1
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Aygün N, Vuong C, Krupa O, Mory J, Le BD, Valone JM, Liang D, Shafie B, Zhang P, Salinda A, Wen C, Gandal MJ, Love MI, de la Torre-Ubieta L, Stein JL. Genetics of cell-type-specific post-transcriptional gene regulation during human neurogenesis. Am J Hum Genet 2024; 111:1877-1898. [PMID: 39168119 PMCID: PMC11393701 DOI: 10.1016/j.ajhg.2024.07.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 07/18/2024] [Accepted: 07/23/2024] [Indexed: 08/23/2024] Open
Abstract
The function of some genetic variants associated with brain-relevant traits has been explained through colocalization with expression quantitative trait loci (eQTL) conducted in bulk postmortem adult brain tissue. However, many brain-trait associated loci have unknown cellular or molecular function. These genetic variants may exert context-specific function on different molecular phenotypes including post-transcriptional changes. Here, we identified genetic regulation of RNA editing and alternative polyadenylation (APA) within a cell-type-specific population of human neural progenitors and neurons. More RNA editing and isoforms utilizing longer polyadenylation sequences were observed in neurons, likely due to higher expression of genes encoding the proteins mediating these post-transcriptional events. We also detected hundreds of cell-type-specific editing quantitative trait loci (edQTLs) and alternative polyadenylation QTLs (apaQTLs). We found colocalizations of a neuron edQTL in CCDC88A with educational attainment and a progenitor apaQTL in EP300 with schizophrenia, suggesting that genetically mediated post-transcriptional regulation during brain development leads to differences in brain function.
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Affiliation(s)
- Nil Aygün
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Celine Vuong
- Intellectual and Developmental Disabilities Research Center, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Oleh Krupa
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jessica Mory
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Brandon D Le
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jordan M Valone
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Dan Liang
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Beck Shafie
- Intellectual and Developmental Disabilities Research Center, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Pan Zhang
- Intellectual and Developmental Disabilities Research Center, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Angelo Salinda
- Intellectual and Developmental Disabilities Research Center, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Cindy Wen
- Intellectual and Developmental Disabilities Research Center, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Michael J Gandal
- Intellectual and Developmental Disabilities Research Center, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael I Love
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Luis de la Torre-Ubieta
- Intellectual and Developmental Disabilities Research Center, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jason L Stein
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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2
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Bai D, Deng F, Jia Q, Ou K, Wang X, Hou J, Zhu L, Guo M, Yang S, Jiang G, Li S, Li XJ, Yin P. Pathogenic TDP-43 accelerates the generation of toxic exon1 HTT in Huntington's disease knock-in mice. Aging Cell 2024:e14325. [PMID: 39185703 DOI: 10.1111/acel.14325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 08/05/2024] [Accepted: 08/13/2024] [Indexed: 08/27/2024] Open
Abstract
Huntington's disease (HD) is caused by a CAG repeat expansion in exon1 of the HTT gene that encodes a polyglutamine tract in huntingtin protein. The formation of HTT exon1 fragments with an expanded polyglutamine repeat has been implicated as a key step in the pathogenesis of HD. It was reported that the CAG repeat length-dependent aberrant splicing of exon1 HTT results in a short polyadenylated mRNA that is translated into an exon1 HTT protein. Under normal conditions, TDP-43 is predominantly found in the nucleus, where it regulates gene expression. However, in various pathological conditions, TDP-43 is mislocalized in the cytoplasm. By investigating HD knock-in mice, we explore whether the pathogenic TDP-43 in the cytoplasm contributes to HD pathogenesis, through expressing the cytoplasmic TDP-43 without nuclear localization signal. We found that the cytoplasmic TDP-43 is increased in the HD mouse brain and that its mislocalization could deteriorate the motor and gait behavior. Importantly, the cytoplasmic TDP-43, via its binding to the intron1 sequence (GU/UG)n of the mouse Htt pre-mRNA, promotes the transport of exon1-intron1 Htt onto ribosome, resulting in the aberrant generation of exon1 Htt. Our findings suggest that cytoplasmic TDP-43 contributes to HD pathogenesis via its binding to and transport of nuclear un-spliced mRNA to the ribosome for the generation of a toxic protein product.
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Affiliation(s)
- Dazhang Bai
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Key Laboratory of non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong, China
- Department of Neurology, Affiliated Hospital of North Sichuan Medical College, Institute of Neurological Diseases, North Sichuan Medical College, Nanchong, Sichuan, China
| | - Fuyu Deng
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Key Laboratory of non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong, China
- Shenzhen Institute for Drug Control, Shenzhen Testing Center of Medical Devices, In Vitro Diagnostic Reagents Testing Department, Shenzhen, Guangdong, China
| | - Qingqing Jia
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Key Laboratory of non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong, China
| | - Kaili Ou
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Key Laboratory of non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong, China
| | - Xiang Wang
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Key Laboratory of non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong, China
| | - Junqi Hou
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Key Laboratory of non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong, China
| | - Longhong Zhu
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Key Laboratory of non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong, China
| | - Mingwei Guo
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Key Laboratory of non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong, China
| | - Su Yang
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Key Laboratory of non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong, China
| | - Guohui Jiang
- Department of Neurology, Affiliated Hospital of North Sichuan Medical College, Institute of Neurological Diseases, North Sichuan Medical College, Nanchong, Sichuan, China
| | - Shihua Li
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Key Laboratory of non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong, China
| | - Xiao-Jiang Li
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Key Laboratory of non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong, China
| | - Peng Yin
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Key Laboratory of non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong, China
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Romo L, Findlay SD, Burge CB. Regulatory features aid interpretation of 3'UTR variants. Am J Hum Genet 2024; 111:350-363. [PMID: 38237594 PMCID: PMC10870128 DOI: 10.1016/j.ajhg.2023.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 12/13/2023] [Accepted: 12/14/2023] [Indexed: 01/30/2024] Open
Abstract
Our ability to determine the clinical impact of variants in 3' untranslated regions (UTRs) of genes remains poor. We provide a thorough analysis of 3' UTR variants from several datasets. Variants in putative regulatory elements, including RNA-binding protein motifs, eCLIP peaks, and microRNA sites, are up to 16 times more likely than variants not in these elements to have gene expression and phenotype associations. Variants in regulatory motifs result in allele-specific protein binding in cell lines and allele-specific gene expression differences in population studies. In addition, variants in shared regions of alternatively polyadenylated isoforms and those proximal to polyA sites are more likely to affect gene expression and phenotype. Finally, pathogenic 3' UTR variants in ClinVar are up to 20 times more likely than benign variants to fall in a regulatory site. We incorporated these findings into RegVar, a software tool that interprets regulatory elements and annotations for any 3' UTR variant and predicts whether the variant is likely to affect gene expression or phenotype. This tool will help prioritize variants for experimental studies and identify pathogenic variants in individuals.
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Affiliation(s)
- Lindsay Romo
- Harvard Medical Genetics Training Program, Boston Children's Hospital, Boston, MA 02115, USA.
| | - Scott D Findlay
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Christopher B Burge
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
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4
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Grlickova-Duzevik E, Reimonn TM, Michael M, Tian T, Owyoung J, McGrath-Conwell A, Neufeld P, Mueth M, Molliver DC, Ward PJ, Harrison BJ. Members of the CUGBP Elav-like family of RNA-binding proteins are expressed in distinct populations of primary sensory neurons. J Comp Neurol 2023; 531:1425-1442. [PMID: 37537886 DOI: 10.1002/cne.25520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 05/16/2023] [Accepted: 06/10/2023] [Indexed: 08/05/2023]
Abstract
Primary sensory dorsal root ganglia (DRG) neurons are diverse, with distinct populations that respond to specific stimuli. Previously, we observed that functionally distinct populations of DRG neurons express mRNA transcript variants with different 3' untranslated regions (3'UTRs). 3'UTRs harbor binding sites for interaction with RNA-binding proteins (RBPs) for transporting mRNAs to subcellular domains, modulating transcript stability, and regulating the rate of translation. In the current study, analysis of publicly available single-cell RNA-sequencing data generated from adult mice revealed that 17 3'UTR-binding RBPs were enriched in specific populations of DRG neurons. This included four members of the CUG triplet repeat (CUGBP) Elav-like family (CELF): CELF2 and CELF4 were enriched in peptidergic, CELF6 in both peptidergic and nonpeptidergic, and CELF3 in tyrosine hydroxylase-expressing neurons. Immunofluorescence studies confirmed that 60% of CELF4+ neurons are small-diameter C fibers and 33% medium-diameter myelinated (likely Aδ) fibers and showed that CELF4 is distributed to peripheral termini. Coexpression analyses using transcriptomic data and immunofluorescence revealed that CELF4 is enriched in nociceptive neurons that express GFRA3, CGRP, and the capsaicin receptor TRPV1. Reanalysis of published transcriptomic data from macaque DRG revealed a highly similar distribution of CELF members, and reanalysis of single-nucleus RNA-sequencing data derived from mouse and rat DRG after sciatic injury revealed differential expression of CELFs in specific populations of sensory neurons. We propose that CELF RBPs may regulate the fate of mRNAs in populations of nociceptors, and may play a role in pain and/or neuronal regeneration following nerve injury.
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Affiliation(s)
- Eliza Grlickova-Duzevik
- Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, Maine, USA
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, USA
| | - Thomas M Reimonn
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Merilla Michael
- Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, Maine, USA
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, USA
| | - Tina Tian
- Medical Scientist Training Program, Emory University, Atlanta, Georgia, USA
- Neuroscience Graduate Program, Emory University, Atlanta, Georgia, USA
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Jordan Owyoung
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA
- Genetics and Molecular Biology Graduate Program, Emory University, Atlanta, Georgia, USA
| | - Aidan McGrath-Conwell
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, USA
- College of Arts and Sciences, University of New England, Biddeford, Maine, USA
| | - Peter Neufeld
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, USA
- College of Arts and Sciences, University of New England, Biddeford, Maine, USA
| | - Madison Mueth
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, USA
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine, USA
| | - Derek C Molliver
- Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, Maine, USA
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, USA
| | - Patricia Jillian Ward
- Neuroscience Graduate Program, Emory University, Atlanta, Georgia, USA
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Benjamin J Harrison
- Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, Maine, USA
- Center for Excellence in the Neurosciences, University of New England, Biddeford, Maine, USA
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5
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Aygün N, Krupa O, Mory J, Le B, Valone J, Liang D, Love MI, Stein JL. Genetics of cell-type-specific post-transcriptional gene regulation during human neurogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.30.555019. [PMID: 37693528 PMCID: PMC10491258 DOI: 10.1101/2023.08.30.555019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
The function of some genetic variants associated with brain-relevant traits has been explained through colocalization with expression quantitative trait loci (eQTL) conducted in bulk post-mortem adult brain tissue. However, many brain-trait associated loci have unknown cellular or molecular function. These genetic variants may exert context-specific function on different molecular phenotypes including post-transcriptional changes. Here, we identified genetic regulation of RNA-editing and alternative polyadenylation (APA), within a cell-type-specific population of human neural progenitors and neurons. More RNA-editing and isoforms utilizing longer polyadenylation sequences were observed in neurons, likely due to higher expression of genes encoding the proteins mediating these post-transcriptional events. We also detected hundreds of cell-type-specific editing quantitative trait loci (edQTLs) and alternative polyadenylation QTLs (apaQTLs). We found colocalizations of a neuron edQTL in CCDC88A with educational attainment and a progenitor apaQTL in EP300 with schizophrenia, suggesting genetically mediated post-transcriptional regulation during brain development lead to differences in brain function.
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Affiliation(s)
- Nil Aygün
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- UNC Neuroscience Center University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Oleh Krupa
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- UNC Neuroscience Center University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jessica Mory
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- UNC Neuroscience Center University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Brandon Le
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- UNC Neuroscience Center University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jordan Valone
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- UNC Neuroscience Center University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Dan Liang
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- UNC Neuroscience Center University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Michael I. Love
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jason L. Stein
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- UNC Neuroscience Center University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Lead contact
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6
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Romo L, Findlay SD, Burge CB. Regulatory features aid interpretation of 3'UTR Variants. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.01.551549. [PMID: 37577470 PMCID: PMC10418266 DOI: 10.1101/2023.08.01.551549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Our ability to determine the clinical impact of variants in 3' untranslated regions (UTRs) of genes remains poor. We provide a thorough analysis of 3'UTR variants from several datasets. Variants in putative regulatory elements including RNA-binding protein motifs, eCLIP peaks, and microRNA sites are up to 16 times more likely than other variants to have gene expression and phenotype associations. Heterozygous variants in regulatory motifs result in allele-specific protein binding in cell lines and allele-specific gene expression differences in population studies. In addition, variants in shared regions of alternatively polyadenylated isoforms and those proximal to polyA sites are more likely to affect gene expression and phenotype. Finally, pathogenic 3'UTR variants in ClinVar are 20 times more likely than benign variants to fall in a regulatory site. We incorporated these findings into RegVar, a software tool that interprets regulatory elements and annotations for any 3'UTR variant, and predicts whether the variant is likely to affect gene expression or phenotype. This tool will help prioritize variants for experimental studies and identify pathogenic variants in patients.
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Affiliation(s)
- Lindsay Romo
- Harvard Medical Genetics Training Program, Boston Children’s Hospital, Boston, MA 02115
| | - Scott D. Findlay
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02142
| | - Christopher B. Burge
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02142
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7
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LaForce GR, Philippidou P, Schaffer AE. mRNA isoform balance in neuronal development and disease. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1762. [PMID: 36123820 PMCID: PMC10024649 DOI: 10.1002/wrna.1762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/11/2022] [Accepted: 08/15/2022] [Indexed: 11/07/2022]
Abstract
Balanced mRNA isoform diversity and abundance are spatially and temporally regulated throughout cellular differentiation. The proportion of expressed isoforms contributes to cell type specification and determines key properties of the differentiated cells. Neurons are unique cell types with intricate developmental programs, characteristic cellular morphologies, and electrophysiological potential. Neuron-specific gene expression programs establish these distinctive cellular characteristics and drive diversity among neuronal subtypes. Genes with neuron-specific alternative processing are enriched in key neuronal functions, including synaptic proteins, adhesion molecules, and scaffold proteins. Despite the similarity of neuronal gene expression programs, each neuronal subclass can be distinguished by unique alternative mRNA processing events. Alternative processing of developmentally important transcripts alters coding and regulatory information, including interaction domains, transcript stability, subcellular localization, and targeting by RNA binding proteins. Fine-tuning of mRNA processing is essential for neuronal activity and maintenance. Thus, the focus of neuronal RNA biology research is to dissect the transcriptomic mechanisms that underlie neuronal homeostasis, and consequently, predispose neuronal subtypes to disease. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.
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Affiliation(s)
- Geneva R LaForce
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Polyxeni Philippidou
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Ashleigh E Schaffer
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, USA
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8
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Cui Y, Arnold FJ, Peng F, Wang D, Li JS, Michels S, Wagner EJ, La Spada AR, Li W. Alternative polyadenylation transcriptome-wide association study identifies APA-linked susceptibility genes in brain disorders. Nat Commun 2023; 14:583. [PMID: 36737438 PMCID: PMC9898543 DOI: 10.1038/s41467-023-36311-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 01/25/2023] [Indexed: 02/05/2023] Open
Abstract
Alternative polyadenylation (APA) plays an essential role in brain development; however, current transcriptome-wide association studies (TWAS) largely overlook APA in nominating susceptibility genes. Here, we performed a 3' untranslated region (3'UTR) APA TWAS (3'aTWAS) for 11 brain disorders by combining their genome-wide association studies data with 17,300 RNA-seq samples across 2,937 individuals. We identified 354 3'aTWAS-significant genes, including known APA-linked risk genes, such as SNCA in Parkinson's disease. Among these 354 genes, ~57% are not significant in traditional expression- and splicing-TWAS studies, since APA may regulate the translation, localization and protein-protein interaction of the target genes independent of mRNA level expression or splicing. Furthermore, we discovered ATXN3 as a 3'aTWAS-significant gene for amyotrophic lateral sclerosis, and its modulation substantially impacted pathological hallmarks of amyotrophic lateral sclerosis in vitro. Together, 3'aTWAS is a powerful strategy to nominate important APA-linked brain disorder susceptibility genes, most of which are largely overlooked by conventional expression and splicing analyses.
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Affiliation(s)
- Ya Cui
- Division of Computational Biomedicine, Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA, 92697, USA
| | - Frederick J Arnold
- Departments of Pathology & Laboratory Medicine, Neurology, and Biological Chemistry, School of Medicine, and the UCI Institute for Neurotherapeutics, University of California Irvine, Irvine, CA, 92697, USA
| | - Fanglue Peng
- Department of Molecular and Cellular Biology, University Baylor College of Medicine, Houston, TX, 77030, USA
| | - Dan Wang
- Department of Medicine, Division of Cardiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Jason Sheng Li
- Division of Computational Biomedicine, Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA, 92697, USA
| | - Sebastian Michels
- Departments of Pathology & Laboratory Medicine, Neurology, and Biological Chemistry, School of Medicine, and the UCI Institute for Neurotherapeutics, University of California Irvine, Irvine, CA, 92697, USA
| | - Eric J Wagner
- School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Albert R La Spada
- Departments of Pathology & Laboratory Medicine, Neurology, and Biological Chemistry, School of Medicine, and the UCI Institute for Neurotherapeutics, University of California Irvine, Irvine, CA, 92697, USA.
| | - Wei Li
- Division of Computational Biomedicine, Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA, 92697, USA.
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9
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Fienko S, Landles C, Sathasivam K, McAteer SJ, Milton RE, Osborne GF, Smith EJ, Jones ST, Bondulich MK, Danby ECE, Phillips J, Taxy BA, Kordasiewicz HB, Bates GP. Alternative processing of human HTT mRNA with implications for Huntington's disease therapeutics. Brain 2022; 145:4409-4424. [PMID: 35793238 PMCID: PMC9762945 DOI: 10.1093/brain/awac241] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 05/17/2022] [Accepted: 06/11/2022] [Indexed: 11/14/2022] Open
Abstract
Huntington disease is caused by a CAG repeat expansion in exon 1 of the huntingtin gene (HTT) that is translated into a polyglutamine stretch in the huntingtin protein (HTT). We previously showed that HTT mRNA carrying an expanded CAG repeat was incompletely spliced to generate HTT1a, an exon 1 only transcript, which was translated to produce the highly aggregation-prone and pathogenic exon 1 HTT protein. This occurred in all knock-in mouse models of Huntington's disease and could be detected in patient cell lines and post-mortem brains. To extend these findings to a model system expressing human HTT, we took advantage of YAC128 mice that are transgenic for a yeast artificial chromosome carrying human HTT with an expanded CAG repeat. We discovered that the HTT1a transcript could be detected throughout the brains of YAC128 mice. We implemented RNAscope to visualize HTT transcripts at the single molecule level and found that full-length HTT and HTT1a were retained together in large nuclear RNA clusters, as well as being present as single transcripts in the cytoplasm. Homogeneous time-resolved fluorescence analysis demonstrated that the HTT1a transcript had been translated to produce the exon 1 HTT protein. The levels of exon 1 HTT in YAC128 mice, correlated with HTT aggregation, supportive of the hypothesis that exon 1 HTT initiates the aggregation process. Huntingtin-lowering strategies are a major focus of therapeutic development for Huntington's disease. These approaches often target full-length HTT alone and would not be expected to reduce pathogenic exon 1 HTT levels. We have established YAC128 mouse embryonic fibroblast lines and shown that, together with our QuantiGene multiplex assay, these provide an effective screening tool for agents that target HTT transcripts. The effects of current targeting strategies on nuclear RNA clusters are unknown, structures that may have a pathogenic role or alternatively could be protective by retaining HTT1a in the nucleus and preventing it from being translated. In light of recently halted antisense oligonucleotide trials, it is vital that agents targeting HTT1a are developed, and that the effects of HTT-lowering strategies on the subcellular levels of all HTT transcripts and their various HTT protein isoforms are understood.
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Affiliation(s)
- Sandra Fienko
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Christian Landles
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Kirupa Sathasivam
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Sean J McAteer
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Rebecca E Milton
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Georgina F Osborne
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Edward J Smith
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Samuel T Jones
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Marie K Bondulich
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Emily C E Danby
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Jemima Phillips
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Bridget A Taxy
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | | | - Gillian P Bates
- Department of Neurodegenerative Disease, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
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10
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Pupak A, Singh A, Sancho-Balsells A, Alcalá-Vida R, Espina M, Giralt A, Martí E, Ørom UAV, Ginés S, Brito V. Altered m6A RNA methylation contributes to hippocampal memory deficits in Huntington's disease mice. Cell Mol Life Sci 2022; 79:416. [PMID: 35819730 PMCID: PMC9276730 DOI: 10.1007/s00018-022-04444-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/07/2022] [Accepted: 06/22/2022] [Indexed: 11/30/2022]
Abstract
N6-methyladenosine (m6A) regulates many aspects of RNA metabolism and is involved in learning and memory processes. Yet, the impact of a dysregulation of post-transcriptional m6A editing on synaptic impairments in neurodegenerative disorders remains unknown. Here we investigated the m6A methylation pattern in the hippocampus of Huntington’s disease (HD) mice and the potential role of the m6A RNA modification in HD cognitive symptomatology. m6A modifications were evaluated in HD mice subjected to a hippocampal cognitive training task through m6A immunoprecipitation sequencing (MeRIP-seq) and the relative levels of m6A-modifying proteins (FTO and METTL14) by subcellular fractionation and Western blot analysis. Stereotaxic CA1 hippocampal delivery of AAV-shFTO was performed to investigate the effect of RNA m6A dysregulation in HD memory deficits. Our results reveal a m6A hypermethylation in relevant HD and synaptic related genes in the hippocampal transcriptome of Hdh+/Q111 mice. Conversely, m6A is aberrantly regulated in an experience-dependent manner in the HD hippocampus leading to demethylation of important components of synapse organization. Notably, the levels of RNA demethylase (FTO) and methyltransferase (METTL14) were modulated after training in the hippocampus of WT mice but not in Hdh+/Q111 mice. Finally, inhibition of FTO expression in the hippocampal CA1 region restored memory disturbances in symptomatic Hdh+/Q111 mice. Altogether, our results suggest that a differential RNA methylation landscape contributes to HD cognitive symptoms and uncover a role of m6A as a novel hallmark of HD.
