title: Hexanucleotide repeats in ALS/FTD form length-dependent RNA foci, sequester RNA binding proteins, and are neurotoxic.
abstract: The GGGGCC (G4C2) intronic repeat expansion within C9ORF72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Intranuclear neuronal RNA foci have been observed in ALS and FTD tissues, suggesting that G4C2 RNA may be toxic. Here, we demonstrate that the expression of 38× and 72× G4C2 repeats form intranuclear RNA foci that initiate apoptotic cell death in neuronal cell lines and zebrafish embryos. The foci colocalize with a subset of RNA binding proteins, including SF2, SC35, and hnRNP-H in transfected cells. Only hnRNP-H binds directly to G4C2 repeats following RNA immunoprecipitation, and only hnRNP-H colocalizes with 70% of G4C2 RNA foci detected in C9ORF72 mutant ALS and FTD brain tissues. We show that expanded G4C2 repeats are potently neurotoxic and bind hnRNP-H and other RNA binding proteins. We propose that RNA toxicity and protein sequestration may disrupt RNA processing and contribute to neurodegeneration.
authors.affiliation: Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
authors.forename: Youn-Bok
authors.initials: YB
authors.lastname: Lee
authors.affiliation: Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
authors.forename: Han-Jou
authors.initials: HJ
authors.lastname: Chen
authors.affiliation: MRC Centre for Developmental Neurobiology, London SE1 1UL, UK.
authors.forename: João N
authors.initials: JN
authors.lastname: Peres
authors.affiliation: Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
authors.forename: Jorge
authors.initials: J
authors.lastname: Gomez-Deza
authors.affiliation: Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
authors.forename: Jan
authors.initials: J
authors.lastname: Attig
authors.affiliation: Department of Biotechnology, Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
authors.forename: Maja
authors.initials: M
authors.lastname: Stalekar
authors.affiliation: Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Troakes
authors.affiliation: Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
authors.forename: Agnes L
authors.initials: AL
authors.lastname: Nishimura
authors.affiliation: Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Scotter
authors.affiliation: Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
authors.forename: Caroline
authors.initials: C
authors.lastname: Vance
authors.affiliation: Department of Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Adachi
authors.affiliation: Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK; Department of Public Health, Neuroscience, Experimental, and Forensic Medicine, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Sardone
authors.affiliation: Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
authors.forename: Jack W
authors.initials: JW
authors.lastname: Miller
authors.affiliation: Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
authors.forename: Bradley N
authors.initials: BN
authors.lastname: Smith
authors.affiliation: Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Gallo
authors.affiliation: MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
authors.forename: Jernej
authors.initials: J
authors.lastname: Ule
authors.affiliation: Department of Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
authors.forename: Frank
authors.initials: F
authors.lastname: Hirth
authors.affiliation: Department of Biotechnology, Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
authors.forename: Boris
authors.initials: B
authors.lastname: Rogelj
authors.affiliation: MRC Centre for Developmental Neurobiology, London SE1 1UL, UK.
authors.forename: Corinne
authors.initials: C
authors.lastname: Houart
authors.affiliation: Department of Clinical Neuroscience, King's College London, Institute of Psychiatry, London SE5 8AF, UK. Electronic address: christopher.shaw@kcl.ac.uk.
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Shaw
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D000073885:C9orf72 Protein; D016022:Case-Control Studies; D045744:Cell Line, Tumor; D005260:Female; D057180:Frontotemporal Dementia / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D011485:Protein Binding; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D015027:Zebrafish
chemical_list: D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; D011506:Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins