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Cantara S, Simoncelli G, Ricci C. Antisense Oligonucleotides (ASOs) in Motor Neuron Diseases: A Road to Cure in Light and Shade. Int J Mol Sci 2024; 25:4809. [PMID: 38732027 PMCID: PMC11083842 DOI: 10.3390/ijms25094809] [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: 02/28/2024] [Revised: 04/23/2024] [Accepted: 04/26/2024] [Indexed: 05/13/2024] Open
Abstract
Antisense oligonucleotides (ASOs) are short oligodeoxynucleotides designed to bind to specific regions of target mRNA. ASOs can modulate pre-mRNA splicing, increase levels of functional proteins, and decrease levels of toxic proteins. ASOs are being developed for the treatment of motor neuron diseases (MNDs), including spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS) and spinal and bulbar muscular atrophy (SBMA). The biggest success has been the ASO known as nusinersen, the first effective therapy for SMA, able to improve symptoms and slow disease progression. Another success is tofersen, an ASO designed to treat ALS patients with SOD1 gene mutations. Both ASOs have been approved by the FDA and EMA. On the other hand, ASO treatment in ALS patients with the C9orf72 gene mutation did not show any improvement in disease progression. The aim of this review is to provide an up-to-date overview of ASO research in MNDs, from preclinical studies to clinical trials and, where available, regulatory approval. We highlight the successes and failures, underline the strengths and limitations of the current ASO research, and suggest possible approaches that could lead to more effective treatments.
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Affiliation(s)
- Silvia Cantara
- Department of Medical, Surgical and Neurological Sciences, University of Siena, 53100 Siena, Italy;
| | - Giorgia Simoncelli
- Unit of Neurology and Clinical Neurophysiology, Department of Neurological and Motor Sciences, Azienda Ospedaliero-Universitaria Senese, 53100 Siena, