1
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Fair B, Buen Abad Najar CF, Zhao J, Lozano S, Reilly A, Mossian G, Staley JP, Wang J, Li YI. Global impact of unproductive splicing on human gene expression. Nat Genet 2024:10.1038/s41588-024-01872-x. [PMID: 39223315 DOI: 10.1038/s41588-024-01872-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 07/16/2024] [Indexed: 09/04/2024]
Abstract
Alternative splicing (AS) in human genes is widely viewed as a mechanism for enhancing proteomic diversity. AS can also impact gene expression levels without increasing protein diversity by producing 'unproductive' transcripts that are targeted for rapid degradation by nonsense-mediated decay (NMD). However, the relative importance of this regulatory mechanism remains underexplored. To better understand the impact of AS-NMD relative to other regulatory mechanisms, we analyzed population-scale genomic data across eight molecular assays, covering various stages from transcription to cytoplasmic decay. We report threefold more unproductive splicing compared with prior estimates using steady-state RNA. This unproductive splicing compounds across multi-intronic genes, resulting in 15% of transcript molecules from protein-coding genes being unproductive. Leveraging genetic variation across cell lines, we find that GWAS trait-associated loci explained by AS are as often associated with NMD-induced expression level differences as with differences in protein isoform usage. Our findings suggest that much of the impact of AS is mediated by NMD-induced changes in gene expression 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, USA
| | | | - Junxing Zhao
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, USA
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL, USA
| | - Stephanie Lozano
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL, USA
- Center for Neuroscience, University of California Davis, Davis, CA, USA
| | - Austin Reilly
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL, USA
| | - Gabriela Mossian
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL, USA
| | - Jonathan P Staley
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
| | - Jingxin Wang
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, USA
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL, USA
| | - Yang I Li
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL, USA.
- Department of Human Genetics, University of Chicago, Chicago, IL, USA.
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2
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Herrero-Vicente J, Black DL, Valcárcel J. Splice-modifying drug mechanisms. Nat Chem Biol 2024; 20:1103-1105. [PMID: 39060391 DOI: 10.1038/s41589-024-01678-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Affiliation(s)
- Jorge Herrero-Vicente
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Douglas L Black
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, USA
| | - Juan Valcárcel
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.
- Universitat Pompeu Fabra (UPF), Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
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3
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Chi Y, Lu X, Li S, Wang J, Xi J, Zhou X, Tang C, Chen M, Yuan H, Lin S, Xiao Y, Lai L, Zou Q. A compact, versatile drug-induced splicing switch system with minimal background expression. CELL REPORTS METHODS 2024:100842. [PMID: 39236714 DOI: 10.1016/j.crmeth.2024.100842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 07/01/2024] [Accepted: 08/06/2024] [Indexed: 09/07/2024]
Abstract
Gene-switch techniques hold promising applications in contemporary genetics research, particularly in disease treatment and genetic engineering. Here, we developed a compact drug-induced splicing system that maintains low background using a human ubiquitin C (hUBC) promoter and optimized drug (LMI070) binding sequences based on the Xon switch system. To ensure precise subcellular localization of the protein of interest (POI), we inserted a 2A self-cleaving peptide between the extra N-terminal peptide and POI. This streamlined and optimized switch system, named miniXon2G, effectively regulated POIs in different subcellular localizations both in vitro and in vivo. Furthermore, miniXon2G could be integrated into endogenous gene loci, resulting in precise, reversible regulation of target genes by both endogenous regulators and drugs. Overall, these findings highlight the performance of miniXon2G in controlling protein expression with great potential for general applicability to diverse biological scenarios requiring precise and delicate regulation.
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Affiliation(s)
- Yue Chi
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China
| | - Xuan Lu
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China
| | - Shuangpeng Li
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China
| | - Jinling Wang
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China
| | - Jiahui Xi
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China
| | - Xiaoqing Zhou
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China
| | - Chengcheng Tang
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China
| | - Min Chen
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China
| | - Hui Yuan
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China
| | - Shuo Lin
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China
| | - Yingying Xiao
- Jiangmen Wuyi Traditional Chinese Medicine Hospital, Jiangmen 529000, China
| | - Liangxue Lai
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China; CAS Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.
| | - Qingjian Zou
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China.
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4
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Rot G, Wehling A, Schmucki R, Berntenis N, Zhang JD, Ebeling M. splicekit: an integrative toolkit for splicing analysis from short-read RNA-seq. BIOINFORMATICS ADVANCES 2024; 4:vbae121. [PMID: 39219843 PMCID: PMC11364168 DOI: 10.1093/bioadv/vbae121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 07/16/2024] [Accepted: 08/16/2024] [Indexed: 09/04/2024]
Abstract
Motivation Analysis of alternative splicing using short-read RNA-seq data is a complex process that involves several steps: alignment of reads to the reference genome, identification of alternatively spliced features, motif discovery, analysis of RNA-protein binding near donor and acceptor splice sites, and exploratory data visualization. To the best of our knowledge, there is currently no integrative open-source software dedicated to this task. Results Here, we introduce splicekit, a Python package that provides and integrates a set of existing and novel splicing analysis tools for conducting splicing analysis. Availability and implementation The software splicekit is open-source and available at Github (https://github.com/bedapub/splicekit) and via the Python Package Index.
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Affiliation(s)
- Gregor Rot
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Arne Wehling
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Roland Schmucki
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Nikolaos Berntenis
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Jitao David Zhang
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Martin Ebeling
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
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5
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Gentile JE, Corridon TL, Mortberg MA, D'Souza EN, Whiffin N, Minikel EV, Vallabh SM. Modulation of prion protein expression through cryptic splice site manipulation. J Biol Chem 2024; 300:107560. [PMID: 39002681 PMCID: PMC11342779 DOI: 10.1016/j.jbc.2024.107560] [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: 01/04/2024] [Revised: 06/15/2024] [Accepted: 07/05/2024] [Indexed: 07/15/2024] Open
Abstract
Lowering expression of prion protein (PrP) is a well-validated therapeutic strategy in prion disease, but additional modalities are urgently needed. In other diseases, small molecules have proven capable of modulating pre-mRNA splicing, sometimes by forcing inclusion of cryptic exons that reduce gene expression. Here, we characterize a cryptic exon located in human PRNP's sole intron and evaluate its potential to reduce PrP expression through incorporation into the 5' untranslated region. This exon is homologous to exon 2 in nonprimate species but contains a start codon that would yield an upstream open reading frame with a stop codon prior to a splice site if included in PRNP mRNA, potentially downregulating PrP expression through translational repression or nonsense-mediated decay. We establish a minigene transfection system and test a panel of splice site alterations, identifying mutants that reduce PrP expression by as much as 78%. Our findings nominate a new therapeutic target for lowering PrP.
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Affiliation(s)
- Juliana E Gentile
- McCance Center for Brain Health and Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Taylor L Corridon
- McCance Center for Brain Health and Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Meredith A Mortberg
- McCance Center for Brain Health and Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Elston Neil D'Souza
- Big Data Institute and Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Nicola Whiffin
- Big Data Institute and Centre for Human Genetics, University of Oxford, Oxford, UK; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Eric Vallabh Minikel
- McCance Center for Brain Health and Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Sonia M Vallabh
- McCance Center for Brain Health and Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA.
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6
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Zhang X. Splice-switching antisense oligonucleotides for pediatric neurological disorders. Front Mol Neurosci 2024; 17:1412964. [PMID: 39119251 PMCID: PMC11306167 DOI: 10.3389/fnmol.2024.1412964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Accepted: 07/12/2024] [Indexed: 08/10/2024] Open
Abstract
Pediatric neurological disorders are frequently devastating and present unmet needs for effective medicine. The successful treatment of spinal muscular atrophy with splice-switching antisense oligonucleotides (SSO) indicates a feasible path to targeting neurological disorders by redirecting pre-mRNA splicing. One direct outcome is the development of SSOs to treat haploinsufficient disorders by targeting naturally occurring non-productive splice isoforms. The development of personalized SSO treatment further inspired the therapeutic exploration of rare diseases. This review will discuss the recent advances that utilize SSOs to treat pediatric neurological disorders.
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Affiliation(s)
- Xiaochang Zhang
- Department of Human Genetics, The Neuroscience Institute, University of Chicago, Chicago, IL, United States
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7
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Mohsen M, Midy MK, Balaji A, Breaker RR. Engineered Branaplam Aptamers Exploit Structural Elements from Natural Riboswitches. ACS Chem Biol 2024; 19:1447-1452. [PMID: 38954594 PMCID: PMC11267568 DOI: 10.1021/acschembio.4c00358] [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: 05/23/2024] [Revised: 06/05/2024] [Accepted: 06/13/2024] [Indexed: 07/04/2024]
Abstract
Drug candidates that fail in clinical trials for efficacy reasons might still have favorable safety and bioavailability characteristics that could be exploited. A failed drug candidate could be repurposed if a receptor, such as an aptamer, were created that binds the compound with high specificity. Branaplam is a small molecule that was previously in development to treat spinal muscular atrophy and Huntington's disease. Here, we report the development of a small (48-nucleotide) RNA aptamer for branaplam with a dissociation constant of ∼150 nM. Starting with a combinatorial RNA pool integrating the secondary and tertiary structural scaffold of a Guanine-I riboswitch aptamer interspersed with regions of random sequence, in vitro selection yielded aptamer candidates for branaplam. Reselection and rational design were employed to improve binding of a representative branaplam aptamer candidate. A resulting variant retains the pseudoknot and two of the paired elements (P2 and P3) from the scaffold but lacks the enclosing paired element (P1) that is essential for the function of the natural Guanine-I riboswitch aptamer. A second combinatorial RNA pool based on the scaffold for TPP (thiamin pyrophosphate) riboswitches also yielded a candidate offering additional opportunities for branaplam aptamer development.
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Affiliation(s)
- Michael
G. Mohsen
- Department
of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06511, United States
- Howard
Hughes Medical Institute, Yale University, New Haven, Connecticut 06511, United States
| | - Matthew K. Midy
- Department
of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, United States
| | - Aparaajita Balaji
- Department
of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06511, United States
| | - Ronald R. Breaker
- Department
of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06511, United States
- Department
of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, United States
- Howard
Hughes Medical Institute, Yale University, New Haven, Connecticut 06511, United States
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8
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Shimo T, Ueda O, Yamamoto S. Design and evaluation of antisense sequence length for modified mouse U7 small nuclear RNA to induce efficient pre-messenger RNA splicing modulation in vitro. PLoS One 2024; 19:e0305012. [PMID: 38980892 PMCID: PMC11232981 DOI: 10.1371/journal.pone.0305012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 05/21/2024] [Indexed: 07/11/2024] Open
Abstract
Pre-messenger RNA (pre-mRNA) splicing modulation is an attractive approach for investigating the mechanisms of genetic disorders caused by mis-splicing. Previous reports have indicated that a modified U7 small nuclear RNA (U7 snRNA) is a prospective tool for modulating splicing both in vitro and in vivo. To date, very few studies have investigated the role of antisense sequence length in modified U7 snRNA. In this study, we designed a series of antisense sequences with various lengths and evaluated their efficiency in inducing splicing modulation. To express modified U7 snRNAs, we constructed a series of plasmid DNA sequences which codes cytomegalovirus (CMV) enhancer, human U1 promoter, and modified mouse U7 snRNAs with antisense sequences of different lengths. We evaluated in vitro splicing modulation efficiency using a luciferase reporter system for simple and precise evaluation as well as reverse transcription-polymerase chain reaction to monitor splicing patterns. Our in vitro assay findings suggest that antisense sequences of modified mouse U7 snRNAs have an optimal length for efficient splicing modulation, which depends on the target exon. In addition, antisense sequences that were either too long or too short decreased splicing modulation efficiency. To confirm reproducibility, we performed an in vitro assay using two target genes, mouse Fas and mouse Dmd. Together, our data suggests that the antisense sequence length should be optimized for modified mouse U7 snRNAs to induce efficient splicing modulation.
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Affiliation(s)
- Takenori Shimo
- Research Division, Chugai Pharmaceutical Co., Ltd., Yokohama, Kanagawa, Japan
| | - Otoya Ueda
- Research Division, Chugai Pharmaceutical Co., Ltd., Yokohama, Kanagawa, Japan
| | - Satoshi Yamamoto
- Research Division, Chugai Pharmaceutical Co., Ltd., Yokohama, Kanagawa, Japan
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9
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Simon CM, Delestree N, Montes J, Gerstner F, Carranza E, Sowoidnich L, Buettner JM, Pagiazitis JG, Prat-Ortega G, Ensel S, Donadio S, Garcia JL, Kratimenos P, Chung WK, Sumner CJ, Weimer LH, Pirondini E, Capogrosso M, Pellizzoni L, De Vivo DC, Mentis GZ. Dysfunction of proprioceptive sensory synapses is a pathogenic event and therapeutic target in mice and humans with spinal muscular atrophy. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.06.03.24308132. [PMID: 38883729 PMCID: PMC11177917 DOI: 10.1101/2024.06.03.24308132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by a varying degree of severity that correlates with the reduction of SMN protein levels. Motor neuron degeneration and skeletal muscle atrophy are hallmarks of SMA, but it is unknown whether other mechanisms contribute to the spectrum of clinical phenotypes. Here, through a combination of physiological and morphological studies in mouse models and SMA patients, we identify dysfunction and loss of proprioceptive sensory synapses as key signatures of SMA pathology. We demonstrate that SMA patients exhibit impaired proprioception, and their proprioceptive sensory synapses are dysfunctional as measured by the neurophysiological test of the Hoffmann reflex (H-reflex). We further show that loss of excitatory afferent synapses and altered potassium channel expression in SMA motor neurons are conserved pathogenic events found in both severely affected patients and mouse models. Lastly, we report that improved motor function and fatigability in ambulatory SMA patients and mouse models treated with SMN-inducing drugs correlate with increased function of sensory-motor circuits that can be accurately captured by the H-reflex assay. Thus, sensory synaptic dysfunction is a clinically relevant event in SMA, and the H-reflex is a suitable assay to monitor disease progression and treatment efficacy of motor circuit pathology.
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Affiliation(s)
- CM Simon
- Center for Motor Neuron Biology and Disease, Columbia University, NY, USA
- Dept. of Neurology, Columbia University, NY, USA
- Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany
| | - N Delestree
- Center for Motor Neuron Biology and Disease, Columbia University, NY, USA
- Dept. of Neurology, Columbia University, NY, USA
| | - J Montes
- Center for Motor Neuron Biology and Disease, Columbia University, NY, USA
- Dept. of Rehabilitation and Regenerative Medicine, Columbia University, NY, USA
| | - F Gerstner
- Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany
| | - E Carranza
- Depts. Physical Medicine & Rehabilitation & Bioengineering, University of Pittsburgh, PA, USA
- Rehab and Neural Engineering Labs, University of Pittsburgh, PA, USA
| | - L Sowoidnich
- Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany
| | - JM Buettner
- Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany
| | - JG Pagiazitis
- Center for Motor Neuron Biology and Disease, Columbia University, NY, USA
- Dept. of Neurology, Columbia University, NY, USA
| | - G Prat-Ortega
- Rehab and Neural Engineering Labs, University of Pittsburgh, PA, USA
- Depts. of Neurological Surgery & Bioengineering, University of Pittsburgh, PA, USA
| | - S Ensel
- Rehab and Neural Engineering Labs, University of Pittsburgh, PA, USA
- Depts. of Neurological Surgery & Bioengineering, University of Pittsburgh, PA, USA
| | - S Donadio
- Rehab and Neural Engineering Labs, University of Pittsburgh, PA, USA
- Depts. of Neurological Surgery & Bioengineering, University of Pittsburgh, PA, USA
| | - JL Garcia
- Dept. of Neurology, Columbia University, NY, USA
| | - P Kratimenos
- Center for Neuroscience Research, Children’s National Res. Institute, Washington, DC, USA
- Dept. of Pediatrics, G Washington Univ. Sch. of Medicine, Washington, DC, USA
| | - WK Chung
- Dept. of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, MA USA
| | - CJ Sumner
- Depts. of Neurology, Neuroscience and Genetic Medicine, Johns Hopkins University School of Medicine, MD, USA
| | - LH Weimer
- Dept. of Neurology, Columbia University, NY, USA
| | - E Pirondini
- Depts. Physical Medicine & Rehabilitation & Bioengineering, University of Pittsburgh, PA, USA
- Rehab and Neural Engineering Labs, University of Pittsburgh, PA, USA
| | - M Capogrosso
- Rehab and Neural Engineering Labs, University of Pittsburgh, PA, USA
- Depts. of Neurological Surgery & Bioengineering, University of Pittsburgh, PA, USA
| | - L Pellizzoni
- Center for Motor Neuron Biology and Disease, Columbia University, NY, USA
- Dept. of Neurology, Columbia University, NY, USA
- Dept. of Pathology and Cell Biology, Columbia University, NY, USA
| | - DC De Vivo
- Center for Motor Neuron Biology and Disease, Columbia University, NY, USA
- Dept. of Neurology, Columbia University, NY, USA
| | - GZ Mentis
- Center for Motor Neuron Biology and Disease, Columbia University, NY, USA
- Dept. of Neurology, Columbia University, NY, USA
- Dept. of Pathology and Cell Biology, Columbia University, NY, USA
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10
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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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11
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Kovachka S, Tong Y, Childs-Disney JL, Disney MD. Heterobifunctional small molecules to modulate RNA function. Trends Pharmacol Sci 2024; 45:449-463. [PMID: 38641489 DOI: 10.1016/j.tips.2024.03.006] [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: 03/02/2024] [Revised: 03/27/2024] [Accepted: 03/27/2024] [Indexed: 04/21/2024]
Abstract
RNA has diverse cellular functionality, including regulating gene expression, protein translation, and cellular response to stimuli, due to its intricate structures. Over the past decade, small molecules have been discovered that target functional structures within cellular RNAs and modulate their function. Simple binding, however, is often insufficient, resulting in low or even no biological activity. To overcome this challenge, heterobifunctional compounds have been developed that can covalently bind to the RNA target, alter RNA sequence, or induce its cleavage. Herein, we review the recent progress in the field of RNA-targeted heterobifunctional compounds using representative case studies. We identify critical gaps and limitations and propose a strategic pathway for future developments of RNA-targeted molecules with augmented functionalities.
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Affiliation(s)
- Sandra Kovachka
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation and Technology, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Yuquan Tong
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation and Technology, 130 Scripps Way, Jupiter, FL 33458, USA; The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Jessica L Childs-Disney
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation and Technology, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Matthew D Disney
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation and Technology, 130 Scripps Way, Jupiter, FL 33458, USA; The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
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12
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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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13
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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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14
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Cheng Y, Zhang S, Shang H. Latest advances on new promising molecular-based therapeutic approaches for Huntington's disease. J Transl Int Med 2024; 12:134-147. [PMID: 38779119 PMCID: PMC11107186 DOI: 10.2478/jtim-2023-0142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024] Open
Abstract
Huntington's disease (HD) is a devastating, autosomal-dominant inherited, neurodegenerative disorder characterized by progressive motor deficits, cognitive impairments, and neuropsychiatric symptoms. It is caused by excessive cytosine-adenine-guanine (CAG) trinucleotide repeats within the huntingtin gene (HTT). Presently, therapeutic interventions capable of altering the trajectory of HD are lacking, while medications for abnormal movement and psychiatric symptoms are limited. Numerous pre-clinical and clinical studies have been conducted and are currently underway to test the efficacy of therapeutic approaches targeting some of these mechanisms with varying degrees of success. In this review, we update the latest advances on new promising molecular-based therapeutic strategies for this disorder, including DNA-targeting techniques such as zinc-finger proteins, transcription activator-like effector nucleases, and CRISPR/Cas9; post-transcriptional huntingtin-lowering approaches such as RNAi, antisense oligonucleotides, and small-molecule splicing modulators; and novel methods to clear the mHTT protein, such as proteolysis-targeting chimeras. We mainly focus on the ongoing clinical trials and the latest pre-clinical studies to explore the progress of emerging potential HD therapeutics.
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Affiliation(s)
- Yangfan Cheng
- Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare disease center, West China Hospital, Sichuan University, Chengdu610041, Sichuan Province, China
| | - Sirui Zhang
- Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare disease center, West China Hospital, Sichuan University, Chengdu610041, Sichuan Province, China
| | - Huifang Shang
- Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare disease center, West China Hospital, Sichuan University, Chengdu610041, Sichuan Province, China
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15
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Kaur J, Sharma A, Mundlia P, Sood V, Pandey A, Singh G, Barnwal RP. RNA-Small-Molecule Interaction: Challenging the "Undruggable" Tag. J Med Chem 2024. [PMID: 38498010 DOI: 10.1021/acs.jmedchem.3c01354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
RNA targeting, specifically with small molecules, is a relatively new and rapidly emerging avenue with the promise to expand the target space in the drug discovery field. From being "disregarded" as an "undruggable" messenger molecule to FDA approval of an RNA-targeting small-molecule drug Risdiplam, a radical change in perspective toward RNA has been observed in the past decade. RNAs serve important regulatory functions beyond canonical protein synthesis, and their dysregulation has been reported in many diseases. A deeper understanding of RNA biology reveals that RNA molecules can adopt a variety of structures, carrying defined binding pockets that can accommodate small-molecule drugs. Due to its functional diversity and structural complexity, RNA can be perceived as a prospective target for therapeutic intervention. This perspective highlights the proof of concept of RNA-small-molecule interactions, exemplified by targeting of various transcripts with functional modulators. The advent of RNA-oriented knowledge would help expedite drug discovery.
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Affiliation(s)
- Jaskirat Kaur
- Department of Biophysics, Panjab University, Chandigarh 160014, India
| | - Akanksha Sharma
- Department of Biophysics, Panjab University, Chandigarh 160014, India
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh 160014, India
| | - Poonam Mundlia
- Department of Biophysics, Panjab University, Chandigarh 160014, India
| | - Vikas Sood
- Department of Biochemistry, Jamia Hamdard, New Delhi 110062, India
| | - Ankur Pandey
- Department of Chemistry, Panjab University, Chandigarh 160014, India
| | - Gurpal Singh
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh 160014, India
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16
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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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17
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Jaiswal AK, Thaxton ML, Scherer GM, Sorrentino JP, Garg NK, Rao DS. Small molecule inhibition of RNA binding proteins in haematologic cancer. RNA Biol 2024; 21:1-14. [PMID: 38329136 PMCID: PMC10857685 DOI: 10.1080/15476286.2024.2303558] [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] [Accepted: 01/05/2024] [Indexed: 02/09/2024] Open
Abstract
In recent years, advances in biomedicine have revealed an important role for post-transcriptional mechanisms of gene expression regulation in pathologic conditions. In cancer in general and leukaemia specifically, RNA binding proteins have emerged as important regulator of RNA homoeostasis that are often dysregulated in the disease state. Having established the importance of these pathogenetic mechanisms, there have been a number of efforts to target RNA binding proteins using oligonucleotide-based strategies, as well as with small organic molecules. The field is at an exciting inflection point with the convergence of biomedical knowledge, small molecule screening strategies and improved chemical methods for synthesis and construction of sophisticated small molecules. Here, we review the mechanisms of post-transcriptional gene regulation, specifically in leukaemia, current small-molecule based efforts to target RNA binding proteins, and future prospects.
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Affiliation(s)
- Amit K. Jaiswal
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA, USA
| | - Michelle L. Thaxton
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA, USA
| | - Georgia M. Scherer
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Jacob P. Sorrentino
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Neil K. Garg
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Dinesh S. Rao
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, University of California Los Angeles, CA, USA
- Broad Stem Cell Research Center, University of California, Los Angeles, CA, USA
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18
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Gentile JE, Corridon TL, Mortberg MA, D'Souza EN, Whiffin N, Minikel EV, Vallabh SM. Modulation of prion protein expression through cryptic splice site manipulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.19.572439. [PMID: 38187635 PMCID: PMC10769280 DOI: 10.1101/2023.12.19.572439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Lowering expression of prion protein (PrP) is a well-validated therapeutic strategy in prion disease, but additional modalities are urgently needed. In other diseases, small molecules have proven capable of modulating pre-mRNA splicing, sometimes by forcing inclusion of cryptic exons that reduce gene expression. Here, we characterize a cryptic exon located in human PRNP's sole intron and evaluate its potential to reduce PrP expression through incorporation into the 5' untranslated region (5'UTR). This exon is homologous to exon 2 in non-primate species, but contains a start codon that would yield an upstream open reading frame (uORF) with a stop codon prior to a splice site if included in PRNP mRNA, potentially downregulating PrP expression through translational repression or nonsense-mediated decay. We establish a minigene transfection system and test a panel of splice site alterations, identifying mutants that reduce PrP expression by as much as 78%. Our findings nominate a new therapeutic target for lowering PrP.
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Affiliation(s)
- Juliana E Gentile
- McCance Center for Brain Health and Department of Neurology, Massachusetts General Hospital, Boston, MA 02114
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142
| | - Taylor L Corridon
- McCance Center for Brain Health and Department of Neurology, Massachusetts General Hospital, Boston, MA 02114
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142
| | - Meredith A Mortberg
- McCance Center for Brain Health and Department of Neurology, Massachusetts General Hospital, Boston, MA 02114
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142
| | - Elston Neil D'Souza
- Big Data Institute and Centre for Human Genetics, University of Oxford, Oxford OX3 7LF, UK
| | - Nicola Whiffin
- Big Data Institute and Centre for Human Genetics, University of Oxford, Oxford OX3 7LF, UK
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA
| | - Eric Vallabh Minikel
- McCance Center for Brain Health and Department of Neurology, Massachusetts General Hospital, Boston, MA 02114
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142
| | - Sonia M Vallabh
- McCance Center for Brain Health and Department of Neurology, Massachusetts General Hospital, Boston, MA 02114
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142
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19
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Li A, Bouhss A, Clément MJ, Bauvais C, Taylor JP, Bollot G, Pastré D. Using the structural diversity of RNA: protein interfaces to selectively target RNA with small molecules in cells: methods and perspectives. Front Mol Biosci 2023; 10:1298441. [PMID: 38033386 PMCID: PMC10687564 DOI: 10.3389/fmolb.2023.1298441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 10/24/2023] [Indexed: 12/02/2023] Open
Abstract
In recent years, RNA has gained traction both as a therapeutic molecule and as a therapeutic target in several human pathologies. In this review, we consider the approach of targeting RNA using small molecules for both research and therapeutic purposes. Given the primary challenge presented by the low structural diversity of RNA, we discuss the potential for targeting RNA: protein interactions to enhance the structural and sequence specificity of drug candidates. We review available tools and inherent challenges in this approach, ranging from adapted bioinformatics tools to in vitro and cellular high-throughput screening and functional analysis. We further consider two critical steps in targeting RNA/protein interactions: first, the integration of in silico and structural analyses to improve the efficacy of molecules by identifying scaffolds with high affinity, and second, increasing the likelihood of identifying on-target compounds in cells through a combination of high-throughput approaches and functional assays. We anticipate that the development of a new class of molecules targeting RNA: protein interactions to prevent physio-pathological mechanisms could significantly expand the arsenal of effective therapeutic compounds.
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Affiliation(s)
- Aixiao Li
- Synsight, Genopole Entreprises, Evry, France
| | - Ahmed Bouhss
- Université Paris-Saclay, INSERM U1204, Université d’Évry, Structure-Activité des Biomolécules Normales et Pathologiques (SABNP), Evry, France
| | - Marie-Jeanne Clément
- Université Paris-Saclay, INSERM U1204, Université d’Évry, Structure-Activité des Biomolécules Normales et Pathologiques (SABNP), Evry, France
| | | | - J. Paul Taylor
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, United States
| | | | - David Pastré
- Université Paris-Saclay, INSERM U1204, Université d’Évry, Structure-Activité des Biomolécules Normales et Pathologiques (SABNP), Evry, France
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20
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Valsecchi V, Errico F, Bassareo V, Marino C, Nuzzo T, Brancaccio P, Laudati G, Casamassa A, Grimaldi M, D'Amico A, Carta M, Bertini E, Pignataro G, D'Ursi AM, Usiello A. SMN deficiency perturbs monoamine neurotransmitter metabolism in spinal muscular atrophy. Commun Biol 2023; 6:1155. [PMID: 37957344 PMCID: PMC10643621 DOI: 10.1038/s42003-023-05543-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 11/03/2023] [Indexed: 11/15/2023] Open
Abstract
Beyond motor neuron degeneration, homozygous mutations in the survival motor neuron 1 (SMN1) gene cause multiorgan and metabolic defects in patients with spinal muscular atrophy (SMA). However, the precise biochemical features of these alterations and the age of onset in the brain and peripheral organs remain unclear. Using untargeted NMR-based metabolomics in SMA mice, we identify cerebral and hepatic abnormalities related to energy homeostasis pathways and amino acid metabolism, emerging already at postnatal day 3 (P3) in the liver. Through HPLC, we find that SMN deficiency induces a drop in cerebral norepinephrine levels in overt symptomatic SMA mice at P11, affecting the mRNA and protein expression of key genes regulating monoamine metabolism, including aromatic L-amino acid decarboxylase (AADC), dopamine beta-hydroxylase (DβH) and monoamine oxidase A (MAO-A). In support of the translational value of our preclinical observations, we also discovered that SMN upregulation increases cerebrospinal fluid norepinephrine concentration in Nusinersen-treated SMA1 patients. Our findings highlight a previously unrecognized harmful influence of low SMN levels on the expression of critical enzymes involved in monoamine metabolism, suggesting that SMN-inducing therapies may modulate catecholamine neurotransmission. These results may also be relevant for setting therapeutic approaches to counteract peripheral metabolic defects in SMA.
