1
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Herrero-Vicente J, Black DL, Valcárcel J. Splice-modifying drug mechanisms. Nat Chem Biol 2024:10.1038/s41589-024-01678-2. [PMID: 39060391 DOI: 10.1038/s41589-024-01678-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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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2
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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 DOI: 10.1016/j.jbc.2024.107560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [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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3
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Xiang JS, Schafer DM, Rothamel KL, Yeo GW. Decoding protein-RNA interactions using CLIP-based methodologies. Nat Rev Genet 2024:10.1038/s41576-024-00749-3. [PMID: 38982239 DOI: 10.1038/s41576-024-00749-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2024] [Indexed: 07/11/2024]
Abstract
Protein-RNA interactions are central to all RNA processing events, with pivotal roles in the regulation of gene expression and cellular functions. Dysregulation of these interactions has been increasingly linked to the pathogenesis of human diseases. High-throughput approaches to identify RNA-binding proteins and their binding sites on RNA - in particular, ultraviolet crosslinking followed by immunoprecipitation (CLIP) - have helped to map the RNA interactome, yielding transcriptome-wide protein-RNA atlases that have contributed to key mechanistic insights into gene expression and gene-regulatory networks. Here, we review these recent advances, explore the effects of cellular context on RNA binding, and discuss how these insights are shaping our understanding of cellular biology. We also review the potential therapeutic applications arising from new knowledge of protein-RNA interactions.
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Affiliation(s)
- Joy S Xiang
- Division of Biomedical Sciences, UC Riverside, Riverside, CA, USA
| | - Danielle M Schafer
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA, USA
- Sanford Stem Cell Institute and Stem Cell Program, UC San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine, UC San Diego, La Jolla, CA, USA
| | - Katherine L Rothamel
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA, USA
- Sanford Stem Cell Institute and Stem Cell Program, UC San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine, UC San Diego, La Jolla, CA, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA, USA.
- Sanford Stem Cell Institute and Stem Cell Program, UC San Diego, La Jolla, CA, USA.
- Institute for Genomic Medicine, UC San Diego, La Jolla, CA, USA.
- Sanford Laboratories for Innovative Medicines, La Jolla, CA, USA.
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4
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Cao X, Zhang Y, Ding Y, Wan Y. Identification of RNA structures and their roles in RNA functions. Nat Rev Mol Cell Biol 2024:10.1038/s41580-024-00748-6. [PMID: 38926530 DOI: 10.1038/s41580-024-00748-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2024] [Indexed: 06/28/2024]
Abstract
The development of high-throughput RNA structure profiling methods in the past decade has greatly facilitated our ability to map and characterize different aspects of RNA structures transcriptome-wide in cell populations, single cells and single molecules. The resulting high-resolution data have provided insights into the static and dynamic nature of RNA structures, revealing their complexity as they perform their respective functions in the cell. In this Review, we discuss recent technical advances in the determination of RNA structures, and the roles of RNA structures in RNA biogenesis and functions, including in transcription, processing, translation, degradation, localization and RNA structure-dependent condensates. We also discuss the current understanding of how RNA structures could guide drug design for treating genetic diseases and battling pathogenic viruses, and highlight existing challenges and future directions in RNA structure research.
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Affiliation(s)
- Xinang Cao
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore, Singapore
| | - Yueying Zhang
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, UK
| | - Yiliang Ding
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, UK.
| | - Yue Wan
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore, Singapore.
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
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5
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Zhang Y, Wang L, Wang F, Chu X, Jiang JH. G-Quadruplex mRNAs Silencing with Inducible Ribonuclease Targeting Chimera for Precision Tumor Therapy. J Am Chem Soc 2024; 146:15815-15824. [PMID: 38832857 DOI: 10.1021/jacs.4c02091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Ribonuclease targeting chimera (RIBOTAC) represents an emerging strategy for targeted therapy. However, RIBOTAC that is selectively activated by bio-orthogonal or cell-specific triggers has not been explored. We developed a strategy of inducible RIBOTAC (iRIBOTAC) that enables on-demand degradation of G-quadruplex (G4) RNAs for precision cancer therapy. iRIBOTAC is designed by coupling an RNA G4 binder with a caged ribonuclease recruiter, which can be decaged by a bio-orthogonal reaction, tumor-specific enzyme, or metabolite. A bivalent G4 binder is engineered by conjugating a near-infrared (NIR) fluorescence G4 ligand to a noncompetitive G4 ligand, conferring fluorescence activation on binding G4s with synergistically enhanced affinity. iRIBOTAC is demonstrated to greatly knockdown G4 RNAs upon activation under bio-orthogonal or cell-specific stimulus, with dysregulation of gene expressions involving cell killing, channel regulator activity, and metabolism as revealed by RNA sequencing. This strategy also shows a crucial effect on cell fate with remarkable biochemical hallmarks of apoptosis. Mice model studies demonstrate that iRIBOTAC allows selective imaging and growth suppression of tumors with bio-orthogonal and tumor-specific controls, highlighting G4 RNA targeting and inducible silencing as a valuable RIBOTAC paradigm for cancer therapy.
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Affiliation(s)
- Yuan Zhang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Lingyan Wang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Fenglin Wang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Xia Chu
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Jian-Hui Jiang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
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6
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Bosio S, Bernetti M, Rocchia W, Masetti M. Similarities and Differences in Ligand Binding to Protein and RNA Targets: The Case of Riboflavin. J Chem Inf Model 2024; 64:4570-4586. [PMID: 38800845 DOI: 10.1021/acs.jcim.4c00420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
It is nowadays clear that RNA molecules can play active roles in several biological processes. As a result, an increasing number of RNAs are gradually being identified as potentially druggable targets. In particular, noncoding RNAs can adopt highly organized conformations that are suitable for drug binding. However, RNAs are still considered challenging targets due to their complex structural dynamics and high charge density. Thus, elucidating relevant features of drug-RNA binding is fundamental for advancing drug discovery. Here, by using Molecular Dynamics simulations, we compare key features of ligand binding to proteins with those observed in RNA. Specifically, we explore similarities and differences in terms of (i) conformational flexibility of the target, (ii) electrostatic contribution to binding free energy, and (iii) water and ligand dynamics. As a test case, we examine binding of the same ligand, namely riboflavin, to protein and RNA targets, specifically the riboflavin (RF) kinase and flavin mononucleotide (FMN) riboswitch. The FMN riboswitch exhibited enhanced fluctuations and explored a wider conformational space, compared to the protein target, underscoring the importance of RNA flexibility in ligand binding. Conversely, a similar electrostatic contribution to the binding free energy of riboflavin was found. Finally, greater stability of water molecules was observed in the FMN riboswitch compared to the RF kinase, possibly due to the different shape and polarity of the pockets.