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Affiliation(s)
- Anika Pupak
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Casanova 143, 08036, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Ankita Singh
- Department for Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Anna Sancho-Balsells
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Casanova 143, 08036, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Rafael Alcalá-Vida
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), University of Strasbourg, Strasbourg, France
| | - Marc Espina
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Casanova 143, 08036, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Albert Giralt
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Casanova 143, 08036, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Eulàlia Martí
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Casanova 143, 08036, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | | | - Silvia Ginés
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Casanova 143, 08036, Barcelona, Spain. .,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain. .,Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
| | - Verónica Brito
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurosciències, Universitat de Barcelona, Casanova 143, 08036, Barcelona, Spain. .,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain. .,Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
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11
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Implications of Poly(A) Tail Processing in Repeat Expansion Diseases. Cells 2022; 11:cells11040677. [PMID: 35203324 PMCID: PMC8870147 DOI: 10.3390/cells11040677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/11/2022] [Accepted: 02/13/2022] [Indexed: 11/21/2022] Open
Abstract
Repeat expansion diseases are a group of more than 40 disorders that affect mainly the nervous and/or muscular system and include myotonic dystrophies, Huntington’s disease, and fragile X syndrome. The mutation-driven expanded repeat tract occurs in specific genes and is composed of tri- to dodeca-nucleotide-long units. Mutant mRNA is a pathogenic factor or important contributor to the disease and has great potential as a therapeutic target. Although repeat expansion diseases are quite well known, there are limited studies concerning polyadenylation events for implicated transcripts that could have profound effects on transcript stability, localization, and translation efficiency. In this review, we briefly present polyadenylation and alternative polyadenylation (APA) mechanisms and discuss their role in the pathogenesis of selected diseases. We also discuss several methods for poly(A) tail measurement (both transcript-specific and transcriptome-wide analyses) and APA site identification—the further development and use of which may contribute to a better understanding of the correlation between APA events and repeat expansion diseases. Finally, we point out some future perspectives on the research into repeat expansion diseases, as well as APA studies.
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12
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Sidibé H, Khalfallah Y, Xiao S, Gómez NB, Fakim H, Tank EMH, Di Tomasso G, Bareke E, Aulas A, McKeever PM, Melamed Z, Destroimaisons L, Deshaies JE, Zinman L, Parker JA, Legault P, Tétreault M, Barmada SJ, Robertson J, Vande Velde C. TDP-43 stabilizes G3BP1 mRNA: relevance to amyotrophic lateral sclerosis/frontotemporal dementia. Brain 2021; 144:3461-3476. [PMID: 34115105 PMCID: PMC8677511 DOI: 10.1093/brain/awab217] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 03/26/2021] [Accepted: 05/27/2021] [Indexed: 12/04/2022] Open
Abstract
TDP-43 nuclear depletion and concurrent cytoplasmic accumulation in vulnerable neurons is a hallmark feature of progressive neurodegenerative proteinopathies such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Cellular stress signalling and stress granule dynamics are now recognized to play a role in ALS/FTD pathogenesis. Defective stress granule assembly is associated with increased cellular vulnerability and death. Ras-GAP SH3-domain-binding protein 1 (G3BP1) is a critical stress granule assembly factor. Here, we define that TDP-43 stabilizes G3BP1 transcripts via direct binding of a highly conserved cis regulatory element within the 3' untranslated region. Moreover, we show in vitro and in vivo that nuclear TDP-43 depletion is sufficient to reduce G3BP1 protein levels. Finally, we establish that G3BP1 transcripts are reduced in ALS/FTD patient neurons bearing TDP-43 cytoplasmic inclusions/nuclear depletion. Thus, our data indicate that, in ALS/FTD, there is a compromised stress granule response in disease-affected neurons due to impaired G3BP1 mRNA stability caused by TDP-43 nuclear depletion. These data implicate TDP-43 and G3BP1 loss of function as contributors to disease.
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Affiliation(s)
- Hadjara Sidibé
- Department of Neurosciences, Université de Montréal, Montréal, QC H3A 0E8, Canada
- CHUM Research Center, Montréal, QC H2X 0A9, Canada
| | - Yousra Khalfallah
- CHUM Research Center, Montréal, QC H2X 0A9, Canada
- Department of Biochemistry, Université de Montréal, Montréal, QC H3A 0E8, Canada
| | - Shangxi Xiao
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON M5T 0S8, Canada
| | - Nicolás B Gómez
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hana Fakim
- Department of Neurosciences, Université de Montréal, Montréal, QC H3A 0E8, Canada
- CHUM Research Center, Montréal, QC H2X 0A9, Canada
| | - Elizabeth M H Tank
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Geneviève Di Tomasso
- Department of Biochemistry, Université de Montréal, Montréal, QC H3A 0E8, Canada
| | - Eric Bareke
- CHUM Research Center, Montréal, QC H2X 0A9, Canada
| | - Anaïs Aulas
- CHUM Research Center, Montréal, QC H2X 0A9, Canada
- Department of Biochemistry, Université de Montréal, Montréal, QC H3A 0E8, Canada
| | - Paul M McKeever
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON M5T 0S8, Canada
| | - Ze’ev Melamed
- University of California, San Diego/Ludwig Institute for Cancer Research, San Diego, CA 92093, USA
| | | | | | - Lorne Zinman
- Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON M4N 3M5, Canada
| | - J Alex Parker
- Department of Neurosciences, Université de Montréal, Montréal, QC H3A 0E8, Canada
- CHUM Research Center, Montréal, QC H2X 0A9, Canada
| | - Pascale Legault
- Department of Biochemistry, Université de Montréal, Montréal, QC H3A 0E8, Canada
| | - Martine Tétreault
- Department of Neurosciences, Université de Montréal, Montréal, QC H3A 0E8, Canada
- CHUM Research Center, Montréal, QC H2X 0A9, Canada
| | - Sami J Barmada
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Janice Robertson
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON M5T 0S8, Canada
| | - Christine Vande Velde
- Department of Neurosciences, Université de Montréal, Montréal, QC H3A 0E8, Canada
- CHUM Research Center, Montréal, QC H2X 0A9, Canada
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13
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Larsen K, Heide-Jørgensen MP. Conservation of A-to-I RNA editing in bowhead whale and pig. PLoS One 2021; 16:e0260081. [PMID: 34882682 PMCID: PMC8659423 DOI: 10.1371/journal.pone.0260081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 11/02/2021] [Indexed: 01/18/2023] Open
Abstract
RNA editing is a post-transcriptional process in which nucleotide changes are introduced into an RNA sequence, many of which can contribute to proteomic sequence variation. The most common type of RNA editing, contributing to nearly 99% of all editing events in RNA, is A-to-I (adenosine-to-inosine) editing mediated by double-stranded RNA-specific adenosine deaminase (ADAR) enzymes. A-to-I editing at 'recoding' sites results in non-synonymous substitutions in protein-coding sequences. Here, we present studies of the conservation of A-to-I editing in selected mRNAs between pigs, bowhead whales, humans and two shark species. All examined mRNAs-NEIL1, COG3, GRIA2, FLNA, FLNB, IGFBP7, AZIN1, BLCAP, GLI1, SON, HTR2C and ADAR2 -showed conservation of A-to-I editing of recoding sites. In addition, novel editing sites were identified in NEIL1 and GLI1 in bowhead whales. The A-to-I editing site of human NEIL1 in position 242 was conserved in the bowhead and porcine homologues. A novel editing site was discovered in Tyr244. Differential editing was detected at the two adenosines in the NEIL1 242 codon in both pig and bowhead NEIL1 mRNAs in various tissues and organs. No conservation of editing of KCNB1 and EEF1A mRNAs was seen in bowhead whales. In silico analyses revealed conservation of five adenosines in ADAR2, some of which are subject to A-to-I editing in bowheads and pigs, and conservation of a regulatory sequence in GRIA2 mRNA that is responsible for recognition of the ADAR editing enzyme.