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Affiliation(s)
- Valeria Valsecchi
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples "Federico II", 80131, Naples, Italy
| | - Francesco Errico
- Department of Agricultural Sciences, University of Naples "Federico II", 80055, Portici, Italy
- Laboratory of Translational Neuroscience, Ceinge Biotecnologie Avanzate, 80145, Naples, Italy
| | - Valentina Bassareo
- Department of Biomedical Sciences, University of Cagliari, 09042, Monserrato, Italy
| | - Carmen Marino
- Department of Pharmacy, University of Salerno, 84084, Fisciano, Salerno, Italy
| | - Tommaso Nuzzo
- Laboratory of Translational Neuroscience, Ceinge Biotecnologie Avanzate, 80145, Naples, Italy
- Department of Environmental, Biological and Pharmaceutical Science and Technologies, Università degli Studi della Campania "Luigi Vanvitelli", 81100, Caserta, Italy
| | - Paola Brancaccio
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples "Federico II", 80131, Naples, Italy
| | - Giusy Laudati
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples "Federico II", 80131, Naples, Italy
| | | | - Manuela Grimaldi
- Department of Pharmacy, University of Salerno, 84084, Fisciano, Salerno, Italy
| | - Adele D'Amico
- Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesù Children's Hospital IRCCS, 00163, Rome, Italy
| | - Manolo Carta
- Department of Biomedical Sciences, University of Cagliari, 09042, Monserrato, Italy
| | - Enrico Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesù Children's Hospital IRCCS, 00163, Rome, Italy
| | - Giuseppe Pignataro
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples "Federico II", 80131, Naples, Italy
| | - Anna Maria D'Ursi
- Department of Pharmacy, University of Salerno, 84084, Fisciano, Salerno, Italy
| | - Alessandro Usiello
- Laboratory of Translational Neuroscience, Ceinge Biotecnologie Avanzate, 80145, Naples, Italy.
- Department of Environmental, Biological and Pharmaceutical Science and Technologies, Università degli Studi della Campania "Luigi Vanvitelli", 81100, Caserta, Italy.
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21
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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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22
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Walters K, Sajek MP, Murphy E, Issaian A, Baldwin A, Harrison E, Daniels M, Reisz JA, Hansen K, D'Alessandro A, Mukherjee N. Small-molecule Ro-08-2750 interacts with many RNA-binding proteins and elicits MUSASHI2-independent phenotypes. RNA (NEW YORK, N.Y.) 2023; 29:1458-1470. [PMID: 37369529 PMCID: PMC10578479 DOI: 10.1261/rna.079605.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023]
Abstract
RNA-binding proteins (RBPs) are key regulators of gene expression. Small molecules targeting these RBP-RNA interactions are a rapidly emerging class of therapeutics for treating a variety of diseases. Ro-08-2750 (Ro) is a small molecule identified as a competitive inhibitor of Musashi (MSI)-RNA interactions. Here, we show that multiple Ro-dependent cellular phenotypes, specifically adrenocortical steroid production and cell viability, are Musashi-2 (MSI2)-independent. Using an unbiased proteome-wide approach, we discovered Ro broadly interacts with RBPs, many containing RRM domains. To confirm this finding, we leveraged the large-scale ENCODE data to identify a subset of RBPs whose depletion phenocopies Ro inhibition, indicating Ro is a promiscuous inhibitor of multiple RBPs. Consistent with broad disruption of ribonucleoprotein complexes, Ro treatment leads to stress granule formation. This strategy represents a generalizable framework for validating the specificity and identifying targets of RBP inhibitors in a cellular context.
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Affiliation(s)
- Kathryn Walters
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Marcin Piotr Sajek
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
- Institute of Human Genetics, Polish Academy of Sciences, 60-479 Poznan, Poland
| | - Elisabeth Murphy
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Aaron Issaian
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Amber Baldwin
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Evan Harrison
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Miles Daniels
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
- Howard University Karsh STEM Scholars Program, Washington DC 20059, USA
| | - Julie A Reisz
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Kirk Hansen
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Neelanjan Mukherjee
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
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23
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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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24
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Jiang T, Wang L, Tang L, Zeb A, Hou Y. Identification of two short peptide motifs from serine/arginine-rich protein ribonucleic acid recognition motif-1 domain acting as splicing regulators. PeerJ 2023; 11:e16103. [PMID: 37744237 PMCID: PMC10512959 DOI: 10.7717/peerj.16103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 08/25/2023] [Indexed: 09/26/2023] Open
Abstract
Background Serine/arginine-rich (SR) proteins regulate pre-mRNA splicing. However, structurally similar proteins often behave differently in splicing regulation and the underlying mechanisms are largely unknown. Here, using SMN1/2 minigenes we extensively analyzed four SR proteins, SRSF1/5/6/9. Methods In this study, the effects of these proteins on SMN1/2 exon 7 splicing when tethered at either intron 6 or 7 were evaluated using an MS2-tethering assay. Deletion analysis in four SR proteins and co-overexpression analysis were performed. Results Splicing outcomes varied among all four SR proteins, SRSF1 and SRSF5 function the same at the two sites, acting as repressor and stimulator, respectively; while SRSF6 and SRSF9 promote exon 7 inclusion at only one site. Further, the key domains of each SR proteins were investigated, which identified a potent inhibitory nonapeptide in the C-terminus of SRSF1/9 ribonucleic acid recognition motif-1 (RRM1) and a potent stimulatory heptapeptide at the N-terminus of SRSF5/6 RRM1. Conclusion The insight of the four SR proteins and their domains in affecting SMN gene splicing brings a new perspective on the modes of action of SR proteins; and the functional peptides obtained here offers new ideas for developing splice switching-related therapies.
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Affiliation(s)
- Tao Jiang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University Army Medical University, Chongqing, China
| | - Li Wang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
| | - Liang Tang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
| | - Azhar Zeb
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
| | - Yanjun Hou
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
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25
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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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26
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Bergant V, Schnepf D, de Andrade Krätzig N, Hubel P, Urban C, Engleitner T, Dijkman R, Ryffel B, Steiger K, Knolle PA, Kochs G, Rad R, Staeheli P, Pichlmair A. mRNA 3'UTR lengthening by alternative polyadenylation attenuates inflammatory responses and correlates with virulence of Influenza A virus. Nat Commun 2023; 14:4906. [PMID: 37582777 PMCID: PMC10427651 DOI: 10.1038/s41467-023-40469-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 07/27/2023] [Indexed: 08/17/2023] Open
Abstract
Changes of mRNA 3'UTRs by alternative polyadenylation (APA) have been associated to numerous pathologies, but the mechanisms and consequences often remain enigmatic. By combining transcriptomics, proteomics and recombinant viruses we show that all tested strains of IAV, including A/PR/8/34(H1N1) (PR8) and A/Cal/07/2009 (H1N1) (Cal09), cause APA. We mapped the effect to the highly conserved glycine residue at position 184 (G184) of the viral non-structural protein 1 (NS1). Unbiased mass spectrometry-based analyses indicate that NS1 causes APA by perturbing the function of CPSF4 and that this function is unrelated to virus-induced transcriptional shutoff. Accordingly, IAV strain PR8, expressing an NS1 variant with weak CPSF binding, does not induce host shutoff but only APA. However, recombinant IAV (PR8) expressing NS1(G184R) lacks binding to CPSF4 and thereby also the ability to cause APA. Functionally, the impaired ability to induce APA leads to an increased inflammatory cytokine production and an attenuated phenotype in a mouse infection model. Investigating diverse viral infection models showed that APA induction is a frequent ability of many pathogens. Collectively, we propose that targeting of the CPSF complex, leading to widespread alternative polyadenylation of host transcripts, constitutes a general immunevasion mechanism employed by a variety of pathogenic viruses.
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Affiliation(s)
- Valter Bergant
- Institute of Virology, TUM School of Medicine, Technical University of Munich, Munich, Germany
- Max Planck Institute of Biochemistry, Munich, Germany
| | - Daniel Schnepf
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
- Immunoregulation Laboratory, The Francis Crick Institute, London, UK
| | - Niklas de Andrade Krätzig
- Institute of Molecular Oncology and Functional Genomics, TUM School of Medicine, Technical University of Munich, Munich, Germany
- Center for Translational Cancer Research (TranslaTUM), TUM School of Medicine, Technical University of Munich, Munich, Germany
| | - Philipp Hubel
- Max Planck Institute of Biochemistry, Munich, Germany
| | - Christian Urban
- Institute of Virology, TUM School of Medicine, Technical University of Munich, Munich, Germany
- Max Planck Institute of Biochemistry, Munich, Germany
| | - Thomas Engleitner
- Institute of Molecular Oncology and Functional Genomics, TUM School of Medicine, Technical University of Munich, Munich, Germany
- Center for Translational Cancer Research (TranslaTUM), TUM School of Medicine, Technical University of Munich, Munich, Germany
| | - Ronald Dijkman
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
- Institute of Virology and Immunology, Bern & Mittelhäusern, Switzerland
- Department of Infectious diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Bernhard Ryffel
- CNRS, UMR7355, Orleans, France
- Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
| | - Katja Steiger
- Institut für allgemeine Pathologie und Pathologische Anatomie, TUM School of Medicine, Technical University of Munich, Munich, Germany
| | - Percy A Knolle
- Institute of Molecular Immunology and Experimental Oncology, TUM School of Medicine, Technical University of Munich, Munich, Germany
| | - Georg Kochs
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Roland Rad
- Institute of Molecular Oncology and Functional Genomics, TUM School of Medicine, Technical University of Munich, Munich, Germany
- Center for Translational Cancer Research (TranslaTUM), TUM School of Medicine, Technical University of Munich, Munich, Germany
- Department of Medicine II, TUM School of Medicine, Technical University of Munich, Munich, Germany
| | - Peter Staeheli
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
| | - Andreas Pichlmair
- Institute of Virology, TUM School of Medicine, Technical University of Munich, Munich, Germany.