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Affiliation(s)
- Stefano Bosio
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum - University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy
- Computational and Chemical Biology, Fondazione Istituto Italiano di Tecnologia, Via Morego 30, I-16163 Genova, Italy
| | - Mattia Bernetti
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum - University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy
- Computational and Chemical Biology, Fondazione Istituto Italiano di Tecnologia, Via Morego 30, I-16163 Genova, Italy
| | - Walter Rocchia
- Computational mOdelling of NanosCalE and bioPhysical sysTems (CONCEPT) Lab, Istituto Italiano di Tecnologia, Via Melen - 83, B Block, 16152 Genova, Italy
| | - Matteo Masetti
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum - University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy
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7
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Riveros II, Yildirim I. Prediction of 3D RNA Structures from Sequence Using Energy Landscapes of RNA Dimers: Application to RNA Tetraloops. J Chem Theory Comput 2024; 20:4363-4376. [PMID: 38728627 DOI: 10.1021/acs.jctc.4c00189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2024]
Abstract
Access to the three-dimensional structure of RNA enables an ability to gain a more profound understanding of its biological mechanisms, as well as the ability to design RNA-targeting drugs, which can take advantage of the unique chemical environment imposed by a folded RNA structure. Due to the dynamic and structurally complex properties of RNA, both experimental and traditional computational methods have difficulty in determining RNA's 3D structure. Herein, we introduce TAPERSS (Theoretical Analyses, Prediction, and Evaluation of RNA Structures from Sequence), a physics-based fragment assembly method for predicting 3D RNA structures from sequence. Using a fragment library created using discrete path sampling calculations of RNA dinucleoside monophosphates, TAPERSS can sample the physics-based energy landscapes of any RNA sequence with relatively low computational complexity. We have benchmarked TAPERSS on 21 RNA tetraloops, using a combinatorial algorithm as a proof-of-concept. We show that TAPERSS was successfully able to predict the apo-state structures of all 21 RNA hairpins, with 16 of those structures also having low predicted energies as well. We demonstrate that TAPERSS performs most accurately on GNRA-like tetraloops with mostly stacked loop-nucleotides, while having limited success with more dynamic UNCG and CUYG tetraloops, most likely due to the influence of the RNA force field used to create the fragment library. Moreover, we show that TAPERSS can successfully predict the majority of the experimental non-apo states, highlighting its potential in anticipating biologically significant yet unobserved states. This holds great promise for future applications in drug design and related studies. With discussed improvements and implementation of more efficient sampling algorithms, we believe TAPERSS may serve as a useful tool for a physics-based conformational sampling of large RNA structures.
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Affiliation(s)
- Ivan Isaac Riveros
- Department of Chemistry and Biochemistry, Florida Atlantic University, Jupiter, Florida 33458, United States
| | - Ilyas Yildirim
- Department of Chemistry and Biochemistry, Florida Atlantic University, Jupiter, Florida 33458, United States
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8
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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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9
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Campagne S. U1 snRNP Biogenesis Defects in Neurodegenerative Diseases. Chembiochem 2024; 25:e202300864. [PMID: 38459794 DOI: 10.1002/cbic.202300864] [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: 12/22/2023] [Revised: 03/07/2024] [Accepted: 03/08/2024] [Indexed: 03/10/2024]
Abstract
The U1 small ribonucleoprotein (U1 snRNP) plays a pivotal role in the intricate process of gene expression, specifically within nuclear RNA processing. By initiating the splicing reaction and modulating 3'-end processing, U1 snRNP exerts precise control over RNA metabolism and gene expression. This ribonucleoparticle is abundantly present, and its complex biogenesis necessitates shuttling between the nuclear and cytoplasmic compartments. Over the past three decades, extensive research has illuminated the crucial connection between disrupted U snRNP biogenesis and several prominent human diseases, notably various neurodegenerative conditions. The perturbation of U1 snRNP homeostasis has been firmly established in diseases such as Spinal Muscular Atrophy, Pontocerebellar hypoplasia, and FUS-mediated Amyotrophic Lateral Sclerosis. Intriguingly, compelling evidence suggests a potential correlation in Fronto-temporal dementia and Alzheimer's disease as well. Although the U snRNP biogenesis pathway is conserved across all eukaryotic cells, neurons, in particular, appear to be highly susceptible to alterations in spliceosome homeostasis. In contrast, other cell types exhibit a greater resilience to such disturbances. This vulnerability underscores the intricate relationship between U1 snRNP dynamics and the health of neuronal cells, shedding light on potential avenues for understanding and addressing neurodegenerative disorders.
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Affiliation(s)
- Sebastien Campagne
- University of Bordeaux, INSERM U1212, CNRS UMR5320, ARNA unit 146, rue Leo Saignat, 33077, Bordeaux
- Institut Européen de Chimie et de Biologie, 2, rue Robert Escarpit, 33600, Pessac
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10
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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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11
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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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12
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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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13
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Cao J, Wei Z, Nie Y, Chen HZ. Therapeutic potential of alternative splicing in cardiovascular diseases. EBioMedicine 2024; 101:104995. [PMID: 38350330 PMCID: PMC10874720 DOI: 10.1016/j.ebiom.2024.104995] [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: 09/24/2023] [Revised: 01/19/2024] [Accepted: 01/21/2024] [Indexed: 02/15/2024] Open
Abstract
RNA splicing is an important RNA processing step required by multiexon protein-coding mRNAs and some noncoding RNAs. Precise RNA splicing is required for maintaining gene and cell function; however, mis-spliced RNA transcripts can lead to loss- or gain-of-function effects in human diseases. Mis-spliced RNAs induced by gene mutations or the dysregulation of splicing regulators may result in frameshifts, nonsense-mediated decay (NMD), or inclusion/exclusion of exons. Genetic animal models have characterised multiple splicing factors required for cardiac development or function. Moreover, sarcomeric and ion channel genes, which are closely associated with cardiovascular function and disease, are hotspots for AS. Here, we summarise splicing factors and their targets that are associated with cardiovascular diseases, introduce some therapies potentially related to pathological AS targets, and raise outstanding questions and future directions in this field.
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Affiliation(s)
- Jun Cao
- College of Chemistry and Life Science, Beijing University of Technology, Beijing, 100124, PR China; University of Texas Medical Branch at Galveston, TX, 77555, USA
| | - Ziyu Wei
- Department of Biochemistry & Molecular Biology, State Key Laboratory of Common Mechanism Research for Major Diseases, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China
| | - Yu Nie
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China.
| | - Hou-Zao Chen
- Department of Biochemistry & Molecular Biology, State Key Laboratory of Common Mechanism Research for Major Diseases, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China; Medical Epigenetics Research Center, Chinese Academy of Medical Sciences, Beijing, China.
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14
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Kovachka S, Panosetti M, Grimaldi B, Azoulay S, Di Giorgio A, Duca M. Small molecule approaches to targeting RNA. Nat Rev Chem 2024; 8:120-135. [PMID: 38278932 DOI: 10.1038/s41570-023-00569-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2023] [Indexed: 01/28/2024]
Abstract
The development of innovative methodologies to identify RNA binders has attracted enormous attention in chemical biology and drug discovery. Although antibiotics targeting bacterial ribosomal RNA have been on the market for decades, the renewed interest in RNA targeting reflects the need to better understand complex intracellular processes involving RNA. In this context, small molecules are privileged tools used to explore the biological functions of RNA and to validate RNAs as therapeutic targets, and they eventually are to become new drugs. Despite recent progress, the rational design of specific RNA binders requires a better understanding of the interactions which occur with the RNA target to reach the desired biological response. In this Review, we discuss the challenges to approaching this underexplored chemical space, together with recent strategies to bind, interact and affect biologically relevant RNAs.
