newly discovered functional relationship. When deficient, Fragile X Mental Retardation Protein (FMRP) causes developmental deficits and autistic behaviors while TAR-DNA Binding Protein (TDP-43) dysregulation causes age dependent neuronal degeneration. Recent findings that FMRP and TDP-43 associate in ribonuclear protein particles and share mRNA targets in neurons highlight the critical importance of translation regulation in synaptic plasticity and provide new perspectives on neuronal vulnerability during lifespan.
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Affiliation(s)
- Diana Ferro
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, United States
| | - Stephen Yao
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, United States
| | - Daniela C Zarnescu
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, United States; Department of Neuroscience, University of Arizona, Tucson, AZ, United States; Department of Neurology, University of Arizona, Tucson AZ, United States.
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Jewett KA, Lee KY, Eagleman DE, Soriano S, Tsai NP. Dysregulation and restoration of homeostatic network plasticity in fragile X syndrome mice. Neuropharmacology 2018; 138:182-192. [PMID: 29890190 DOI: 10.1016/j.neuropharm.2018.06.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 05/01/2018] [Accepted: 06/06/2018] [Indexed: 01/06/2023]
Abstract
Chronic activity perturbations in neurons induce homeostatic plasticity through modulation of synaptic strength or other intrinsic properties to maintain the correct physiological range of excitability. Although similar plasticity can also occur at the population level, what molecular mechanisms are involved remain unclear. In the current study, we utilized a multielectrode array (MEA) recording system to evaluate homeostatic neural network activity of primary mouse cortical neuron cultures. We demonstrated that chronic elevation of neuronal activity through the inhibition of GABA(A) receptors elicits synchronization of neural network activity and homeostatic reduction of the amplitude of spontaneous neural network spikes. We subsequently showed that this phenomenon is mediated by the ubiquitination of tumor suppressor p53, which is triggered by murine double minute-2 (Mdm2). Using a mouse model of fragile X syndrome, in which fragile X mental retardation protein (FMRP) is absent (Fmr1 knockout), we found that Mdm2-p53 signaling, network synchronization, and the reduction of network spike amplitude upon chronic activity stimulation were all impaired. Pharmacologically inhibiting p53 with Pifithrin-α or genetically employing p53 heterozygous mice to enforce the inactivation of p53 in Fmr1 knockout cultures restored the synchronization of neural network activity after chronic activity stimulation and partially corrects the homeostatic reduction of neural network spike amplitude. Together, our findings reveal the roles of both Fmr1 and Mdm2-p53 signaling in the homeostatic regulation of neural network activity and provide insight into the deficits of excitability homeostasis seen when Fmr1 is compromised, such as occurs with fragile X syndrome.
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Affiliation(s)
- Kathryn A Jewett
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Kwan Young Lee
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Daphne E Eagleman
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Stephanie Soriano
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Nien-Pei Tsai
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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Zhou Y, Dong F, Mao Y. Control of CNS functions by RNA-binding proteins in neurological diseases. ACTA ACUST UNITED AC 2018; 4:301-313. [PMID: 30410853 DOI: 10.1007/s40495-018-0140-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Purpose of Review This review summarizes recent studies on the molecular mechanisms of RNA binding proteins (RBPs) that control neurological functions and pathogenesis in various neurodevelopmental and neurodegenerative diseases, including autism spectrum disorders, schizophrenia, Alzheimer's disease, amyotrophic lateral sclerosis, frontotemporal dementia, and spinocerebellar ataxia. Recent Findings RBPs are critical players in gene expression that regulate every step of posttranscriptional modifications. Recent genome-wide approaches revealed that many proteins associate with RNA, but do not contain any known RNA binding motifs. Additionally, many causal and risk genes of neurodevelopmental and neurodegenerative diseases are RBPs. Development of high-throughput sequencing methods has mapped out the fingerprints of RBPs on transcripts and provides unprecedented potential to discover new mechanisms of neurological diseases. Insights into how RBPs modulate neural development are important for designing effective therapies for numerous neurodevelopmental and neurodegenerative diseases. Summary RBPs have diverse mechanisms for modulating RNA processing and, thereby, controlling neurogenesis. Understanding the role of disease-associated RBPs in neurogenesis is vital for developing novel treatments for neurological diseases.
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Affiliation(s)
- Yijing Zhou
- Department of Biology, Pennsylvania State University, University Park, PA, 16802, USA
| | - Fengping Dong
- Department of Biology, Pennsylvania State University, University Park, PA, 16802, USA
| | - Yingwei Mao
- Department of Biology, Pennsylvania State University, University Park, PA, 16802, USA
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Drozd M, Bardoni B, Capovilla M. Modeling Fragile X Syndrome in Drosophila. Front Mol Neurosci 2018; 11:124. [PMID: 29713264 PMCID: PMC5911982 DOI: 10.3389/fnmol.2018.00124] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 03/29/2018] [Indexed: 01/18/2023] Open
Abstract
Intellectual disability (ID) and autism are hallmarks of Fragile X Syndrome (FXS), a hereditary neurodevelopmental disorder. The gene responsible for FXS is Fragile X Mental Retardation gene 1 (FMR1) encoding the Fragile X Mental Retardation Protein (FMRP), an RNA-binding protein involved in RNA metabolism and modulating the expression level of many targets. Most cases of FXS are caused by silencing of FMR1 due to CGG expansions in the 5'-UTR of the gene. Humans also carry the FXR1 and FXR2 paralogs of FMR1 while flies have only one FMR1 gene, here called dFMR1, sharing the same level of sequence homology with all three human genes, but functionally most similar to FMR1. This enables a much easier approach for FMR1 genetic studies. Drosophila has been widely used to investigate FMR1 functions at genetic, cellular, and molecular levels since dFMR1 mutants have many phenotypes in common with the wide spectrum of FMR1 functions that underlay the disease. In this review, we present very recent Drosophila studies investigating FMRP functions at genetic, cellular, molecular, and electrophysiological levels in addition to research on pharmacological treatments in the fly model. These studies have the potential to aid the discovery of pharmacological therapies for FXS.
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Affiliation(s)
- Małgorzata Drozd
- Université Côte d'Azur, CNRS, IPMC, Valbonne, France.,CNRS LIA (Neogenex), Valbonne, France
| | - Barbara Bardoni
- CNRS LIA (Neogenex), Valbonne, France.,Université Côte d'Azur, INSERM, CNRS, IPMC, Valbonne, France
| | - Maria Capovilla
- Université Côte d'Azur, CNRS, IPMC, Valbonne, France.,CNRS LIA (Neogenex), Valbonne, France
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