- Max Planck Institute of Biochemistry, Munich, Germany.
- German Center for Infection Research (DZIF), Munich Partner Site, Munich, Germany.
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27
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Gotthardt M, Badillo-Lisakowski V, Parikh VN, Ashley E, Furtado M, Carmo-Fonseca M, Schudy S, Meder B, Grosch M, Steinmetz L, Crocini C, Leinwand L. Cardiac splicing as a diagnostic and therapeutic target. Nat Rev Cardiol 2023; 20:517-530. [PMID: 36653465 DOI: 10.1038/s41569-022-00828-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/09/2022] [Indexed: 01/19/2023]
Abstract
Despite advances in therapeutics for heart failure and arrhythmias, a substantial proportion of patients with cardiomyopathy do not respond to interventions, indicating a need to identify novel modifiable myocardial pathobiology. Human genetic variation associated with severe forms of cardiomyopathy and arrhythmias has highlighted the crucial role of alternative splicing in myocardial health and disease, given that it determines which mature RNA transcripts drive the mechanical, structural, signalling and metabolic properties of the heart. In this Review, we discuss how the analysis of cardiac isoform expression has been facilitated by technical advances in multiomics and long-read and single-cell sequencing technologies. The resulting insights into the regulation of alternative splicing - including the identification of cardiac splice regulators as therapeutic targets and the development of a translational pipeline to evaluate splice modulators in human engineered heart tissue, animal models and clinical trials - provide a basis for improved diagnosis and therapy. Finally, we consider how the medical and scientific communities can benefit from facilitated acquisition and interpretation of splicing data towards improved clinical decision-making and patient care.
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Affiliation(s)
- Michael Gotthardt
- Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.
- DZHK (German Center for Cardiovascular Research Partner Site Berlin), Berlin, Germany.
- Department of Cardiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
| | - Victor Badillo-Lisakowski
- Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- DZHK (German Center for Cardiovascular Research Partner Site Berlin), Berlin, Germany
| | - Victoria Nicole Parikh
- Stanford Center for Inherited Cardiovascular Disease, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Euan Ashley
- Stanford Center for Inherited Cardiovascular Disease, Stanford University School of Medicine, Palo Alto, CA, USA
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, USA
- Department of Genetics, School of Medicine, Stanford University, Stanford, CA, USA
| | - Marta Furtado
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Maria Carmo-Fonseca
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Sarah Schudy
- Institute for Cardiomyopathies, Department of Medicine III, University of Heidelberg, Heidelberg, Germany
| | - Benjamin Meder
- Institute for Cardiomyopathies, Department of Medicine III, University of Heidelberg, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research Partner Site Heidelberg-Mannheim), Heidelberg, Germany
| | - Markus Grosch
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Lars Steinmetz
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, USA
- Department of Genetics, School of Medicine, Stanford University, Stanford, CA, USA
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Claudia Crocini
- Department of Molecular, Cellular, and Developmental Biology and BioFrontiers Institute, University of Colorado, Boulder, CO, USA
| | - Leslie Leinwand
- Department of Molecular, Cellular, and Developmental Biology and BioFrontiers Institute, University of Colorado, Boulder, CO, USA
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28
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Ottesen EW, Singh NN, Luo D, Kaas B, Gillette B, Seo J, Jorgensen H, Singh RN. Diverse targets of SMN2-directed splicing-modulating small molecule therapeutics for spinal muscular atrophy. Nucleic Acids Res 2023; 51:5948-5980. [PMID: 37026480 PMCID: PMC10325915 DOI: 10.1093/nar/gkad259] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 03/13/2023] [Accepted: 03/28/2023] [Indexed: 04/08/2023] Open
Abstract
Designing an RNA-interacting molecule that displays high therapeutic efficacy while retaining specificity within a broad concentration range remains a challenging task. Risdiplam is an FDA-approved small molecule for the treatment of spinal muscular atrophy (SMA), the leading genetic cause of infant mortality. Branaplam is another small molecule which has undergone clinical trials. The therapeutic merit of both compounds is based on their ability to restore body-wide inclusion of Survival Motor Neuron 2 (SMN2) exon 7 upon oral administration. Here we compare the transcriptome-wide off-target effects of these compounds in SMA patient cells. We captured concentration-dependent compound-specific changes, including aberrant expression of genes associated with DNA replication, cell cycle, RNA metabolism, cell signaling and metabolic pathways. Both compounds triggered massive perturbations of splicing events, inducing off-target exon inclusion, exon skipping, intron retention, intron removal and alternative splice site usage. Our results of minigenes expressed in HeLa cells provide mechanistic insights into how these molecules targeted towards a single gene produce different off-target effects. We show the advantages of combined treatments with low doses of risdiplam and branaplam. Our findings are instructive for devising better dosing regimens as well as for developing the next generation of small molecule therapeutics aimed at splicing modulation.
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Affiliation(s)
- Eric W Ottesen
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Natalia N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Diou Luo
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Bailey Kaas
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Benjamin J Gillette
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Joonbae Seo
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Hannah J Jorgensen
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Ravindra N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
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29
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Kathman SG, Koo SJ, Lindsey GL, Her HL, Blue SM, Li H, Jaensch S, Remsberg JR, Ahn K, Yeo GW, Ghosh B, Cravatt BF. Remodeling oncogenic transcriptomes by small molecules targeting NONO. Nat Chem Biol 2023; 19:825-836. [PMID: 36864190 PMCID: PMC10337234 DOI: 10.1038/s41589-023-01270-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 01/20/2023] [Indexed: 03/04/2023]
Abstract
Much of the human proteome is involved in mRNA homeostasis, but most RNA-binding proteins lack chemical probes. Here we identify electrophilic small molecules that rapidly and stereoselectively decrease the expression of transcripts encoding the androgen receptor and its splice variants in prostate cancer cells. We show by chemical proteomics that the compounds engage C145 of the RNA-binding protein NONO. Broader profiling revealed that covalent NONO ligands suppress an array of cancer-relevant genes and impair cancer cell proliferation. Surprisingly, these effects were not observed in cells genetically disrupted for NONO, which were instead resistant to NONO ligands. Reintroduction of wild-type NONO, but not a C145S mutant, restored ligand sensitivity in NONO-disrupted cells. The ligands promoted NONO accumulation in nuclear foci and stabilized NONO-RNA interactions, supporting a trapping mechanism that may prevent compensatory action of paralog proteins PSPC1 and SFPQ. These findings show that NONO can be co-opted by covalent small molecules to suppress protumorigenic transcriptional networks.
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Affiliation(s)
- Stefan G Kathman
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA.
| | - Seong Joo Koo
- Molecular and Cellular Pharmacology, Discovery Technologies and Molecular Pharmacology, Janssen Research and Development, Beerse, Belgium
| | - Garrett L Lindsey
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - Hsuan-Lin Her
- Bioinformatics and Systems Biology Program, University of California San Diego, La Jolla, CA, USA
| | - Steven M Blue
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Haoxin Li
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - Steffen Jaensch
- High Dimensional and Computational Biology, Discovery Technologies and Molecular Pharmacology, Janssen Research and Development, Beerse, Belgium
| | - Jarrett R Remsberg
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - Kay Ahn
- Molecular and Cellular Pharmacology, Discovery Technologies and Molecular Pharmacology, Janssen Research and Development, Spring House, PA, USA.
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA.
| | - Brahma Ghosh
- Discovery Chemistry, Janssen Research and Development, Spring House, PA, USA.
| | - Benjamin F Cravatt
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA.
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30
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Kenderdine T, Fabris D. The multifaceted roles of mass spectrometric analysis in nucleic acids drug discovery and development. MASS SPECTROMETRY REVIEWS 2023; 42:1332-1357. [PMID: 34939674 PMCID: PMC9218015 DOI: 10.1002/mas.21766] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 09/23/2021] [Accepted: 11/22/2021] [Indexed: 06/07/2023]
Abstract
The deceptively simple concepts of mass determination and fragment analysis are the basis for the application of mass spectrometry (MS) to a boundless range of analytes, including fundamental components and polymeric forms of nucleic acids (NAs). This platform affords the intrinsic ability to observe first-hand the effects of NA-active drugs on the chemical structure, composition, and conformation of their targets, which might affect their ability to interact with cognate NAs, proteins, and other biomolecules present in a natural environment. The possibility of interfacing with high-performance separation techniques represents a multiplying factor that extends these capabilities to cover complex sample mixtures obtained from organisms that were exposed to NA-active drugs. This report provides a brief overview of these capabilities in the context of the analysis of the products of NA-drug activity and NA therapeutics. The selected examples offer proof-of-principle of the applicability of this platform to all phases of the journey undertaken by any successful NA drug from laboratory to bedside, and provide the rationale for its rapid expansion outside traditional laboratory settings in support to ever growing manufacturing operations.
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Affiliation(s)
| | - Dan Fabris
- Department of Chemistry, University of Connecticut
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31
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Loewa A, Feng JJ, Hedtrich S. Human disease models in drug development. NATURE REVIEWS BIOENGINEERING 2023; 1:1-15. [PMID: 37359774 PMCID: PMC10173243 DOI: 10.1038/s44222-023-00063-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/30/2023] [Indexed: 06/20/2023]
Abstract
Biomedical research is undergoing a paradigm shift towards approaches centred on human disease models owing to the notoriously high failure rates of the current drug development process. Major drivers for this transition are the limitations of animal models, which, despite remaining the gold standard in basic and preclinical research, suffer from interspecies differences and poor prediction of human physiological and pathological conditions. To bridge this translational gap, bioengineered human disease models with high clinical mimicry are being developed. In this Review, we discuss preclinical and clinical studies that benefited from these models, focusing on organoids, bioengineered tissue models and organs-on-chips. Furthermore, we provide a high-level design framework to facilitate clinical translation and accelerate drug development using bioengineered human disease models.