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Affiliation(s)
- Sandra Kovachka
- Université Côte d'Azur, CNRS, Institute of Chemistry of Nice, Nice, France
| | - Marc Panosetti
- Université Côte d'Azur, CNRS, Institute of Chemistry of Nice, Nice, France
- Molecular Medicine Research Line, Istituto Italiano di Tecnologia (IIT), Genoa, Italy
| | - Benedetto Grimaldi
- Molecular Medicine Research Line, Istituto Italiano di Tecnologia (IIT), Genoa, Italy
| | - Stéphane Azoulay
- Université Côte d'Azur, CNRS, Institute of Chemistry of Nice, Nice, France
| | - Audrey Di Giorgio
- Université Côte d'Azur, CNRS, Institute of Chemistry of Nice, Nice, France
| | - Maria Duca
- Université Côte d'Azur, CNRS, Institute of Chemistry of Nice, Nice, France.
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15
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Romanelli MN, Braconi L, Gabellini A, Manetti D, Marotta G, Teodori E. Synthetic Approaches to Piperazine-Containing Drugs Approved by FDA in the Period of 2011-2023. Molecules 2023; 29:68. [PMID: 38202651 PMCID: PMC10780301 DOI: 10.3390/molecules29010068] [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: 11/24/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
The piperazine moiety is often found in drugs or in bioactive molecules. This widespread presence is due to different possible roles depending on the position in the molecule and on the therapeutic class, but it also depends on the chemical reactivity of piperazine-based synthons, which facilitate its insertion into the molecule. In this paper, we take into consideration the piperazine-containing drugs approved by the Food and Drug Administration between January 2011 and June 2023, and the synthetic methodologies used to prepare the compounds in the discovery and process chemistry are reviewed.
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Affiliation(s)
- Maria Novella Romanelli
- Section of Pharmaceutical and Nutraceutical Science, Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Via Ugo Schiff, 6, Sesto Fiorentino, 50019 Florence, Italy; (L.B.); (A.G.); (D.M.); (G.M.); (E.T.)
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16
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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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17
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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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18
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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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19
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Signoria I, van der Pol WL, Groen EJN. Innovating spinal muscular atrophy models in the therapeutic era. Dis Model Mech 2023; 16:dmm050352. [PMID: 37787662 PMCID: PMC10565113 DOI: 10.1242/dmm.050352] [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] [Indexed: 10/04/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a severe, monogenetic, neuromuscular disease. A thorough understanding of its genetic cause and the availability of robust models has led to the development and approval of three gene-targeting therapies. This is a unique and exciting development for the field of neuromuscular diseases, many of which remain untreatable. The development of therapies for SMA not only opens the door to future therapeutic possibilities for other genetic neuromuscular diseases, but also informs us about the limitations of such treatments. For example, treatment response varies widely and, for many patients, significant disability remains. Currently available SMA models best recapitulate the severe types of SMA, and these models are genetically and phenotypically more homogeneous than patients. Furthermore, treating patients is leading to a shift in phenotypes with increased variability in SMA clinical presentation. Therefore, there is a need to generate model systems that better reflect these developments. Here, we will first discuss current animal models of SMA and their limitations. Next, we will discuss the characteristics required to future-proof models to assist the field in the development of additional, novel therapies for SMA.
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Affiliation(s)
- Ilaria Signoria
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - W. Ludo van der Pol
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Ewout J. N. Groen
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
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20
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Li Q, Kang C. Targeting RNA-binding proteins with small molecules: Perspectives, pitfalls and bifunctional molecules. FEBS Lett 2023; 597:2031-2047. [PMID: 37519019 DOI: 10.1002/1873-3468.14710] [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: 03/01/2023] [Revised: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 08/01/2023]
Abstract
RNA-binding proteins (RBPs) play vital roles in organisms through binding with RNAs to regulate their functions. Small molecules affecting the function of RBPs have been developed, providing new avenues for drug discovery. Herein, we describe the perspectives on developing small molecule regulators of RBPs. The following types of small molecule modulators are of great interest in drug discovery: small molecules binding to RBPs to affect interactions with RNA molecules, bifunctional molecules binding to RNA or RBP to influence their interactions, and other types of molecules that affect the stability of RNA or RBPs. Moreover, we emphasize that the bifunctional molecules may play important roles in small molecule development to overcome the challenges encountered in the process of drug discovery.
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Affiliation(s)
- Qingxin Li
- Guangdong Provincial Engineering Laboratory of Biomass High Value Utilization, Institute of Biological and Medical Engineering, Guangdong Academy of Sciences, Guangzhou, China
| | - Congbao Kang
- Experimental Drug Development Centre, Agency for Science, Technology and Research, Singapore, Singapore
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21
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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: 0] [Impact Index Per Article: 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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22
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Zhang L, Xie X, Djokovic N, Nikolic K, Kosenkov D, Abendroth F, Vázquez O. Reversible Control of RNA Splicing by Photoswitchable Small Molecules. J Am Chem Soc 2023. [PMID: 37276581 DOI: 10.1021/jacs.3c03275] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Dynamics are intrinsic to both RNA function and structure. Yet, the available means to precisely provide RNA-based processes with spatiotemporal resolution are scarce. Here, our work pioneers a reversible approach to regulate RNA splicing within primary patient-derived cells by synthetic photoswitches. Our small molecule enables conditional real-time control at mRNA and protein levels. NMR experiments, together with theoretical calculations, photochemical characterization, fluorescence polarization measurements, and living cell-based assays, confirmed light-dependent exon inclusion as well as an increase in the target functional protein. Therefore, we first demonstrated the potential of photopharmacology modulation in splicing, tweaking the current optochemical toolkit. The timeliness on the consolidation of RNA research as the driving force toward therapeutical innovation holds the promise that our approach will contribute to redrawing the vision of RNA.
