1
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Kudriavskii VV, Goncharov AO, Eremeev AV, Ruchko ES, Veselovsky VA, Klimina KM, Bogomazova AN, Lagarkova MA, Moshkovskii SA, Kliuchnikova AA. RNA Editing by ADAR Adenosine Deaminases in the Cell Models of CAG Repeat Expansion Diseases: Significant Effect of Differentiation from Stem Cells into Brain Organoids in the Absence of Substantial Influence of CAG Repeats on the Level of Editing. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:1474-1489. [PMID: 39245456 DOI: 10.1134/s0006297924080078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 06/24/2024] [Accepted: 07/11/2024] [Indexed: 09/10/2024]
Abstract
Expansion of CAG repeats in certain genes is a known cause of several neurodegenerative diseases, but exact mechanism behind this is not yet fully understood. It is believed that the double-stranded RNA regions formed by CAG repeats could be harmful to the cell. This study aimed to test the hypothesis that these RNA regions might potentially interfere with ADAR RNA editing enzymes, leading to the reduced A-to-I editing of RNA and activation of the interferon response. We studied induced pluripotent stem cells (iPSCs) derived from the patients with Huntington's disease or ataxia type 17, as well as midbrain organoids developed from these cells. A targeted panel for next-generation sequencing was used to assess editing in the specific RNA regions. Differentiation of iPSCs into brain organoids led to increase in the ADAR2 gene expression and decrease in the expression of protein inhibitors of RNA editing. As a result, there was increase in the editing of specific ADAR2 substrates, which allowed identification of differential substrates of ADAR isoforms. However, comparison of the pathology and control groups did not show differences in the editing levels among the iPSCs. Additionally, brain organoids with 42-46 CAG repeats did not exhibit global changes. On the other hand, brain organoids with the highest number of CAG repeats in the huntingtin gene (76) showed significant decrease in the level of RNA editing of specific transcripts, potentially involving ADAR1. Notably, editing of the long non-coding RNA PWAR5 was nearly absent in this sample. It could be stated in conclusion that in most cultures with repeat expansion, the hypothesized effect on RNA editing was not confirmed.
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Affiliation(s)
- Viacheslav V Kudriavskii
- Pirogov Russian National Research Medical University, Moscow, 117997, Russia
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow, 121205, Russia.
| | - Anton O Goncharov
- Pirogov Russian National Research Medical University, Moscow, 117997, Russia
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Artem V Eremeev
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Evgenii S Ruchko
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Vladimir A Veselovsky
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Ksenia M Klimina
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Alexandra N Bogomazova
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Maria A Lagarkova
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Sergei A Moshkovskii
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
- Institute of Biomedical Chemistry, Moscow, 119121, Russia
- Max Planck Institute for Interdisciplinary Research, Göttingen, 37077, Germany.
| | - Anna A Kliuchnikova
- Pirogov Russian National Research Medical University, Moscow, 117997, Russia
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
- Institute of Biomedical Chemistry, Moscow, 119121, Russia
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2
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Li L, Wang M, Huang L, Zheng X, Wang L, Miao H. Ataxin-2: a powerful RNA-binding protein. Discov Oncol 2024; 15:298. [PMID: 39039334 PMCID: PMC11263328 DOI: 10.1007/s12672-024-01158-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 07/15/2024] [Indexed: 07/24/2024] Open
Abstract
Ataxin-2 (ATXN2) was originally discovered in the context of spinocerebellar ataxia type 2 (SCA2), but it has become a key player in various neurodegenerative diseases. This review delves into the multifaceted roles of ATXN2 in human diseases, revealing its diverse molecular and cellular pathways. The impact of ATXN2 on diseases extends beyond functional outcomes; it mainly interacts with various RNA-binding proteins (RBPs) to regulate different stages of post-transcriptional gene expression in diseases. With the progress of research, ATXN2 has also been found to play an important role in the development of various cancers, including breast cancer, gastric cancer, pancreatic cancer, colon cancer, and esophageal cancer. This comprehensive exploration underscores the crucial role of ATXN2 in the pathogenesis of diseases and warrants further investigation by the scientific community. By reviewing the latest discoveries on the regulatory functions of ATXN2 in diseases, this article helps us understand the complex molecular mechanisms of a series of human diseases related to this intriguing protein.
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Affiliation(s)
- Lulu Li
- Department of Clinical and Military Laboratory Medicine, College of Medical Laboratory Science, Army Medical University, Chongqing, 400038, China
- Department of Clinical and Military Laboratory Medicine, College of Medical Laboratory Science, Army Medical University, Chongqing, 400038, China
| | - Meng Wang
- Department of Pathophysiology, College of High Altitude Military Medicine, Army Medical University, Chongqing, 400038, China
| | - Lai Huang
- Department of Clinical and Military Laboratory Medicine, College of Medical Laboratory Science, Army Medical University, Chongqing, 400038, China
| | - Xiaoli Zheng
- Department of Clinical and Military Laboratory Medicine, College of Medical Laboratory Science, Army Medical University, Chongqing, 400038, China.
| | - Lina Wang
- Department of Clinical and Military Laboratory Medicine, College of Medical Laboratory Science, Army Medical University, Chongqing, 400038, China.
| | - Hongming Miao
- Department of Pathophysiology, College of High Altitude Military Medicine, Army Medical University, Chongqing, 400038, China.
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3
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Grove DJ, Russell PJ, Kearse MG. To initiate or not to initiate: A critical assessment of eIF2A, eIF2D, and MCT-1·DENR to deliver initiator tRNA to ribosomes. WILEY INTERDISCIPLINARY REVIEWS. RNA 2024; 15:e1833. [PMID: 38433101 PMCID: PMC11260288 DOI: 10.1002/wrna.1833] [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: 10/31/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 03/05/2024]
Abstract
Selection of the correct start codon is critical for high-fidelity protein synthesis. In eukaryotes, this is typically governed by a multitude of initiation factors (eIFs), including eIF2·GTP that directly delivers the initiator tRNA (Met-tRNAi Met ) to the P site of the ribosome. However, numerous reports, some dating back to the early 1970s, have described other initiation factors having high affinity for the initiator tRNA and the ability of delivering it to the ribosome, which has provided a foundation for further work demonstrating non-canonical initiation mechanisms using alternative initiation factors. Here we provide a critical analysis of current understanding of eIF2A, eIF2D, and the MCT-1·DENR dimer, the evidence surrounding their ability to initiate translation, their implications in human disease, and lay out important key questions for the field. This article is categorized under: RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes Translation > Mechanisms Translation > Regulation.
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Affiliation(s)
- Daisy J. Grove
- The Ohio State Biochemistry Program, Department of Biological Chemistry, Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| | - Paul J. Russell
- The Ohio State Biochemistry Program, Department of Biological Chemistry, Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
- The Cellular, Molecular, Biochemical Sciences Program, Department of Biological Chemistry, Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| | - Michael G. Kearse
- The Ohio State Biochemistry Program, Department of Biological Chemistry, Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
- The Cellular, Molecular, Biochemical Sciences Program, Department of Biological Chemistry, Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
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4
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Rösing S, Ullrich F, Meisterfeld S, Schmidt F, Mlitzko L, Croon M, Nattrass RG, Eberl N, Mahlberg J, Schlee M, Wieland A, Simon P, Hilbig D, Reuner U, Rapp A, Bremser J, Mirtschink P, Drukewitz S, Zillinger T, Beissert S, Paeschke K, Hartmann G, Trifunovic A, Bartok E, Günther C. Chronic endoplasmic reticulum stress in myotonic dystrophy type 2 promotes autoimmunity via mitochondrial DNA release. Nat Commun 2024; 15:1534. [PMID: 38378748 PMCID: PMC10879130 DOI: 10.1038/s41467-024-45535-1] [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: 08/19/2022] [Accepted: 01/22/2024] [Indexed: 02/22/2024] Open
Abstract
Myotonic dystrophy type 2 (DM2) is a tetranucleotide CCTG repeat expansion disease associated with an increased prevalence of autoimmunity. Here, we identified an elevated type I interferon (IFN) signature in peripheral blood mononuclear cells and primary fibroblasts of DM2 patients as a trigger of chronic immune stimulation. Although RNA-repeat accumulation was prevalent in the cytosol of DM2-patient fibroblasts, type-I IFN release did not depend on innate RNA immune sensors but rather the DNA sensor cGAS and the prevalence of mitochondrial DNA (mtDNA) in the cytoplasm. Sublethal mtDNA release was promoted by a chronic activation of the ATF6 branch of the unfolded protein response (UPR) in reaction to RNA-repeat accumulation and non-AUG translated tetrapeptide expansion proteins. ATF6-dependent mtDNA release and resulting cGAS/STING activation could also be recapitulated in human THP-1 monocytes exposed to chronic endoplasmic reticulum (ER) stress. Altogether, our study demonstrates a novel mechanism by which large repeat expansions cause chronic endoplasmic reticulum stress and associated mtDNA leakage. This mtDNA is, in turn, sensed by the cGAS/STING pathway and induces a type-I IFN response predisposing to autoimmunity. Elucidating this pathway reveals new potential therapeutic targets for autoimmune disorders associated with repeat expansion diseases.
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Affiliation(s)
- Sarah Rösing
- Department of Dermatology, University Hospital Carl Gustav Carus, TU Dresden, 01307, Dresden, Germany
| | - Fabian Ullrich
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, 53127, Bonn, Germany
- Institute of Experimental Haematology and Transfusion Medicine, University Hospital Bonn, 53127, Bonn, Germany
| | - Susann Meisterfeld
- Department of Dermatology, University Hospital Carl Gustav Carus, TU Dresden, 01307, Dresden, Germany
| | - Franziska Schmidt
- Department of Dermatology, University Hospital Carl Gustav Carus, TU Dresden, 01307, Dresden, Germany
| | - Laura Mlitzko
- Department of Dermatology, University Hospital Carl Gustav Carus, TU Dresden, 01307, Dresden, Germany
| | - Marijana Croon
- Institute for Mitochondrial Diseases and Aging, Faculty of Medicine, CECAD Research Center, 50931, Cologne, Germany
| | - Ryan G Nattrass
- Institute of Experimental Haematology and Transfusion Medicine, University Hospital Bonn, 53127, Bonn, Germany
| | - Nadia Eberl
- Department of Dermatology, University Hospital Carl Gustav Carus, TU Dresden, 01307, Dresden, Germany
| | - Julia Mahlberg
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, 53127, Bonn, Germany
| | - Martin Schlee
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, 53127, Bonn, Germany
| | - Anja Wieland
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, 53127, Bonn, Germany
| | - Philipp Simon
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, 53127, Bonn, Germany
- Department of Oncology, Hematology, Rheumatology and Immune-Oncology, University Hospital Bonn, 53127, Bonn, Germany
| | - Daniel Hilbig
- Department of Oncology, Hematology, Rheumatology and Immune-Oncology, University Hospital Bonn, 53127, Bonn, Germany
| | - Ulrike Reuner
- Department of Neurology, University Hospital Carl Gustav Carus, TU Dresden, 01307, Dresden, Germany
| | - Alexander Rapp
- Department of Biology, Cell biology and Epigenetic, Technical University of Darmstadt, Darmstadt, Germany
| | - Julia Bremser
- Institute of Experimental Haematology and Transfusion Medicine, University Hospital Bonn, 53127, Bonn, Germany
| | - Peter Mirtschink
- Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine, TU Dresden, 01307, Dresden, Germany
| | - Stephan Drukewitz
- Core Unit for Molecular Tumor Diagnostics (CMTD), National Center for Tumor Diseases (NCT), Partner Site Dresden, Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Thomas Zillinger
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, 53127, Bonn, Germany
| | - Stefan Beissert
- Department of Dermatology, University Hospital Carl Gustav Carus, TU Dresden, 01307, Dresden, Germany
| | - Katrin Paeschke
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, 53127, Bonn, Germany
- Department of Oncology, Hematology, Rheumatology and Immune-Oncology, University Hospital Bonn, 53127, Bonn, Germany
| | - Gunther Hartmann
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, 53127, Bonn, Germany
| | - Aleksandra Trifunovic
- Institute for Mitochondrial Diseases and Aging, Faculty of Medicine, CECAD Research Center, 50931, Cologne, Germany
| | - Eva Bartok
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, 53127, Bonn, Germany
- Institute of Experimental Haematology and Transfusion Medicine, University Hospital Bonn, 53127, Bonn, Germany
- Unit of Experimental Immunology, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Claudia Günther
- Department of Dermatology, University Hospital Carl Gustav Carus, TU Dresden, 01307, Dresden, Germany.
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5
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Ikenoshita S, Matsuo K, Yabuki Y, Kawakubo K, Asamitsu S, Hori K, Usuki S, Hirose Y, Bando T, Araki K, Ueda M, Sugiyama H, Shioda N. A cyclic pyrrole-imidazole polyamide reduces pathogenic RNA in CAG/CTG triplet repeat neurological disease models. J Clin Invest 2023; 133:e164792. [PMID: 37707954 PMCID: PMC10645379 DOI: 10.1172/jci164792] [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: 08/24/2022] [Accepted: 09/12/2023] [Indexed: 09/16/2023] Open
Abstract
Expansion of CAG and CTG (CWG) triplet repeats causes several inherited neurological diseases. The CWG repeat diseases are thought to involve complex pathogenic mechanisms through expanded CWG repeat-derived RNAs in a noncoding region and polypeptides in a coding region, respectively. However, an effective therapeutic approach has not been established for the CWG repeat diseases. Here, we show that a CWG repeat DNA-targeting compound, cyclic pyrrole-imidazole polyamide (CWG-cPIP), suppressed the pathogenesis of coding and noncoding CWG repeat diseases. CWG-cPIP bound to the hairpin form of mismatched CWG DNA, interfering with transcription elongation by RNA polymerase through a preferential activity toward repeat-expanded DNA. We found that CWG-cPIP selectively inhibited pathogenic mRNA transcripts from expanded CWG repeats, reducing CUG RNA foci and polyglutamine accumulation in cells from patients with myotonic dystrophy type 1 (DM1) and Huntington's disease (HD). Treatment with CWG-cPIP ameliorated behavioral deficits in adeno-associated virus-mediated CWG repeat-expressing mice and in a genetic mouse model of HD, without cytotoxicity or off-target effects. Together, we present a candidate compound that targets expanded CWG repeat DNA independently of its genomic location and reduces both pathogenic RNA and protein levels. CWG-cPIP may be used for the treatment of CWG repeat diseases and improvement of clinical outcomes.
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Affiliation(s)
- Susumu Ikenoshita
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG)
- Department of Neurology, Graduate School of Medical Sciences
| | - Kazuya Matsuo
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG)
| | - Yasushi Yabuki
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG)
- Graduate School of Pharmaceutical Sciences, and
| | - Kosuke Kawakubo
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG)
- Graduate School of Pharmaceutical Sciences, and
| | - Sefan Asamitsu
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG)
| | - Karin Hori
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG)
| | - Shingo Usuki
- Liaison Laboratory Research Promotion Center, IMEG, Kumamoto University, Kumamoto, Japan
| | - Yuki Hirose
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Toshikazu Bando
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Kimi Araki
- Institute of Resource Development and Analysis and
- Center for Metabolic Regulation of Healthy Aging, Kumamoto University, Kumamoto, Japan
| | - Mitsuharu Ueda
- Department of Neurology, Graduate School of Medical Sciences
| | - Hiroshi Sugiyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan
- Institute for Integrated Cell-Material Science (iCeMS), Kyoto University, Kyoto, Japan
| | - Norifumi Shioda
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG)
- Graduate School of Pharmaceutical Sciences, and
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6
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Grove DJ, Levine DJ, Kearse MG. Increased levels of eIF2A inhibit translation by sequestering 40S ribosomal subunits. Nucleic Acids Res 2023; 51:9983-10000. [PMID: 37602404 PMCID: PMC10570035 DOI: 10.1093/nar/gkad683] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 08/03/2023] [Accepted: 08/09/2023] [Indexed: 08/22/2023] Open
Abstract
eIF2A was the first eukaryotic initiator tRNA carrier discovered but its exact function has remained enigmatic. Uncharacteristic of translation initiation factors, eIF2A is reported to be non-cytosolic in multiple human cancer cell lines. Attempts to study eIF2A mechanistically have been limited by the inability to achieve high yield of soluble recombinant protein. Here, we developed a purification paradigm that yields ∼360-fold and ∼6000-fold more recombinant human eIF2A from Escherichia coli and insect cells, respectively, than previous reports. Using a mammalian in vitro translation system, we found that increased levels of recombinant human eIF2A inhibit translation of multiple reporter mRNAs, including those that are translated by cognate and near-cognate start codons, and does so prior to start codon recognition. eIF2A also inhibited translation directed by all four types of cap-independent viral IRESs, including the CrPV IGR IRES that does not require initiation factors or initiator tRNA, suggesting excess eIF2A sequesters 40S subunits. Supplementation with additional 40S subunits prevented eIF2A-mediated inhibition and pull-down assays demonstrated direct binding between recombinant eIF2A and purified 40S subunits. These data support a model that eIF2A must be kept away from the translation machinery to avoid sequestering 40S ribosomal subunits.
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Affiliation(s)
- Daisy J Grove
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
- Department of Biological Chemistry and Pharmacology, Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Daniel J Levine
- Department of Biological Chemistry and Pharmacology, Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Michael G Kearse
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
- Department of Biological Chemistry and Pharmacology, Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
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7
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Gibaut QR, Bush JA, Tong Y, Baisden JT, Taghavi A, Olafson H, Yao X, Childs-Disney JL, Wang ET, Disney MD. Transcriptome-Wide Studies of RNA-Targeted Small Molecules Provide a Simple and Selective r(CUG) exp Degrader in Myotonic Dystrophy. ACS CENTRAL SCIENCE 2023; 9:1342-1353. [PMID: 37521782 PMCID: PMC10375898 DOI: 10.1021/acscentsci.2c01223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Indexed: 08/01/2023]
Abstract
Myotonic dystrophy type 1 (DM1) is caused by a highly structured RNA repeat expansion, r(CUG)exp, harbored in the 3' untranslated region (3' UTR) of dystrophia myotonica protein kinase (DMPK) mRNA and drives disease through a gain-of-function mechanism. A panel of low-molecular-weight fragments capable of reacting with RNA upon UV irradiation was studied for cross-linking to r(CUG)expin vitro, affording perimidin-2-amine diazirine (1) that bound to r(CUG)exp. The interactions between the small molecule and RNA were further studied by nuclear magnetic resonance (NMR) spectroscopy and molecular modeling. Binding of 1 in DM1 myotubes was profiled transcriptome-wide, identifying 12 transcripts including DMPK that were bound by 1. Augmenting the functionality of 1 with cleaving capability created a chimeric degrader that specifically targets r(CUG)exp for elimination. The degrader broadly improved DM1-associated defects as assessed by RNA-seq, while having limited effects on healthy myotubes. This study (i) provides a platform to investigate molecular recognition of ligands directly in disease-affected cells; (ii) illustrates that RNA degraders can be more specific than the binders from which they are derived; and (iii) suggests that repeating transcripts can be selectively degraded due to the presence of multiple ligand binding sites.
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Affiliation(s)
- Quentin
M. R. Gibaut
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Jessica A. Bush
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Yuquan Tong
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Jared T. Baisden
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Amirhossein Taghavi
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Hailey Olafson
- Center
for NeuroGenetics, University of Florida, Gainesville, Florida 32610, United States
- Department
of Molecular Genetics & Microbiology, College of Medicine, University of Florida, Gainesville, Florida 32610, United States
| | - Xiyuan Yao
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Jessica L. Childs-Disney
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Eric T. Wang
- Center
for NeuroGenetics, University of Florida, Gainesville, Florida 32610, United States
- Department
of Molecular Genetics & Microbiology, College of Medicine, University of Florida, Gainesville, Florida 32610, United States
| | - Matthew D. Disney
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
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8
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Zhang S, Pei G, Li B, Li P, Lin Y. Abnormal phase separation of biomacromolecules in human diseases. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1133-1152. [PMID: 37475546 PMCID: PMC10423695 DOI: 10.3724/abbs.2023139] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 07/07/2023] [Indexed: 07/22/2023] Open
Abstract
Membrane-less organelles (MLOs) formed through liquid-liquid phase separation (LLPS) are associated with numerous important biological functions, but the abnormal phase separation will also dysregulate the physiological processes. Emerging evidence points to the importance of LLPS in human health and diseases. Nevertheless, despite recent advancements, our knowledge of the molecular relationship between LLPS and diseases is frequently incomplete. In this review, we outline our current understanding about how aberrant LLPS affects developmental disorders, tandem repeat disorders, cancers and viral infection. We also examine disease mechanisms driven by aberrant condensates, and highlight potential treatment approaches. This study seeks to expand our understanding of LLPS by providing a valuable new paradigm for understanding phase separation and human disorders, as well as to further translate our current knowledge regarding LLPS into therapeutic discoveries.
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Affiliation(s)
- Songhao Zhang
- State Key Laboratory of Membrane BiologyTsinghua University-Peking University Joint Centre for Life SciencesSchool of Life SciencesTsinghua UniversityBeijing100084China
- IDG/McGovern Institute for Brain Research at Tsinghua UniversityBeijing100084China
| | - Gaofeng Pei
- State Key Laboratory of Membrane BiologyTsinghua University-Peking University Joint Centre for Life SciencesSchool of Life SciencesTsinghua UniversityBeijing100084China
- Frontier Research Center for Biological StructureTsinghua UniversityBeijing100084China
| | - Boya Li
- State Key Laboratory of Membrane BiologyTsinghua University-Peking University Joint Centre for Life SciencesSchool of Life SciencesTsinghua UniversityBeijing100084China
- IDG/McGovern Institute for Brain Research at Tsinghua UniversityBeijing100084China
| | - Pilong Li
- State Key Laboratory of Membrane BiologyTsinghua University-Peking University Joint Centre for Life SciencesSchool of Life SciencesTsinghua UniversityBeijing100084China
- Frontier Research Center for Biological StructureTsinghua UniversityBeijing100084China
| | - Yi Lin
- State Key Laboratory of Membrane BiologyTsinghua University-Peking University Joint Centre for Life SciencesSchool of Life SciencesTsinghua UniversityBeijing100084China
- IDG/McGovern Institute for Brain Research at Tsinghua UniversityBeijing100084China
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9
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Parameswaran J, Zhang N, Braems E, Tilahun K, Pant DC, Yin K, Asress S, Heeren K, Banerjee A, Davis E, Schwartz SL, Conn GL, Bassell GJ, Van Den Bosch L, Jiang J. Antisense, but not sense, repeat expanded RNAs activate PKR/eIF2α-dependent ISR in C9ORF72 FTD/ALS. eLife 2023; 12:e85902. [PMID: 37073950 PMCID: PMC10188109 DOI: 10.7554/elife.85902] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 04/18/2023] [Indexed: 04/20/2023] Open
Abstract
GGGGCC (G4C2) hexanucleotide repeat expansion in the C9ORF72 gene is the most common genetic cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). The repeat is bidirectionally transcribed and confers gain of toxicity. However, the underlying toxic species is debated, and it is not clear whether antisense CCCCGG (C4G2) repeat expanded RNAs contribute to disease pathogenesis. Our study shows that C9ORF72 antisense C4G2 repeat expanded RNAs trigger the activation of the PKR/eIF2α-dependent integrated stress response independent of dipeptide repeat proteins that are produced through repeat-associated non-AUG-initiated translation, leading to global translation inhibition and stress granule formation. Reducing PKR levels with either siRNA or morpholinos mitigates integrated stress response and toxicity caused by the antisense C4G2 RNAs in cell lines, primary neurons, and zebrafish. Increased phosphorylation of PKR/eIF2α is also observed in the frontal cortex of C9ORF72 FTD/ALS patients. Finally, only antisense C4G2, but not sense G4C2, repeat expanded RNAs robustly activate the PKR/eIF2α pathway and induce aberrant stress granule formation. These results provide a mechanism by which antisense C4G2 repeat expanded RNAs elicit neuronal toxicity in FTD/ALS caused by C9ORF72 repeat expansions.
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Affiliation(s)
| | - Nancy Zhang
- Department of Cell Biology, Emory UniversityAtlantaUnited States
| | - Elke Braems
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute, KU LeuvenLeuvenBelgium
- Center for Brain & Disease Research, Laboratory of Neurobiology, VIB, Campus GasthuisbergLeuvenBelgium
| | | | - Devesh C Pant
- Department of Cell Biology, Emory UniversityAtlantaUnited States
| | - Keena Yin
- Department of Cell Biology, Emory UniversityAtlantaUnited States
| | - Seneshaw Asress
- Department of Neurology, Emory UniversityAtlantaUnited States
| | - Kara Heeren
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute, KU LeuvenLeuvenBelgium
- Center for Brain & Disease Research, Laboratory of Neurobiology, VIB, Campus GasthuisbergLeuvenBelgium
| | - Anwesha Banerjee
- Department of Cell Biology, Emory UniversityAtlantaUnited States
| | - Emma Davis
- Department of Cell Biology, Emory UniversityAtlantaUnited States
| | | | - Graeme L Conn
- Department of Biochemistry, Emory UniversityAtlantaUnited States
| | - Gary J Bassell
- Department of Cell Biology, Emory UniversityAtlantaUnited States
| | - Ludo Van Den Bosch
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute, KU LeuvenLeuvenBelgium
- Center for Brain & Disease Research, Laboratory of Neurobiology, VIB, Campus GasthuisbergLeuvenBelgium
| | - Jie Jiang
- Department of Cell Biology, Emory UniversityAtlantaUnited States
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10
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Corbet GA, Burke JM, Parker R. Nucleic acid-protein condensates in innate immune signaling. EMBO J 2023; 42:e111870. [PMID: 36178199 PMCID: PMC10068312 DOI: 10.15252/embj.2022111870] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/24/2022] [Accepted: 09/19/2022] [Indexed: 11/09/2022] Open
Abstract
The presence of foreign nucleic acids in the cytosol is a marker of infection. Cells have sensors, also known as pattern recognition receptors (PRRs), in the cytosol that detect foreign nucleic acid and initiate an innate immune response. Recent studies have reported the condensation of multiple PRRs including PKR, NLRP6, and cGAS, with their nucleic acid activators into discrete nucleoprotein assemblies. Nucleic acid-protein condensates form due to multivalent interactions and can create high local concentrations of components. The formation of PRR-containing condensates may alter the magnitude or timing of PRR activation. In addition, unique condensates form following RNase L activation or during paracrine signaling from virally infected cells that may play roles in antiviral defense. These observations suggest that condensate formation may be a conserved mechanism that cells use to regulate activation of the innate immune response and open an avenue for further investigation into the composition and function of these condensates. Here we review the nucleic acid-protein granules that are implicated in the innate immune response, discuss general consequences of condensate formation and signal transduction, as well as what outstanding questions remain.
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Affiliation(s)
- Giulia A Corbet
- Department of BiochemistryUniversity of ColoradoBoulderCOUSA
| | - James M Burke
- Department of BiochemistryUniversity of ColoradoBoulderCOUSA
- Present address:
Department of Molecular MedicineUniversity of Florida Scripps Biomedical ResearchJupiterFLUSA
| | - Roy Parker
- Department of BiochemistryUniversity of ColoradoBoulderCOUSA
- Howard Hughes Medical InstituteChevy ChaseMDUSA
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11
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Childs-Disney JL, Yang X, Gibaut QMR, Tong Y, Batey RT, Disney MD. Targeting RNA structures with small molecules. Nat Rev Drug Discov 2022; 21:736-762. [PMID: 35941229 PMCID: PMC9360655 DOI: 10.1038/s41573-022-00521-4] [Citation(s) in RCA: 173] [Impact Index Per Article: 86.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2022] [Indexed: 01/07/2023]
Abstract
RNA adopts 3D structures that confer varied functional roles in human biology and dysfunction in disease. Approaches to therapeutically target RNA structures with small molecules are being actively pursued, aided by key advances in the field including the development of computational tools that predict evolutionarily conserved RNA structures, as well as strategies that expand mode of action and facilitate interactions with cellular machinery. Existing RNA-targeted small molecules use a range of mechanisms including directing splicing - by acting as molecular glues with cellular proteins (such as branaplam and the FDA-approved risdiplam), inhibition of translation of undruggable proteins and deactivation of functional structures in noncoding RNAs. Here, we describe strategies to identify, validate and optimize small molecules that target the functional transcriptome, laying out a roadmap to advance these agents into the next decade.
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Affiliation(s)
| | - Xueyi Yang
- Department of Chemistry, Scripps Research, Jupiter, FL, USA
| | | | - Yuquan Tong
- Department of Chemistry, Scripps Research, Jupiter, FL, USA
| | - Robert T Batey
- Department of Biochemistry, University of Colorado, Boulder, CO, USA.
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12
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Corbet GA, Burke JM, Bublitz GR, Tay JW, Parker R. dsRNA-induced condensation of antiviral proteins modulates PKR activity. Proc Natl Acad Sci U S A 2022; 119:e2204235119. [PMID: 35939694 PMCID: PMC9388085 DOI: 10.1073/pnas.2204235119] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 07/01/2022] [Indexed: 12/21/2022] Open
Abstract
Mammalian cells respond to dsRNA in multiple manners. One key response to dsRNA is the activation of PKR, an eIF2α kinase, which triggers translational arrest and the formation of stress granules. However, the process of PKR activation in cells is not fully understood. In response to increased endogenous or exogenous dsRNA, we observed that PKR forms novel cytosolic condensates, referred to as dsRNA-induced foci (dRIFs). dRIFs contain dsRNA, form in proportion to dsRNA, and are enhanced by longer dsRNAs. dRIFs enrich several other dsRNA-binding proteins, including ADAR1, Stau1, NLRP1, and PACT. Strikingly, dRIFs correlate with and form before translation repression by PKR and localize to regions of cells where PKR activation is initiated. We hypothesize that dRIF formation is a mechanism that cells use to enhance the sensitivity of PKR activation in response to low levels of dsRNA or to overcome viral inhibitors of PKR activation.
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Affiliation(s)
- Giulia A. Corbet
- Department of Biochemistry, University of Colorado, Boulder, CO 80309
| | - James M. Burke
- Department of Biochemistry, University of Colorado, Boulder, CO 80309
| | - Gaia R. Bublitz
- Department of Biochemistry, University of Colorado, Boulder, CO 80309
| | | | - Roy Parker
- Department of Biochemistry, University of Colorado, Boulder, CO 80309
- BioFrontiers Institute, Boulder, CO 80309
- Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789
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13
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An Y, Chen ZS, Chan H, Ngo J. Molecular insights into the interaction of CAG trinucleotide RNA repeats with nucleolin and its implication in polyglutamine diseases. Nucleic Acids Res 2022; 50:7655-7668. [PMID: 35776134 PMCID: PMC9303306 DOI: 10.1093/nar/gkac532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 05/08/2022] [Accepted: 06/08/2022] [Indexed: 11/13/2022] Open
Abstract
Polyglutamine (polyQ) diseases are a type of inherited neurodegenerative disorders caused by cytosine-adenine-guanine (CAG) trinucleotide expansion within the coding region of the disease-associated genes. We previously demonstrated that a pathogenic interaction between expanded CAG RNA and the nucleolin (NCL) protein triggers the nucleolar stress and neuronal cell death in polyQ diseases. However, mechanisms behind the molecular interaction remain unknown. Here, we report a 1.45 Å crystal structure of the r(CAG)5 oligo that comprises a full A'-form helical turn with widened grooves. Based on this structure, we simulated a model of r(CAG)5 RNA complexed with the RNA recognition motif 2 (RRM2) of NCL and identified NCL residues that are critical for its binding to CAG RNA. Combined with in vitro and in vivo site-directed mutagenesis studies, our model reveals that CAG RNA binds to NCL sites that are not important for other cellular functions like gene expression and rRNA synthesis regulation, indicating that toxic CAG RNA interferes with NCL functions by sequestering it. Accordingly, an NCL mutant that is aberrant in CAG RNA-binding could rescue RNA-induced cytotoxicity effectively. Taken together, our study provides new molecular insights into the pathogenic mechanism of polyQ diseases mediated by NCL-CAG RNA interaction.
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Affiliation(s)
- Ying An
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Zhefan S Chen
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Ho Yin Edwin Chan
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Jacky Chi Ki Ngo
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Center for Novel Biomaterials, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
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14
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Pharmacotherapy alleviates pathological changes in human direct reprogrammed neuronal cell model of myotonic dystrophy type 1. PLoS One 2022; 17:e0269683. [PMID: 35776705 PMCID: PMC9249217 DOI: 10.1371/journal.pone.0269683] [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: 11/17/2021] [Accepted: 05/25/2022] [Indexed: 12/02/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a trinucleotide repeat disorder affecting multiple organs. However, most of the research is focused on studying and treating its muscular symptoms. On the other hand, despite the significant impact of the neurological symptoms on patients’ quality of life, no drug therapy was studied due to insufficient reproducibility in DM1 brain-specific animal models. To establish DM1 neuronal model, human skin fibroblasts were directly converted into neurons by using lentivirus expressing small hairpin RNA (shRNA) against poly-pyrimidine tract binding protein (PTBP). We found faster degeneration in DM1 human induced neurons (DM1 hiNeurons) compared to control human induced neurons (ctrl hiNeurons), represented by lower viability from 10 days post viral-infection (DPI) and abnormal axonal growth at 15 DPI. Nuclear RNA foci were present in most of DM1 hiNeurons at 10 DPI. Furthermore, DM1 hiNeurons modelled aberrant splicing of MBNL1 and 2, MAPT, CSNK1D and MPRIP at 10 DPI. We tested two drugs that were shown to be effective for DM1 in non-neuronal model and found that treatment of DM1 hiNeurons with 100 nM or 200 nM actinomycin D (ACT) for 24 h resulted in more than 50% reduction in the number of RNA foci per nucleus in a dose dependent manner, with 16.5% reduction in the number of nuclei containing RNA foci at 200 nM and treatment with erythromycin at 35 μM or 65 μM for 48 h rescued mis-splicing of MBNL1 exon 5 and MBNL 2 exons 5 and 8 up to 17.5%, 10% and 8.5%, respectively. Moreover, erythromycin rescued the aberrant splicing of MAPT exon 2, CSNK1D exon 9 and MPRIP exon 9 to a maximum of 46.4%, 30.7% and 19.9%, respectively. These results prove that our model is a promising tool for detailed pathogenetic examination and novel drug screening for the nervous system.
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15
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Baud A, Derbis M, Tutak K, Sobczak K. Partners in crime: Proteins implicated in
RNA
repeat expansion diseases. WIRES RNA 2022; 13:e1709. [PMID: 35229468 PMCID: PMC9539487 DOI: 10.1002/wrna.1709] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 11/06/2022]
Affiliation(s)
- Anna Baud
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Magdalena Derbis
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Katarzyna Tutak
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Krzysztof Sobczak
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
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16
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Ravel-Chapuis A, Duchesne E, Jasmin BJ. Pharmacological and exercise-induced activation of AMPK as emerging therapies for myotonic dystrophy type 1 patients. J Physiol 2022; 600:3249-3264. [PMID: 35695045 DOI: 10.1113/jp282725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 06/07/2022] [Indexed: 11/08/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a multisystemic disorder with variable clinical features. Currently, there is no cure or effective treatment for DM1. The disease is caused by an expansion of CUG repeats in the 3' UTR of DMPK mRNAs. Mutant DMPK mRNAs accumulate in nuclei as RNA foci and trigger an imbalance in the level and localization of RNA-binding proteins causing the characteristic missplicing events that account for the varied DM1 symptoms, a disease mechanism referred to as RNA toxicity. In recent years, multiple signalling pathways have been identified as being aberrantly regulated in skeletal muscle in response to the CUG expansion, including AMPK, a sensor of energy status, as well as a master regulator of cellular energy homeostasis. Converging lines of evidence highlight the benefits of activating AMPK signalling pharmacologically on RNA toxicity, as well as on muscle histology and function, in preclinical DM1 models. Importantly, a clinical trial with metformin, an activator of AMPK, resulted in functional benefits in DM1 patients. In addition, exercise, a known AMPK activator, has shown promising effects on RNA toxicity and muscle function in DM1 mice. Finally, clinical trials involving moderate-intensity exercise also induced functional benefits for DM1 patients. Taken together, these studies clearly demonstrate the molecular, histological and functional benefits of AMPK activation and exercise-based interventions on the DM1 phenotype. Despite these advances, several key questions remain; in particular, the extent of the true implication of AMPK in the observed beneficial improvements, as well as how, mechanistically, activation of AMPK signalling improves the DM1 pathophysiology.
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Affiliation(s)
- Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Elise Duchesne
- Département des sciences de la santé, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada.,Groupe de Recherche Interdisciplinaire sur les Maladies Neuromusculaires (GRIMN), Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-Saint-Jean, Hôpital de Jonquière, QC, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
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17
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A Structural Potential of Rare Trinucleotide Repeat Tracts in RNA. Int J Mol Sci 2022; 23:ijms23105850. [PMID: 35628656 PMCID: PMC9144543 DOI: 10.3390/ijms23105850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 01/27/2023] Open
Abstract
Among types of trinucleotide repeats, there is some disproportion in the frequency of their occurrence in the human exome. This research presents new data describing the folding and thermodynamic stability of short, tandem RNA repeats of 23 types, focusing on the rare, yet poorly analyzed ones. UV-melting experiments included the presence of PEG or potassium and magnesium ions to determine their effect on the stability of RNA repeats structures. Rare repeats predominantly stayed single-stranded but had the potential for base pairing with other partially complementary repeat tracts. A coexistence of suitably complementary repeat types in a single RNA creates opportunities for interaction in the context of the secondary structure of RNA. We searched the human transcriptome for model RNAs in which different, particularly rare trinucleotide repeats coexist and selected the GABRA4 and CHIC1 RNAs to study intramolecular interactions between the repeat tracts that they contain. In vitro secondary structure probing results showed that the UAA and UUG repeat tracts, present in GABRA4 3' UTR, form a double helix, which separates one of its structural domains. For the RNA CHIC1 ORF fragment containing four short AGG repeat tracts and the CGU tract, we proved the formation of quadruplexes that blocked reverse transcription.
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18
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Guo S, Nguyen L, Ranum LPW. RAN proteins in neurodegenerative disease: Repeating themes and unifying therapeutic strategies. Curr Opin Neurobiol 2021; 72:160-170. [PMID: 34953315 DOI: 10.1016/j.conb.2021.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 11/01/2021] [Accepted: 11/02/2021] [Indexed: 11/29/2022]
Abstract
Microsatellite-expansion mutations cause >50 neurological diseases but there are no effective treatments. Mechanistic studies have historically focused on protein loss-of-function and protein or RNA gain-of-function effects. It is now clear that many expansion mutations are bidirectionally transcribed producing two toxic expansion RNAs, which can produce up to six mutant proteins by repeat associated non-AUG (RAN) translation. Multiple types of RAN proteins have been shown to be toxic in cell and animal models, to lead to common types of neuropathological changes, and to dysregulate key pathways. How RAN proteins are produced without the canonical AUG or close-cognate AUG-like initiation codons is not yet completely understood but RNA structure, flanking sequences and stress pathways have been shown to be important. Here, we summarize recent progress in understanding the role of RAN proteins, mechanistic insights into their production, and the identification of novel therapeutic strategies that may be applicable across these neurodegenerative disorders.
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Affiliation(s)
- Shu Guo
- Center for NeuroGenetics, College of Medicine, University of Florida, USA; Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, USA
| | - Lien Nguyen
- Center for NeuroGenetics, College of Medicine, University of Florida, USA; Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, USA.
| | - Laura P W Ranum
- Center for NeuroGenetics, College of Medicine, University of Florida, USA; Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, USA; Genetics Institute, University of Florida, USA; McKnight Brain Institute, University of Florida, USA; Norman Fixel Institute for Neurological Diseases, University of Florida, USA.
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19
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Perez BA, Shorrock HK, Banez‐Coronel M, Zu T, Romano LEL, Laboissonniere LA, Reid T, Ikeda Y, Reddy K, Gomez CM, Bird T, Ashizawa T, Schut LJ, Brusco A, Berglund JA, Hasholt LF, Nielsen JE, Subramony SH, Ranum LPW. CCG•CGG interruptions in high-penetrance SCA8 families increase RAN translation and protein toxicity. EMBO Mol Med 2021; 13:e14095. [PMID: 34632710 PMCID: PMC8573593 DOI: 10.15252/emmm.202114095] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 09/09/2021] [Accepted: 09/10/2021] [Indexed: 12/28/2022] Open
Abstract
Spinocerebellar ataxia type 8 (SCA8), a dominantly inherited neurodegenerative disorder caused by a CTG•CAG expansion, is unusual because most individuals that carry the mutation do not develop ataxia. To understand the variable penetrance of SCA8, we studied the molecular differences between highly penetrant families and more common sporadic cases (82%) using a large cohort of SCA8 families (n = 77). We show that repeat expansion mutations from individuals with multiple affected family members have CCG•CGG interruptions at a higher frequency than sporadic SCA8 cases and that the number of CCG•CGG interruptions correlates with age at onset. At the molecular level, CCG•CGG interruptions increase RNA hairpin stability, and in cell culture experiments, increase p-eIF2α and polyAla and polySer RAN protein levels. Additionally, CCG•CGG interruptions, which encode arginine interruptions in the polyGln frame, increase toxicity of the resulting proteins. In summary, SCA8 CCG•CGG interruptions increase polyAla and polySer RAN protein levels, polyGln protein toxicity, and disease penetrance and provide novel insight into the molecular differences between SCA8 families with high vs. low disease penetrance.
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Affiliation(s)
- Barbara A Perez
- Center for NeuroGeneticsUniversity of FloridaGainesvilleFLUSA
- Department of Molecular Genetics and MicrobiologyUniversity of FloridaGainesvilleFLUSA
| | - Hannah K Shorrock
- Center for NeuroGeneticsUniversity of FloridaGainesvilleFLUSA
- Department of Molecular Genetics and MicrobiologyUniversity of FloridaGainesvilleFLUSA
| | - Monica Banez‐Coronel
- Center for NeuroGeneticsUniversity of FloridaGainesvilleFLUSA
- Department of Molecular Genetics and MicrobiologyUniversity of FloridaGainesvilleFLUSA
| | - Tao Zu
- Center for NeuroGeneticsUniversity of FloridaGainesvilleFLUSA
- Department of Molecular Genetics and MicrobiologyUniversity of FloridaGainesvilleFLUSA
| | - Lisa EL Romano
- Center for NeuroGeneticsUniversity of FloridaGainesvilleFLUSA
- Department of Molecular Genetics and MicrobiologyUniversity of FloridaGainesvilleFLUSA
| | - Lauren A Laboissonniere
- Center for NeuroGeneticsUniversity of FloridaGainesvilleFLUSA
- Department of Molecular Genetics and MicrobiologyUniversity of FloridaGainesvilleFLUSA
| | - Tammy Reid
- Center for NeuroGeneticsUniversity of FloridaGainesvilleFLUSA
- Department of Molecular Genetics and MicrobiologyUniversity of FloridaGainesvilleFLUSA
| | - Yoshio Ikeda
- Department of NeurologyGunma UniversityMaebashiJapan
| | - Kaalak Reddy
- RNA InstituteUniversity at Albany–SUNYAlbanyNYUSA
| | | | - Thomas Bird
- Department of NeurologyUniversity of WashingtonSeattleWAUSA
- Geriatrics Research SectionVA Puget Sound Health Care SystemSeattleWAUSA
| | - Tetsuo Ashizawa
- Department of NeurologyHouston Methodist Research InstituteHoustonTXUSA
| | | | - Alfredo Brusco
- Department of Medical SciencesUniversity of TorinoTorinoItaly
- Medical Genetics Units“Città della Salute e della Scienza” University HospitalTorinoItaly
| | - J Andrew Berglund
- Center for NeuroGeneticsUniversity of FloridaGainesvilleFLUSA
- RNA InstituteUniversity at Albany–SUNYAlbanyNYUSA
| | - Lis F Hasholt
- Institute of Cellular and Molecular MedicineUniversity of CopenhagenCopenhagenDenmark
| | - Jorgen E Nielsen
- Department of NeurologyRigshospitaletUniversity of CopenhagenCopenhagenDenmark
| | - SH Subramony
- Center for NeuroGeneticsUniversity of FloridaGainesvilleFLUSA
- McKnight Brain InstituteUniversity of FloridaGainesvilleFLUSA
| | - Laura PW Ranum
- Center for NeuroGeneticsUniversity of FloridaGainesvilleFLUSA
- Department of Molecular Genetics and MicrobiologyUniversity of FloridaGainesvilleFLUSA
- McKnight Brain InstituteUniversity of FloridaGainesvilleFLUSA
- Genetics InstituteUniversity of FloridaGainesvilleFLUSA
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20
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McGurk L, Rifai OM, Shcherbakova O, Perlegos AE, Byrns CN, Carranza FR, Zhou HW, Kim HJ, Zhu Y, Bonini NM. Toxicity of pathogenic ataxin-2 in Drosophila shows dependence on a pure CAG repeat sequence. Hum Mol Genet 2021; 30:1797-1810. [PMID: 34077532 PMCID: PMC8444453 DOI: 10.1093/hmg/ddab148] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/12/2021] [Accepted: 05/24/2021] [Indexed: 12/31/2022] Open
Abstract
Spinocerebellar ataxia type 2 is a polyglutamine (polyQ) disease associated with an expanded polyQ domain within the protein product of the ATXN2 gene. Interestingly, polyQ repeat expansions in ATXN2 are also associated with amyotrophic lateral sclerosis (ALS) and parkinsonism depending upon the length of the polyQ repeat expansion. The sequence encoding the polyQ repeat also varies with disease presentation: a pure CAG repeat is associated with SCA2, whereas the CAG repeat in ALS and parkinsonism is typically interrupted with the glutamine encoding CAA codon. Here, we asked if the purity of the CAG sequence encoding the polyQ repeat in ATXN2 could impact the toxicity of the ataxin-2 protein in vivo in Drosophila. We found that ataxin-2 encoded by a pure CAG repeat conferred toxicity in the retina and nervous system, whereas ataxin-2 encoded by a CAA-interrupted repeat or CAA-only repeat failed to confer toxicity, despite expression of the protein at similar levels. Furthermore, the CAG-encoded ataxin-2 protein aggregated in the fly eye, while ataxin-2 encoded by either a CAA/G or CAA repeat remained diffuse. The toxicity of the CAG-encoded ataxin-2 protein was also sensitive to the translation factor eIF4H, a known modifier of the toxic GGGGCC repeat in flies. These data indicate that ataxin-2 encoded by a pure CAG versus interrupted CAA/G polyQ repeat domain is associated with differential toxicity, indicating that mechanisms associated with the purity of the sequence of the polyQ domain contribute to disease.
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Affiliation(s)
- Leeanne McGurk
- Division of Cell & Developmental Biology, School of Life Sciences, University of Dundee, Dundee, UK
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Olivia M Rifai
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | | | | | - China N Byrns
- Neurosciences Graduate Group, University of Pennsylvania, Philadelphia, PA, USA
- Medical Sciences Training Program, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Faith R Carranza
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Henry W Zhou
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Hyung-Jun Kim
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Yongqing Zhu
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Nancy M Bonini
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
- Neurosciences Graduate Group, University of Pennsylvania, Philadelphia, PA, USA
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21
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Neault N, O’Reilly S, Baig AT, Plaza-Diaz J, Azimi M, Farooq F, Baird SD, MacKenzie A. High-throughput kinome-RNAi screen identifies protein kinase R activator (PACT) as a novel genetic modifier of CUG foci integrity in myotonic dystrophy type 1 (DM1). PLoS One 2021; 16:e0256276. [PMID: 34520479 PMCID: PMC8439471 DOI: 10.1371/journal.pone.0256276] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 08/03/2021] [Indexed: 11/24/2022] Open
Abstract
Myotonic Dystrophy Type 1 (DM1) is the most common form of adult muscular dystrophy (~1:8000). In DM1, expansion of CTG trinucleotide repeats in the 3' untranslated region of the dystrophia myotonica protein kinase (DMPK) gene results in DMPK mRNA hairpin structures which aggregate as insoluble ribonuclear foci and sequester several RNA-binding proteins. The resulting sequestration and misregulation of important splicing factors, such as muscleblind-like 1 (MBNL1), causes the aberrant expression of fetal transcripts for several genes that contribute to the disease phenotype. Previous work has shown that antisense oligonucleotide-mediated disaggregation of the intranuclear foci has the potential to reverse downstream anomalies. To explore whether the nuclear foci are, to some extent, controlled by cell signalling pathways, we have performed a screen using a small interfering RNA (siRNA) library targeting 518 protein kinases to look at kinomic modulation of foci integrity. RNA foci were visualized by in situ hybridization of a fluorescent-tagged (CAG)10 probe directed towards the expanded DMPK mRNA and the cross-sectional area and number of foci per nuclei were recorded. From our screen, we have identified PACT (protein kinase R (PKR) activator) as a novel modulator of foci integrity and have shown that PACT knockdown can both increase MBNL1 protein levels; however, these changes are not suffcient for significant correction of downstream spliceopathies.