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Affiliation(s)
- Knud Larsen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
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14
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RNA Modifications and RNA Metabolism in Neurological Disease Pathogenesis. Int J Mol Sci 2021; 22:ijms222111870. [PMID: 34769301 PMCID: PMC8584444 DOI: 10.3390/ijms222111870] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/16/2021] [Accepted: 10/26/2021] [Indexed: 02/06/2023] Open
Abstract
The intrinsic cellular heterogeneity and molecular complexity of the mammalian nervous system relies substantially on the dynamic nature and spatiotemporal patterning of gene expression. These features of gene expression are achieved in part through mechanisms involving various epigenetic processes such as DNA methylation, post-translational histone modifications, and non-coding RNA activity, amongst others. In concert, another regulatory layer by which RNA bases and sugar residues are chemically modified enhances neuronal transcriptome complexity. Similar RNA modifications in other systems collectively constitute the cellular epitranscriptome that integrates and impacts various physiological processes. The epitranscriptome is dynamic and is reshaped constantly to regulate vital processes such as development, differentiation and stress responses. Perturbations of the epitranscriptome can lead to various pathogenic conditions, including cancer, cardiovascular abnormalities and neurological diseases. Recent advances in next-generation sequencing technologies have enabled us to identify and locate modified bases/sugars on different RNA species. These RNA modifications modulate the stability, transport and, most importantly, translation of RNA. In this review, we discuss the formation and functions of some frequently observed RNA modifications—including methylations of adenine and cytosine bases, and isomerization of uridine to pseudouridine—at various layers of RNA metabolism, together with their contributions to abnormal physiological conditions that can lead to various neurodevelopmental and neurological disorders.
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15
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Mohanan NK, Shaji F, Koshre GR, Laishram RS. Alternative polyadenylation: An enigma of transcript length variation in health and disease. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 13:e1692. [PMID: 34581021 DOI: 10.1002/wrna.1692] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/16/2021] [Accepted: 08/24/2021] [Indexed: 12/19/2022]
Abstract
Alternative polyadenylation (APA) is a molecular mechanism during a pre-mRNA processing that involves usage of more than one polyadenylation site (PA-site) generating transcripts of varying length from a single gene. The location of a PA-site affects transcript length and coding potential of an mRNA contributing to both mRNA and protein diversification. This variation in the transcript length affects mRNA stability and translation, mRNA subcellular and tissue localization, and protein function. APA is now considered as an important regulatory mechanism in the pathophysiology of human diseases. An important consequence of the changes in the length of 3'-untranslated region (UTR) from disease-induced APA is altered protein expression. Yet, the relationship between 3'-UTR length and protein expression remains a paradox in a majority of diseases. Here, we review occurrence of APA, mechanism of PA-site selection, and consequences of transcript length variation in different diseases. Emerging evidence reveals coordinated involvement of core RNA processing factors including poly(A) polymerases in the PA-site selection in diseases-associated APAs. Targeting such APA regulators will be therapeutically significant in combating drug resistance in cancer and other complex diseases. This article is categorized under: RNA Processing > 3' End Processing RNA in Disease and Development > RNA in Disease Translation > Regulation.
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Affiliation(s)
- Neeraja K Mohanan
- Cardiovascular and Diabetes Biology Group, Rajiv Gandhi Centre for Biotechnology, Trivandrum, India
- Manipal Academy of Higher Education, Manipal, India
| | - Feba Shaji
- Cardiovascular and Diabetes Biology Group, Rajiv Gandhi Centre for Biotechnology, Trivandrum, India
- Regional Centre for Biotechnology, Faridabad, India
| | - Ganesh R Koshre
- Cardiovascular and Diabetes Biology Group, Rajiv Gandhi Centre for Biotechnology, Trivandrum, India
- Manipal Academy of Higher Education, Manipal, India
| | - Rakesh S Laishram
- Cardiovascular and Diabetes Biology Group, Rajiv Gandhi Centre for Biotechnology, Trivandrum, India
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16
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Yang M, Ke Y, Kim P, Zhou X. ExonSkipAD provides the functional genomic landscape of exon skipping events in Alzheimer's disease. Brief Bioinform 2021; 22:bbaa438. [PMID: 33497435 PMCID: PMC8425305 DOI: 10.1093/bib/bbaa438] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 12/18/2022] Open
Abstract
Exon skipping (ES), the most common alternative splicing event, has been reported to contribute to diverse human diseases due to the loss of functional domains/sites or frameshifting of the open reading frame (ORF) and noticed as therapeutic targets. Accumulating transcriptomic studies of aging brains show the splicing disruption is a widespread hallmark of neurodegenerative diseases such as Alzheimer's disease (AD). Here, we built ExonSkipAD, the ES annotation database aiming to provide a resource/reference for functional annotation of ES events in AD and identify therapeutic targets in exon units. We identified 16 414 genes that have ~156 K, ~ 69 K, ~ 231 K ES events from the three representative AD cohorts of ROSMAP, MSBB and Mayo, respectively. For these ES events, we performed multiple functional annotations relating to ES mechanisms or downstream. Specifically, through the functional feature retention studies followed by the open reading frames (ORFs), we identified 275 important cellular regulators that might lose their cellular regulator roles due to exon skipping in AD. ExonSkipAD provides twelve categories of annotations: gene summary, gene structures and expression levels, exon skipping events with PSIs, ORF annotation, exon skipping events in the canonical protein sequence, 3'-UTR located exon skipping events lost miRNA-binding sites, SNversus in the skipped exons with a depth of coverage, AD stage-associated exon skipping events, splicing quantitative trait loci (sQTLs) in the skipped exons, correlation with RNA-binding proteins, and related drugs & diseases. ExonSkipAD will be a unique resource of transcriptomic diversity research for understanding the mechanisms of neurodegenerative disease development and identifying potential therapeutic targets in AD. Significance AS the first comprehensive resource of the functional genomics of the alternative splicing events in AD, ExonSkipAD will be useful for many researchers in the fields of pathology, AD genomics and precision medicine, and pharmaceutical and therapeutic researches.
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17
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Dharmalingam P, Mahalingam R, Yalamanchili HK, Weng T, Karmouty-Quintana H, Guha A, A Thandavarayan R. Emerging roles of alternative cleavage and polyadenylation (APA) in human disease. J Cell Physiol 2021; 237:149-160. [PMID: 34378793 DOI: 10.1002/jcp.30549] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 07/13/2021] [Accepted: 07/20/2021] [Indexed: 12/11/2022]
Abstract
In the messenger RNA (mRNA) maturation process, the 3'-end of pre-mRNA is cleaved and a poly(A) sequence is added, this is an important determinant of mRNA stability and its cellular functions. More than 60%-70% of human genes have three or more polyadenylation (APA) sites and can be cleaved at different sites, generating mRNA transcripts of varying lengths. This phenomenon is termed as alternative cleavage and polyadenylation (APA) and it plays role in key biological processes like gene regulation, cell proliferation, senescence, and also in various human diseases. Loss of regulatory microRNA binding sites and interactions with RNA-binding proteins leading to APA are largely investigated in human diseases. However, the functions of the core APA machinery and related factors during disease conditions remain largely unknown. In this review, we discuss the roles of polyadenylation machinery in relation to brain disease, cardiac failure, pulmonary fibrosis, cancer, infectious conditions, and other human diseases. Collectively, we believe this review will be a useful avenue for understanding the emerging role of APA in the pathobiology of various human diseases.