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Affiliation(s)
- Lei Zhang
- Department of Chemistry, University of Marburg, Marburg, D-35043, Germany
| | - Xiulan Xie
- Department of Chemistry, University of Marburg, Marburg, D-35043, Germany
| | - Nemanja Djokovic
- Department of Pharmaceutical Chemistry, University of Belgrade, Belgrade, 11000, Serbia
| | - Katarina Nikolic
- Department of Pharmaceutical Chemistry, University of Belgrade, Belgrade, 11000, Serbia
| | - Dmitri Kosenkov
- Department of Chemistry and Physics, Monmouth University, West Long Branch, New Jersey 07764, United States
| | - Frank Abendroth
- Department of Chemistry, University of Marburg, Marburg, D-35043, Germany
| | - Olalla Vázquez
- Department of Chemistry, University of Marburg, Marburg, D-35043, Germany
- Center for Synthetic Microbiology (SYNMIKRO), University of Marburg, Marburg, D-35043, Germany
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23
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Lim WF, Rinaldi C. RNA Transcript Diversity in Neuromuscular Research. J Neuromuscul Dis 2023:JND221601. [PMID: 37182892 DOI: 10.3233/jnd-221601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Three decades since the Human Genome Project began, scientists have now identified more then 25,000 protein coding genes in the human genome. The vast majority of the protein coding genes (> 90%) are multi-exonic, with the coding DNA being interrupted by intronic sequences, which are removed from the pre-mRNA transcripts before being translated into proteins, a process called splicing maturation. Variations in this process, i.e. by exon skipping, intron retention, alternative 5' splice site (5'ss), 3' splice site (3'ss), or polyadenylation usage, lead to remarkable transcriptome and proteome diversity in human tissues. Given its critical biological importance, alternative splicing is tightly regulated in a tissue- and developmental stage-specific manner. The central nervous system and skeletal muscle are amongst the tissues with the highest number of differentially expressed alternative exons, revealing a remarkable degree of transcriptome complexity. It is therefore not surprising that splicing mis-regulation is causally associated with a myriad of neuromuscular diseases, including but not limited to amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), Duchenne muscular dystrophy (DMD), and myotonic dystrophy type 1 and 2 (DM1, DM2). A gene's transcript diversity has since become an integral and an important consideration for drug design, development and therapy. In this review, we will discuss transcript diversity in the context of neuromuscular diseases and current approaches to address splicing mis-regulation.
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Affiliation(s)
- Wooi Fang Lim
- Department of Paediatrics and Institute of Developmental and Regenerative Medicine, University of Oxford, Oxford, UK
| | - Carlo Rinaldi
- Department of Paediatrics and Institute of Developmental and Regenerative Medicine, University of Oxford, Oxford, UK
- MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford, UK
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24
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Rogalska ME, Vivori C, Valcárcel J. Regulation of pre-mRNA splicing: roles in physiology and disease, and therapeutic prospects. Nat Rev Genet 2023; 24:251-269. [PMID: 36526860 DOI: 10.1038/s41576-022-00556-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2022] [Indexed: 12/23/2022]
Abstract
The removal of introns from mRNA precursors and its regulation by alternative splicing are key for eukaryotic gene expression and cellular function, as evidenced by the numerous pathologies induced or modified by splicing alterations. Major recent advances have been made in understanding the structures and functions of the splicing machinery, in the description and classification of physiological and pathological isoforms and in the development of the first therapies for genetic diseases based on modulation of splicing. Here, we review this progress and discuss important remaining challenges, including predicting splice sites from genomic sequences, understanding the variety of molecular mechanisms and logic of splicing regulation, and harnessing this knowledge for probing gene function and disease aetiology and for the design of novel therapeutic approaches.
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Affiliation(s)
- Malgorzata Ewa Rogalska
- Genome Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Claudia Vivori
- Genome Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Department of Medicine and Life Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain
- The Francis Crick Institute, London, UK
| | - Juan Valcárcel
- Genome Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.
- Department of Medicine and Life Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
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25
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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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26
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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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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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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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Bracamonte AG. Current Advances in Nanotechnology for the Next Generation of Sequencing (NGS). BIOSENSORS 2023; 13:260. [PMID: 36832027 PMCID: PMC9954403 DOI: 10.3390/bios13020260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/03/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
This communication aims at discussing strategies based on developments from nanotechnology focused on the next generation of sequencing (NGS). In this regard, it should be noted that even in the advanced current situation of many techniques and methods accompanied with developments of technology, there are still existing challenges and needs focused on real samples and low concentrations of genomic materials. The approaches discussed/described adopt spectroscopical techniques and new optical setups. PCR bases are introduced to understand the role of non-covalent interactions by discussing about Nobel prizes related to genomic material detection. The review also discusses colorimetric methods, polymeric transducers, fluorescence detection methods, enhanced plasmonic techniques such as metal-enhanced fluorescence (MEF), semiconductors, and developments in metamaterials. In addition, nano-optics, challenges linked to signal transductions, and how the limitations reported in each technique could be overcome are considered in real samples. Accordingly, this study shows developments where optical active nanoplatforms generate signal detection and transduction with enhanced performances and, in many cases, enhanced signaling from single double-stranded deoxyribonucleic acid (DNA) interactions. Future perspectives on miniaturized instrumentation, chips, and devices aimed at detecting genomic material are analyzed. However, the main concept in this report derives from gained insights into nanochemistry and nano-optics. Such concepts could be incorporated into other higher-sized substrates and experimental and optical setups.
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Affiliation(s)
- Angel Guillermo Bracamonte
- Instituto de Investigaciones en Físicoquímica de Córdoba (INFIQC), Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina; or
- Departement de Chimie et Centre d’Optique, Photonique et Laser (COPL), Université Laval, Québec, QC G1V 0A6, Canada
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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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Childs-Disney JL, Yang X, Gibaut QMR, Tong Y, Batey RT, Disney MD. Targeting RNA structures with small molecules. Nat Rev Drug Discov 2022; 21:736-762. [PMID: 35941229 PMCID: PMC9360655 DOI: 10.1038/s41573-022-00521-4] [Citation(s) in RCA: 159] [Impact Index Per Article: 79.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2022] [Indexed: 01/07/2023]
Abstract
RNA adopts 3D structures that confer varied functional roles in human biology and dysfunction in disease. Approaches to therapeutically target RNA structures with small molecules are being actively pursued, aided by key advances in the field including the development of computational tools that predict evolutionarily conserved RNA structures, as well as strategies that expand mode of action and facilitate interactions with cellular machinery. Existing RNA-targeted small molecules use a range of mechanisms including directing splicing - by acting as molecular glues with cellular proteins (such as branaplam and the FDA-approved risdiplam), inhibition of translation of undruggable proteins and deactivation of functional structures in noncoding RNAs. Here, we describe strategies to identify, validate and optimize small molecules that target the functional transcriptome, laying out a roadmap to advance these agents into the next decade.
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Affiliation(s)
| | - Xueyi Yang
- Department of Chemistry, Scripps Research, Jupiter, FL, USA
| | | | - Yuquan Tong
- Department of Chemistry, Scripps Research, Jupiter, FL, USA
| | - Robert T Batey
- Department of Biochemistry, University of Colorado, Boulder, CO, USA.
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Rozza R, Janoš P, Spinello A, Magistrato A. Role of computational and structural biology in the development of small-molecule modulators of the spliceosome. Expert Opin Drug Discov 2022; 17:1095-1109. [PMID: 35983696 DOI: 10.1080/17460441.2022.2114452] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
INTRODUCTION RNA splicing is a pivotal step of eukaryotic gene expression during which the introns are excised from the precursor (pre-)RNA and the exons are joined together to form mature RNA products (i.e a protein-coding mRNA or long non-coding (lnc)RNAs). The spliceosome, a complex ribonucleoprotein machine, performs pre-RNA splicing with extreme precision. Deregulated splicing is linked to cancer, genetic, and neurodegenerative diseases. Hence, the discovery of small-molecules targeting core spliceosome components represents an appealing therapeutic opportunity. AREA COVERED Several atomic-level structures of the spliceosome and distinct splicing-modulators bound to its protein/RNA components have been solved. Here, we review recent advances in the discovery of small-molecule splicing-modulators, discuss opportunities and challenges for their therapeutic applicability, and showcase how structural data and/or all-atom simulations can illuminate key facets of their mechanism, thus contributing to future drug-discovery campaigns. EXPERT OPINION This review highlights the potential of modulating pre-RNA splicing with small-molecules, and anticipates how the synergy of computer and wet-lab experiments will enrich our understanding of splicing regulation/deregulation mechanisms. This information will aid future structure-based drug-discovery efforts aimed to expand the currently limited portfolio of selective splicing-modulators.
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Affiliation(s)
- Riccardo Rozza
- National Research Council of Italy, Institute of Materials-foundry (CNR-IOM) C/o SISSA, Trieste, Italy
| | - Pavel Janoš
- National Research Council of Italy, Institute of Materials-foundry (CNR-IOM) C/o SISSA, Trieste, Italy
| | - Angelo Spinello
- Department of Biological, Chemical and Pharmaceutical Sciences, University of Palermo, Palermo, Italy
| | - Alessandra Magistrato
- National Research Council of Italy, Institute of Materials-foundry (CNR-IOM) C/o SISSA, Trieste, Italy
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Romanelli MN, Manetti D, Braconi L, Dei S, Gabellini A, Teodori E. The piperazine scaffold for novel drug discovery efforts: the evidence to date. Expert Opin Drug Discov 2022; 17:969-984. [PMID: 35848922 DOI: 10.1080/17460441.2022.2103535] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION . Piperazine is a structural element present in drugs belonging to various chemical classes and used for numerous different therapeutic applications; it has been considered a privileged scaffold for drug design. AREAS COVERED The authors have searched examples of piperazine-containing compounds among drugs recently approved by the FDA, and in some research fields (nicotinic receptor modulators, compounds acting against cancer and bacterial multi-drug resistance), looking in particular to the design behind the insertion of this moiety. EXPERT OPINION Piperazine is widely used due to its peculiar characteristics, such as solubility, basicity, chemical reactivity, and conformational properties. This moiety has represented an important tool to modulate pharmacokinetic and pharmacodynamic properties of drugs.
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Affiliation(s)
- Maria Novella Romanelli
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), University of Florence, Section of Pharmaceutical and Nutraceutical Sciences, Via Ugo Schiff 6, 50019, Sesto Fiorentino, Italy
| | - Dina Manetti
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), University of Florence, Section of Pharmaceutical and Nutraceutical Sciences, Via Ugo Schiff 6, 50019, Sesto Fiorentino, Italy
| | - Laura Braconi
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), University of Florence, Section of Pharmaceutical and Nutraceutical Sciences, Via Ugo Schiff 6, 50019, Sesto Fiorentino, Italy
| | - Silvia Dei
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), University of Florence, Section of Pharmaceutical and Nutraceutical Sciences, Via Ugo Schiff 6, 50019, Sesto Fiorentino, Italy
| | - Alessio Gabellini
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), University of Florence, Section of Pharmaceutical and Nutraceutical Sciences, Via Ugo Schiff 6, 50019, Sesto Fiorentino, Italy
| | - Elisabetta Teodori
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), University of Florence, Section of Pharmaceutical and Nutraceutical Sciences, Via Ugo Schiff 6, 50019, Sesto Fiorentino, Italy
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Singh NN, O'Leary CA, Eich T, Moss WN, Singh RN. Structural Context of a Critical Exon of Spinal Muscular Atrophy Gene. Front Mol Biosci 2022; 9:928581. [PMID: 35847983 PMCID: PMC9283826 DOI: 10.3389/fmolb.2022.928581] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
Humans contain two nearly identical copies of Survival Motor Neuron genes, SMN1 and SMN2. Deletion or mutation of SMN1 causes spinal muscular atrophy (SMA), one of the leading genetic diseases associated with infant mortality. SMN2 is unable to compensate for the loss of SMN1 due to predominant exon 7 skipping, leading to the production of a truncated protein. Antisense oligonucleotide and small molecule-based strategies aimed at the restoration of SMN2 exon 7 inclusion are approved therapies of SMA. Many cis-elements and transacting factors have been implicated in regulation of SMN exon 7 splicing. Also, several structural elements, including those formed by a long-distance interaction, have been implicated in the modulation of SMN exon 7 splicing. Several of these structures have been confirmed by enzymatic and chemical structure-probing methods. Additional structures formed by inter-intronic interactions have been predicted by computational algorithms. SMN genes generate a vast repertoire of circular RNAs through inter-intronic secondary structures formed by inverted Alu repeats present in large number in SMN genes. Here, we review the structural context of the exonic and intronic cis-elements that promote or prevent exon 7 recognition. We discuss how structural rearrangements triggered by single nucleotide substitutions could bring drastic changes in SMN2 exon 7 splicing. We also propose potential mechanisms by which inter-intronic structures might impact the splicing outcomes.
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Affiliation(s)
- Natalia N. Singh
- Department of Biomedical Science, Iowa State University, Ames, IA, United States
| | - Collin A. O'Leary
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
| | - Taylor Eich
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
| | - Walter N. Moss
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
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Donlic A, Swanson EG, Chiu LY, Wicks SL, Umuhire Juru A, Cai Z, Kassam K, Laudeman C, Sanaba BG, Sugarman A, Han E, Tolbert BS, Hargrove AE. R-BIND 2.0: An Updated Database of Bioactive RNA-Targeting Small Molecules and Associated RNA Secondary Structures. ACS Chem Biol 2022; 17:1556-1566. [PMID: 35594415 PMCID: PMC9343015 DOI: 10.1021/acschembio.2c00224] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Discoveries of RNA roles in cellular physiology and pathology are increasing the need for new tools that modulate the structure and function of these biomolecules, and small molecules are proving useful. In 2017, we curated the RNA-targeted BIoactive ligaNd Database (R-BIND) and discovered distinguishing physicochemical properties of RNA-targeting ligands, leading us to propose the existence of an "RNA-privileged" chemical space. Biennial updates of the database and the establishment of a website platform (rbind.chem.duke.edu) have provided new insights and tools to design small molecules based on the analyzed physicochemical and spatial properties. In this report and R-BIND 2.0 update, we refined the curation approach and ligand classification system as well as conducted analyses of RNA structure elements for the first time to identify new targeting strategies. Specifically, we curated and analyzed RNA target structural motifs to determine the properties of small molecules that may confer selectivity for distinct RNA secondary and tertiary structures. Additionally, we collected sequences of target structures and incorporated an RNA structure search algorithm into the website that outputs small molecules targeting similar motifs without a priori secondary structure knowledge. Cheminformatic analyses revealed that, despite the 50% increase in small molecule library size, the distinguishing properties of R-BIND ligands remained significantly different from that of proteins and are therefore still relevant to RNA-targeted probe discovery. Combined, we expect these novel insights and website features to enable the rational design of RNA-targeted ligands and to serve as a resource and inspiration for a variety of scientists interested in RNA targeting.