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Affiliation(s)
- Nafisa Neault
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Sean O’Reilly
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Aiman Tariq Baig
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Julio Plaza-Diaz
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Mehrdad Azimi
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Faraz Farooq
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Stephen D. Baird
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Alex MacKenzie
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
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22
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Malik I, Kelley CP, Wang ET, Todd PK. Molecular mechanisms underlying nucleotide repeat expansion disorders. Nat Rev Mol Cell Biol 2021; 22:589-607. [PMID: 34140671 PMCID: PMC9612635 DOI: 10.1038/s41580-021-00382-6] [Citation(s) in RCA: 159] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2021] [Indexed: 02/05/2023]
Abstract
The human genome contains over one million short tandem repeats. Expansion of a subset of these repeat tracts underlies over fifty human disorders, including common genetic causes of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (C9orf72), polyglutamine-associated ataxias and Huntington disease, myotonic dystrophy, and intellectual disability disorders such as Fragile X syndrome. In this Review, we discuss the four major mechanisms by which expansion of short tandem repeats causes disease: loss of function through transcription repression, RNA-mediated gain of function through gelation and sequestration of RNA-binding proteins, gain of function of canonically translated repeat-harbouring proteins, and repeat-associated non-AUG translation of toxic repeat peptides. Somatic repeat instability amplifies these mechanisms and influences both disease age of onset and tissue specificity of pathogenic features. We focus on the crosstalk between these disease mechanisms, and argue that they often synergize to drive pathogenesis. We also discuss the emerging native functions of repeat elements and how their dynamics might contribute to disease at a larger scale than currently appreciated. Lastly, we propose that lynchpins tying these disease mechanisms and native functions together offer promising therapeutic targets with potential shared applications across this class of human disorders.
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Affiliation(s)
- Indranil Malik
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Chase P Kelley
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics, Genetics Institute, University of Florida, Gainesville, FL, USA
- Genetics and Genomics Graduate Program, University of Florida, Gainesville, FL, USA
| | - Eric T Wang
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics, Genetics Institute, University of Florida, Gainesville, FL, USA.
| | - Peter K Todd
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA.
- VA Ann Arbor Healthcare System, Ann Arbor, MI, USA.
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23
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Zhao X, Usdin K. (Dys)function Follows Form: Nucleic Acid Structure, Repeat Expansion, and Disease Pathology in FMR1 Disorders. Int J Mol Sci 2021; 22:ijms22179167. [PMID: 34502075 PMCID: PMC8431139 DOI: 10.3390/ijms22179167] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Fragile X-related disorders (FXDs), also known as FMR1 disorders, are examples of repeat expansion diseases (REDs), clinical conditions that arise from an increase in the number of repeats in a disease-specific microsatellite. In the case of FXDs, the repeat unit is CGG/CCG and the repeat tract is located in the 5' UTR of the X-linked FMR1 gene. Expansion can result in neurodegeneration, ovarian dysfunction, or intellectual disability depending on the number of repeats in the expanded allele. A growing body of evidence suggests that the mutational mechanisms responsible for many REDs share several common features. It is also increasingly apparent that in some of these diseases the pathologic consequences of expansion may arise in similar ways. It has long been known that many of the disease-associated repeats form unusual DNA and RNA structures. This review will focus on what is known about these structures, the proteins with which they interact, and how they may be related to the causative mutation and disease pathology in the FMR1 disorders.
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Affiliation(s)
- Xiaonan Zhao
- Correspondence: (X.Z.); (K.U.); Tel.: +1-301-451-6322 (X.Z.); +1-301-496-2189 (K.U.)
| | - Karen Usdin
- Correspondence: (X.Z.); (K.U.); Tel.: +1-301-451-6322 (X.Z.); +1-301-496-2189 (K.U.)
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24
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Martinez NW, Gómez FE, Matus S. The Potential Role of Protein Kinase R as a Regulator of Age-Related Neurodegeneration. Front Aging Neurosci 2021; 13:638208. [PMID: 33994991 PMCID: PMC8113420 DOI: 10.3389/fnagi.2021.638208] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 03/10/2021] [Indexed: 01/25/2023] Open
Abstract
There is a growing evidence describing a decline in adaptive homeostasis in aging-related diseases affecting the central nervous system (CNS), many of which are characterized by the appearance of non-native protein aggregates. One signaling pathway that allows cell adaptation is the integrated stress response (ISR), which senses stress stimuli through four kinases. ISR activation promotes translational arrest through the phosphorylation of the eukaryotic translation initiation factor 2 alpha (eIF2α) and the induction of a gene expression program to restore cellular homeostasis. However, depending on the stimulus, ISR can also induce cell death. One of the ISR sensors is the double-stranded RNA-dependent protein kinase [protein kinase R (PKR)], initially described as a viral infection sensor, and now a growing evidence supports a role for PKR on CNS physiology. PKR has been largely involved in the Alzheimer’s disease (AD) pathological process. Here, we reviewed the antecedents supporting the role of PKR on the efficiency of synaptic transmission and cognition. Then, we review PKR’s contribution to AD and discuss the possible participation of PKR as a player in the neurodegenerative process involved in aging-related pathologies affecting the CNS.
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Affiliation(s)
- Nicolás W Martinez
- Fundación Ciencia & Vida, Santiago, Chile.,Departamento de Ciencias Básicas, Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
| | | | - Soledad Matus
- Fundación Ciencia & Vida, Santiago, Chile.,Departamento de Ciencias Básicas, Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
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25
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Tusi SK, Nguyen L, Thangaraju K, Li J, Cleary JD, Zu T, Ranum LPW. The alternative initiation factor eIF2A plays key role in RAN translation of myotonic dystrophy type 2 CCUG•CAGG repeats. Hum Mol Genet 2021; 30:1020-1029. [PMID: 33856033 DOI: 10.1093/hmg/ddab098] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/26/2021] [Accepted: 03/31/2021] [Indexed: 01/29/2023] Open
Abstract
Repeat-associated non-ATG (RAN) proteins have been reported in 11 microsatellite expansion disorders but the factors that allow RAN translation to occur and the effects of different repeat motifs and alternative AUG-like initiation codons are unclear. We studied the mechanisms of RAN translation across myotonic dystrophy type 2 (DM2) expansion transcripts with (CCUG) or without (CAGG) efficient alternative AUG-like codons. To better understand how DM2 LPAC and QAGR RAN proteins are expressed, we generated a series of CRISPR/Cas9-edited HEK293T cell lines. We show that LPAC and QAGR RAN protein levels are reduced in protein kinase R (PKR)-/- and PKR-like endoplasmic reticulum kinase (PERK)-/- cells, with more substantial reductions of CAGG-encoded QAGR in PKR-/- cells. Experiments using mutant eIF2α-S51A HEK293T cells show that p-eIF2α is required for QAGR production. In contrast, LPAC levels were only partially reduced in these cells, suggesting that both non-AUG and close-cognate initiation occur across CCUG RNAs. Overexpression of the alternative initiation factor eIF2A increases LPAC and QAGR protein levels but, notably, has a much larger effect on QAGR expressed from CAGG-expansion RNAs that lack efficient close-cognate codons. The effects of eIF2A on increasing LPAC are consistent with previous reports that eIF2A affects CUG-initiation translation. The observation that eIF2A also increases QAGR proteins is novel because CAGG expansion transcripts do not contain CUG or similarly efficient close-cognate AUG-like codons. For QAGR but not LPAC, the eIF2A-dependent increases are not seen when p-eIF2α is blocked. These data highlight the differential regulation of DM2 RAN proteins and eIF2A as a potential therapeutic target for DM2 and other RAN diseases.
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Affiliation(s)
- Solaleh Khoramian Tusi
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Lien Nguyen
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Kiruphagaran Thangaraju
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Jian Li
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - John D Cleary
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Tao Zu
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Laura P W Ranum
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
- McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
- Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32610, USA
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26
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Fernandes N, Buchan JR. RNAs as Regulators of Cellular Matchmaking. Front Mol Biosci 2021; 8:634146. [PMID: 33898516 PMCID: PMC8062979 DOI: 10.3389/fmolb.2021.634146] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/22/2021] [Indexed: 12/30/2022] Open
Abstract
RNA molecules are increasingly being identified as facilitating or impeding the interaction of proteins and nucleic acids, serving as so-called scaffolds or decoys. Long non-coding RNAs have been commonly implicated in such roles, particularly in the regulation of nuclear processes including chromosome topology, regulation of chromatin state and gene transcription, and assembly of nuclear biomolecular condensates such as paraspeckles. Recently, an increased awareness of cytoplasmic RNA scaffolds and decoys has begun to emerge, including the identification of non-coding regions of mRNAs that can also function in a scaffold-like manner to regulate interactions of nascently translated proteins. Collectively, cytoplasmic RNA scaffolds and decoys are now implicated in processes such as mRNA translation, decay, protein localization, protein degradation and assembly of cytoplasmic biomolecular condensates such as P-bodies. Here, we review examples of RNA scaffolds and decoys in both the nucleus and cytoplasm, illustrating common themes, the suitability of RNA to such roles, and future challenges in identifying and better understanding RNA scaffolding and decoy functions.
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Affiliation(s)
| | - J. Ross Buchan
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, United States
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27
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Schmitz A, Pinheiro Marques J, Oertig I, Maharjan N, Saxena S. Emerging Perspectives on Dipeptide Repeat Proteins in C9ORF72 ALS/FTD. Front Cell Neurosci 2021; 15:637548. [PMID: 33679328 PMCID: PMC7930069 DOI: 10.3389/fncel.2021.637548] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 01/07/2021] [Indexed: 11/13/2022] Open
Abstract
The most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) is a hexanucleotide expansion in the chromosome 9 open reading frame 72 gene (C9ORF72). This hexanucleotide expansion consists of GGGGCC (G4C2) repeats that have been implicated to lead to three main modes of disease pathology: loss of function of the C9ORF72 protein, the generation of RNA foci, and the production of dipeptide repeat proteins (DPRs) through repeat-associated non-AUG (RAN) translation. Five different DPRs are currently known to be formed: glycine-alanine (GA) and glycine-arginine (GR) from the sense strand, proline-alanine (PA), and proline-arginine (PR) from the antisense strand, and glycine-proline (GP) from both strands. The exact contribution of each DPR to disease pathology is currently under intense scrutiny and is still poorly understood. However, recent advances in both neuropathological and cellular studies have provided us with clues enabling us to better understand the effect of individual DPRs on disease pathogenesis. In this review, we compile the current knowledge of specific DPR involvement on disease development and highlight recent advances, such as the impact of arginine-rich DPRs on nucleolar protein quality control, the correlation of poly-GR with neurodegeneration, and the possible involvement of chimeric DPR species. Further, we discuss recent findings regarding the mechanisms of RAN translation, its modulators, and other promising therapeutic options.
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Affiliation(s)
- Alexander Schmitz
- Department of Neurology, Center for Experimental Neurology, Inselspital University Hospital, Bern, Switzerland
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - João Pinheiro Marques
- Department of Neurology, Center for Experimental Neurology, Inselspital University Hospital, Bern, Switzerland
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Irina Oertig
- Department of Neurology, Center for Experimental Neurology, Inselspital University Hospital, Bern, Switzerland
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Niran Maharjan
- Department of Neurology, Center for Experimental Neurology, Inselspital University Hospital, Bern, Switzerland
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Smita Saxena
- Department of Neurology, Center for Experimental Neurology, Inselspital University Hospital, Bern, Switzerland
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
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28
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Johnson SJ, Cooper TA. Overlapping mechanisms of lncRNA and expanded microsatellite RNA. WILEY INTERDISCIPLINARY REVIEWS. RNA 2021; 12:e1634. [PMID: 33191580 PMCID: PMC7880542 DOI: 10.1002/wrna.1634] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/14/2020] [Accepted: 10/20/2020] [Indexed: 12/15/2022]
Abstract
RNA has major regulatory roles in a wide range of biological processes and a surge of RNA research has led to the classification of numerous functional RNA species. One example is long noncoding RNAs (lncRNAs) that are structurally complex transcripts >200 nucleotides (nt) in length and lacking a canonical open reading frame (ORF). Despite a general lack of sequence conservation and low expression levels, many lncRNAs have been shown to have functionality in diverse biological processes as well as in mechanisms of disease. In parallel with the growing understanding of lncRNA functions, there is a growing subset of microsatellite expansion disorders in which the primary mechanism of pathogenesis is an RNA gain of function arising from RNA transcripts from the mutant allele. Microsatellite expansion disorders are caused by an expansion of short (3-10 nt) repeats located within coding genes. Expanded repeat-containing RNA mediates toxicity through multiple mechanisms, the details of which remain only partially understood. The purpose of this review is to highlight the links between functional mechanisms of lncRNAs and the potential pathogenic mechanisms of expanded microsatellite RNA. These shared mechanisms include protein sequestration, peptide translation, micro-RNA (miRNA) processing, and miRNA sequestration. Recognizing the parallels between the normal functions of lncRNAs and the negative impact of expanded microsatellite RNA on biological processes can provide reciprocal understanding to the roles of both RNA species. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease.