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Affiliation(s)
- Anna Loewa
- Department of Infectious Diseases and Respiratory Medicine, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
| | - James J. Feng
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC Canada
- Department of Mathematics, University of British Columbia, Vancouver, BC Canada
| | - Sarah Hedtrich
- Department of Infectious Diseases and Respiratory Medicine, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
- Center of Biological Design, Berlin Institute of Health at Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC Canada
- Max-Delbrück Center for Molecular Medicine (MCD), Helmholtz Association, Berlin, Germany
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32
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Bagnolini G, Luu TB, Hargrove AE. Recognizing the power of machine learning and other computational methods to accelerate progress in small molecule targeting of RNA. RNA (NEW YORK, N.Y.) 2023; 29:473-488. [PMID: 36693763 PMCID: PMC10019373 DOI: 10.1261/rna.079497.122] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
RNA structures regulate a wide range of processes in biology and disease, yet small molecule chemical probes or drugs that can modulate these functions are rare. Machine learning and other computational methods are well poised to fill gaps in knowledge and overcome the inherent challenges in RNA targeting, such as the dynamic nature of RNA and the difficulty of obtaining RNA high-resolution structures. Successful tools to date include principal component analysis, linear discriminate analysis, k-nearest neighbor, artificial neural networks, multiple linear regression, and many others. Employment of these tools has revealed critical factors for selective recognition in RNA:small molecule complexes, predictable differences in RNA- and protein-binding ligands, and quantitative structure activity relationships that allow the rational design of small molecules for a given RNA target. Herein we present our perspective on the value of using machine learning and other computation methods to advance RNA:small molecule targeting, including select examples and their validation as well as necessary and promising future directions that will be key to accelerate discoveries in this important field.
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Affiliation(s)
- Greta Bagnolini
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - TinTin B Luu
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Amanda E Hargrove
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA
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33
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Nickbarg EB, Spencer KB, Mortison JD, Lee JT. Targeting RNA with small molecules: lessons learned from Xist RNA. RNA (NEW YORK, N.Y.) 2023; 29:463-472. [PMID: 36725318 PMCID: PMC10019374 DOI: 10.1261/rna.079523.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Although more than 98% of the human genome is noncoding, nearly all drugs on the market target one of about 700 disease-related proteins. However, an increasing number of diseases are now being attributed to noncoding RNA and the ability to target them would vastly expand the chemical space for drug development. We recently devised a screening strategy based upon affinity-selection mass spectrometry and succeeded in identifying bioactive compounds for the noncoding RNA prototype, Xist. One such compound, termed X1, has drug-like properties and binds specifically to the RepA motif of Xist in vitro and in vivo. Small-angle X-ray scattering analysis reveals that X1 changes the conformation of RepA in solution, thereby explaining the displacement of cognate interacting protein factors (PRC2 and SPEN) and inhibition of X-chromosome inactivation. In this Perspective, we discuss lessons learned from these proof-of-concept experiments and suggest that RNA can be systematically targeted by drug-like compounds to disrupt RNA structure and function.
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Affiliation(s)
| | | | | | - Jeannie T Lee
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
- Department of Genetics, The Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
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Nadal M, Anton R, Dorca‐Arévalo J, Estébanez‐Perpiñá E, Tizzano EF, Fuentes‐Prior P. Structure and function analysis of Sam68 and hnRNP A1 synergy in the exclusion of exon 7 from SMN2 transcripts. Protein Sci 2023; 32:e4553. [PMID: 36560896 PMCID: PMC10031812 DOI: 10.1002/pro.4553] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 12/13/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022]
Abstract
Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by the absence of a functional copy of the Survival of Motor Neuron 1 gene (SMN1). The nearly identical paralog, SMN2, cannot compensate for the loss of SMN1 because exon 7 is aberrantly skipped from most SMN2 transcripts, a process mediated by synergistic activities of Src-associated during mitosis, 68 kDa (Sam68/KHDRBS1) and heterogeneous nuclear ribonucleoprotein (hnRNP) A1. This results in the production of a truncated, nonfunctional protein that is rapidly degraded. Here, we present several crystal structures of Sam68 RNA-binding domain (RBD). Sam68-RBD forms stable symmetric homodimers by antiparallel association of helices α3 from two monomers. However, the details of domain organization and the dimerization interface differ significantly from previously characterized homologs. We demonstrate that Sam68 and hnRNP A1 can simultaneously bind proximal motifs within the central region of SMN2 (ex7). Furthermore, we show that the RNA-binding pockets of the two proteins are close to each other in their heterodimeric complex and identify contact residues using crosslinking-mass spectrometry. We present a model of the ternary Sam68·SMN2 (ex7)·hnRNP A1 complex that reconciles all available information on SMN1/2 splicing. Our findings have important implications for the etiology of SMA and open new avenues for the design of novel therapeutics to treat splicing diseases.
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Affiliation(s)
- Marta Nadal
- Molecular Bases of DiseaseBiomedical Research Institute Sant Pau (IIB Sant Pau)BarcelonaSpain
| | - Rosa Anton
- Molecular Bases of DiseaseBiomedical Research Institute Sant Pau (IIB Sant Pau)BarcelonaSpain
| | - Jonatan Dorca‐Arévalo
- Molecular Bases of DiseaseBiomedical Research Institute Sant Pau (IIB Sant Pau)BarcelonaSpain
- Present address:
Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Campus of BellvitgeHospitalet de Llobregat, University of BarcelonaBarcelonaSpain
| | - Eva Estébanez‐Perpiñá
- Structural Biology of Nuclear Receptors, Department of Biochemistry and Molecular Biomedicine, Faculty of BiologyInstitute of Biomedicine (IBUB) of the University of Barcelona (UB)BarcelonaSpain
| | - Eduardo F. Tizzano
- Medicine Genetics GroupVall d'Hebron Research Institute (VHIR)BarcelonaSpain
- Department of Clinical and Molecular GeneticsHospital Vall d'HebronBarcelonaSpain
| | - Pablo Fuentes‐Prior
- Molecular Bases of DiseaseBiomedical Research Institute Sant Pau (IIB Sant Pau)BarcelonaSpain
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35
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Theil D, Kuhle J, Brees D, Tritto E, Pognan F, Frieauff W, Penraat K, Meseck E, Valdez R, Hartmann A. Neurofilament Light Chain: A Translational Safety Biomarker for Drug-Induced Peripheral Neurotoxicity. Toxicol Pathol 2023; 51:135-147. [PMID: 37439009 DOI: 10.1177/01926233231180179] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Branaplam is a splicing modulator previously under development as a therapeutic agent for Spinal Muscular Atrophy Type 1 and Huntington's disease. Branaplam increased the levels of survival motor neuron protein in preclinical studies and was well tolerated in early clinical studies; however, peripheral neurotoxicity was observed in a preclinical safety study in juvenile dogs. The aim of this study was to determine whether serum neurofilament light chain (NfL) concentrations in dogs could serve as a monitoring biomarker for branaplam-induced peripheral neurotoxicity. A 30-week time-course investigative study in dogs treated with vehicle control (negative control), neurotoxic pyridoxine (positive control), or branaplam was conducted to assess neuropathology, nerve morphometry, electrophysiological measurements, gene expression profiles, and correlation to NfL serum concentrations. In branaplam-treated animals, a mild to moderate nerve fiber degeneration was observed in peripheral nerves correlating with increased serum NfL concentrations, but there were no observed signs or changes in electrophysiological parameters. Dogs with pyridoxine-induced peripheral axonal degeneration displayed clinical signs and electrophysiological changes in addition to elevated serum NfL. This study suggests that NfL may be useful as an exploratory biomarker to assist in detecting and monitoring treatment-related peripheral nerve injury, with or without clinical signs, associated with administration of branaplam and other compounds bearing a neurotoxic risk.
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Affiliation(s)
- Diethilde Theil
- Novartis Pharma AG, Basel, Switzerland
- F. Hoffmann-La Roche AG, Basel, Switzerland
| | | | | | | | | | | | - Kelley Penraat
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, USA
| | - Emily Meseck
- Novartis Pharmaceuticals Corporation, East Hanover, New Jersey, USA
| | - Reginald Valdez
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, USA
- Amgen, Inc., Cambridge, Massachusetts, USA
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36
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How does precursor RNA structure influence RNA processing and gene expression? Biosci Rep 2023; 43:232489. [PMID: 36689327 PMCID: PMC9977717 DOI: 10.1042/bsr20220149] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 01/17/2023] [Accepted: 01/23/2023] [Indexed: 01/24/2023] Open
Abstract
RNA is a fundamental biomolecule that has many purposes within cells. Due to its single-stranded and flexible nature, RNA naturally folds into complex and dynamic structures. Recent technological and computational advances have produced an explosion of RNA structural data. Many RNA structures have regulatory and functional properties. Studying the structure of nascent RNAs is particularly challenging due to their low abundance and long length, but their structures are important because they can influence RNA processing. Precursor RNA processing is a nexus of pathways that determines mature isoform composition and that controls gene expression. In this review, we examine what is known about human nascent RNA structure and the influence of RNA structure on processing of precursor RNAs. These known structures provide examples of how other nascent RNAs may be structured and show how novel RNA structures may influence RNA processing including splicing and polyadenylation. RNA structures can be targeted therapeutically to treat disease.