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Affiliation(s)
| | | | - Liang-Yuan Chiu
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 441106, United States
| | - Sarah L. Wicks
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
| | - Aline Umuhire Juru
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
| | - Zhengguo Cai
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
| | - Kamillah Kassam
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
| | - Chris Laudeman
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
| | - Bilva G. Sanaba
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
| | - Andrew Sugarman
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 441106, United States
| | - Eunseong Han
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
| | - Blanton S. Tolbert
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 441106, United States
| | - Amanda E. Hargrove
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
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Byun WG, Lim D, Park SB. Small-molecule modulators of protein–RNA interactions. Curr Opin Chem Biol 2022; 68:102149. [DOI: 10.1016/j.cbpa.2022.102149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/17/2022] [Accepted: 03/21/2022] [Indexed: 11/16/2022]
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Zhang L, Abendroth F, Vázquez O. A Chemical Biology Perspective to Therapeutic Regulation of RNA Splicing in Spinal Muscular Atrophy (SMA). ACS Chem Biol 2022; 17:1293-1307. [PMID: 35639849 DOI: 10.1021/acschembio.2c00161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Manipulation of RNA splicing machinery has emerged as a drug modality. Here, we illustrate the potential of this novel paradigm to correct aberrant splicing events focused on the recent therapeutic advances in spinal muscular atrophy (SMA). SMA is an incurable neuromuscular disorder and at present the primary genetic cause of early infant death. This Review summarizes the exciting journey from the first reported SMA cases to the currently approved splicing-switching treatments, i.e., antisense oligonucleotides and small-molecule modifiers. We emphasize both chemical structures and molecular bases for recognition. We briefly discuss the advantages and disadvantages of these treatments and include the remaining challenges and future directions. Finally, we also predict that these success stories will contribute to further therapies for human diseases by RNA-splicing control.
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Affiliation(s)
- Lei Zhang
- Department of Chemistry, University of Marburg, Hans-Meerwein-Straße 4, 35043, Marburg, Germany
| | - Frank Abendroth
- Department of Chemistry, University of Marburg, Hans-Meerwein-Straße 4, 35043, Marburg, Germany
| | - Olalla Vázquez
- Department of Chemistry, University of Marburg, Hans-Meerwein-Straße 4, 35043, Marburg, Germany
- Center for Synthetic Microbiology (SYNMIKRO), University of Marburg, Karl-von-Frisch-Straße 14, 35043 Marburg, Germany
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Phenotypic drug discovery: recent successes, lessons learned and new directions. Nat Rev Drug Discov 2022; 21:899-914. [DOI: 10.1038/s41573-022-00472-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2022] [Indexed: 12/29/2022]
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Autophagy regulation by RNA alternative splicing and implications in human diseases. Nat Commun 2022; 13:2735. [PMID: 35585060 PMCID: PMC9117662 DOI: 10.1038/s41467-022-30433-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 04/29/2022] [Indexed: 02/06/2023] Open
Abstract
Autophagy and RNA alternative splicing are two evolutionarily conserved processes involved in overlapping physiological and pathological processes. However, the extent of functional connection is not well defined. Here, we consider the role for alternative splicing and generation of autophagy-related gene isoforms in the regulation of autophagy in recent work. The impact of changes to the RNA alternative splicing machinery and production of alternative spliced isoforms on autophagy are reviewed with particular focus on disease relevance. The use of drugs targeting both alternative splicing and autophagy as well as the selective regulation of single autophagy-related protein isoforms, are considered as therapeutic strategies. Both alternative splicing and autophagy are core cell biological processes, but where they intersect has received little attention. Here, the authors reflect on recent connections identified between these pathways and consider their impact on human disease.
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Möller L, Guerci L, Isert C, Atz K, Schneider G. Translating from proteins to ribonucleic acids for ligand-binding site detection. Mol Inform 2022; 41:e2200059. [PMID: 35577762 DOI: 10.1002/minf.202200059] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 05/16/2022] [Indexed: 11/10/2022]
Abstract
Identifying druggable ligand-binding sites on the surface of the macromolecular targets is an important process in structure-based drug discovery. Deep-learning models have been shown to successfully predict ligand-binding sites of proteins. As a step toward predicting binding sites in RNA and RNA-protein complexes, we employ three-dimensional convolutional neural networks. We introduce a dataset splitting approach to minimize structure-related bias in training data, and investigate the influence of protein-based neural network pre-training before fine-tuning on RNA structures. Models that were pre-trained on proteins considerably outperformed the models that were trained exclusively on RNA structures. Overall, 71% of the known RNA binding sites were correctly located within 4 Å of their true centres with a structural overlap of at least 25%.
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Markati T, Fisher G, Ramdas S, Servais L. Risdiplam: an investigational motor neuron-2 (SMN-2) splicing modifier for spinal muscular atrophy (SMA). Expert Opin Investig Drugs 2022; 31:451-461. [PMID: 35316106 DOI: 10.1080/13543784.2022.2056836] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Spinal muscular atrophy (SMA) is a rare autosomal recessive neuromuscular disease which is characterized by muscle atrophy and early death in most patients. Risdiplam is the third overall and first oral drug approved for SMA with disease-modifying potential. Risdiplam acts as a survival motor neuron 2 (SMN2) pre-mRNA splicing modifier with satisfactory safety and efficacy profile. This review aims to critically appraise the place of risdiplam in the map of SMA therapeutics. AREAS COVERED This review gives an overview of the current market for SMA and presents the mechanism of action and the pharmacological properties of risdiplam. It also outlines the development of risdiplam from early preclinical stages through to the most recently published results from phase 2/3 clinical trials. Risdiplam has proved its efficacy in pivotal trials for SMA Types 1, 2, and 3 with a satisfactory safety profile. EXPERT OPINION In the absence of comparative data with the other two approved drugs, the role of risdiplam in the treatment algorithm of affected individuals is examined in three different patient populations based on the age and diagnosis method (newborn screening or clinical, symptom-driven diagnosis). Long-term data and real-world data will play a fundamental role in its future.
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Affiliation(s)
- Theodora Markati
- MDUK Oxford Neuromuscular Center, Department of Paediatrics, University of Oxford, Oxford, UK.,Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Gemma Fisher
- MDUK Oxford Neuromuscular Center, Department of Paediatrics, University of Oxford, Oxford, UK.,Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Sithara Ramdas
- MDUK Oxford Neuromuscular Center, Department of Paediatrics, University of Oxford, Oxford, UK.,Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Laurent Servais
- MDUK Oxford Neuromuscular Center, Department of Paediatrics, University of Oxford, Oxford, UK.,Oxford University Hospitals NHS Foundation Trust, Oxford, UK.,Division of Child Neurology, Centre de Références des Maladies Neuromusculaires, Department of Pediatrics, University Hospital Liège & University of Liège, Belgium
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Reprogramming RNA processing: an emerging therapeutic landscape. Trends Pharmacol Sci 2022; 43:437-454. [PMID: 35331569 DOI: 10.1016/j.tips.2022.02.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 12/13/2022]
Abstract
The production of a mature mRNA requires coordination of multiple processing steps, which ultimately control its content, localization, and stability. These steps include some of the largest macromolecular machines in the cell, which were, until recently, considered undruggable due to their biological complexity. Building from an expanded understanding of the underlying mechanisms that drive these processes, a new wave of therapeutics is seeking to target RNA processing. With a focus on impacting gene regulation at the RNA level, such modalities offer potential for sequence-specific resolution in drug design. Here, we review our current understanding of RNA-processing events and their role in gene regulation, with a focus on the therapeutic opportunities that have emerged within this landscape.
