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Zhao G, Zhu M, Li Y, Zhang G, Li Y. Using DNA-encoded libraries of fragments for hit discovery of challenging therapeutic targets. Expert Opin Drug Discov 2024; 19:725-740. [PMID: 38753553 DOI: 10.1080/17460441.2024.2354287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 05/08/2024] [Indexed: 05/18/2024]
Abstract
INTRODUCTION The effectiveness of Fragment-based drug design (FBDD) for targeting challenging therapeutic targets has been hindered by two factors: the small library size and the complexity of the fragment-to-hit optimization process. The DNA-encoded library (DEL) technology offers a compelling and robust high-throughput selection approach to potentially address these limitations. AREA COVERED In this review, the authors propose the viewpoint that the DEL technology matches perfectly with the concept of FBDD to facilitate hit discovery. They begin by analyzing the technical limitations of FBDD from a medicinal chemistry perspective and explain why DEL may offer potential solutions to these limitations. Subsequently, they elaborate in detail on how the integration of DEL with FBDD works. In addition, they present case studies involving both de novo hit discovery and full ligand discovery, especially for challenging therapeutic targets harboring broad drug-target interfaces. EXPERT OPINION The future of DEL-based fragment discovery may be promoted by both technical advances and application scopes. From the technical aspect, expanding the chemical diversity of DEL will be essential to achieve success in fragment-based drug discovery. From the application scope side, DEL-based fragment discovery holds promise for tackling a series of challenging targets.
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Affiliation(s)
- Guixian Zhao
- Chongqing University FuLing Hospital, Chongqing University, Chongqing, China
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing, China
| | - Mengping Zhu
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing, China
| | - Yangfeng Li
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing, China
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing, China
| | - Gong Zhang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing, China
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing, China
| | - Yizhou Li
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing, China
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing, China
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2
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Malard F, Wolter AC, Marquevielle J, Morvan E, Ecoutin A, Rüdisser S, Allain FT, Campagne S. The diversity of splicing modifiers acting on A-1 bulged 5'-splice sites reveals rules for rational drug design. Nucleic Acids Res 2024; 52:4124-4136. [PMID: 38554107 PMCID: PMC11077090 DOI: 10.1093/nar/gkae201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 12/07/2023] [Accepted: 03/07/2024] [Indexed: 04/01/2024] Open
Abstract
Pharmacological modulation of RNA splicing by small molecules is an emerging facet of drug discovery. In this context, the SMN2 splicing modifier SMN-C5 was used as a prototype to understand the mode of action of small molecule splicing modifiers and propose the concept of 5'-splice site bulge repair. In this study, we combined in vitro binding assays and structure determination by NMR spectroscopy to identify the binding modes of four other small molecule splicing modifiers that switch the splicing of either the SMN2 or the HTT gene. Here, we determined the solution structures of risdiplam, branaplam, SMN-CX and SMN-CY bound to the intermolecular RNA helix epitope containing an unpaired adenine within the G-2A-1G+1U+2 motif of the 5'-splice site. Despite notable differences in their scaffolds, risdiplam, SMN-CX, SMN-CY and branaplam contact the RNA epitope similarly to SMN-C5, suggesting that the 5'-splice site bulge repair mechanism can be generalised. These findings not only deepen our understanding of the chemical diversity of splicing modifiers that target A-1 bulged 5'-splice sites, but also identify common pharmacophores required for modulating 5'-splice site selection with small molecules.
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Affiliation(s)
- Florian Malard
- Université de Bordeaux, Inserm U1212, CNRS UMR5320, ARNA unit, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
- Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607 Pessac Cedex, France
| | - Antje C Wolter
- ETH Zürich, Department of Biology, Institute of Biochemistry, Hönggerbergring 64, 8093 Zürich, Switzerland
| | - Julien Marquevielle
- Université de Bordeaux, Inserm U1212, CNRS UMR5320, ARNA unit, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
- Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607 Pessac Cedex, France
| | - Estelle Morvan
- Institut Européen de Chimie et Biologie, UAR3033 CNRS, Université de Bordeaux, INSERM US01, Pessac 33600, France
| | - Agathe Ecoutin
- Université de Bordeaux, Inserm U1212, CNRS UMR5320, ARNA unit, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
- Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607 Pessac Cedex, France
| | - Simon H Rüdisser
- ETH Zürich, Department of Biology, BioNMR platform, Hönggerbergring 64, 8093 Zürich, Switzerland
| | - Frédéric H T Allain
- ETH Zürich, Department of Biology, Institute of Biochemistry, Hönggerbergring 64, 8093 Zürich, Switzerland
| | - Sebastien Campagne
- Université de Bordeaux, Inserm U1212, CNRS UMR5320, ARNA unit, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
- Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607 Pessac Cedex, France
- ETH Zürich, Department of Biology, Institute of Biochemistry, Hönggerbergring 64, 8093 Zürich, Switzerland
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Bouton L, Ecoutin A, Malard F, Campagne S. Small molecules modulating RNA splicing: a review of targets and future perspectives. RSC Med Chem 2024; 15:1109-1126. [PMID: 38665842 PMCID: PMC11042171 DOI: 10.1039/d3md00685a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 01/03/2024] [Indexed: 04/28/2024] Open
Abstract
In eukaryotic cells, RNA splicing is crucial for gene expression. Dysregulation of this process can result in incorrect mRNA processing, leading to aberrant gene expression patterns. Such abnormalities are implicated in many inherited diseases and cancers. Historically, antisense oligonucleotides, which bind to specific RNA targets, have been used to correct these splicing abnormalities. Despite their high specificity of action, these oligonucleotides have drawbacks, such as lack of oral bioavailability and the need for chemical modifications to enhance cellular uptake and stability. As a result, recent efforts focused on the development of small organic molecules that can correct abnormal RNA splicing event under disease conditions. This review discusses known and potential targets of these molecules, including RNA structures, trans-acting splicing factors, and the spliceosome - the macromolecular complex responsible for RNA splicing. We also rely on recent advances to discuss therapeutic applications of RNA-targeting small molecules in splicing correction. Overall, this review presents an update on strategies for RNA splicing modulation, emphasizing the therapeutic promise of small molecules.
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Affiliation(s)
- Léa Bouton
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux 146 rue Léo Saignat 33076 Bordeaux Cedex France
- Institut Européen de Chimie et de Biologie F-33600 Pessac France
| | - Agathe Ecoutin
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux 146 rue Léo Saignat 33076 Bordeaux Cedex France
- Institut Européen de Chimie et de Biologie F-33600 Pessac France
| | - Florian Malard
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux 146 rue Léo Saignat 33076 Bordeaux Cedex France
- Institut Européen de Chimie et de Biologie F-33600 Pessac France
| | - Sébastien Campagne
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux 146 rue Léo Saignat 33076 Bordeaux Cedex France
- Institut Européen de Chimie et de Biologie F-33600 Pessac France
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4
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White DS, Dunyak BM, Vaillancourt FH, Hoskins AA. A Sequential Binding Mechanism for 5' Splice Site Recognition and Modulation for the Human U1 snRNP. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.18.590139. [PMID: 38659798 PMCID: PMC11042371 DOI: 10.1101/2024.04.18.590139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Splice site recognition is essential for defining the transcriptome. Drugs like risdiplam and branaplam change how U1 snRNP recognizes particular 5' splice sites (5'SS) and promote U1 snRNP binding and splicing at these locations. Despite the therapeutic potential of 5'SS modulators, the complexity of their interactions and snRNP substrates have precluded defining a mechanism for 5'SS modulation. We have determined a sequential binding mechanism for modulation of -1A bulged 5'SS by branaplam using a combination of ensemble kinetic measurements and colocalization single molecule spectroscopy (CoSMoS). Our mechanism establishes that U1-C protein binds reversibly to U1 snRNP, and branaplam binds to the U1 snRNP/U1-C complex only after it has engaged a -1A bulged 5'SS. Obligate orders of binding and unbinding explain how reversible branaplam interactions cause formation of long-lived U1 snRNP/5'SS complexes. Branaplam is a ribonucleoprotein, not RNA duplex alone, targeting drug whose action depends on fundamental properties of 5'SS recognition.
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Affiliation(s)
- David S. White
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI
- Present Address: Element Biosciences, San Diego, CA
| | | | | | - Aaron A. Hoskins
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI
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5
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McLean ZL, Gao D, Correia K, Roy JCL, Shibata S, Farnum IN, Valdepenas-Mellor Z, Kovalenko M, Rapuru M, Morini E, Ruliera J, Gillis T, Lucente D, Kleinstiver BP, Lee JM, MacDonald ME, Wheeler VC, Mouro Pinto R, Gusella JF. Splice modulators target PMS1 to reduce somatic expansion of the Huntington's disease-associated CAG repeat. Nat Commun 2024; 15:3182. [PMID: 38609352 PMCID: PMC11015039 DOI: 10.1038/s41467-024-47485-0] [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: 07/24/2023] [Accepted: 03/30/2024] [Indexed: 04/14/2024] Open
Abstract
Huntington's disease (HD) is a dominant neurological disorder caused by an expanded HTT exon 1 CAG repeat that lengthens huntingtin's polyglutamine tract. Lowering mutant huntingtin has been proposed for treating HD, but genetic modifiers implicate somatic CAG repeat expansion as the driver of onset. We find that branaplam and risdiplam, small molecule splice modulators that lower huntingtin by promoting HTT pseudoexon inclusion, also decrease expansion of an unstable HTT exon 1 CAG repeat in an engineered cell model. Targeted CRISPR-Cas9 editing shows this effect is not due to huntingtin lowering, pointing instead to pseudoexon inclusion in PMS1. Homozygous but not heterozygous inactivation of PMS1 also reduces CAG repeat expansion, supporting PMS1 as a genetic modifier of HD and a potential target for therapeutic intervention. Although splice modulation provides one strategy, genome-wide transcriptomics also emphasize consideration of cell-type specific effects and polymorphic variation at both target and off-target sites.
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Affiliation(s)
- Zachariah L McLean
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, 02142, USA
| | - Dadi Gao
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, 02142, USA
| | - Kevin Correia
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Jennie C L Roy
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
| | - Shota Shibata
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, 02142, USA
| | - Iris N Farnum
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Zoe Valdepenas-Mellor
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Marina Kovalenko
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Manasa Rapuru
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Elisabetta Morini
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
| | - Jayla Ruliera
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Tammy Gillis
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Diane Lucente
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Benjamin P Kleinstiver
- Center for Genomic Medicine and Department of Pathology, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Pathology, Harvard Medical School, Boston, MA, 02115, USA
| | - Jong-Min Lee
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, 02142, USA
| | - Marcy E MacDonald
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, 02142, USA
| | - Vanessa C Wheeler
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, 02142, USA
| | - Ricardo Mouro Pinto
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, 02142, USA
| | - James F Gusella
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA.
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, 02142, USA.
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA.
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6
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Sharma KR, Malik A, Roof RA, Boyce JP, Verma SK. New approaches for challenging therapeutic targets. Drug Discov Today 2024; 29:103942. [PMID: 38447929 PMCID: PMC10997441 DOI: 10.1016/j.drudis.2024.103942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/20/2024] [Accepted: 02/29/2024] [Indexed: 03/08/2024]
Abstract
Despite successes with new drug approvals over the past two decades through conventional drug development approaches, many human diseases remain intractable to current therapeutic interventions. Possible barriers may be that the complexity of the target, and disease biology, are impervious to such conventional drug development approaches. The US National Institutes of Health hosted a workshop with the goal of identifying challenges and opportunities with alternative modalities for developing treatments across diseases associated with historically undruggable targets. This report highlights key issues discussed during the workshop that, if addressed, could expand the pool of therapeutic approaches for treating various diseases.
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Affiliation(s)
- Karlie R Sharma
- National Center for Advancing Translational Sciences, National Institutes of Health, 6701 Democracy Blvd, Bethesda, MD 20892, USA.
| | - Abir Malik
- National Center for Advancing Translational Sciences, National Institutes of Health, 6701 Democracy Blvd, Bethesda, MD 20892, USA
| | - Rebecca A Roof
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Jim P Boyce
- National Institute of Allergy and Infectious Disease, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Sharad K Verma
- National Cancer Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
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7
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Tong H, Yang T, Xu S, Li X, Liu L, Zhou G, Yang S, Yin S, Li XJ, Li S. Huntington's Disease: Complex Pathogenesis and Therapeutic Strategies. Int J Mol Sci 2024; 25:3845. [PMID: 38612657 PMCID: PMC11011923 DOI: 10.3390/ijms25073845] [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: 02/19/2024] [Revised: 03/21/2024] [Accepted: 03/26/2024] [Indexed: 04/14/2024] Open
Abstract
Huntington's disease (HD) arises from the abnormal expansion of CAG repeats in the huntingtin gene (HTT), resulting in the production of the mutant huntingtin protein (mHTT) with a polyglutamine stretch in its N-terminus. The pathogenic mechanisms underlying HD are complex and not yet fully elucidated. However, mHTT forms aggregates and accumulates abnormally in neuronal nuclei and processes, leading to disruptions in multiple cellular functions. Although there is currently no effective curative treatment for HD, significant progress has been made in developing various therapeutic strategies to treat HD. In addition to drugs targeting the neuronal toxicity of mHTT, gene therapy approaches that aim to reduce the expression of the mutant HTT gene hold great promise for effective HD therapy. This review provides an overview of current HD treatments, discusses different therapeutic strategies, and aims to facilitate future therapeutic advancements in the field.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Xiao-Jiang Li
- Guangdong Key Laboratory of Non-Human Primate Research, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China; (H.T.); (T.Y.); (S.X.); (X.L.); (L.L.); (G.Z.); (S.Y.); (S.Y.)
| | - Shihua Li
- Guangdong Key Laboratory of Non-Human Primate Research, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China; (H.T.); (T.Y.); (S.X.); (X.L.); (L.L.); (G.Z.); (S.Y.); (S.Y.)
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8
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Caron NS, Aly AEE, Findlay Black H, Martin DDO, Schmidt ME, Ko S, Anderson C, Harvey EM, Casal LL, Anderson LM, Rahavi SMR, Reid GSD, Oda MN, Stanimirovic D, Abulrob A, McBride JL, Leavitt BR, Hayden MR. Systemic delivery of mutant huntingtin lowering antisense oligonucleotides to the brain using apolipoprotein A-I nanodisks for Huntington disease. J Control Release 2024; 367:27-44. [PMID: 38215984 DOI: 10.1016/j.jconrel.2024.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 12/09/2023] [Accepted: 01/09/2024] [Indexed: 01/14/2024]
Abstract
Efficient delivery of therapeutics to the central nervous system (CNS) remains a major challenge for the treatment of neurological diseases. Huntington disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG trinucleotide expansion mutation in the HTT gene which codes for a toxic mutant huntingtin (mHTT) protein. Pharmacological reduction of mHTT in the CNS using antisense oligonucleotides (ASO) ameliorates HD-like phenotypes in rodent models of HD, with such therapies being investigated in clinical trials for HD. In this study, we report the optimization of apolipoprotein A-I nanodisks (apoA-I NDs) as vehicles for delivery of a HTT-targeted ASO (HTT ASO) to the brain and peripheral organs for HD. We demonstrate that apoA-I wild type (WT) and the apoA-I K133C mutant incubated with a synthetic lipid, 1,2-dimyristoyl-sn-glycero-3-phosphocholine, can self-assemble into monodisperse discoidal particles with diameters <20 nm that transmigrate across an in vitro blood-brain barrier model of HD. We demonstrate that apoA-I NDs are well tolerated in vivo, and that apoA-I K133C NDs show enhanced distribution to the CNS and peripheral organs compared to apoA-I WT NDs following systemic administration. ApoA-I K133C conjugated with HTT ASO forms NDs (HTT ASO NDs) that induce significant mHTT lowering in the liver, skeletal muscle and heart as well as in the brain when delivered intravenously in the BACHD mouse model of HD. Furthermore, HTT ASO NDs increase the magnitude of mHTT lowering in the striatum and cortex compared to HTT ASO alone following intracerebroventricular administration. These findings demonstrate the potential utility of apoA-I NDs as biocompatible vehicles for enhancing delivery of mutant HTT lowering ASOs to the CNS and peripheral organs for HD.
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Affiliation(s)
- Nicholas S Caron
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amirah E-E Aly
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hailey Findlay Black
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dale D O Martin
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada; Department of Biology, University of Waterloo, Ontario, Canada
| | - Mandi E Schmidt
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Neuroscience, University of British Columbia, Vancouver, British Columbia, Canada
| | - Seunghyun Ko
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada
| | - Christine Anderson
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada
| | - Emily M Harvey
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada
| | - Lorenzo L Casal
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada
| | - Lisa M Anderson
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada
| | - Seyed M R Rahavi
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Gregor S D Reid
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Danica Stanimirovic
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Abedelnasser Abulrob
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Jodi L McBride
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA; Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, USA
| | - Blair R Leavitt
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada.
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9
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Ishigami Y, Wong MS, Martí-Gómez C, Ayaz A, Kooshkbaghi M, Hanson SM, McCandlish DM, Krainer AR, Kinney JB. Specificity, synergy, and mechanisms of splice-modifying drugs. Nat Commun 2024; 15:1880. [PMID: 38424098 PMCID: PMC10904865 DOI: 10.1038/s41467-024-46090-5] [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: 02/22/2023] [Accepted: 02/10/2024] [Indexed: 03/02/2024] Open
Abstract
Drugs that target pre-mRNA splicing hold great therapeutic potential, but the quantitative understanding of how these drugs work is limited. Here we introduce mechanistically interpretable quantitative models for the sequence-specific and concentration-dependent behavior of splice-modifying drugs. Using massively parallel splicing assays, RNA-seq experiments, and precision dose-response curves, we obtain quantitative models for two small-molecule drugs, risdiplam and branaplam, developed for treating spinal muscular atrophy. The results quantitatively characterize the specificities of risdiplam and branaplam for 5' splice site sequences, suggest that branaplam recognizes 5' splice sites via two distinct interaction modes, and contradict the prevailing two-site hypothesis for risdiplam activity at SMN2 exon 7. The results also show that anomalous single-drug cooperativity, as well as multi-drug synergy, are widespread among small-molecule drugs and antisense-oligonucleotide drugs that promote exon inclusion. Our quantitative models thus clarify the mechanisms of existing treatments and provide a basis for the rational development of new therapies.