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37
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Meanwell NA. The pyridazine heterocycle in molecular recognition and drug discovery. Med Chem Res 2023; 32:1-69. [PMID: 37362319 PMCID: PMC10015555 DOI: 10.1007/s00044-023-03035-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Accepted: 02/06/2023] [Indexed: 03/17/2023]
Abstract
The pyridazine ring is endowed with unique physicochemical properties, characterized by weak basicity, a high dipole moment that subtends π-π stacking interactions and robust, dual hydrogen-bonding capacity that can be of importance in drug-target interactions. These properties contribute to unique applications in molecular recognition while the inherent polarity, low cytochrome P450 inhibitory effects and potential to reduce interaction of a molecule with the cardiac hERG potassium channel add additional value in drug discovery and development. The recent approvals of the gonadotropin-releasing hormone receptor antagonist relugolix (24) and the allosteric tyrosine kinase 2 inhibitor deucravacitinib (25) represent the first examples of FDA-approved drugs that incorporate a pyridazine ring. In this review, the properties of the pyridazine ring are summarized in comparison to the other azines and its potential in drug discovery is illustrated through vignettes that explore applications that take advantage of the inherent physicochemical properties as an approach to solving challenges associated with candidate optimization. Graphical Abstract
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38
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Ichijo R, Kamimura T, Kawai G. Interaction between a fluoroquinolone derivative KG022 and RNAs: Effect of base pairs 3′ adjacent to the bulged residues. Front Mol Biosci 2023; 10:1145528. [PMID: 36999159 PMCID: PMC10043337 DOI: 10.3389/fmolb.2023.1145528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 02/27/2023] [Indexed: 03/18/2023] Open
Abstract
RNA-targeted small molecules are a promising modality in drug discovery. Recently, we found that a fluoroquinolone derivative, KG022, can bind to RNAs with bulged C or G. To clarify the RNA specificity of KG022, we analyzed the effect of the base pair located at the 3′side of the bulged residue. It was found that KG022 prefers G-C and A-U base pairs at the 3′side. Solution structures of the complexes of KG022 with the four RNA molecules with bulged C or G and G-C or A-U base pairs at the 3′side of the bulged residue were determined to find that the fluoroquinolone moiety is located between two purine bases, and this may be the mechanism of the specificity. This work provides an important example of the specificity of RNA-targeted small molecules.
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Affiliation(s)
- Rika Ichijo
- Graduate School of Engineering, Chiba Institute of Technology, Chiba, Japan
| | | | - Gota Kawai
- Graduate School of Engineering, Chiba Institute of Technology, Chiba, Japan
- *Correspondence: Gota Kawai,
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39
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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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40
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Reproductive findings in male animals exposed to selective survival of motor neuron-2 (SMN2) gene splicing modifying agents. Reprod Toxicol 2023; 118:108360. [PMID: 36894038 DOI: 10.1016/j.reprotox.2023.108360] [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: 12/27/2022] [Revised: 02/23/2023] [Accepted: 03/01/2023] [Indexed: 03/09/2023]
Abstract
Risdiplam is a daily, orally dosed, SMN2 mRNA splicing modifying agent approved for the treatment of spinal muscular atrophy (SMA). RG7800 is a closely related SMN2 mRNA splicing compound. Effects on secondary mRNA splice targets such as FOXM1 and MADD, which have been implicated in cell cycle regulation, were observed in non-clinical studies with both risdiplam and RG7800. Potential effects of risdiplam on male fertility via FOXM1 and MADD are important as these secondary splice targets exist in humans. This publication reports the findings from 14 in vivo studies that investigated the reproductive tissues of male animals in various stages of development. Exposure to risdiplam or RG7800 induced changes within the germ cells in the testes of male cynomolgus monkeys and rats. Germ cell changes included both cell cycle gene changes (alteration of mRNA splicing variants) and seminiferous tubular degeneration. In monkeys treated with RG7800 there was no evidence of damage to spermatogonia. Observed testicular changes were stage-specific with spermatocytes in the pachytene stage of meiosis and were fully reversible in monkeys following a sufficient recovery period of eight weeks following cessation of RG7800. In rats, seminiferous tubule degeneration was present, and full reversibility of germ cell degeneration in the testes was observed among half of the rats that were exposed to risdiplam or RG7800 and then allowed to recover. With these results, coupled with histopathological findings, the effects on the male reproductive system are expected to be reversible in humans for these types of SMN2 mRNA splicing modifiers.
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Morini E, Chekuri A, Logan EM, Bolduc JM, Kirchner EG, Salani M, Krauson AJ, Narasimhan J, Gabbeta V, Grover S, Dakka A, Mollin A, Jung SP, Zhao X, Zhang N, Zhang S, Arnold M, Woll MG, Naryshkin NA, Weetall M, Slaugenhaupt SA. Development of an oral treatment that rescues gait ataxia and retinal degeneration in a phenotypic mouse model of familial dysautonomia. Am J Hum Genet 2023; 110:531-547. [PMID: 36809767 PMCID: PMC10027479 DOI: 10.1016/j.ajhg.2023.01.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 01/30/2023] [Indexed: 02/22/2023] Open
Abstract
Familial dysautonomia (FD) is a rare neurodegenerative disease caused by a splicing mutation in elongator acetyltransferase complex subunit 1 (ELP1). This mutation leads to the skipping of exon 20 and a tissue-specific reduction of ELP1, mainly in the central and peripheral nervous systems. FD is a complex neurological disorder accompanied by severe gait ataxia and retinal degeneration. There is currently no effective treatment to restore ELP1 production in individuals with FD, and the disease is ultimately fatal. After identifying kinetin as a small molecule able to correct the ELP1 splicing defect, we worked on its optimization to generate novel splicing modulator compounds (SMCs) that can be used in individuals with FD. Here, we optimize the potency, efficacy, and bio-distribution of second-generation kinetin derivatives to develop an oral treatment for FD that can efficiently pass the blood-brain barrier and correct the ELP1 splicing defect in the nervous system. We demonstrate that the novel compound PTC258 efficiently restores correct ELP1 splicing in mouse tissues, including brain, and most importantly, prevents the progressive neuronal degeneration that is characteristic of FD. Postnatal oral administration of PTC258 to the phenotypic mouse model TgFD9;Elp1Δ20/flox increases full-length ELP1 transcript in a dose-dependent manner and leads to a 2-fold increase in functional ELP1 in the brain. Remarkably, PTC258 treatment improves survival, gait ataxia, and retinal degeneration in the phenotypic FD mice. Our findings highlight the great therapeutic potential of this novel class of small molecules as an oral treatment for FD.
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Affiliation(s)
- Elisabetta Morini
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA.
| | - Anil Chekuri
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA; Grousbeck Gene Therapy Center, Schepens Eye Research Institute and Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Emily M Logan
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Jessica M Bolduc
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Emily G Kirchner
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Monica Salani
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Aram J Krauson
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | | | | | | | - Amal Dakka
- PTC Therapeutics, Inc., South Plainfield, NJ 07080, USA
| | - Anna Mollin
- PTC Therapeutics, Inc., South Plainfield, NJ 07080, USA
| | | | - Xin Zhao
- PTC Therapeutics, Inc., South Plainfield, NJ 07080, USA
| | - Nanjing Zhang
- PTC Therapeutics, Inc., South Plainfield, NJ 07080, USA
| | - Sophie Zhang
- PTC Therapeutics, Inc., South Plainfield, NJ 07080, USA
| | | | | | | | - Marla Weetall
- PTC Therapeutics, Inc., South Plainfield, NJ 07080, USA
| | - Susan A Slaugenhaupt
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA.
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Shortridge MD, Chaubey B, Zhang HJ, Pavelitz T, Vidadala V, Tang C, Olsen GL, Calin GA, Varani G. Drug-Like Small Molecules That Inhibit Expression of the Oncogenic MicroRNA-21. ACS Chem Biol 2023; 18:237-250. [PMID: 36727622 PMCID: PMC10593481 DOI: 10.1021/acschembio.2c00502] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We report the discovery of drug-like small molecules that bind specifically to the precursor of the oncogenic and pro-inflammatory microRNA-21 with mid-nanomolar affinity. The small molecules target a local structure at the Dicer cleavage site and induce distinctive structural changes in the RNA, which correlate with specific inhibition of miRNA processing. Structurally conservative single nucleotide substitutions eliminate the conformational change induced by the small molecules, which is also not observed in other miRNA precursors. The most potent of these compounds reduces cellular proliferation and miR-21 levels in cancer cell lines without inhibiting kinases or classical receptors, while closely related compounds without this specific binding activity are inactive in cells. These molecules are highly ligand-efficient (MW < 330) and display specific biochemical and cellular activity by suppressing the maturation of miR-21, thereby providing an avenue toward therapeutic development in multiple diseases where miR-21 is abnormally expressed.
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Affiliation(s)
- Matthew D Shortridge
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Bhawna Chaubey
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Huanyu J Zhang
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
| | - Thomas Pavelitz
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Venkata Vidadala
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Changyan Tang
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Gregory L Olsen
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - George A Calin
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
| | - Gabriele Varani
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
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Yang X, Childs-Disney JL, Disney MD. A meditation on accelerating the development of small molecule medicines targeting RNA. Expert Opin Drug Discov 2023; 18:115-117. [PMID: 35658797 PMCID: PMC9878438 DOI: 10.1080/17460441.2022.2084528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/27/2022] [Indexed: 02/06/2023]
Affiliation(s)
- Xueyi Yang
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458
| | | | - Matthew D. Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458
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44
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Torroba B, Macabuag N, Haisma EM, O'Neill A, Herva ME, Redis RS, Templin MV, Black LE, Fischer DF. RNA-based drug discovery for spinal muscular atrophy: a story of small molecules and antisense oligonucleotides. Expert Opin Drug Discov 2023; 18:181-192. [PMID: 36408582 DOI: 10.1080/17460441.2022.2149733] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Spinal Muscular Atrophy (SMA), the second most prevalent autosomal genetic disease affecting infants, is caused by the lack of SMN1, which encodes a neuron functioning vital protein, SMN. Improving exon 7 splicing in the paralogous gene SMN2, also coding for SMN protein, increases protein production efficiency from SMN2 to overcome the genetic deficit in SMN1. Several molecular mechanisms have been investigated to improve SMN2 functional splicing. AREAS COVERED This manuscript will cover two of the three mechanistically distinct available treatment options for SMA, both targeting the SMN2 splicing mechanism. The first therapeutic, nusinersen (Spinraza®, 2017), is an antisense oligonucleotide (ASO) targeting the splicing inhibitory sequence in the intron downstream of exon 7 from SMN2, thus increasing exon 7 inclusion. The second drug is a small molecule, risdiplam (Evrysdi®, 2021), that enhances the binding of splice factors and also promotes exon 7 inclusion. Both therapies, albeit through different mechanisms, increase full-length SMN protein expression. EXPERT OPINION Nusinersen and risdiplam have directly helped SMA patients and families, but they also herald a sea change in drug development for genetic diseases. This piece aims to draw parallels between both development histories; this may help chart the course for future targeted agents.