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Affiliation(s)
- Sara J Johnson
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Thomas A Cooper
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas, USA
- Department of Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA
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29
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Zhang N, Bewick B, Xia G, Furling D, Ashizawa T. A CRISPR-Cas13a Based Strategy That Tracks and Degrades Toxic RNA in Myotonic Dystrophy Type 1. Front Genet 2020; 11:594576. [PMID: 33362853 PMCID: PMC7758406 DOI: 10.3389/fgene.2020.594576] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Cas13a, an effector of type VI CRISPR-Cas systems, is an RNA guided RNase with multiplexing and therapeutic potential. This study employs the Leptotrichia shahii (Lsh) Cas13a and a repeat-based CRISPR RNA (crRNA) to track and eliminate toxic RNA aggregates in myotonic dystrophy type 1 (DM1) – a neuromuscular disease caused by CTG expansion in the DMPK gene. We demonstrate that LshCas13a cleaves CUG repeat RNA in biochemical assays and reduces toxic RNA load in patient-derived myoblasts. As a result, LshCas13a reverses the characteristic adult-to-embryonic missplicing events in several key genes that contribute to DM1 phenotype. The deactivated LshCas13a can further be repurposed to track RNA-rich organelles within cells. Our data highlights the reprogrammability of LshCas13a and the possible use of Cas13a to target expanded repeat sequences in microsatellite expansion diseases.
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Affiliation(s)
- Nan Zhang
- Department of Neurology, Houston Methodist Research Institute, Houston, TX, United States
| | - Brittani Bewick
- Department of Neurology, Houston Methodist Research Institute, Houston, TX, United States
| | - Guangbin Xia
- Indiana University School of Medicine, Fort Wayne, IN, United States
| | - Denis Furling
- Institut National de la Sante et de la Recherche Medicale (INSERM), Centre de Recherche en Myologie (CRM), Association Institut de Myologie, Sorbonne Université, Paris, France
| | - Tetsuo Ashizawa
- Department of Neurology, Houston Methodist Research Institute, Houston, TX, United States
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30
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Dicing the Disease with Dicer: The Implications of Dicer Ribonuclease in Human Pathologies. Int J Mol Sci 2020; 21:ijms21197223. [PMID: 33007856 PMCID: PMC7583940 DOI: 10.3390/ijms21197223] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/27/2020] [Accepted: 09/27/2020] [Indexed: 12/12/2022] Open
Abstract
Gene expression dictates fundamental cellular processes and its de-regulation leads to pathological conditions. A key contributor to the fine-tuning of gene expression is Dicer, an RNA-binding protein (RBPs) that forms complexes and affects transcription by acting at the post-transcriptional level via the targeting of mRNAs by Dicer-produced small non-coding RNAs. This review aims to present the contribution of Dicer protein in a wide spectrum of human pathological conditions, including cancer, neurological, autoimmune, reproductive and cardiovascular diseases, as well as viral infections. Germline mutations of Dicer have been linked to Dicer1 syndrome, a rare genetic disorder that predisposes to the development of both benign and malignant tumors, but the exact correlation of Dicer protein expression within the different cancer types is unclear, and there are contradictions in the data. Downregulation of Dicer is related to Geographic atrophy (GA), a severe eye-disease that is a leading cause of blindness in industrialized countries, as well as to psychiatric and neurological diseases such as depression and Parkinson's disease, respectively. Both loss and upregulation of Dicer protein expression is implicated in severe autoimmune disorders, including psoriasis, ankylosing spondylitis, rheumatoid arthritis, multiple sclerosis and autoimmune thyroid diseases. Loss of Dicer contributes to cardiovascular diseases and causes defective germ cell differentiation and reproductive system abnormalities in both sexes. Dicer can also act as a strong antiviral with a crucial role in RNA-based antiviral immunity. In conclusion, Dicer is an essential enzyme for the maintenance of physiology due to its pivotal role in several cellular processes, and its loss or aberrant expression contributes to the development of severe human diseases. Further exploitation is required for the development of novel, more effective Dicer-based diagnostic and therapeutic strategies, with the goal of new clinical benefits and better quality of life for patients.
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31
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Tauber D, Tauber G, Parker R. Mechanisms and Regulation of RNA Condensation in RNP Granule Formation. Trends Biochem Sci 2020; 45:764-778. [PMID: 32475683 PMCID: PMC7211619 DOI: 10.1016/j.tibs.2020.05.002] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/20/2020] [Accepted: 05/05/2020] [Indexed: 01/01/2023]
Abstract
Ribonucleoprotein (RNP) granules are RNA-protein assemblies that are involved in multiple aspects of RNA metabolism and are linked to memory, development, and disease. Some RNP granules form, in part, through the formation of intermolecular RNA-RNA interactions. In vitro, such trans RNA condensation occurs readily, suggesting that cells require mechanisms to modulate RNA-based condensation. We assess the mechanisms of RNA condensation and how cells modulate this phenomenon. We propose that cells control RNA condensation through ATP-dependent processes, static RNA buffering, and dynamic post-translational mechanisms. Moreover, perturbations in these mechanisms can be involved in disease. This reveals multiple cellular mechanisms of kinetic and thermodynamic control that maintain the proper distribution of RNA molecules between dispersed and condensed forms.
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Affiliation(s)
- Devin Tauber
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80308, USA
| | - Gabriel Tauber
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80308, USA; Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80308, USA.
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32
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Rosbash M. Metformin treatment of the C9orf72 ALS/FTD mouse: Almost too good for words. Proc Natl Acad Sci U S A 2020; 117:19627-19628. [PMID: 32727895 PMCID: PMC7443920 DOI: 10.1073/pnas.2012363117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
- Michael Rosbash
- Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02453;
- Department of Biology, Brandeis University, Waltham, MA 02453
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33
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Ballester-Lopez A, Núñez-Manchón J, Koehorst E, Linares-Pardo I, Almendrote M, Lucente G, Guanyabens N, Lopez-Osias M, Suárez-Mesa A, Hanick SA, Chojnacki J, Lucia A, Pintos-Morell G, Coll-Cantí J, Martínez-Piñeiro A, Ramos-Fransi A, Nogales-Gadea G. Three-dimensional imaging in myotonic dystrophy type 1: Linking molecular alterations with disease phenotype. NEUROLOGY-GENETICS 2020; 6:e484. [PMID: 32802949 PMCID: PMC7413607 DOI: 10.1212/nxg.0000000000000484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 06/05/2020] [Indexed: 12/31/2022]
Abstract
Objective We aimed to determine whether 3D imaging reconstruction allows identifying molecular:clinical associations in myotonic dystrophy type 1 (DM1). Methods We obtained myoblasts from 6 patients with DM1 and 6 controls. We measured cytosine-thymine-guanine (CTG) expansion and detected RNA foci and muscleblind like 1 (MBNL1) through 3D reconstruction. We studied dystrophia myotonica protein kinase (DMPK) expression and splicing alterations of MBNL1, insulin receptor, and sarcoplasmic reticulum Ca(2+)-ATPase 1. Results Three-dimensional analysis showed that RNA foci (nuclear and/or cytoplasmic) were present in 45%-100% of DM1-derived myoblasts we studied (range: 0-6 foci per cell). RNA foci represented <0.6% of the total myoblast nuclear volume. CTG expansion size was associated with the number of RNA foci per myoblast (r = 0.876 [95% confidence interval 0.222-0.986]) as well as with the number of cytoplasmic RNA foci (r = 0.943 [0.559-0.994]). Although MBNL1 colocalized with RNA foci in all DM1 myoblast cell lines, colocalization only accounted for 1% of total MBNL1 expression, with the absence of DM1 alternative splicing patterns. The number of RNA foci was associated with DMPK expression (r = 0.967 [0.079-0.999]). On the other hand, the number of cytoplasmic RNA foci was correlated with the age at disease onset (r = -0.818 [-0.979 to 0.019]). Conclusions CTG expansion size modulates RNA foci number in myoblasts derived from patients with DM1. MBNL1 sequestration plays only a minor role in the pathobiology of the disease in these cells. Higher number of cytoplasmic RNA foci is related to an early onset of the disease, a finding that should be corroborated in future studies.
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Affiliation(s)
- Alfonsina Ballester-Lopez
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Judit Núñez-Manchón
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Emma Koehorst
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Ian Linares-Pardo
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Miriam Almendrote
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Giuseppe Lucente
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Nicolau Guanyabens
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Marta Lopez-Osias
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Adrián Suárez-Mesa
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Shaliza Ann Hanick
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Jakub Chojnacki
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Alejandro Lucia
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Guillem Pintos-Morell
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Jaume Coll-Cantí
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Alicia Martínez-Piñeiro
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Alba Ramos-Fransi
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
| | - Gisela Nogales-Gadea
- Neuromuscular and Neuropediatric Research Group (A.B.-L., J.N.-M., E.K., I.L.-P., M.A., G.L., M.L.-O., A.S.-M., S.A.H., G.P.-M., J.C.-C., A.M.-P., A.R.-F., G.N.-G.), Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) (A.B.-L., G.P.-M., J.C.-C., G.N.-G.), Instituto de Salud Carlos III, Madrid; Neuromuscular Pathology Unit. Neurology Service. Neuroscience department (M.A., G.L., N.G., J.C.-C., A.M.-P., A.R.-F.), Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona; IrsiCaixa AIDS Research Institute (J.C.), Badalona, Spain; Faculty of Sport Sciences (A.L.), Universidad Europea de Madrid; Instituto de Investigación Hospital 12 de Octubre (i+12) (A.L.), Madrid; and Division of Rare Diseases. University Hospital Vall d'Hebron (G.P.-M.), Barcelona, Spain
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Metformin inhibits RAN translation through PKR pathway and mitigates disease in C9orf72 ALS/FTD mice. Proc Natl Acad Sci U S A 2020; 117:18591-18599. [PMID: 32690681 PMCID: PMC7414156 DOI: 10.1073/pnas.2005748117] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Repeat-associated non-AUG (RAN) proteins accumulate in patient brains and contribute to a growing number of neurodegenerative diseases. There is an urgent need to understand why expression of these proteins does not require canonical or near-cognate AUG start codons and to develop ways to block RAN protein production. We show several types of repeat-expansion RNAs activate the double-stranded RNA-dependent protein kinase (PKR) pathway and that blocking PKR reduces RAN protein levels in cells. PKR is activated in C9orf72 ALS/FTD human and mouse brains and PKR inhibition using AAV-PKR-K296R or the FDA-approved drug metformin decreases RAN protein levels and improves disease in ALS/FTD mice. Targeting PKR using gene therapy or metformin are promising therapeutic approaches for C9orf72 ALS/FTD and other expansion diseases. Repeat associated non-AUG (RAN) translation is found in a growing number of microsatellite expansion diseases, but the mechanisms remain unclear. We show that RAN translation is highly regulated by the double-stranded RNA-dependent protein kinase (PKR). In cells, structured CAG, CCUG, CAGG, and G4C2 expansion RNAs activate PKR, which leads to increased levels of multiple RAN proteins. Blocking PKR using PKR-K296R, the TAR RNA binding protein or PKR-KO cells, reduces RAN protein levels. p-PKR is elevated in C9orf72 ALS/FTD human and mouse brains, and inhibiting PKR in C9orf72 BAC transgenic mice using AAV-PKR-K296R or the Food and Drug Administration (FDA)-approved drug metformin, decreases RAN proteins, and improves behavior and pathology. In summary, targeting PKR, including by use of metformin, is a promising therapeutic approach for C9orf72 ALS/FTD and other expansion diseases.
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Swinnen B, Robberecht W, Van Den Bosch L. RNA toxicity in non-coding repeat expansion disorders. EMBO J 2020; 39:e101112. [PMID: 31721251 PMCID: PMC6939197 DOI: 10.15252/embj.2018101112] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 09/30/2019] [Accepted: 10/09/2019] [Indexed: 12/11/2022] Open
Abstract
Several neurodegenerative disorders like amyotrophic lateral sclerosis (ALS) and spinocerebellar ataxia (SCA) are caused by non-coding nucleotide repeat expansions. Different pathogenic mechanisms may underlie these non-coding repeat expansion disorders. While gain-of-function mechanisms, such as toxicity associated with expression of repeat RNA or toxicity associated with repeat-associated non-ATG (RAN) products, are most frequently connected with these disorders, loss-of-function mechanisms have also been implicated. We review the different pathways that have been linked to non-coding repeat expansion disorders such as C9ORF72-linked ALS/frontotemporal dementia (FTD), myotonic dystrophy, fragile X tremor/ataxia syndrome (FXTAS), SCA, and Huntington's disease-like 2. We discuss modes of RNA toxicity focusing on the identity and the interacting partners of the toxic RNA species. Using the C9ORF72 ALS/FTD paradigm, we further explore the efforts and different methods used to disentangle RNA vs. RAN toxicity. Overall, we conclude that there is ample evidence for a role of RNA toxicity in non-coding repeat expansion diseases.