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Affiliation(s)
- Yuma Ishigami
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Mandy S Wong
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
- Beam Therapeutics, Cambridge, MA, 02142, USA
| | | | - Andalus Ayaz
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Mahdi Kooshkbaghi
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
- The Estée Lauder Companies, New York, NY, 10153, USA
| | | | | | - Adrian R Krainer
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA.
| | - Justin B Kinney
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA.
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10
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Tramutola A, Bakels HS, Perrone F, Di Nottia M, Mazza T, Abruzzese MP, Zoccola M, Pagnotta S, Carrozzo R, de Bot ST, Perluigi M, van Roon-Mom WMC, Squitieri F. GLUT-1 changes in paediatric Huntington disease brain cortex and fibroblasts: an observational case-control study. EBioMedicine 2023; 97:104849. [PMID: 37898095 PMCID: PMC10630613 DOI: 10.1016/j.ebiom.2023.104849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 10/09/2023] [Accepted: 10/11/2023] [Indexed: 10/30/2023] Open
Abstract
BACKGROUND Paediatric Huntington disease with highly expanded mutations (HE-PHD; >80 CAG repeats) presents atypically, compared to adult-onset Huntington disease (AOHD), with neurodevelopmental delay, epilepsy, abnormal brain glucose metabolism, early striatal damage, and reduced lifespan. Since genetic GLUT-1 deficiency syndrome shows a symptom spectrum similar to HE-PHD, we investigated the potential role of the two main glucose transporters, GLUT-1 and GLUT-3, in HE-PHD. METHODS We compared GLUT-1 and GLUT-3 protein expression in HE-PHD, juvenile-onset (JOHD), and AOHD brains (n = 2; n = 3; n = 6) and periphery (n = 3; n = 2; n = 2) versus healthy adult controls (n = 6; n = 6). We also investigated mitochondrial complexes and hexokinase-II protein expression. FINDINGS GLUT-1 and GLUT-3 expression were significantly lower in HE-PHD frontal cortex (p = 0.009, 95% [CI 13.4, 14.7]; p = 0.017, 95% [CI 14.2, 14.5]) versus controls. In fibroblasts, GLUT-1 and GLUT-3 expression were lower compared to controls (p < 0.0001, 95% [CI 0.91, 1.09]; p = 0.046, 95% [CI 0.93, 1.07]). In the frontal cortex, this occurred without evidence of extensive neuronal degeneration. Patients with HE-PHD had deregulated mitochondrial complex expression, particularly complexes II-III, levels of which were lower in frontal cortex versus controls (p = 0.027, 95% [CI 17.1, 17.6]; p = 0.002, 95% CI [16.6, 16.9]) and patients with AOHD (p = 0.052, 95% [CI 17.0, 17.6]; p = 0.002, 95% [CI 16.6, 16.7]). Hexokinase-II expression was also lower in HE-PHD frontal cortex and striatum versus controls (p = 0.010, 95% [CI 17.8, 18.2]; p = 0.045, 95% [CI 18.6, 18.7]) and in frontal cortex versus patients with AOHD (p = 0.013, 95% [CI 17.7, 18.1]). Expression JOHD levels were consistently different to those of HE-PHD but similar to those of AOHD. INTERPRETATION Our data suggest a dysfunctional hypometabolic state occurring specifically in paediatric Huntington disease brains. FUNDING '5 × 1000' Personal Income Tax donation to LIRH Foundation; Italian Ministry of HealthRC2301MH04 and RF-2016-02364123 to CSS.
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Affiliation(s)
- Antonella Tramutola
- Department of Biochemical Sciences, Sapienza University of Rome, Rome 00185, Italy
| | - Hannah S Bakels
- Department of Neurology, Leiden University Medical Centre, ZA Leiden 2311, the Netherlands
| | - Federica Perrone
- Huntington and Rare Diseases Unit, IRCCS Casa Sollievo della Sofferenza (CSS) Research Hospital, San Giovanni Rotondo 71013, Italy
| | - Michela Di Nottia
- Unit of Cellular Biology and Mitochondrial Diseases, IRCCS Bambino Gesú Children's Hospital, Rome 00146, Italy
| | - Tommaso Mazza
- Bioinformatics Unit, IRCCS Casa Sollievo della Sofferenza (CSS) Research Hospital, San Giovanni Rotondo 71013, Italy
| | - Maria Pia Abruzzese
- Huntington and Rare Diseases Unit, IRCCS Casa Sollievo della Sofferenza (CSS) Research Hospital, San Giovanni Rotondo 71013, Italy
| | - Martina Zoccola
- Unit of Cellular Biology and Mitochondrial Diseases, IRCCS Bambino Gesú Children's Hospital, Rome 00146, Italy
| | - Sara Pagnotta
- Department of Biochemical Sciences, Sapienza University of Rome, Rome 00185, Italy
| | - Rosalba Carrozzo
- Unit of Cellular Biology and Mitochondrial Diseases, IRCCS Bambino Gesú Children's Hospital, Rome 00146, Italy
| | - Susanne T de Bot
- Department of Neurology, Leiden University Medical Centre, ZA Leiden 2311, the Netherlands
| | - Marzia Perluigi
- Department of Biochemical Sciences, Sapienza University of Rome, Rome 00185, Italy
| | | | - Ferdinando Squitieri
- Huntington and Rare Diseases Unit, IRCCS Casa Sollievo della Sofferenza (CSS) Research Hospital, San Giovanni Rotondo 71013, Italy; Centre for Rare Neurological Diseases (CMRN), Italian League for Research on Huntington (LIRH) Foundation, Viale di Villa Massimo 4, Rome 00161, Italy.
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11
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Bragg RM, Coffey SR, Cantle JP, Hu S, Singh S, Legg SR, McHugh CA, Toor A, Zeitlin SO, Kwak S, Howland D, Vogt TF, Monga SP, Carroll JB. Huntingtin loss in hepatocytes is associated with altered metabolism, adhesion, and liver zonation. Life Sci Alliance 2023; 6:e202302098. [PMID: 37684045 PMCID: PMC10488683 DOI: 10.26508/lsa.202302098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023] Open
Abstract
Huntington's disease arises from a toxic gain of function in the huntingtin (HTT) gene. As a result, many HTT-lowering therapies are being pursued in clinical studies, including those that reduce HTT RNA and protein expression in the liver. To investigate potential impacts, we characterized molecular, cellular, and metabolic impacts of chronic HTT lowering in mouse hepatocytes. Lifelong hepatocyte HTT loss is associated with multiple physiological changes, including increased circulating bile acids, cholesterol and urea, hypoglycemia, and impaired adhesion. HTT loss causes a clear shift in the normal zonal patterns of liver gene expression, such that pericentral gene expression is reduced. These alterations in liver zonation in livers lacking HTT are observed at the transcriptional, histological, and plasma metabolite levels. We have extended these phenotypes physiologically with a metabolic challenge of acetaminophen, for which the HTT loss results in toxicity resistance. Our data reveal an unexpected role for HTT in regulating hepatic zonation, and we find that loss of HTT in hepatocytes mimics the phenotypes caused by impaired hepatic β-catenin function.
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Affiliation(s)
- Robert M Bragg
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham, WA, USA
| | - Sydney R Coffey
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham, WA, USA
| | - Jeffrey P Cantle
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham, WA, USA
| | - Shikai Hu
- School of Medicine, Tsinghua University, Beijing, China
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Sucha Singh
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Samuel Rw Legg
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham, WA, USA
| | - Cassandra A McHugh
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham, WA, USA
| | - Amreen Toor
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham, WA, USA
| | - Scott O Zeitlin
- https://ror.org/0153tk833 Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | | | | | | | - Satdarshan P Monga
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Pittsburgh Liver Research Center, University of Pittsburgh Medical Center and University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jeffrey B Carroll
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham, WA, USA
- https://ror.org/00cvxb145 Department of Neurology, University of Washington, Seattle, WA, USA
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12
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Fair B, Najar CBA, Zhao J, Lozano S, Reilly A, Mossian G, Staley JP, Wang J, Li YI. Global impact of aberrant splicing on human gene expression levels. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.13.557588. [PMID: 37745605 PMCID: PMC10515962 DOI: 10.1101/2023.09.13.557588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Alternative splicing (AS) is pervasive in human genes, yet the specific function of most AS events remains unknown. It is widely assumed that the primary function of AS is to diversify the proteome, however AS can also influence gene expression levels by producing transcripts rapidly degraded by nonsense-mediated decay (NMD). Currently, there are no precise estimates for how often the coupling of AS and NMD (AS-NMD) impacts gene expression levels because rapidly degraded NMD transcripts are challenging to capture. To better understand the impact of AS on gene expression levels, we analyzed population-scale genomic data in lymphoblastoid cell lines across eight molecular assays that capture gene regulation before, during, and after transcription and cytoplasmic decay. Sequencing nascent mRNA transcripts revealed frequent aberrant splicing of human introns, which results in remarkably high levels of mRNA transcripts subject to NMD. We estimate that ~15% of all protein-coding transcripts are degraded by NMD, and this estimate increases to nearly half of all transcripts for lowly-expressed genes with many introns. Leveraging genetic variation across cell lines, we find that GWAS trait-associated loci explained by AS are similarly likely to associate with NMD-induced expression level differences as with differences in protein isoform usage. Additionally, we used the splice-switching drug risdiplam to perturb AS at hundreds of genes, finding that ~3/4 of the splicing perturbations induce NMD. Thus, we conclude that AS-NMD substantially impacts the expression levels of most human genes. Our work further suggests that much of the molecular impact of AS is mediated by changes in protein expression levels rather than diversification of the proteome.