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Affiliation(s)
| | | | | | - Amy O'Neill
- Charles River Laboratories, Saffron Walden, UK
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Morishita EC. Discovery of RNA-targeted small molecules through the merging of experimental and computational technologies. Expert Opin Drug Discov 2023; 18:207-226. [PMID: 36322542 DOI: 10.1080/17460441.2022.2134852] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The field of RNA-targeted small molecules is rapidly evolving, owing to the advances in experimental and computational technologies. With the identification of several bioactive small molecules that target RNA, including the FDA-approved risdiplam, the biopharmaceutical industry is gaining confidence in the field. This review, based on the literature obtained from PubMed, aims to disseminate information about the various technologies developed for targeting RNA with small molecules and propose areas for improvement to develop drugs more efficiently, particularly those linked to diseases with unmet medical needs. AREAS COVERED The technologies for the identification of RNA targets, screening of chemical libraries against RNA, assessing the bioactivity and target engagement of the hit compounds, structure determination, and hit-to-lead optimization are reviewed. Along with the description of the technologies, their strengths, limitations, and examples of how they can impact drug discovery are provided. EXPERT OPINION Many existing technologies employed for protein targets have been repurposed for use in the discovery of RNA-targeted small molecules. In addition, technologies tailored for RNA targets have been developed. Nevertheless, more improvements are necessary, such as artificial intelligence to dissect important RNA structures and RNA-small-molecule interactions and more powerful chemical probing and structure prediction techniques.
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Dimitrova YN, Gutierrez JA, Huard K. It's ok to be outnumbered - sub-stoichiometric modulation of homomeric protein complexes. RSC Med Chem 2023; 14:22-46. [PMID: 36760737 PMCID: PMC9890894 DOI: 10.1039/d2md00212d] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022] Open
Abstract
An arsenal of molecular tools with increasingly diversified mechanisms of action is being developed by the scientific community to enable biological interrogation and pharmaceutical modulation of targets and pathways of ever increasing complexity. While most small molecules interact with the target of interest in a 1 : 1 relationship, a noteworthy number of recent examples were reported to bind in a sub-stoichiometric manner to a homomeric protein complex. This approach requires molecular understanding of the physiologically relevant protein assemblies and in-depth characterization of the compound's mechanism of action. The recent literature examples summarized here were selected to illustrate methods used to identify and characterize molecules with such mechanisms. The concept of one small molecule targeting a homomeric protein assembly is not new but the subject deserves renewed inspection in light of emerging technologies and increasingly diverse target biology, to ensure relevant in vitro systems are used and valuable compounds with potentially novel sub-stoichiometric mechanisms of action aren't overlooked.
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Affiliation(s)
| | | | - Kim Huard
- Genentech 1 DNA Way South San Francisco CA 94080 USA
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Lightfoot HL, Smith GF. Targeting RNA with small molecules-A safety perspective. Br J Pharmacol 2023. [PMID: 36631428 DOI: 10.1111/bph.16027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 06/30/2022] [Accepted: 12/20/2022] [Indexed: 01/13/2023] Open
Abstract
RNA is a major player in cellular function, and consequently can drive a number of disease pathologies. Over the past several years, small molecule-RNA targeting (smRNA targeting) has developed into a promising drug discovery approach. Numerous techniques, tools, and assays have been developed to support this field, and significant investments have been made by pharmaceutical and biotechnology companies. To date, the focus has been on identifying disease validated primary targets for smRNA drug development, yet RNA as a secondary (off) target for all small molecule drug programs largely has been unexplored. In this perspective, we discuss structure, target, and mechanism-driven safety aspects of smRNAs and highlight how these parameters can be evaluated in drug discovery programs to produce potentially safer drugs.
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Affiliation(s)
- Helen L Lightfoot
- Safety and Mechanistic Pharmacology, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, UK
| | - Graham F Smith
- Data Science and AI, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, UK
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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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Suresh BM, Akahori Y, Taghavi A, Crynen G, Gibaut QMR, Li Y, Disney MD. Low-Molecular Weight Small Molecules Can Potently Bind RNA and Affect Oncogenic Pathways in Cells. J Am Chem Soc 2022; 144:20815-20824. [PMID: 36322830 PMCID: PMC9930674 DOI: 10.1021/jacs.2c08770] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
RNA is challenging to target with bioactive small molecules, particularly those of low molecular weight that bind with sufficient affinity and specificity. In this report, we developed a platform to address this challenge, affording a novel bioactive interaction. An RNA-focused small-molecule fragment collection (n = 2500) was constructed by analyzing features in all publicly reported compounds that bind RNA, the largest collection of RNA-focused fragments to date. The RNA-binding landscape for each fragment was studied by using a library-versus-library selection with an RNA library displaying a discrete structural element, probing over 12.8 million interactions, the greatest number of interactions between fragments and biomolecules probed experimentally. Mining of this dataset across the human transcriptome defined a drug-like fragment that potently and specifically targeted the microRNA-372 hairpin precursor, inhibiting its processing into the mature, functional microRNA and alleviating invasive and proliferative oncogenic phenotypes in gastric cancer cells. Importantly, this fragment has favorable properties, including an affinity for the RNA target of 300 ± 130 nM, a molecular weight of 273 Da, and quantitative estimate of drug-likeness (QED) score of 0.8. (For comparison, the mean QED of oral medicines is 0.6 ± 0.2). Thus, these studies demonstrate that a low-molecular weight, fragment-like compound can specifically and potently modulate RNA targets.
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Affiliation(s)
- Blessy M. Suresh
- Department of Chemistry, The Scripps Research Institute & UF Scripps Biomedical Research, 130 Scripps Way, Jupiter, FL 33458, United States
| | - Yoshihiro Akahori
- Department of Chemistry, The Scripps Research Institute & UF Scripps Biomedical Research, 130 Scripps Way, Jupiter, FL 33458, United States
| | - Amirhossein Taghavi
- Department of Chemistry, The Scripps Research Institute & UF Scripps Biomedical Research, 130 Scripps Way, Jupiter, FL 33458, United States
| | - Gogce Crynen
- Bioinformatics and Statistics Core, The Scripps Research Institute & UF Scripps Biomedical Research, 130 Scripps Way, Jupiter, FL 33458, United States
| | - Quentin M. R. Gibaut
- Department of Chemistry, The Scripps Research Institute & UF Scripps Biomedical Research, 130 Scripps Way, Jupiter, FL 33458, United States
| | - Yue Li
- Department of Chemistry, The Scripps Research Institute & UF Scripps Biomedical Research, 130 Scripps Way, Jupiter, FL 33458, United States
| | - Matthew D. Disney
- Department of Chemistry, The Scripps Research Institute & UF Scripps Biomedical Research, 130 Scripps Way, Jupiter, FL 33458, United States
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An H, Elvers KT, Gillespie JA, Jones K, Atack JR, Grubisha O, Shelkovnikova TA. A toolkit for the identification of NEAT1_2/paraspeckle modulators. Nucleic Acids Res 2022; 50:e119. [PMID: 36099417 PMCID: PMC9723620 DOI: 10.1093/nar/gkac771] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 07/26/2022] [Accepted: 08/29/2022] [Indexed: 12/24/2022] Open
Abstract
Paraspeckles are ribonucleoprotein granules assembled by NEAT1_2 lncRNA, an isoform of Nuclear Paraspeckle Assembly Transcript 1 (NEAT1). Dysregulation of NEAT1_2/paraspeckles has been linked to multiple human diseases making them an attractive drug target. However currently NEAT1_2/paraspeckle-focused translational research and drug discovery are hindered by a limited toolkit. To fill this gap, we developed and validated a set of tools for the identification of NEAT1_2 binders and modulators comprised of biochemical and cell-based assays. The NEAT1_2 triple helix stability element was utilized as the target in the biochemical assays, and the cellular assay ('ParaQuant') was based on high-content imaging of NEAT1_2 in fixed cells. As a proof of principle, these assays were used to screen a 1,200-compound FDA-approved drug library and a 170-compound kinase inhibitor library and to confirm the screening hits. The assays are simple to establish, use only commercially-available reagents and are scalable for higher throughput. In particular, ParaQuant is a cost-efficient assay suitable for any cells growing in adherent culture and amenable to multiplexing. Using ParaQuant, we identified dual PI3K/mTOR inhibitors as potent negative modulators of paraspeckles. The tools we describe herein should boost paraspeckle studies and help guide the search, validation and optimization of NEAT1_2/paraspeckle-targeted small molecules.
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Affiliation(s)
- Haiyan An
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Cardiff CF10 3AT, UK
| | - Karen T Elvers
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Cardiff CF10 3AT, UK
| | - Jason A Gillespie
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Cardiff CF10 3AT, UK
| | - Kimberley Jones
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Cardiff CF10 3AT, UK
| | - John R Atack
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Cardiff CF10 3AT, UK
| | - Olivera Grubisha
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Cardiff CF10 3AT, UK
| | - Tatyana A Shelkovnikova
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Cardiff CF10 3AT, UK.,Sheffield Institute for Translational Neuroscience, Department of Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
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