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43
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Cao S, Kang S, Mao H, Yao J, Gu L, Zheng N. Defining molecular glues with a dual-nanobody cannabidiol sensor. Nat Commun 2022; 13:815. [PMID: 35145136 PMCID: PMC8831599 DOI: 10.1038/s41467-022-28507-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/27/2022] [Indexed: 12/14/2022] Open
Abstract
"Molecular glue" (MG) is a term coined to describe the mechanism of action of the plant hormone auxin and subsequently used to characterize synthetic small molecule protein degraders exemplified by immune-modulatory imide drugs (IMiDs). Prospective development of MGs, however, has been hampered by its elusive definition and thermodynamic characteristics. Here, we report the crystal structure of a dual-nanobody cannabidiol-sensing system, in which the ligand promotes protein-protein interaction in a manner analogous to auxin. Through quantitative analyses, we draw close parallels among the dual-nanobody cannabidiol sensor, the auxin perception complex, and the IMiDs-bound CRL4CRBN E3, which can bind and ubiquitinate "neo-substrates". All three systems, including the recruitment of IKZF1 and CK1α to CRBN, are characterized by the lack of ligand binding activity in at least one protein partner and an under-appreciated preexisting low micromolar affinity between the two proteinaceous subunits that is enhanced by the ligand to reach the nanomolar range. These two unifying features define MGs as a special class of proximity inducers distinct from bifunctional compounds and can be used as criteria to guide target selection for future rational discovery of MGs.
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Affiliation(s)
- Shiyun Cao
- Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA
| | - Shoukai Kang
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Haibin Mao
- Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA
| | - Jiayu Yao
- Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA
| | - Liangcai Gu
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Ning Zheng
- Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA.
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44
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Jobbins AM, Campagne S, Weinmeister R, Lucas CM, Gosliga AR, Clery A, Chen L, Eperon LP, Hodson MJ, Hudson AJ, Allain FHT, Eperon IC. Exon-independent recruitment of SRSF1 is mediated by U1 snRNP stem-loop 3. EMBO J 2022; 41:e107640. [PMID: 34779515 PMCID: PMC8724738 DOI: 10.15252/embj.2021107640] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 10/04/2021] [Accepted: 10/07/2021] [Indexed: 12/11/2022] Open
Abstract
SRSF1 protein and U1 snRNPs are closely connected splicing factors. They both stimulate exon inclusion, SRSF1 by binding to exonic splicing enhancer sequences (ESEs) and U1 snRNPs by binding to the downstream 5' splice site (SS), and both factors affect 5' SS selection. The binding of U1 snRNPs initiates spliceosome assembly, but SR proteins such as SRSF1 can in some cases substitute for it. The mechanistic basis of this relationship is poorly understood. We show here by single-molecule methods that a single molecule of SRSF1 can be recruited by a U1 snRNP. This reaction is independent of exon sequences and separate from the U1-independent process of binding to an ESE. Structural analysis and cross-linking data show that SRSF1 contacts U1 snRNA stem-loop 3, which is required for splicing. We suggest that the recruitment of SRSF1 to a U1 snRNP at a 5'SS is the basis for exon definition by U1 snRNP and might be one of the principal functions of U1 snRNPs in the core reactions of splicing in mammals.
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Affiliation(s)
- Andrew M Jobbins
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
- Present address:
MRC London Institute of Medical SciencesLondonUK
- Present address:
Institute of Clinical SciencesImperial College LondonLondonUK
| | - Sébastien Campagne
- Institute of BiochemistryETH ZürichSwitzerland
- Present address:
Inserm U1212CNRS UMR5320ARNA LaboratoryBordeaux CedexFrance
| | - Robert Weinmeister
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
- Leicester Institute of Structural & Chemical Biology and Department of ChemistryUniversity of LeicesterLeicesterUK
| | - Christian M Lucas
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| | - Alison R Gosliga
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
- Present address:
Institut für Industrielle GenetikAbt.(eilung) SystembiologieUniversität StuttgartStuttgartGermany
| | | | - Li Chen
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| | - Lucy P Eperon
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| | - Mark J Hodson
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| | - Andrew J Hudson
- Leicester Institute of Structural & Chemical Biology and Department of ChemistryUniversity of LeicesterLeicesterUK
| | | | - Ian C Eperon
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
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45
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Jablonka S, Hennlein L, Sendtner M. Therapy development for spinal muscular atrophy: perspectives for muscular dystrophies and neurodegenerative disorders. Neurol Res Pract 2022; 4:2. [PMID: 34983696 PMCID: PMC8725368 DOI: 10.1186/s42466-021-00162-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 10/21/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Major efforts have been made in the last decade to develop and improve therapies for proximal spinal muscular atrophy (SMA). The introduction of Nusinersen/Spinraza™ as an antisense oligonucleotide therapy, Onasemnogene abeparvovec/Zolgensma™ as an AAV9-based gene therapy and Risdiplam/Evrysdi™ as a small molecule modifier of pre-mRNA splicing have set new standards for interference with neurodegeneration. MAIN BODY Therapies for SMA are designed to interfere with the cellular basis of the disease by modifying pre-mRNA splicing and enhancing expression of the Survival Motor Neuron (SMN) protein, which is only expressed at low levels in this disorder. The corresponding strategies also can be applied to other disease mechanisms caused by loss of function or toxic gain of function mutations. The development of therapies for SMA was based on the use of cell culture systems and mouse models, as well as innovative clinical trials that included readouts that had originally been introduced and optimized in preclinical studies. This is summarized in the first part of this review. The second part discusses current developments and perspectives for amyotrophic lateral sclerosis, muscular dystrophies, Parkinson's and Alzheimer's disease, as well as the obstacles that need to be overcome to introduce RNA-based therapies and gene therapies for these disorders. CONCLUSION RNA-based therapies offer chances for therapy development of complex neurodegenerative disorders such as amyotrophic lateral sclerosis, muscular dystrophies, Parkinson's and Alzheimer's disease. The experiences made with these new drugs for SMA, and also the experiences in AAV gene therapies could help to broaden the spectrum of current approaches to interfere with pathophysiological mechanisms in neurodegeneration.
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Affiliation(s)
- Sibylle Jablonka
- Institute of Clinical Neurobiology, University Hospital of Wuerzburg, Versbacher Str. 5, 97078, Wuerzburg, Germany.
| | - Luisa Hennlein
- Institute of Clinical Neurobiology, University Hospital of Wuerzburg, Versbacher Str. 5, 97078, Wuerzburg, Germany
| | - Michael Sendtner
- Institute of Clinical Neurobiology, University Hospital of Wuerzburg, Versbacher Str. 5, 97078, Wuerzburg, Germany.