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Affiliation(s)
- Benjamin Fair
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Carlos Buen Abad Najar
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Junxing Zhao
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA
| | - Stephanie Lozano
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
- Present address: Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - Austin Reilly
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Gabriela Mossian
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Jonathan P Staley
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Jingxin Wang
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA
| | - Yang I Li
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
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13
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Liu L, Malagu K, Haughan AF, Khetarpal V, Stott AJ, Esmieu W, Vater HD, Webster SJ, Van de Poël AJ, Clissold C, Cosgrove B, Sutton B, Spencer JA, Breccia P, Gancia E, Bonomo S, Ladduwahetty T, Lazari O, Patel H, Atton HC, Clifton S, Mota DM, Magnani D, O'Neill A, Stebbeds M, Macabuag N, Todd D, Herva ME, Mitchell P, Visser M, Compte Sancerni S, Grand Moursel L, da Silva M, Kritikou E, Heikkinen TT, Bolkvadze T, Fodale V, Spadafora D, Daldin M, Bresciani A, Mangette JE, Doherty EM, Lee MR, Herbst T, Monteagudo E, Macdonald D, Plotnikov NV, Chambers M, McAllister G, Muňoz-Sanjuan I, Dominguez C. Identification and Optimization of RNA-Splicing Modulators as Huntingtin Protein-Lowering Agents for the Treatment of Huntington's Disease. J Med Chem 2023; 66:13205-13246. [PMID: 37712656 DOI: 10.1021/acs.jmedchem.3c01173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023]
Abstract
Huntington's disease (HD) is caused by an expanded CAG trinucleotide repeat in exon 1 of the huntingtin (HTT) gene. We report the design of a series of HTT pre-mRNA splicing modulators that lower huntingtin (HTT) protein, including the toxic mutant huntingtin (mHTT), by promoting insertion of a pseudoexon containing a premature termination codon at the exon 49-50 junction. The resulting transcript undergoes nonsense-mediated decay, leading to a reduction of HTT mRNA transcripts and protein levels. The starting benzamide core was modified to pyrazine amide and further optimized to give a potent, CNS-penetrant, and orally bioavailable HTT-splicing modulator 27. This compound reduced canonical splicing of the HTT RNA exon 49-50 and demonstrated significant HTT-lowering in both human HD stem cells and mouse BACHD models. Compound 27 is a structurally diverse HTT-splicing modulator that may help understand the mechanism of adverse effects such as peripheral neuropathy associated with branaplam.
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Affiliation(s)
- Longbin Liu
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, California 90045, United States
| | - Karine Malagu
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Alan F Haughan
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Vinod Khetarpal
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, California 90045, United States
| | - Andrew J Stott
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - William Esmieu
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Huw D Vater
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Stephen J Webster
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Amanda J Van de Poël
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Cole Clissold
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Brett Cosgrove
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Benjamin Sutton
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Jonathan A Spencer
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Perla Breccia
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Emanuela Gancia
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Silvia Bonomo
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Tammy Ladduwahetty
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Ovadia Lazari
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Hiral Patel
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Helen C Atton
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Steve Clifton
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Daniel M Mota
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Dario Magnani
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Amy O'Neill
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Marta Stebbeds
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Natsuko Macabuag
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Daniel Todd
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Maria E Herva
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Philip Mitchell
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - Mijke Visser
- Charles River, Darwinweg 24, 2333 CR Leiden, The Netherlands
| | | | | | - Marta da Silva
- Charles River, Darwinweg 24, 2333 CR Leiden, The Netherlands
| | - Eva Kritikou
- Charles River, Darwinweg 24, 2333 CR Leiden, The Netherlands
| | | | | | | | | | | | | | | | - Elizabeth M Doherty
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, California 90045, United States
| | - Matthew R Lee
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, California 90045, United States
| | - Todd Herbst
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, California 90045, United States
| | - Edith Monteagudo
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, California 90045, United States
| | - Douglas Macdonald
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, California 90045, United States
| | - Nikolay V Plotnikov
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, California 90045, United States
| | - Mark Chambers
- Discovery from Charles River, Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, U.K
| | - George McAllister
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, California 90045, United States
| | - Ignacio Muňoz-Sanjuan
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, California 90045, United States
| | - Celia Dominguez
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, California 90045, United States
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14
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Campagne S, Jutzi D, Malard F, Matoga M, Romane K, Feldmuller M, Colombo M, Ruepp MD, Allain FHT. Molecular basis of RNA-binding and autoregulation by the cancer-associated splicing factor RBM39. Nat Commun 2023; 14:5366. [PMID: 37666821 PMCID: PMC10477243 DOI: 10.1038/s41467-023-40254-5] [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: 10/25/2022] [Accepted: 07/14/2023] [Indexed: 09/06/2023] Open
Abstract
Pharmacologic depletion of RNA-binding motif 39 (RBM39) using aryl sulfonamides represents a promising anti-cancer therapy but requires high levels of the adaptor protein DCAF15. Consequently, novel approaches to deplete RBM39 in an DCAF15-independent manner are required. Here, we uncover that RBM39 autoregulates via the inclusion of a poison exon into its own pre-mRNA and identify the cis-acting elements that govern this regulation. We also determine the NMR solution structures of RBM39's tandem RNA recognition motifs (RRM1 and RRM2) bound to their respective RNA targets, revealing how RRM1 recognises RNA stem loops whereas RRM2 binds specifically to single-stranded N(G/U)NUUUG. Our results support a model where RRM2 selects the 3'-splice site of a poison exon and the RRM3 and RS domain stabilise the U2 snRNP at the branchpoint. Our work provides molecular insights into RBM39-dependent 3'-splice site selection and constitutes a solid basis to design alternative anti-cancer therapies.
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Affiliation(s)
- Sébastien Campagne
- ETH Zurich, Department of Biology, Institute of Biochemistry, 8093, Zurich, Switzerland.
- University of Bordeaux, Inserm U1212, CNRS UMR5320, ARNA Laboratory, 33077, Bordeaux, France.
| | - Daniel Jutzi
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, SE5 9NU, UK
| | - Florian Malard
- ETH Zurich, Department of Biology, Institute of Biochemistry, 8093, Zurich, Switzerland
- University of Bordeaux, Inserm U1212, CNRS UMR5320, ARNA Laboratory, 33077, Bordeaux, France
| | - Maja Matoga
- ETH Zurich, Department of Biology, Institute of Biochemistry, 8093, Zurich, Switzerland
| | - Ksenija Romane
- ETH Zurich, Department of Biology, Institute of Biochemistry, 8093, Zurich, Switzerland
| | - Miki Feldmuller
- ETH Zurich, Department of Biology, Institute of Biochemistry, 8093, Zurich, Switzerland
| | - Martino Colombo
- University of Bern, Department of Chemistry and Biochemistry, 3012, Bern, Switzerland
- Celgene Institute of Translational Research in Europe (CITRE), Bristol Myers Squibb, 41092, Seville, Spain
| | - Marc-David Ruepp
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, SE5 9NU, UK.
| | - Frédéric H-T Allain
- ETH Zurich, Department of Biology, Institute of Biochemistry, 8093, Zurich, Switzerland.
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15
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McLean ZL, Gao D, Correia K, Roy JCL, Shibata S, Farnum IN, Valdepenas-Mellor Z, Rapuru M, Morini E, Ruliera J, Gillis T, Lucente D, Kleinstiver BP, Lee JM, MacDonald ME, Wheeler VC, Pinto RM, Gusella JF. PMS1 as a target for splice modulation to prevent somatic CAG repeat expansion in Huntington's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.25.550489. [PMID: 37547003 PMCID: PMC10402039 DOI: 10.1101/2023.07.25.550489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder whose motor, cognitive, and behavioral manifestations are caused by an expanded, somatically unstable CAG repeat in the first exon of HTT that lengthens a polyglutamine tract in huntingtin. Genome-wide association studies (GWAS) have revealed DNA repair genes that influence the age-at-onset of HD and implicate somatic CAG repeat expansion as the primary driver of disease timing. To prevent the consequent neuronal damage, small molecule splice modulators (e.g., branaplam) that target HTT to reduce the levels of huntingtin are being investigated as potential HD therapeutics. We found that the effectiveness of the splice modulators can be influenced by genetic variants, both at HTT and other genes where they promote pseudoexon inclusion. Surprisingly, in a novel hTERT-immortalized retinal pigment epithelial cell (RPE1) model for assessing CAG repeat instability, these drugs also reduced the rate of HTT CAG expansion. We determined that the splice modulators also affect the expression of the mismatch repair gene PMS1, a known modifier of HD age-at-onset. Genome editing at specific HTT and PMS1 sequences using CRISPR-Cas9 nuclease confirmed that branaplam suppresses CAG expansion by promoting the inclusion of a pseudoexon in PMS1, making splice modulation of PMS1 a potential strategy for delaying HD onset. Comparison with another splice modulator, risdiplam, suggests that other genes affected by these splice modulators also influence CAG instability and might provide additional therapeutic targets.