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Affiliation(s)
- Prakash Dharmalingam
- Department of Biochemistry, Saveetha Dental College & Hospitals, Saveetha Institute of Medical & Technical Sciences, Saveetha University, Chennai, India
| | - Rajasekaran Mahalingam
- Laboratory of Neuroimmunology, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Hari Krishna Yalamanchili
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,Department of Pediatrics - Neurology, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA.,Department of Pediatrics, USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas, USA
| | - Tingting Weng
- Department of Biochemistry and Molecular Biology & Divisions of Critical Care, Pulmonary and Sleep Medicine, Department of Internal Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Harry Karmouty-Quintana
- Department of Biochemistry and Molecular Biology & Divisions of Critical Care, Pulmonary and Sleep Medicine, Department of Internal Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Ashrith Guha
- Department of Cardiology, Houston Methodist DeBakey Heart & Vascular Center, Houston, Texas, USA
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18
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Ye C, Zhao D, Ye W, Wu X, Ji G, Li QQ, Lin J. QuantifyPoly(A): reshaping alternative polyadenylation landscapes of eukaryotes with weighted density peak clustering. Brief Bioinform 2021; 22:6319934. [PMID: 34255024 DOI: 10.1093/bib/bbab268] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 06/23/2021] [Accepted: 06/23/2021] [Indexed: 01/09/2023] Open
Abstract
The dynamic choice of different polyadenylation sites in a gene is referred to as alternative polyadenylation, which functions in many important biological processes. Large-scale messenger RNA 3' end sequencing has revealed that cleavage sites for polyadenylation are presented with microheterogeneity. To date, the conventional determination of polyadenylation site clusters is subjective and arbitrary, leading to inaccurate annotations. Here, we present a weighted density peak clustering method, QuantifyPoly(A), to accurately quantify genome-wide polyadenylation choices. Applying QuantifyPoly(A) on published 3' end sequencing datasets from both animals and plants, their polyadenylation profiles are reshaped into myriads of novel polyadenylation site clusters. Most of these novel polyadenylation site clusters show significantly dynamic usage across different biological samples or associate with binding sites of trans-acting factors. Upstream sequences of these clusters are enriched with polyadenylation signals UGUA, UAAA and/or AAUAAA in a species-dependent manner. Polyadenylation site clusters also exhibit species specificity, while plants ones generally show higher microheterogeneity than that of animals. QuantifyPoly(A) is broadly applicable to any types of 3' end sequencing data and species for accurate quantification and construction of the complex and dynamic polyadenylation landscape and enables us to decode alternative polyadenylation events invisible to conventional methods at a much higher resolution.
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Affiliation(s)
- Congting Ye
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Danhui Zhao
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Wenbin Ye
- Department of Automation, Xiamen University, Xiamen, Fujian 361102, China
| | - Xiaohui Wu
- Department of Automation, Xiamen University, Xiamen, Fujian 361102, China
| | - Guoli Ji
- Department of Automation, Xiamen University, Xiamen, Fujian 361102, China
| | - Qingshun Q Li
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China.,Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Juncheng Lin
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China.,FAFU-UCR Joint Center, Horticulture Biology and Metabolomics Center, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
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19
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Mason MA, Gomez-Paredes C, Sathasivam K, Neueder A, Papadopoulou AS, Bates GP. Silencing Srsf6 does not modulate incomplete splicing of the huntingtin gene in Huntington's disease models. Sci Rep 2020; 10:14057. [PMID: 32820193 PMCID: PMC7441155 DOI: 10.1038/s41598-020-71111-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 08/06/2020] [Indexed: 12/31/2022] Open
Abstract
We have previously shown that the incomplete splicing of exon 1 to exon 2 of the HTT gene results in the production of a small polyadenylated transcript (Httexon1) that encodes the highly pathogenic exon 1 HTT protein. There is evidence to suggest that the splicing factor SRSF6 is involved in the mechanism that underlies this aberrant splicing event. Therefore, we set out to test this hypothesis, by manipulating SRSF6 levels in Huntington's disease models in which an expanded CAG repeat had been knocked in to the endogenous Htt gene. We began by generating mice that were knocked out for Srsf6, and demonstrated that reduction of SRSF6 to 50% of wild type levels had no effect on incomplete splicing in zQ175 knockin mice. We found that nullizygosity for Srsf6 was embryonic lethal, and therefore, to decrease SRSF6 levels further, we established mouse embryonic fibroblasts (MEFs) from wild type, zQ175, and zQ175::Srsf6+/- mice and transfected them with an Srsf6 siRNA. The incomplete splicing of Htt was recapitulated in the MEFs and we demonstrated that ablation of SRSF6 did not modulate the levels of the Httexon1 transcript. We conclude that SRSF6 is not required for the incomplete splicing of HTT in Huntington's disease.
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Affiliation(s)
- Michael A Mason
- Huntington's Disease Centre, Department of Neurodegenerative Disease and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Casandra Gomez-Paredes
- Huntington's Disease Centre, Department of Neurodegenerative Disease and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Kirupa Sathasivam
- Huntington's Disease Centre, Department of Neurodegenerative Disease and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Andreas Neueder
- Department of Neurology, Ulm University, 89081, Ulm, Germany
| | - Aikaterini-Smaragdi Papadopoulou
- Huntington's Disease Centre, Department of Neurodegenerative Disease and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Gillian P Bates
- Huntington's Disease Centre, Department of Neurodegenerative Disease and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK.
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20
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Emerging Roles for 3' UTRs in Neurons. Int J Mol Sci 2020; 21:ijms21103413. [PMID: 32408514 PMCID: PMC7279237 DOI: 10.3390/ijms21103413] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/06/2020] [Accepted: 05/09/2020] [Indexed: 12/14/2022] Open
Abstract
The 3′ untranslated regions (3′ UTRs) of mRNAs serve as hubs for post-transcriptional control as the targets of microRNAs (miRNAs) and RNA-binding proteins (RBPs). Sequences in 3′ UTRs confer alterations in mRNA stability, direct mRNA localization to subcellular regions, and impart translational control. Thousands of mRNAs are localized to subcellular compartments in neurons—including axons, dendrites, and synapses—where they are thought to undergo local translation. Despite an established role for 3′ UTR sequences in imparting mRNA localization in neurons, the specific RNA sequences and structural features at play remain poorly understood. The nervous system selectively expresses longer 3′ UTR isoforms via alternative polyadenylation (APA). The regulation of APA in neurons and the neuronal functions of longer 3′ UTR mRNA isoforms are starting to be uncovered. Surprising roles for 3′ UTRs are emerging beyond the regulation of protein synthesis and include roles as RBP delivery scaffolds and regulators of alternative splicing. Evidence is also emerging that 3′ UTRs can be cleaved, leading to stable, isolated 3′ UTR fragments which are of unknown function. Mutations in 3′ UTRs are implicated in several neurological disorders—more studies are needed to uncover how these mutations impact gene regulation and what is their relationship to disease severity.
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21
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Bogomazova AN, Eremeev AV, Pozmogova GE, Lagarkova MA. The Role of Mutant RNA in the Pathogenesis of Huntington’s Disease and Other Polyglutamine Diseases. Mol Biol 2019. [DOI: 10.1134/s0026893319060037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Papadopoulou AS, Gomez-Paredes C, Mason MA, Taxy BA, Howland D, Bates GP. Extensive Expression Analysis of Htt Transcripts in Brain Regions from the zQ175 HD Mouse Model Using a QuantiGene Multiplex Assay. Sci Rep 2019; 9:16137. [PMID: 31695145 PMCID: PMC6834638 DOI: 10.1038/s41598-019-52411-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 10/14/2019] [Indexed: 11/18/2022] Open
Abstract
Huntington's disease (HD) is an inherited neurodegenerative disorder caused by a CAG repeat expansion within exon 1 of the huntingtin (HTT) gene. HTT mRNA contains 67 exons and does not always splice between exon 1 and exon 2 leading to the production of a small polyadenylated HTTexon1 transcript, and the full-length HTT mRNA has three 3'UTR isoforms. We have developed a QuantiGene multiplex panel for the simultaneous detection of all of these mouse Htt transcripts directly from tissue lysates and demonstrate that this can replace the more work-intensive Taqman qPCR assays. We have applied this to the analysis of brain regions from the zQ175 HD mouse model and wild type littermates at two months of age. We show that the incomplete splicing of Htt occurs throughout the brain and confirm that this originates from the mutant and not endogenous Htt allele. Given that HTTexon1 encodes the highly pathogenic exon 1 HTT protein, it is essential that the levels of all Htt transcripts can be monitored when evaluating HTT lowering approaches. Our QuantiGene panel will allow the rapid comparative assessment of all Htt transcripts in cell lysates and mouse tissues without the need to first extract RNA.