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Affiliation(s)
- Bart Swinnen
- Department of NeurosciencesExperimental NeurologyLeuven Brain Institute (LBI)KU Leuven – University of LeuvenLeuvenBelgium
- Laboratory of NeurobiologyVIB, Center for Brain & Disease ResearchLeuvenBelgium
- Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Wim Robberecht
- Department of NeurosciencesExperimental NeurologyLeuven Brain Institute (LBI)KU Leuven – University of LeuvenLeuvenBelgium
- Laboratory of NeurobiologyVIB, Center for Brain & Disease ResearchLeuvenBelgium
- Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Ludo Van Den Bosch
- Department of NeurosciencesExperimental NeurologyLeuven Brain Institute (LBI)KU Leuven – University of LeuvenLeuvenBelgium
- Laboratory of NeurobiologyVIB, Center for Brain & Disease ResearchLeuvenBelgium
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Timchenko L. Correction of RNA-Binding Protein CUGBP1 and GSK3β Signaling as Therapeutic Approach for Congenital and Adult Myotonic Dystrophy Type 1. Int J Mol Sci 2019; 21:ijms21010094. [PMID: 31877772 PMCID: PMC6982105 DOI: 10.3390/ijms21010094] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/13/2019] [Accepted: 12/17/2019] [Indexed: 01/02/2023] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a complex genetic disease affecting many tissues. DM1 is caused by an expansion of CTG repeats in the 3′-UTR of the DMPK gene. The mechanistic studies of DM1 suggested that DMPK mRNA, containing expanded CUG repeats, is a major therapeutic target in DM1. Therefore, the removal of the toxic RNA became a primary focus of the therapeutic development in DM1 during the last decade. However, a cure for this devastating disease has not been found. Whereas the degradation of toxic RNA remains a preferential approach for the reduction of DM1 pathology, other approaches targeting early toxic events downstream of the mutant RNA could be also considered. In this review, we discuss the beneficial role of the restoring of the RNA-binding protein, CUGBP1/CELF1, in the correction of DM1 pathology. It has been recently found that the normalization of CUGBP1 activity with the inhibitors of GSK3 has a positive effect on the reduction of skeletal muscle and CNS pathologies in DM1 mouse models. Surprisingly, the inhibitor of GSK3, tideglusib also reduced the toxic CUG-containing RNA. Thus, the development of the therapeutics, based on the correction of the GSK3β-CUGBP1 pathway, is a promising option for this complex disease.
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Affiliation(s)
- Lubov Timchenko
- Departments of Neurology and Pediatrics, Cincinnati Children's Hospital Medical Center and the University of Cincinnati, Cincinnati, OH 45229, USA
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Mondragon-Gonzalez R, Azzag K, Selvaraj S, Yamamoto A, Perlingeiro RCR. Transplantation studies reveal internuclear transfer of toxic RNA in engrafted muscles of myotonic dystrophy 1 mice. EBioMedicine 2019; 47:553-562. [PMID: 31446083 PMCID: PMC6796515 DOI: 10.1016/j.ebiom.2019.08.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 08/05/2019] [Accepted: 08/14/2019] [Indexed: 12/11/2022] Open
Abstract
Background Stem cell transplantation represents a potential therapeutic option for muscular dystrophies (MD). However, to date, most reports have utilized mouse models for recessive types of MD. Here we performed studies to determine whether myotonic dystrophy 1 (DM1), an autosomal dominant type of MD, could benefit from cell transplantation. Methods We injected human pluripotent stem (PS) cell-derived myogenic progenitors into the muscles of a novel mouse model combining immunodeficiency and skeletal muscle pathology of DM1 and investigated transplanted mice for engraftment as well as for the presence of RNA foci and alternative splicing pattern. Findings Engraftment was clearly observed in recipient mice, but unexpectedly, we detected RNA foci in donor-derived engrafted myonuclei. These foci proved to be pathogenic as we observed MBNL1 sequestration and abnormal alternative splicing in donor-derived transcripts. Interpretation It has been assumed that toxic CUG repeat-containing RNA forms foci in situ in the nucleus in which it is expressed, but these data suggest that CUG repeat-containing RNA may also exit the nucleus and traffic to other nuclei in the syncytial myofiber, where it can exert pathological effects. Fund This project was supported by funds from the LaBonte/Shawn family and NIH grants R01 AR055299 and AR071439 (R.C.R.P.). R.M-G. was funded by CONACyT-Mexico (#394378).
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Affiliation(s)
- Ricardo Mondragon-Gonzalez
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA; Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), Mexico City, Mexico
| | - Karim Azzag
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Sridhar Selvaraj
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Ami Yamamoto
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Rita C R Perlingeiro
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA; Stem Cell Institute, University of Minnesota, Minneapolis, MN, USA.
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38
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Reddy K, Jenquin JR, Cleary JD, Berglund JA. Mitigating RNA Toxicity in Myotonic Dystrophy using Small Molecules. Int J Mol Sci 2019; 20:E4017. [PMID: 31426500 PMCID: PMC6720693 DOI: 10.3390/ijms20164017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 12/26/2022] Open
Abstract
This review, one in a series on myotonic dystrophy (DM), is focused on the development and potential use of small molecules as therapeutics for DM. The complex mechanisms and pathogenesis of DM are covered in the associated reviews. Here, we examine the various small molecule approaches taken to target the DNA, RNA, and proteins that contribute to disease onset and progression in myotonic dystrophy type 1 (DM1) and 2 (DM2).
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Affiliation(s)
- Kaalak Reddy
- The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA.
| | - Jana R Jenquin
- Center for NeuroGenetics and Biochemistry & Molecular Biology, University of Florida, Gainesville, FL 32608, USA
| | - John D Cleary
- The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA
| | - J Andrew Berglund
- The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA.
- Center for NeuroGenetics and Biochemistry & Molecular Biology, University of Florida, Gainesville, FL 32608, USA.
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39
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Wang X, Goodrich KJ, Conlon EG, Gao J, Erbse AH, Manley JL, Cech TR. C9orf72 and triplet repeat disorder RNAs: G-quadruplex formation, binding to PRC2 and implications for disease mechanisms. RNA (NEW YORK, N.Y.) 2019; 25:935-947. [PMID: 31048495 PMCID: PMC6633194 DOI: 10.1261/rna.071191.119] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 04/29/2019] [Indexed: 05/12/2023]
Abstract
Some neurological disorders, including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), fragile X syndrome, Huntington's disease, myotonic dystrophy, and various ataxias, can be caused by expansions of short nucleic acid sequence repeats in specific genes. A possible disease mechanism involves the transcribed repeat RNA binding an RNA-binding protein (RBP), resulting in its sequestration and thus dysfunction. Polycomb repressive complex 2 (PRC2), the histone methyltransferase that deposits the H3K27me3 mark of epigenetically silenced chromatin, binds G-rich RNAs and has especially high affinity for G-quadruplex (G-Q) structures. Here, we find that PRC2 target genes are derepressed and the RNA binding subunit EZH2 largely insoluble in postmortem brain samples from ALS/FTD patients with C9ORF72 (C9) repeat expansions, leading to the hypothesis that the (G4C2)n repeat RNA might be sequestering PRC2. Contrary to this expectation, we found that C9 repeat RNAs (n = 6 or 10) bind weakly to purified PRC2, and studies with the G-Q specific BG4 antibody and circular dichroism studies both indicated that these C9 RNAs have little propensity to form G-Qs in vitro. Several GC-rich triplet-repeat expansion RNAs also have low affinity for PRC2 and do not appreciably form G-Qs in vitro. The results are consistent with these sequences forming hairpin structures that outcompete G-Q folding when the repeat length is sufficiently large. We suggest that binding of PRC2 to these GC-rich RNAs is fundamentally weak but may be modulated in vivo by protein factors that affect secondary structure, such as helicases and other RBPs.
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Affiliation(s)
- Xueyin Wang
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA
- BioFrontiers Institute and Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Karen J Goodrich
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA
- BioFrontiers Institute and Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Erin G Conlon
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - Jianchao Gao
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - Annette H Erbse
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - James L Manley
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - Thomas R Cech
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA
- BioFrontiers Institute and Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80309, USA
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Hale MA, Johnson NE, Berglund JA. Repeat-associated RNA structure and aberrant splicing. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194405. [PMID: 31323433 DOI: 10.1016/j.bbagrm.2019.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 12/13/2022]
Abstract
Over 30 hereditary disorders attributed to the expansion of microsatellite repeats have been identified. Despite variant nucleotide content, number of consecutive repeats, and different locations in the genome, many of these diseases have pathogenic RNA gain-of-function mechanisms. The repeat-containing RNAs can form structures in vitro predicted to contribute to the disease through assembly of intracellular RNA aggregates termed foci. The expanded repeat RNAs within these foci sequester RNA binding proteins (RBPs) with important roles in the regulation of RNA metabolism, most notably alternative splicing (AS). These deleterious interactions lead to downstream alterations in transcriptome-wide AS directly linked with disease symptoms. This review summarizes existing knowledge about the association between the repeat RNA structures and RBPs as well as the resulting aberrant AS patterns, specifically in the context of myotonic dystrophy. The connection between toxic, structured RNAs and dysregulation of AS in other repeat expansion diseases is also discussed. This article is part of a Special Issue entitled: RNA structure and splicing regulation edited by Francisco Baralle, Ravindra Singh and Stefan Stamm.
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Affiliation(s)
- Melissa A Hale
- Department of Neurology, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Nicholas E Johnson
- Department of Neurology, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - J Andrew Berglund
- The RNA Institute, Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA.
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Mohibi S, Chen X, Zhang J. Cancer the'RBP'eutics-RNA-binding proteins as therapeutic targets for cancer. Pharmacol Ther 2019; 203:107390. [PMID: 31302171 DOI: 10.1016/j.pharmthera.2019.07.001] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 07/02/2019] [Indexed: 12/11/2022]
Abstract
RNA-binding proteins (RBPs) play a critical role in the regulation of various RNA processes, including splicing, cleavage and polyadenylation, transport, translation and degradation of coding RNAs, non-coding RNAs and microRNAs. Recent studies indicate that RBPs not only play an instrumental role in normal cellular processes but have also emerged as major players in the development and spread of cancer. Herein, we review the current knowledge about RNA binding proteins and their role in tumorigenesis as well as the potential to target RBPs for cancer therapeutics.
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Affiliation(s)
- Shakur Mohibi
- Comparative Oncology Laboratory, Schools of Veterinary Medicine and Medicine, University of California at Davis, United States
| | - Xinbin Chen
- Comparative Oncology Laboratory, Schools of Veterinary Medicine and Medicine, University of California at Davis, United States
| | - Jin Zhang
- Comparative Oncology Laboratory, Schools of Veterinary Medicine and Medicine, University of California at Davis, United States.
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van Cruchten RTP, Wieringa B, Wansink DG. Expanded CUG repeats in DMPK transcripts adopt diverse hairpin conformations without influencing the structure of the flanking sequences. RNA (NEW YORK, N.Y.) 2019; 25:481-495. [PMID: 30700578 PMCID: PMC6426290 DOI: 10.1261/rna.068940.118] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/24/2019] [Indexed: 06/09/2023]
Abstract
Myotonic dystrophy type 1 (DM1) is a complex neuromuscular disorder caused by expansion of a CTG repeat in the 3'-untranslated region (UTR) of the DMPK gene. Mutant DMPK transcripts form aberrant structures and anomalously associate with RNA-binding proteins (RBPs). As a first step toward better understanding of the involvement of abnormal DMPK mRNA folding in DM1 manifestation, we used SHAPE, DMS, CMCT, and RNase T1 structure probing in vitro for modeling of the topology of the DMPK 3'-UTR with normal and pathogenic repeat lengths of up to 197 CUG triplets. The resulting structural information was validated by disruption of base-pairing with LNA antisense oligonucleotides (AONs) and used for prediction of therapeutic AON accessibility and verification of DMPK knockdown efficacy in cells. Our model for DMPK RNA structure demonstrates that the hairpin formed by the CUG repeat has length-dependent conformational plasticity, with a structure that is guided by and embedded in an otherwise rigid architecture of flanking regions in the DMPK 3'-UTR. Evidence is provided that long CUG repeats may form not only single asymmetrical hairpins but also exist as branched structures. These newly identified structures have implications for DM1 pathogenic mechanisms, like sequestration of RBPs and repeat-associated non-AUG (RAN) translation.