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Affiliation(s)
- Zachariah L. McLean
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
| | - Dadi Gao
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
| | - Kevin Correia
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Jennie C. L. Roy
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Shota Shibata
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
| | - Iris N. Farnum
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Zoe Valdepenas-Mellor
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Manasa Rapuru
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Elisabetta Morini
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Jayla Ruliera
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Tammy Gillis
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Diane Lucente
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Benjamin P. Kleinstiver
- Center for Genomic Medicine and Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Jong-Min Lee
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
| | - Marcy E. MacDonald
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
| | - Vanessa C. Wheeler
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Ricardo Mouro Pinto
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
| | - James F. Gusella
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
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16
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Khorkova O, Stahl J, Joji A, Volmar CH, Wahlestedt C. Amplifying gene expression with RNA-targeted therapeutics. Nat Rev Drug Discov 2023; 22:539-561. [PMID: 37253858 PMCID: PMC10227815 DOI: 10.1038/s41573-023-00704-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2023] [Indexed: 06/01/2023]
Abstract
Many diseases are caused by insufficient expression of mutated genes and would benefit from increased expression of the corresponding protein. However, in drug development, it has been historically easier to develop drugs with inhibitory or antagonistic effects. Protein replacement and gene therapy can achieve the goal of increased protein expression but have limitations. Recent discoveries of the extensive regulatory networks formed by non-coding RNAs offer alternative targets and strategies to amplify the production of a specific protein. In addition to RNA-targeting small molecules, new nucleic acid-based therapeutic modalities that allow highly specific modulation of RNA-based regulatory networks are being developed. Such approaches can directly target the stability of mRNAs or modulate non-coding RNA-mediated regulation of transcription and translation. This Review highlights emerging RNA-targeted therapeutics for gene activation, focusing on opportunities and challenges for translation to the clinic.
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Affiliation(s)
- Olga Khorkova
- OPKO Health, Miami, FL, USA
- Center for Therapeutic Innovation, University of Miami, Miami, FL, USA
| | - Jack Stahl
- Center for Therapeutic Innovation, University of Miami, Miami, FL, USA
- Department of Psychiatry and Behavioral Sciences, University of Miami, Miami, FL, USA
| | - Aswathy Joji
- Center for Therapeutic Innovation, University of Miami, Miami, FL, USA
- Department of Chemistry, University of Miami, Miami, FL, USA
| | - Claude-Henry Volmar
- Center for Therapeutic Innovation, University of Miami, Miami, FL, USA
- Department of Psychiatry and Behavioral Sciences, University of Miami, Miami, FL, USA
| | - Claes Wahlestedt
- Center for Therapeutic Innovation, University of Miami, Miami, FL, USA.
- Department of Psychiatry and Behavioral Sciences, University of Miami, Miami, FL, USA.
- Department of Chemistry, University of Miami, Miami, FL, USA.
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17
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Bragg RM, Coffey SR, Cantle JP, Hu S, Singh S, Legg SR, McHugh CA, Toor A, Zeitlin SO, Kwak S, Howland D, Vogt TF, Monga SP, Carroll JB. Huntingtin loss in hepatocytes is associated with altered metabolism, adhesion, and liver zonation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.24.546334. [PMID: 37425835 PMCID: PMC10327156 DOI: 10.1101/2023.06.24.546334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Huntington's disease arises from a toxic gain of function in the huntingtin ( HTT ) gene. As a result, many HTT-lowering therapies are being pursued in clinical studies, including those that reduce HTT RNA and protein expression in the liver. To investigate potential impacts, we characterized molecular, cellular, and metabolic impacts of chronic HTT lowering in mouse hepatocytes. Lifelong hepatocyte HTT loss is associated with multiple physiological changes, including increased circulating bile acids, cholesterol and urea, hypoglycemia, and impaired adhesion. HTT loss causes a clear shift in the normal zonal patterns of liver gene expression, such that pericentral gene expression is reduced. These alterations in liver zonation in livers lacking HTT are observed at the transcriptional, histological and plasma metabolite level. We have extended these phenotypes physiologically with a metabolic challenge of acetaminophen, for which the HTT loss results in toxicity resistance. Our data reveal an unexpected role for HTT in regulating hepatic zonation, and we find that loss of HTT in hepatocytes mimics the phenotypes caused by impaired hepatic β-catenin function.
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Affiliation(s)
- Robert M. Bragg
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham WA 98225
| | - Sydney R. Coffey
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham WA 98225
| | - Jeffrey P. Cantle
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham WA 98225
| | - Shikai Hu
- School of Medicine, Tsinghua University, Beijing, China
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Sucha Singh
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Samuel R.W. Legg
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham WA 98225
| | - Cassandra A. McHugh
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham WA 98225
| | - Amreen Toor
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham WA 98225
| | - Scott O. Zeitlin
- Department of Neuroscience, University of Virginia, Charlottesville, VA 22908
| | | | | | | | - Satdarshan P. Monga
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Pittsburgh Liver Research Center, University of Pittsburgh Medical Center and University of Pittsburgh School of Medicine, Pittsburgh, PA USA; Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Jeffrey B. Carroll
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham WA 98225
- Department of Neurology, University of Washington, Seattle, WA 98104-2499
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18
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19
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Lim WF, Rinaldi C. RNA Transcript Diversity in Neuromuscular Research. J Neuromuscul Dis 2023:JND221601. [PMID: 37182892 DOI: 10.3233/jnd-221601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Three decades since the Human Genome Project began, scientists have now identified more then 25,000 protein coding genes in the human genome. The vast majority of the protein coding genes (> 90%) are multi-exonic, with the coding DNA being interrupted by intronic sequences, which are removed from the pre-mRNA transcripts before being translated into proteins, a process called splicing maturation. Variations in this process, i.e. by exon skipping, intron retention, alternative 5' splice site (5'ss), 3' splice site (3'ss), or polyadenylation usage, lead to remarkable transcriptome and proteome diversity in human tissues. Given its critical biological importance, alternative splicing is tightly regulated in a tissue- and developmental stage-specific manner. The central nervous system and skeletal muscle are amongst the tissues with the highest number of differentially expressed alternative exons, revealing a remarkable degree of transcriptome complexity. It is therefore not surprising that splicing mis-regulation is causally associated with a myriad of neuromuscular diseases, including but not limited to amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), Duchenne muscular dystrophy (DMD), and myotonic dystrophy type 1 and 2 (DM1, DM2). A gene's transcript diversity has since become an integral and an important consideration for drug design, development and therapy. In this review, we will discuss transcript diversity in the context of neuromuscular diseases and current approaches to address splicing mis-regulation.
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Affiliation(s)
- Wooi Fang Lim
- Department of Paediatrics and Institute of Developmental and Regenerative Medicine, University of Oxford, Oxford, UK
| | - Carlo Rinaldi
- Department of Paediatrics and Institute of Developmental and Regenerative Medicine, University of Oxford, Oxford, UK
- MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford, UK
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20
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Garner AL. Contemporary Progress and Opportunities in RNA-Targeted Drug Discovery. ACS Med Chem Lett 2023; 14:251-259. [PMID: 36923915 PMCID: PMC10009794 DOI: 10.1021/acsmedchemlett.3c00020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 02/15/2023] [Indexed: 02/25/2023] Open
Abstract
The surprising discovery that RNAs are the predominant gene products to emerge from the human genome catalyzed a renaissance in RNA biology. It is now well-understood that RNAs act as more than just a messenger and comprise a large and diverse family of ribonucleic acids of differing sizes, structures, and functions. RNAs play expansive roles in the cell, contributing to the regulation and fine-tuning of nearly all aspects of gene expression and genome architecture. In line with the significance of these functions, we have witnessed an explosion in discoveries connecting RNAs with a variety of human diseases. Consequently, the targeting of RNAs, and more broadly RNA biology, has emerged as an untapped area of drug discovery, making the search for RNA-targeted therapeutics of great interest. In this Microperspective, I highlight contemporary learnings in the field and present my views on how to catapult us toward the systematic discovery of RNA-targeted medicines.
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Affiliation(s)
- Amanda L. Garner
- Department of Medicinal Chemistry,
College of Pharmacy, University of Michigan, 1600 Huron Parkway, NCRC B520, Ann Arbor, Michigan 48109, United States
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21
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Therapeutic targeting of Huntington's disease: Molecular and clinical approaches. Biochem Biophys Res Commun 2023; 655:18-24. [PMID: 36913762 DOI: 10.1016/j.bbrc.2023.02.075] [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: 01/16/2023] [Accepted: 02/26/2023] [Indexed: 03/09/2023]
Abstract
Huntington's disease (HD) is an autosomal dominant ailment that affects a larger population. Due to its complex pathology operating at DNA, RNA, and protein levels, it is regarded as a protein-misfolding disease and an expansion repeat disorder. Despite the availability of early genetic diagnostics, disease-modifying treatments are still missing. Importantly, potential therapies are starting to make their way through clinical trials. Still, clinical trials are ongoing to discover potential drugs to relieve HD symptoms. However, now being aware of the root cause, the clinical studies are focused on molecular therapies to target it. The road to success has not been without bumps since a big phase III trial of tominersen was unexpectedly discontinued due to exceeding risks than drug's benefit to the patients. Although the trial's conclusion was disappointing, there is still cause to be optimistic about what this technique may achieve. We have reviewed the present disease-modifying therapies in clinical development for HD and examined the current landscape of developing clinical therapies. We further investigated the pharmaceutical development of Huntington's medicine in the pharma industries and addressed the existing challenges in their therapeutic success.