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46
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Abstract
In Eukarya, immature mRNA transcripts (pre-mRNA) often contain coding sequences, or exons, interleaved by non-coding sequences, or introns. Introns are removed upon splicing, and further regulation of the retained exons leads to alternatively spliced mRNA. The splicing reaction requires the stepwise assembly of the spliceosome, a macromolecular machine composed of small nuclear ribonucleoproteins (snRNPs). This review focuses on the early stage of spliceosome assembly, when U1 snRNP defines each intron 5’-splice site (5ʹss) in the pre-mRNA. We first introduce the splicing reaction and the impact of alternative splicing on gene expression regulation. Thereafter, we extensively discuss splicing descriptors that influence the 5ʹss selection by U1 snRNP, such as sequence determinants, and interactions mediated by U1-specific proteins or U1 small nuclear RNA (U1 snRNA). We also include examples of diseases that affect the 5ʹss selection by U1 snRNP, and discuss recent therapeutic advances that manipulate U1 snRNP 5ʹss selectivity with antisense oligonucleotides and small-molecule splicing switches.
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Affiliation(s)
- Florian Malard
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux, Bordeaux Cedex, France
| | - Cameron D Mackereth
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux, Bordeaux Cedex, France
| | - Sébastien Campagne
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux, Bordeaux Cedex, France
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47
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Campagne S, de Vries T, Allain FHT. Probing the Interactions of Splicing Regulatory Small Molecules and Proteins with U1 snRNP Using NMR Spectroscopy. Methods Mol Biol 2022; 2537:247-262. [PMID: 35895269 DOI: 10.1007/978-1-0716-2521-7_15] [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] [Indexed: 06/15/2023]
Abstract
Alternative RNA splicing is an essential part of gene expression that not only increases the protein diversity of metazoan but also provides an additional layer of gene expression regulation. The U1 small ribonucleoparticle (U1 snRNP) plays an essential role in seeding spliceosome assembly and its binding on weak 5'-splice sites is regulated by transient interactions with splicing factors. Recent progress in allele specific splicing correction has shown the therapeutic potential offered by small molecule splicing modifiers that specifically promotes the recruitment of U1 snRNP to modulate alternative splicing and gene expression. Here, we described a method to reconstitute U1 snRNP in vitro and to study labile interactions with protein or synthetic splicing factors using solution state NMR spectroscopy. This approach allowed us to validate direct interactions between splicing regulators and U1 snRNP and could also be useful for the screening of small molecules acting on splicing regulation.
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Affiliation(s)
- Sébastien Campagne
- ARNA Laboratory, INSERM U1212, CNRS 5320, University of Bordeaux, Bordeaux, France.
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology, Zurich, Switzerland.
| | - Tebbe de Vries
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Frédéric H-T Allain
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology, Zurich, Switzerland.
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48
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Abstract
Targeting of pre-mRNA splicing has yielded a rich variety of strategies for altering gene expression as a treatment for disease. The search for therapeutics that can modulate splicing has been dominated by antisense oligonucleotides (ASOs) and small molecule compounds, with each platform achieving remarkably effective results in the clinic. The success of RNA-targeting drugs has led to the exploration of new strategies to expand the repertoire of this type of therapeutic. Here, we discuss some of the more common causes of faulty gene expression and provide examples of approaches that have been developed to target and correct these defects for therapeutic value.
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Affiliation(s)
- Jessica L Centa
- Center for Genetic Diseases, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Michelle L Hastings
- Center for Genetic Diseases, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA.
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49
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Small molecule splicing modifiers with systemic HTT-lowering activity. Nat Commun 2021; 12:7299. [PMID: 34911927 PMCID: PMC8674292 DOI: 10.1038/s41467-021-27157-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 10/28/2021] [Indexed: 02/07/2023] Open
Abstract
Huntington's disease (HD) is a hereditary neurodegenerative disorder caused by expansion of cytosine-adenine-guanine (CAG) trinucleotide repeats in the huntingtin (HTT) gene. Consequently, the mutant protein is ubiquitously expressed and drives pathogenesis of HD through a toxic gain-of-function mechanism. Animal models of HD have demonstrated that reducing huntingtin (HTT) protein levels alleviates motor and neuropathological abnormalities. Investigational drugs aim to reduce HTT levels by repressing HTT transcription, stability or translation. These drugs require invasive procedures to reach the central nervous system (CNS) and do not achieve broad CNS distribution. Here, we describe the identification of orally bioavailable small molecules with broad distribution throughout the CNS, which lower HTT expression consistently throughout the CNS and periphery through selective modulation of pre-messenger RNA splicing. These compounds act by promoting the inclusion of a pseudoexon containing a premature termination codon (stop-codon psiExon), leading to HTT mRNA degradation and reduction of HTT levels.
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50
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King R, Lin Z, Balbin-Cuesta G, Myers G, Friedman A, Zhu G, McGee B, Saunders TL, Kurita R, Nakamura Y, Engel JD, Reddy P, Khoriaty R. SEC23A rescues SEC23B-deficient congenital dyserythropoietic anemia type II. SCIENCE ADVANCES 2021; 7:eabj5293. [PMID: 34818036 PMCID: PMC8612686 DOI: 10.1126/sciadv.abj5293] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 10/04/2021] [Indexed: 05/12/2023]
Abstract
Congenital dyserythropoietic anemia type II (CDAII) results from loss-of-function mutations in SEC23B. In contrast to humans, SEC23B-deficient mice deletion do not exhibit CDAII but die perinatally with pancreatic degeneration. Here, we demonstrate that expression of the full SEC23A protein (the SEC23B paralog) from the endogenous regulatory elements of Sec23b completely rescues the SEC23B-deficient mouse phenotype. Consistent with these data, while mice with erythroid-specific deletion of either Sec23a or Sec23b do not exhibit CDAII, we now show that mice with erythroid-specific deletion of all four Sec23 alleles die in mid-embryogenesis with features of CDAII and that mice with deletion of three Sec23 alleles exhibit a milder erythroid defect. To test whether the functional overlap between the SEC23 paralogs is conserved in human erythroid cells, we generated SEC23B-deficient HUDEP-2 cells. Upon differentiation, these cells exhibited features of CDAII, which were rescued by increased expression of SEC23A, suggesting a novel therapeutic strategy for CDAII.
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Affiliation(s)
- Richard King
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA
| | - Zesen Lin
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Ginette Balbin-Cuesta
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
- Medical Scientist Training Program, University of Michigan, Ann Arbor, MI, USA
| | - Gregg Myers
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Ann Friedman
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Guojing Zhu
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Beth McGee
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Thomas L. Saunders
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- Transgenic Animal Model Core, University of Michigan, Ann Arbor, MI, USA
| | - Ryo Kurita
- Department of Research and Development, Central Blood Institute, Blood Service Headquarters, Japanese Red Cross Society, Tokyo, Japan
| | - Yukio Nakamura
- Cell Engineering Division, RIKEN BioResource Research Center, Ibaraki, Japan
| | - James Douglas Engel
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Pavan Reddy
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
| | - Rami Khoriaty
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
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