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Affiliation(s)
- Aikaterini S Papadopoulou
- Huntington's Disease Centre, Department of Neurodegenerative Disease and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Casandra Gomez-Paredes
- Huntington's Disease Centre, Department of Neurodegenerative Disease and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Michael A Mason
- Huntington's Disease Centre, Department of Neurodegenerative Disease and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Bridget A Taxy
- Huntington's Disease Centre, Department of Neurodegenerative Disease and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - David Howland
- CHDI Management/CHDI Foundation Inc., New York, NY, 10001, USA
| | - Gillian P Bates
- Huntington's Disease Centre, Department of Neurodegenerative Disease and UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK.
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23
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Full sequence of mutant huntingtin 3'-untranslated region and modulation of its gene regulatory activity by endogenous microRNA. J Hum Genet 2019; 64:995-1004. [PMID: 31296921 DOI: 10.1038/s10038-019-0639-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/02/2019] [Accepted: 06/24/2019] [Indexed: 12/28/2022]
Abstract
Huntington's disease (HD) is caused by an expanded CAG trinucleotide repeat in the first exon of the huntingtin gene (HTT). Since the entire course of the disease starts from this dominant gain-of-function mutation, lowering total or mutant huntingtin mRNA/protein has emerged as an appealing therapeutic strategy. We reasoned that endogenous mechanisms underlying HTT gene regulation may inform strategies to target the source of the disease. As part of our investigation to understand how the expression of HTT is controlled, we performed (1) complete sequencing analysis for mutant HTT 3'-UTR and (2) unbiased screening assays to identify naturally-occurring miRNAs that could lower the HTT mRNA levels. By sequencing HD families inheriting the major European mutant haplotype, we determined the full sequence of HTT 3'-UTRs of the most frequent mutant (i.e., hap.01) and normal (i.e., hap.08) haplotypes, revealing 5 sites with alternative alleles. In subsequent miRNA activity assays using the full-length hap.01 and hap.08 3'-UTR reporter vectors and follow-up validation experiments, hsa-miR-4324 and hsa-miR-4756-5p significantly reduced HTT 3'-UTR reporter activity and endogenous HTT protein levels. However, those miRNAs did not show strong haplotype-specific effects. Nevertheless, our data highlighting full sequences of HTT 3'-UTR haplotypes, effects of miRNAs on HTT levels, and potential interaction sites provide rationale and promising targets for total and mutant-specific HTT lowering intervention strategies using endogenous and artificial miRNAs, respectively.
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24
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Jafari Najaf Abadi MH, Shafabakhsh R, Asemi Z, Mirzaei HR, Sahebnasagh R, Mirzaei H, Hamblin MR. CFIm25 and alternative polyadenylation: Conflicting roles in cancer. Cancer Lett 2019; 459:112-121. [PMID: 31181319 DOI: 10.1016/j.canlet.2019.114430] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/01/2019] [Accepted: 06/04/2019] [Indexed: 12/11/2022]
Abstract
Alternative polyadenylation (APA) is now widely recognized to regulate gene expression. APA is an RNA-processing mechanism that generates distinct 3' termini on mRNAs, producing mRNA isoforms. Different factors influence the initiation and development of this process. CFIm25 (among others) is a cleavage and polyadenylation factor that plays a key role in the regulation of APA. Shortening of the 3'UTRs on mRNAs leads to enhanced cellular proliferation and tumorigenicity. One reason may be the up-regulation of growth promoting factors, such as Cyclin D1. Different studies have reported a dual role of CFIm25 in cancer (both oncogenic and tumor suppressor). microRNAs (miRNAs) may be involved in CFIm25 function as well as competing endogenous RNAs (ceRNAs). The present review focuses on the role of CFIm25 in cancer, cancer treatment, and possible involvement in other human diseases. We highlight the involvement of miRNAs and ceRNAs in the function of CFIm25 to affect gene expression. The lack of understanding of the mechanisms and regulation of CFIm25 and APA has underscored the need for further research regarding their role in cancer and other diseases.
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Affiliation(s)
| | - Rana Shafabakhsh
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran.
| | - Zatollah Asemi
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran.
| | - Hamid Reza Mirzaei
- Department of Medical Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| | - Roxana Sahebnasagh
- Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| | - Hamed Mirzaei
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran.
| | - Michael R Hamblin
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, 40 Blossom Street, Boston, MA, 02114, USA.
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25
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Nahalka J. The role of the protein-RNA recognition code in neurodegeneration. Cell Mol Life Sci 2019; 76:2043-2058. [PMID: 30980111 PMCID: PMC11105320 DOI: 10.1007/s00018-019-03096-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 03/14/2019] [Accepted: 04/08/2019] [Indexed: 12/14/2022]
Abstract
MicroRNAs are small endogenous RNAs that pair and bind to sites on mRNAs to direct post-transcriptional repression. However, there is a possibility that microRNAs directly influence protein structure and activity, and this influence can be termed post-translational riboregulation. This conceptual review explores the literature on neurodegenerative disorders. Research on the association between neurodegeneration and RNA-repeat toxicity provides data that support a protein-RNA recognition code. For example, this code explains why hnRNP H and SFPQ proteins, which are involved in amyotrophic lateral sclerosis, are sequestered by the (GGGGCC)n repeat sequence. Similarly, it explains why MNBL proteins and (CTG)n repeats in RNA, which are involved in myotonic dystrophy, are sequestered into RNA foci. Using this code, proteins involved in diseases can be identified. A simple protein BLAST search of the human genome for amino acid repeats that correspond to the nucleotide repeats reveals new proteins among already known proteins that are involved in diseases. For example, the (CAG)n repeat sequence, when transcribed into possible peptide sequences, leads to the identification of PTCD3, Rem2, MESP2, SYPL2, WDR33, COL23A1, and others. After confirming this approach on RNA repeats, in the next step, the code was used in the opposite manner. Proteins that are involved in diseases were compared with microRNAs involved in those diseases. For example, a reasonable correspondence of microRNA 9 and 107 with amyloid-β-peptide (Aβ42) was identified. In the last step, a miRBase search for micro-nucleotides, obtained by transcription of a prion amino acid sequence, revealed new microRNAs and microRNAs that have previously been identified as involved in prion diseases. This concept provides a useful key for designing RNA or peptide probes.
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Affiliation(s)
- Jozef Nahalka
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dubravska cesta 9, 84538, Bratislava, Slovak Republic.
- Institute of Chemistry, Centre of Excellence for White-green Biotechnology, Slovak Academy of Sciences, Trieda Andreja Hlinku 2, 94976, Nitra, Slovak Republic.