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22
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Gangwani MR, Soto JS, Jami-Alahmadi Y, Tiwari S, Kawaguchi R, Wohlschlegel JA, Khakh BS. Neuronal and astrocytic contributions to Huntington's disease dissected with zinc finger protein transcriptional repressors. Cell Rep 2023; 42:111953. [PMID: 36640336 PMCID: PMC9898160 DOI: 10.1016/j.celrep.2022.111953] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 12/15/2022] [Accepted: 12/15/2022] [Indexed: 01/09/2023] Open
Abstract
Huntington's disease (HD) is caused by expanded CAG repeats in the huntingtin gene (HTT) resulting in expression of mutant HTT proteins (mHTT) with extended polyglutamine tracts, including in striatal neurons and astrocytes. It is unknown whether pathophysiology in vivo can be attenuated by lowering mHTT in either cell type throughout the brain, and the relative contributions of neurons and astrocytes to HD remain undefined. We use zinc finger protein (ZFP) transcriptional repressors to cell-selectively lower mHTT in vivo. Astrocytes display loss of essential functions such as cholesterol metabolism that are partly driven by greater neuronal dysfunctions, which encompass neuromodulation, synaptic, and intracellular signaling pathways. Using transcriptomics, proteomics, electrophysiology, and behavior, we dissect neuronal and astrocytic contributions to HD pathophysiology. Remarkably, brain-wide delivery of neuronal ZFPs results in strong mHTT lowering, rescue of HD-associated behavioral and molecular phenotypes, and significant extension of lifespan, findings that support translational development.
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Affiliation(s)
- Mohitkumar R. Gangwani
- Department of Physiology, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| | - Joselyn S. Soto
- Department of Physiology, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| | - Srushti Tiwari
- Department of Physiology, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| | - Riki Kawaguchi
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| | - James A. Wohlschlegel
- Department of Biological Chemistry, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| | - Baljit S. Khakh
- Department of Physiology, University of California Los Angeles. Los Angeles, CA 90095-1751, USA,Department of Neurobiology, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
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23
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Barraza SJ, Bhattacharyya A, Trotta CR, Woll MG. Targeting strategies for modulating pre-mRNA splicing with small molecules: Recent advances. Drug Discov Today 2023; 28:103431. [PMID: 36356786 DOI: 10.1016/j.drudis.2022.103431] [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: 08/03/2022] [Revised: 10/27/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022]
Abstract
The concept of using small molecules to therapeutically modulate pre-mRNA splicing was validated with the US Food and Drug Administration (FDA) approval of Evrysdi® (risdiplam) in 2020. Since then, efforts have continued unabated toward the discovery of new splicing-modulating drugs. However, the drug development world has evolved in the 10 years since risdiplam precursors were first identified in high-throughput screening (HTS). Now, new mechanistic insights into RNA-processing pathways and regulatory networks afford increasingly feasible targeted approaches. In this review, organized into classes of biological target, we compile and summarize small molecules discovered, devised, and developed since 2020 to alter pre-mRNA splicing.
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Affiliation(s)
- Scott J Barraza
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, USA.
| | | | | | - Matthew G Woll
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, USA
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24
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Ahamad S, Bhat SA. The Emerging Landscape of Small-Molecule Therapeutics for the Treatment of Huntington's Disease. J Med Chem 2022; 65:15993-16032. [PMID: 36490325 DOI: 10.1021/acs.jmedchem.2c00799] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a CAG repeat expansion in the huntingtin gene (HTT). The new insights into HD's cellular and molecular pathways have led to the identification of numerous potent small-molecule therapeutics for HD therapy. The field of HD-targeting small-molecule therapeutics is accelerating, and the approval of these therapeutics to combat HD may be expected in the near future. For instance, preclinical candidates such as naphthyridine-azaquinolone, AN1, AN2, CHDI-00484077, PRE084, EVP4593, and LOC14 have shown promise for further optimization to enter into HD clinical trials. This perspective aims to summarize the advent of small-molecule therapeutics at various stages of clinical development for HD therapy, emphasizing their structure and design, therapeutic effects, and specific mechanisms of action. Further, we have highlighted the key drivers involved in HD pathogenesis to provide insights into the basic principle for designing promising anti-HD therapeutic leads.
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Affiliation(s)
- Shakir Ahamad
- Department of Chemistry, Aligarh Muslim University, Aligarh, Uttar Pradesh202002, India
| | - Shahnawaz A Bhat
- Department of Zoology, Aligarh Muslim University, Aligarh, Uttar Pradesh202002, India
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25
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Estevez-Fraga C, Tabrizi SJ, Wild EJ. Huntington's Disease Clinical Trials Corner: November 2022. J Huntingtons Dis 2022; 11:351-367. [PMID: 36463457 DOI: 10.3233/jhd-229006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
In this edition of the Huntington's Disease Clinical Trials Corner, we expand on the PIVOT HD (PTC518), and SIGNAL (pepinemab) trials, and list all currently registered and ongoing clinical trials in Huntington's disease.We also introduce a 'breaking news' section highlighting recent updates about the SELECT HD, uniQure AMT-130, and VIBRANT HD clinical trials.
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Affiliation(s)
- Carlos Estevez-Fraga
- Huntington's Disease Centre, UCL Queen Square Institute of Neurology, London, UK
| | - Sarah J Tabrizi
- Huntington's Disease Centre, UCL Queen Square Institute of Neurology, London, UK
| | - Edward J Wild
- Huntington's Disease Centre, UCL Queen Square Institute of Neurology, London, UK
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26
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Bridging the Gap With Clinical Pharmacology in Innovative Rare Disease Treatment Modalities: Targeting DNA to RNA to Protein. J Clin Pharmacol 2022; 62 Suppl 2:S95-S109. [DOI: 10.1002/jcph.2172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 10/12/2022] [Indexed: 12/04/2022]
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27
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Wu J, Möhle L, Brüning T, Eiriz I, Rafehi M, Stefan K, Stefan SM, Pahnke J. A Novel Huntington's Disease Assessment Platform to Support Future Drug Discovery and Development. Int J Mol Sci 2022; 23:ijms232314763. [PMID: 36499090 PMCID: PMC9740291 DOI: 10.3390/ijms232314763] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
Huntington's disease (HD) is a lethal neurodegenerative disorder without efficient therapeutic options. The inefficient translation from preclinical and clinical research into clinical use is mainly attributed to the lack of (i) understanding of disease initiation, progression, and involved molecular mechanisms; (ii) knowledge of the possible HD target space and general data awareness; (iii) detailed characterizations of available disease models; (iv) better suitable models; and (v) reliable and sensitive biomarkers. To generate robust HD-like symptoms in a mouse model, the neomycin resistance cassette was excised from zQ175 mice, generating a new line: zQ175Δneo. We entirely describe the dynamics of behavioral, neuropathological, and immunohistological changes from 15-57 weeks of age. Specifically, zQ175Δneo mice showed early astrogliosis from 15 weeks; growth retardation, body weight loss, and anxiety-like behaviors from 29 weeks; motor deficits and reduced muscular strength from 36 weeks; and finally slight microgliosis at 57 weeks of age. Additionally, we collected the entire bioactivity network of small-molecule HD modulators in a multitarget dataset (HD_MDS). Hereby, we uncovered 358 unique compounds addressing over 80 different pharmacological targets and pathways. Our data will support future drug discovery approaches and may serve as useful assessment platform for drug discovery and development against HD.
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Affiliation(s)
- Jingyun Wu
- Department of Pathology, Section of Neuropathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo and Oslo University Hospital, Sognsvannsveien 20, 0372 Oslo, Norway; www.pahnkelab.eu
| | - Luisa Möhle
- Department of Pathology, Section of Neuropathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo and Oslo University Hospital, Sognsvannsveien 20, 0372 Oslo, Norway; www.pahnkelab.eu
| | - Thomas Brüning
- Department of Pathology, Section of Neuropathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo and Oslo University Hospital, Sognsvannsveien 20, 0372 Oslo, Norway; www.pahnkelab.eu
| | - Iván Eiriz
- Department of Pathology, Section of Neuropathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo and Oslo University Hospital, Sognsvannsveien 20, 0372 Oslo, Norway; www.pahnkelab.eu
| | - Muhammad Rafehi
- Institute of Clinical Pharmacology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Katja Stefan
- Department of Pathology, Section of Neuropathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo and Oslo University Hospital, Sognsvannsveien 20, 0372 Oslo, Norway; www.pahnkelab.eu
| | - Sven Marcel Stefan
- Department of Pathology, Section of Neuropathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo and Oslo University Hospital, Sognsvannsveien 20, 0372 Oslo, Norway; www.pahnkelab.eu
- Pahnke Lab (Drug Development and Chemical Biology), Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck and University Medical Center Schleswig-Holstein, Ratzeburger Allee 160, 23538 Lübeck, Germany
- Correspondence: (J.P.); (S.M.S.); Tel.: +47-23-071-466 (J.P.)
| | - Jens Pahnke
- Department of Pathology, Section of Neuropathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo and Oslo University Hospital, Sognsvannsveien 20, 0372 Oslo, Norway; www.pahnkelab.eu
- Pahnke Lab (Drug Development and Chemical Biology), Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck and University Medical Center Schleswig-Holstein, Ratzeburger Allee 160, 23538 Lübeck, Germany
- Department of Pharmacology, Faculty of Medicine, University of Latvia, Jelgavas iela 4, 1004 Rīga, Latvia
- Department of Neurobiology, The Georg S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Correspondence: (J.P.); (S.M.S.); Tel.: +47-23-071-466 (J.P.)