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Affiliation(s)
- Remco T P van Cruchten
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
| | - Bé Wieringa
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
| | - Derick G Wansink
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
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43
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Ravel-Chapuis A, Al-Rewashdy A, Bélanger G, Jasmin BJ. Pharmacological and physiological activation of AMPK improves the spliceopathy in DM1 mouse muscles. Hum Mol Genet 2019; 27:3361-3376. [PMID: 29982462 DOI: 10.1093/hmg/ddy245] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/28/2018] [Indexed: 12/26/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a debilitating multisystemic disorder caused by a triplet repeat expansion in the 3' untranslated region of dystrophia myotonica protein kinase mRNAs. Mutant mRNAs accumulate in the nucleus of affected cells and misregulate RNA-binding proteins, thereby promoting characteristic missplicing events. However, little is known about the signaling pathways that may be affected in DM1. Here, we investigated the status of activated protein kinase (AMPK) signaling in DM1 skeletal muscle and found that the AMPK pathway is markedly repressed in a DM1 mouse model (human skeletal actin-long repeat, HSALR) and patient-derived DM1 myoblasts. Chronic pharmacological activation of AMPK signaling in DM1 mice with 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) has multiple beneficial effects on the DM1 phenotype. Indeed, a 6-week AICAR treatment of DM1 mice promoted expression of a slower, more oxidative phenotype, improved muscle histology and corrected several events associated with RNA toxicity. Importantly, AICAR also had a dose-dependent positive effect on the spliceopathy in patient-derived DM1 myoblasts. In separate experiments, we also show that chronic treatment of DM1 mice with resveratrol as well as voluntary wheel running also rescued missplicing events in muscle. Collectively, our findings demonstrate the therapeutic potential of chronic AMPK stimulation both physiologically and pharmacologically for DM1 patients.
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Affiliation(s)
- Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Ali Al-Rewashdy
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Guy Bélanger
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
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Souidi A, Zmojdzian M, Jagla K. Dissecting Pathogenetic Mechanisms and Therapeutic Strategies in Drosophila Models of Myotonic Dystrophy Type 1. Int J Mol Sci 2018; 19:E4104. [PMID: 30567354 PMCID: PMC6321436 DOI: 10.3390/ijms19124104] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 12/08/2018] [Accepted: 12/13/2018] [Indexed: 12/16/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1), the most common cause of adult-onset muscular dystrophy, is autosomal dominant, multisystemic disease with characteristic symptoms including myotonia, heart defects, cataracts and testicular atrophy. DM1 disease is being successfully modelled in Drosophila allowing to identify and validate new pathogenic mechanisms and potential therapeutic strategies. Here we provide an overview of insights gained from fruit fly DM1 models, either: (i) fundamental with particular focus on newly identified gene deregulations and their link with DM1 symptoms; or (ii) applied via genetic modifiers and drug screens to identify promising therapeutic targets.
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Affiliation(s)
- Anissa Souidi
- GReD, INSERM U1103, CNRS, UMR6293, University of Clermont Auvergne, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France.
| | - Monika Zmojdzian
- GReD, INSERM U1103, CNRS, UMR6293, University of Clermont Auvergne, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France.
| | - Krzysztof Jagla
- GReD, INSERM U1103, CNRS, UMR6293, University of Clermont Auvergne, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France.
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45
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Repeat-Associated Non-ATG Translation in Neurological Diseases. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a033019. [PMID: 29891563 DOI: 10.1101/cshperspect.a033019] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
More than 40 different neurological diseases are caused by microsatellite repeat expansions that locate within translated or untranslated gene regions, including 5' and 3' untranslated regions (UTRs), introns, and protein-coding regions. Expansion mutations are transcribed bidirectionally and have been shown to give rise to proteins, which are synthesized from three reading frames in the absence of an AUG initiation codon through a novel process called repeat-associated non-ATG (RAN) translation. RAN proteins, which were first described in spinocerebellar ataxia type 8 (SCA8) and myotonic dystrophy type 1 (DM1), have now been reported in a growing list of microsatellite expansion diseases. This article reviews what is currently known about RAN proteins in microsatellite expansion diseases and experiments that provide clues on how RAN translation is regulated.
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Abstract
Myotonic dystrophy is an autosomal dominant muscular dystrophy not only associated with muscle weakness, atrophy, and myotonia but also prominent multisystem involvement. There are 2 similar, but distinct, forms of myotonic dystrophy; type 1 is caused by a CTG repeat expansion in the DMPK gene, and type 2 is caused by a CCTG repeat expansion in the CNBP gene. Type 1 is associated with distal limb, neck flexor, and bulbar weakness and results in different phenotypic subtypes with variable onset from congenital to very late-onset as well as variable signs and symptoms. The classically described adult-onset form is the most common. In contrast, myotonic dystrophy type 2 is adult-onset or late-onset, has proximal predominant muscle weakness, and generally has less severe multisystem involvement. In both forms of myotonic dystrophy, the best characterized disease mechanism is a RNA toxic gain-of-function during which RNA repeats form nuclear foci resulting in sequestration of RNA-binding proteins and, therefore, dysregulated splicing of premessenger RNA. There are currently no disease-modifying therapies, but clinical surveillance, preventative measures, and supportive treatments are used to reduce the impact of muscular impairment and other systemic involvement including cataracts, cardiac conduction abnormalities, fatigue, central nervous system dysfunction, respiratory weakness, dysphagia, and endocrine dysfunction. Exciting preclinical progress has been made in identifying a number of potential strategies including genome editing, small molecule therapeutics, and antisense oligonucleotide-based therapies to target the pathogenesis of type 1 and type 2 myotonic dystrophies at the DNA, RNA, or downstream target level.
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Affiliation(s)
- Samantha LoRusso
- Department of Neurology, The Ohio State University, 395 West 12th Avenue, Columbus, OH, 43210, USA
| | - Benjamin Weiner
- The Ohio State University College of Medicine, The Ohio State University, 370 West 9th Avenue, Columbus, OH, 43210, USA
| | - W David Arnold
- Department of Neurology, The Ohio State University, 395 West 12th Avenue, Columbus, OH, 43210, USA.
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Mondragon-Gonzalez R, Perlingeiro RCR. Recapitulating muscle disease phenotypes with myotonic dystrophy 1 induced pluripotent stem cells: a tool for disease modeling and drug discovery. Dis Model Mech 2018; 11:dmm.034728. [PMID: 29898953 PMCID: PMC6078411 DOI: 10.1242/dmm.034728] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/07/2018] [Indexed: 12/27/2022] Open
Abstract
Myotonic dystrophy 1 (DM1) is a multisystem disorder primarily affecting the central nervous system, heart and skeletal muscle. It is caused by an expansion of the CTG trinucleotide repeats in the 3' untranslated region of the DMPK gene. Although patient myoblasts have been used for studying the disease in vitro, the invasiveness as well as the low accessibility to muscle biopsies motivate the development of alternative reliable myogenic models. Here, we established two DM1 induced pluripotent stem (iPS) cell lines from patient-derived fibroblasts and, using the PAX7 conditional expression system, differentiated these into myogenic progenitors and, subsequently, terminally differentiated myotubes. Both DM1 myogenic progenitors and myotubes were found to express the intranuclear RNA foci exhibiting sequestration of MBNL1. Moreover, we found the DM1-related mis-splicing, namely BIN1 exon 11 in DM1 myotubes. We used this model to test a specific therapy, antisense oligonucleotide treatment, and found that this efficiently abolished RNA foci and rescued BIN1 mis-splicing in DM1 iPS cell-derived myotubes. Together, our results demonstrate that myotubes derived from DM1 iPS cells recapitulate the critical molecular features of DM1 and are sensitive to antisense oligonucleotide treatment, confirming that these cells can be used for in vitro disease modeling and candidate drug testing or screening.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Ricardo Mondragon-Gonzalez
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA.,Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México City 07360, Mexico
| | - Rita C R Perlingeiro
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
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Targeting the Polyadenylation Signal of Pre-mRNA: A New Gene Silencing Approach for Facioscapulohumeral Dystrophy. Int J Mol Sci 2018; 19:ijms19051347. [PMID: 29751519 PMCID: PMC5983732 DOI: 10.3390/ijms19051347] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/27/2018] [Accepted: 04/30/2018] [Indexed: 02/07/2023] Open
Abstract
Facioscapulohumeral dystrophy (FSHD) is characterized by the contraction of the D4Z4 array located in the sub-telomeric region of the chromosome 4, leading to the aberrant expression of the DUX4 transcription factor and the mis-regulation of hundreds of genes. Several therapeutic strategies have been proposed among which the possibility to target the polyadenylation signal to silence the causative gene of the disease. Indeed, defects in mRNA polyadenylation leads to an alteration of the transcription termination, a disruption of mRNA transport from the nucleus to the cytoplasm decreasing the mRNA stability and translation efficiency. This review discusses the polyadenylation mechanisms, why alternative polyadenylation impacts gene expression, and how targeting polyadenylation signal may be a potential therapeutic approach for FSHD.
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Thomas JD, Oliveira R, Sznajder ŁJ, Swanson MS. Myotonic Dystrophy and Developmental Regulation of RNA Processing. Compr Physiol 2018; 8:509-553. [PMID: 29687899 PMCID: PMC11323716 DOI: 10.1002/cphy.c170002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Myotonic dystrophy (DM) is a multisystemic disorder caused by microsatellite expansion mutations in two unrelated genes leading to similar, yet distinct, diseases. DM disease presentation is highly variable and distinguished by differences in age-of-onset and symptom severity. In the most severe form, DM presents with congenital onset and profound developmental defects. At the molecular level, DM pathogenesis is characterized by a toxic RNA gain-of-function mechanism that involves the transcription of noncoding microsatellite expansions. These mutant RNAs disrupt key cellular pathways, including RNA processing, localization, and translation. In DM, these toxic RNA effects are predominantly mediated through the modulation of the muscleblind-like and CUGBP and ETR-3-like factor families of RNA binding proteins (RBPs). Dysfunction of these RBPs results in widespread RNA processing defects culminating in the expression of developmentally inappropriate protein isoforms in adult tissues. The tissue that is the focus of this review, skeletal muscle, is particularly sensitive to mutant RNA-responsive perturbations, as patients display a variety of developmental, structural, and functional defects in muscle. Here, we provide a comprehensive overview of DM1 and DM2 clinical presentation and pathology as well as the underlying cellular and molecular defects associated with DM disease onset and progression. Additionally, fundamental aspects of skeletal muscle development altered in DM are highlighted together with ongoing and potential therapeutic avenues to treat this muscular dystrophy. © 2018 American Physiological Society. Compr Physiol 8:509-553, 2018.
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Affiliation(s)
- James D. Thomas
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida, USA
| | - Ruan Oliveira
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida, USA
| | - Łukasz J. Sznajder
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida, USA
| | - Maurice S. Swanson
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida, USA
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50
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Bahal R, Manna A, Hsieh WC, Thadke SA, Sureshkumar G, Ly DH. RNA-Templated Concatenation of Triplet Nucleic-Acid Probe. Chembiochem 2018; 19:674-678. [PMID: 29323790 DOI: 10.1002/cbic.201700574] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Indexed: 01/21/2023]
Abstract
Template-directed synthesis offers several distinct benefits over conventional laboratory creation, including unsurpassed reaction rate and selectivity. Although it is central to many biological processes, such an approach has rarely been applied to the in situ synthesis and recognition of biomedically relevant target. Towards this goal, we report the development of a three-codon nucleic-acid probe containing a C-terminal thioester group and an N-terminal cysteine that is capable of undergoing template-directed oligomerization in the presence of an RNA target and self-deactivation in its absence. The work has implications for the development of millamolecular nucleic-acid probes for targeting RNA-repeated expansions associated with myotonic dystrophy type 1 and other related neuromuscular and neurodegenerative disorders.
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Affiliation(s)
- Raman Bahal
- School of Pharmacy, University of Connecticut, 69 N. Eagleville Road, Storrs, CT, 06269, USA
| | - Arunava Manna
- Department of Chemistry, Institute for Biomolecular Design and Discovery (IBD), and CNAST, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, 15213, USA
| | - Wei-Che Hsieh
- Department of Chemistry, Institute for Biomolecular Design and Discovery (IBD), and CNAST, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, 15213, USA
| | - Shivaji A Thadke
- Department of Chemistry, Institute for Biomolecular Design and Discovery (IBD), and CNAST, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, 15213, USA
| | - Gopalsamy Sureshkumar
- Department of Chemistry, Institute for Biomolecular Design and Discovery (IBD), and CNAST, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, 15213, USA
| | - Danith H Ly
- Department of Chemistry, Institute for Biomolecular Design and Discovery (IBD), and CNAST, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, 15213, USA
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