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26
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Neueder A, Dumas AA, Benjamin AC, Bates GP. Regulatory mechanisms of incomplete huntingtin mRNA splicing. Nat Commun 2018; 9:3955. [PMID: 30262848 PMCID: PMC6160442 DOI: 10.1038/s41467-018-06281-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 08/13/2018] [Indexed: 11/09/2022] Open
Abstract
Huntington’s disease is caused by a CAG repeat expansion in exon 1 of the HTT gene. We have previously shown that exon 1 HTT does not always splice to exon 2 producing a small transcript (HTTexon1) that encodes the highly pathogenic exon 1 HTT protein. The mechanisms by which this incomplete splicing occurs are unknown. Here, we have generated a minigene system that recapitulates the CAG repeat-length dependence of HTTexon1 production, and has allowed us to define the regions of intron 1 necessary for incomplete splicing. We show that manipulation of the expression levels of the splicing factor SRSF6, predicted to bind CAG repeats, modulates this aberrant splicing event and also demonstrate that RNA polymerase II transcription speed regulates the levels of HTTexon1 production. Understanding the mechanisms by which this pathogenic exon 1 HTT is generated may provide the basis for the development of strategies to prevent its production. Incomplete splicing of HTT results in the production of the highly pathogenic exon 1 HTT protein. Here the authors identify the necessary intronic regions and the underlying mechanisms that contribute to this process.
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Affiliation(s)
- Andreas Neueder
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease and Dementia Research Institute, UCL Institute of Neurology, University College London, London, WC1N 3BG, UK. .,Department of Neurology, Ulm University, Ulm, 89081, Germany.
| | - Anaelle A Dumas
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease and Dementia Research Institute, UCL Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Agnesska C Benjamin
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease and Dementia Research Institute, UCL Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Gillian P Bates
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease and Dementia Research Institute, UCL Institute of Neurology, University College London, London, WC1N 3BG, UK.
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27
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Steri M, Idda ML, Whalen MB, Orrù V. Genetic variants in mRNA untranslated regions. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1474. [PMID: 29582564 DOI: 10.1002/wrna.1474] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 02/05/2018] [Accepted: 02/11/2018] [Indexed: 12/24/2022]
Abstract
Genome Wide Association Studies (GWAS) have mapped thousands of genetic variants associated with complex disease risk and regulating quantitative traits, thus exploiting an unprecedented high-resolution genetic characterization of the human genome. A small fraction (3.7%) of the identified associations is located in untranslated regions (UTRs), and the molecular mechanism has been elucidated for few of them. Genetic variations at UTRs may modify regulatory elements affecting the interaction of the UTRs with proteins and microRNAs. The overall functional consequences include modulation of messenger RNA (mRNA) transcription, secondary structure, stability, localization, translation, and access to regulators like microRNAs (miRNAs) and RNA-binding proteins (RBPs). Alterations of these regulatory mechanisms are known to modify molecular pathways and cellular processes, potentially leading to disease processes. Here, we analyze some examples of genetic risk variants mapping in the UTR regulatory elements. We describe a recently identified genetic variant localized in the 3'UTR of the TNFSF13B gene, associated with autoimmunity risk and responsible of an increased stability and translation of TNFSF13B mRNA. We discuss how the correct use and interpretation of public GWAS repositories could lead to a better understanding of etiopathogenetic mechanisms and the generation of robust biological hypothesis as starting point for further functional studies. This article is categorized under: RNA Structure and Dynamics > RNA Structure, Dynamics and Chemistry RNA Evolution and Genomics > Computational Analyses of RNA RNA in Disease and Development > RNA in Disease.
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Affiliation(s)
- Maristella Steri
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche (CNR), Monserrato, Cagliari, Italy
| | - M Laura Idda
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institute of Health, Baltimore, Maryland
| | - Michael B Whalen
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche (CNR), Trento, Italy
| | - Valeria Orrù
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche (CNR), Monserrato, Cagliari, Italy
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28
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Dabrowska M, Juzwa W, Krzyzosiak WJ, Olejniczak M. Precise Excision of the CAG Tract from the Huntingtin Gene by Cas9 Nickases. Front Neurosci 2018. [PMID: 29535594 PMCID: PMC5834764 DOI: 10.3389/fnins.2018.00075] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Huntington's disease (HD) is a progressive autosomal dominant neurodegenerative disorder caused by the expansion of CAG repeats in the first exon of the huntingtin gene (HTT). The accumulation of polyglutamine-rich huntingtin proteins affects various cellular functions and causes selective degeneration of neurons in the striatum. Therapeutic strategies used to date to silence the expression of mutant HTT include antisense oligonucleotides, RNA interference-based approaches and, recently, genome editing with the CRISPR/Cas9 system. Here, we demonstrate that the CAG repeat tract can be precisely excised from the HTT gene with the use of the paired Cas9 nickase strategy. As a model, we used HD patient-derived fibroblasts with varied numbers of CAG repeats. The repeat excision inactivated the HTT gene and abrogated huntingtin synthesis in a CAG repeat length-independent manner. Because Cas9 nickases are known to be safe and specific, our approach provides an attractive treatment tool for HD that can be extended to other polyQ disorders.
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Affiliation(s)
- Magdalena Dabrowska
- Department of Genome Engineering, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Wojciech Juzwa
- Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Poznan, Poland
| | - Wlodzimierz J Krzyzosiak
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Marta Olejniczak
- Department of Genome Engineering, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
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29
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Abstract
Huntington's disease (HD) is an inherited neurodegenerative disorder caused by a mutation that expands the polyglutamine (CAG) repeat in exon 1 of the huntingtin (HTT) gene. Wild-type HTT protein interacts with other proteins to protect cells against toxic stimuli, mediate vesicle transport and endocytosis, and modulate synaptic activity. Mutant HTT protein disrupts autophagy, vesicle transport, neurotransmitter signaling, and mitochondrial function. Although many of the activities of wild-type HTT protein and the toxicities of mutant HTT protein are characterized, less is known about the activities of HTT mRNA. Most putative HD therapies aim to target mutant HTT mRNA before it is translated into the protein. Therefore, it is imperative to learn as much as we can about how cells handle both wild-type and mutant HTT mRNA so that effective therapies can be designed. Here, we review the structure of wild-type and mutant HTT mRNA, with emphasis on their alternatively polyadenylated or spliced isoforms. We then consider the abundance of HTT mRNA isoforms in HD and discuss the potential implications of these findings. Evidence in the review should be used to guide future research aimed at developing mRNA-lowering therapies for HD.
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Affiliation(s)
- Lindsay Romo
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Emily S. Mohn
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - Neil Aronin
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, USA
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30
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Chang JW, Yeh HS, Yong J. Alternative Polyadenylation in Human Diseases. Endocrinol Metab (Seoul) 2017; 32:413-421. [PMID: 29271615 PMCID: PMC5744726 DOI: 10.3803/enm.2017.32.4.413] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 11/23/2017] [Accepted: 11/27/2017] [Indexed: 12/02/2022] Open
Abstract
Varying length of messenger RNA (mRNA) 3'-untranslated region is generated by alternating the usage of polyadenylation sites during pre-mRNA processing. It is prevalent through all eukaryotes and has emerged as a key mechanism for controlling gene expression. Alternative polyadenylation (APA) plays an important role for cell growth, proliferation, and differentiation. In this review, we discuss the functions of APA related with various physiological conditions including cellular metabolism, mRNA processing, and protein diversity in a variety of disease models. We also discuss the molecular mechanisms underlying APA regulation, such as variations in the concentration of mRNA processing factors and RNA-binding proteins, as well as global transcriptome changes under cellular signaling pathway.
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Affiliation(s)
- Jae Woong Chang
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Twin Cities College of Biological Sciences, Minneapolis, MN, USA
| | - Hsin Sung Yeh
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Twin Cities College of Biological Sciences, Minneapolis, MN, USA
| | - Jeongsik Yong
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Twin Cities College of Biological Sciences, Minneapolis, MN, USA.
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