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28
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Palacios DS. Drug Hunting at the Nexus of Medicinal Chemistry and Chemical Biology and the Discovery of Novel Therapeutic Modalities. J Med Chem 2022; 65:13594-13613. [PMID: 36206538 DOI: 10.1021/acs.jmedchem.2c01491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Small molecules designed to modulate protein function have been remarkably successful in advancing human health. As the frontiers of medicine and understanding of disease pathogenesis continue to expand, small molecule scientists must also pursue the development of novel therapeutic modalities beyond functional protein modulation to address diseases of unmet medical need. In this vein, this Perspective will highlight two emerging modalities, selective mRNA splice modulation and targeted protein degradation, as mechanisms that affect protein abundance, rather than protein function, to broaden the scope of low-molecular-weight treatable diseases. Key to the elucidation and development of these mechanisms was the interplay and contemporaneous efforts in medicinal chemistry and chemical biology. Continued research at the intersection of these two fields will be critical for the identification of novel targets and mechanisms toward the development of the next generation of small molecule therapeutics.
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Affiliation(s)
- Daniel S Palacios
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
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29
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van der Bent ML, Evers MM, Vallès A. Emerging Therapies for Huntington's Disease - Focus on N-Terminal Huntingtin and Huntingtin Exon 1. Biologics 2022; 16:141-160. [PMID: 36213816 PMCID: PMC9532260 DOI: 10.2147/btt.s270657] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 09/14/2022] [Indexed: 11/12/2022]
Abstract
Huntington's disease is a devastating heritable neurodegenerative disorder that is caused by the presence of a trinucleotide CAG repeat expansion in the Huntingtin gene, leading to a polyglutamine tract in the protein. Various mechanisms lead to the production of N-terminal Huntingtin protein fragments, which are reportedly more toxic than the full-length protein. In this review, we summarize the current knowledge on the production and toxicity of N-terminal Huntingtin protein fragments. Further, we expand on various therapeutic strategies targeting N-terminal Huntingtin on the protein, RNA and DNA level. Finally, we compare the therapeutic approaches that are clinically most advanced, including those that do not target N-terminal Huntingtin, discussing differences in mode of action and translational applicability.
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Affiliation(s)
| | - Melvin M Evers
- uniQure biopharma B.V., Department of Research and Development, Amsterdam, the Netherlands
| | - Astrid Vallès
- uniQure biopharma B.V., Department of Research and Development, Amsterdam, the Netherlands
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30
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White A, McGlone A, Gomez-Pastor R. Protein Kinase CK2 and Its Potential Role as a Therapeutic Target in Huntington's Disease. Biomedicines 2022; 10:1979. [PMID: 36009526 PMCID: PMC9406209 DOI: 10.3390/biomedicines10081979] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 11/17/2022] Open
Abstract
Huntington's Disease (HD) is a devastating neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the HTT gene, for which no disease modifying therapies are currently available. Much of the recent research has focused on developing therapies to directly lower HTT expression, and while promising, these therapies have presented several challenges regarding administration and efficacy. Another promising therapeutic approach is the modulation of HTT post-translational modifications (PTMs) that are dysregulated in disease and have shown to play a key role in HTT toxicity. Among all PTMs, modulation of HTT phosphorylation has been proposed as an attractive therapeutic option due to the possibility of orally administering specific kinase effectors. One of the kinases described to participate in HTT phosphorylation is Protein Kinase CK2. CK2 has recently emerged as a target for the treatment of several neurological and psychiatric disorders, although its role in HD remains controversial. While pharmacological studies in vitro inhibiting CK2 resulted in reduced HTT phosphorylation and increased toxicity, genetic approaches in mouse models of HD have provided beneficial effects. In this review we discuss potential therapeutic approaches related to the manipulation of HTT-PTMs with special emphasis on the role of CK2 as a therapeutic target in HD.
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Affiliation(s)
| | | | - Rocio Gomez-Pastor
- Department of Neuroscience, School of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
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31
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Wang W, He S, Dong G, Sheng C. Nucleic-Acid-Based Targeted Degradation in Drug Discovery. J Med Chem 2022; 65:10217-10232. [PMID: 35916496 DOI: 10.1021/acs.jmedchem.2c00875] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Targeted protein degradation (TPD), represented by proteolysis-targeting chimera (PROTAC), has emerged as a novel therapeutic modality in drug discovery. However, the application of conventional PROTACs is limited to protein targets containing cytosolic domains with ligandable sites. Recently, nucleic-acid-based modalities, such as modified oligonucleotide mimics and aptamers, opened new avenues to degrade protein targets and greatly expanded the scope of TPD. Beyond constructing protein-degrading chimeras, nucleic acid motifs can also serve as substrates for targeted degradation. Particularly, the new type of chimeric RNA degrader termed ribonuclease-targeting chimera (RIBOTAC) has shown promising features in drug discovery. Here, we provide an overview of the newly emerging TPD strategies based on nucleic acids as well as new strategies for targeted degradation of nucleic acid (RNA) targets. The design strategies, case studies, potential applications, and challenges are focused on.
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Affiliation(s)
- Wei Wang
- School of Pharmacy, Second Military Medical University, Shanghai 200433, China
| | - Shipeng He
- Institute of Translational Medicine, Shanghai University, Shanghai 200444, China
| | - Guoqiang Dong
- School of Pharmacy, Second Military Medical University, Shanghai 200433, China
| | - Chunquan Sheng
- School of Pharmacy, Second Military Medical University, Shanghai 200433, China
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Tabrizi SJ, Estevez-Fraga C, van Roon-Mom WMC, Flower MD, Scahill RI, Wild EJ, Muñoz-Sanjuan I, Sampaio C, Rosser AE, Leavitt BR. Potential disease-modifying therapies for Huntington's disease: lessons learned and future opportunities. Lancet Neurol 2022; 21:645-658. [PMID: 35716694 PMCID: PMC7613206 DOI: 10.1016/s1474-4422(22)00121-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 02/18/2022] [Accepted: 03/04/2022] [Indexed: 01/03/2023]
Abstract
Huntington's disease is the most frequent autosomal dominant neurodegenerative disorder; however, no disease-modifying interventions are available for patients with this disease. The molecular pathogenesis of Huntington's disease is complex, with toxicity that arises from full-length expanded huntingtin and N-terminal fragments of huntingtin, which are both prone to misfolding due to proteolysis; aberrant intron-1 splicing of the HTT gene; and somatic expansion of the CAG repeat in the HTT gene. Potential interventions for Huntington's disease include therapies targeting huntingtin DNA and RNA, clearance of huntingtin protein, DNA repair pathways, and other treatment strategies targeting inflammation and cell replacement. The early termination of trials of the antisense oligonucleotide tominersen suggest that it is time to reflect on lessons learned, where the field stands now, and the challenges and opportunities for the future.
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Affiliation(s)
- Sarah J Tabrizi
- Huntington's Disease Centre, UCL Queen Square Institute of Neurology, University College London, London, UK.
| | - Carlos Estevez-Fraga
- Huntington's Disease Centre, UCL Queen Square Institute of Neurology, University College London, London, UK
| | | | - Michael D Flower
- Huntington's Disease Centre, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Rachael I Scahill
- Huntington's Disease Centre, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Edward J Wild
- Huntington's Disease Centre, UCL Queen Square Institute of Neurology, University College London, London, UK
| | | | - Cristina Sampaio
- CHDI Management, CHDI Foundation Los Angeles, CA, USA; Laboratory of Clinical Pharmacology, Faculdade de Medicina de Lisboa, Lisbon, Portugal
| | - Anne E Rosser
- BRAIN unit, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Blair R Leavitt
- Centre for Huntington's disease, University of British Columbia, Vancouver, BC, Canada
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Estevez-Fraga C, Rodrigues FB, Tabrizi SJ, Wild EJ. Huntington's Disease Clinical Trials Corner: April 2022. J Huntingtons Dis 2022; 11:105-118. [PMID: 35570498 DOI: 10.3233/jhd-229002] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In this edition of the Huntington's Disease Clinical Trials Corner we expand on GENERATION HD1, PRECISION-HD1 and PRECISION-HD2, SELECT-HD, and VIBRANT-HD trials, and list all currently registered and ongoing clinical trials in Huntington's disease.
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Affiliation(s)
- Carlos Estevez-Fraga
- Huntington's Disease Centre, UCL Queen Square Institute of Neurology, London, UK
| | - Filipe B Rodrigues
- Huntington's Disease Centre, UCL Queen Square Institute of Neurology, London, UK.,Laboratory of Clinical Pharmacology and Therapeutics, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Instituto de Medicina Molecular, Lisbon, Portugal
| | - Sarah J Tabrizi
- Huntington's Disease Centre, UCL Queen Square Institute of Neurology, London, UK
| | - Edward J Wild
- Huntington's Disease Centre, UCL Queen Square Institute of Neurology, London, UK
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Gu X, Richman J, Langfelder P, Wang N, Zhang S, Bañez-Coronel M, Wang HB, Yang L, Ramanathan L, Deng L, Park CS, Choi CR, Cantle JP, Gao F, Gray M, Coppola G, Bates GP, Ranum LPW, Horvath S, Colwell CS, Yang XW. Uninterrupted CAG repeat drives striatum-selective transcriptionopathy and nuclear pathogenesis in human Huntingtin BAC mice. Neuron 2022; 110:1173-1192.e7. [PMID: 35114102 PMCID: PMC9462388 DOI: 10.1016/j.neuron.2022.01.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 10/30/2021] [Accepted: 01/06/2022] [Indexed: 02/08/2023]
Abstract
In Huntington's disease (HD), the uninterrupted CAG repeat length, but not the polyglutamine length, predicts disease onset. However, the underlying pathobiology remains unclear. Here, we developed bacterial artificial chromosome (BAC) transgenic mice expressing human mutant huntingtin (mHTT) with uninterrupted, and somatically unstable, CAG repeats that exhibit progressive disease-related phenotypes. Unlike prior mHTT transgenic models with stable, CAA-interrupted, polyglutamine-encoding repeats, BAC-CAG mice show robust striatum-selective nuclear inclusions and transcriptional dysregulation resembling those in murine huntingtin knockin models and HD patients. Importantly, the striatal transcriptionopathy in HD models is significantly correlated with their uninterrupted CAG repeat length but not polyglutamine length. Finally, among the pathogenic entities originating from mHTT genomic transgenes and only present or enriched in the uninterrupted CAG repeat model, somatic CAG repeat instability and nuclear mHTT aggregation are best correlated with early-onset striatum-selective molecular pathogenesis and locomotor and sleep deficits, while repeat RNA-associated pathologies and repeat-associated non-AUG (RAN) translation may play less selective or late pathogenic roles, respectively.
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Affiliation(s)
- Xiaofeng Gu
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jeffrey Richman
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Peter Langfelder
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Nan Wang
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Shasha Zhang
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Monica Bañez-Coronel
- Center for Neurogenetics, Department of Molecular Genetics and Microbiology, College of Medicine, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute of Neurological Diseases, University of Florida, Gainesville, FL, USA
| | - Huei-Bin Wang
- Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Lucia Yang
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Lalini Ramanathan
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Linna Deng
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Chang Sin Park
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Christopher R Choi
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jeffrey P Cantle
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Fuying Gao
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Michelle Gray
- Department of Neurology and Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Giovanni Coppola
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Gillian P Bates
- Huntington's Disease Centre, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Laura P W Ranum
- Center for Neurogenetics, Department of Molecular Genetics and Microbiology, College of Medicine, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute of Neurological Diseases, University of Florida, Gainesville, FL, USA
| | - Steve Horvath
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Christopher S Colwell
- Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - X William Yang
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
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Reprogramming RNA processing: an emerging therapeutic landscape. Trends Pharmacol Sci 2022; 43:437-454. [PMID: 35331569 DOI: 10.1016/j.tips.2022.02.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 12/13/2022]
Abstract
The production of a mature mRNA requires coordination of multiple processing steps, which ultimately control its content, localization, and stability. These steps include some of the largest macromolecular machines in the cell, which were, until recently, considered undruggable due to their biological complexity. Building from an expanded understanding of the underlying mechanisms that drive these processes, a new wave of therapeutics is seeking to target RNA processing. With a focus on impacting gene regulation at the RNA level, such modalities offer potential for sequence-specific resolution in drug design. Here, we review our current understanding of RNA-processing events and their role in gene regulation, with a focus on the therapeutic opportunities that have emerged within this landscape.
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Tang Z, Hegde S, Zhao J, Zhu S, Johnson KA, Lorson CL, Wang J. CRISPR-mediated Enzyme Fragment Complementation Assay for Quantification of the Stability of Splice Isoforms. Chembiochem 2022; 23:e202200012. [PMID: 35235240 DOI: 10.1002/cbic.202200012] [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: 01/05/2022] [Revised: 02/22/2022] [Indexed: 11/06/2022]
Abstract
Small-molecule splicing modulators exemplified by an FDA-approved drug, risdiplam, are a new pharmacological modality for regulating the expression and stability of splice isoforms. We report a CRISPR-mediated enzyme fragment complementation (EFC) assay to quantify the splice isoform stability. The EFC assay harnessed a 42 amino acid split of a β-galactosidase (designate α-tag), which could be fused at the termini of the target genes using CRISPR/cas9. The α-tagged splice isoform would be quantified by measuring the enzymatic activity upon complementation with the rest of β-galactosidase. This EFC assay retained all the sequences of introns and exons of the target gene in the native genomic environment that recapitulates the cell biology of the diseases of interest. For a proof-of-concept, we developed a CRISPR-mediated EFC assay targeting the exon 7 of the survival of motor neuron 2 (SMN2) gene. The EFC assay compatible with 384-well plates robustly quantified the splicing modulation activity of small molecules. In this study, we also discovered that a coumarin derivative, compound 4, potently modulate SMN2 splicing at as low as 1.1 nM.
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Affiliation(s)
- Zhichao Tang
- University of Kansas School of Pharmacy, Medicinal Chemistry, UNITED STATES
| | - Shalakha Hegde
- University of Kansas School of Pharmacy, Medicinal Chemistry, UNITED STATES
| | - Junxing Zhao
- University of Kansas School of Pharmacy, Medicinal Chemistry, UNITED STATES
| | - Shoutian Zhu
- PhenoTarget BioSciences, Inc., Biology, UNITED STATES
| | | | | | - Jingxin Wang
- University of Kansas, Medicinal Chemistry, 2034 Becker Dr, 1050, 66047, Lawrence, UNITED STATES
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37
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Huynh KW, Pamenter ME. Lactate inhibits naked mole-rat cardiac mitochondrial respiration. J Comp Physiol B 2022; 192:501-511. [PMID: 35181821 DOI: 10.1007/s00360-022-01430-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 01/13/2022] [Accepted: 01/29/2022] [Indexed: 12/25/2022]
Abstract
In aerobic conditions, the proton-motive force drives oxidative phosphorylation (OXPHOS) and the conversion of ADP to ATP. In hypoxic environments, OXPHOS is impaired, resulting in energy shortfalls and the accumulation of protons and lactate. This results in cellular acidification, which may impact the activity and/or integrity of mitochondrial enzymes and in turn negatively impact mitochondrial respiration and thus aerobic ATP production. Naked mole-rats (NMRs) are among the most hypoxia-tolerant mammals and putatively experience intermittent hypoxia in their underground burrows. However, if and how NMR cardiac mitochondria are impacted by lactate accumulation in hypoxia is unknown. We predicted that lactate alters mitochondrial respiration in NMR cardiac muscle. To test this, we used high-resolution respirometry to measure mitochondrial respiration in permeabilized cardiac muscle fibres from NMRs exposed to 4 h of in vivo normoxia (21% O2) or hypoxia (7% O2). We found that: (1) cardiac mitochondria cannot directly oxidize lactate, but surprisingly, (2) lactate inhibits mitochondrial respiration, and (3) decreases complex IV maximum respiratory capacity. Finally, (4) in vivo hypoxic exposure decreases the magnitude of lactate-mediated inhibition of mitochondrial respiration. Taken together, our results suggest that lactate may retard electron transport system function in NMR cardiac mitochondria, particularly in normoxia, and that NMR hearts may be primed for anaerobic metabolism.
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Affiliation(s)
- Kenny W Huynh
- Department of Biology, University of Ottawa, 30 Marie Curie Pvt., Ottawa, ON, K1N 6N5, Canada
| | - Matthew E Pamenter
- Department of Biology, University of Ottawa, 30 Marie Curie Pvt., Ottawa, ON, K1N 6N5, Canada. .,University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada.
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38
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Abstract
In Eukarya, immature mRNA transcripts (pre-mRNA) often contain coding sequences, or exons, interleaved by non-coding sequences, or introns. Introns are removed upon splicing, and further regulation of the retained exons leads to alternatively spliced mRNA. The splicing reaction requires the stepwise assembly of the spliceosome, a macromolecular machine composed of small nuclear ribonucleoproteins (snRNPs). This review focuses on the early stage of spliceosome assembly, when U1 snRNP defines each intron 5’-splice site (5ʹss) in the pre-mRNA. We first introduce the splicing reaction and the impact of alternative splicing on gene expression regulation. Thereafter, we extensively discuss splicing descriptors that influence the 5ʹss selection by U1 snRNP, such as sequence determinants, and interactions mediated by U1-specific proteins or U1 small nuclear RNA (U1 snRNA). We also include examples of diseases that affect the 5ʹss selection by U1 snRNP, and discuss recent therapeutic advances that manipulate U1 snRNP 5ʹss selectivity with antisense oligonucleotides and small-molecule splicing switches.
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Affiliation(s)
- Florian Malard
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux, Bordeaux Cedex, France
| | - Cameron D Mackereth
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux, Bordeaux Cedex, France
| | - Sébastien Campagne
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux, Bordeaux Cedex, France
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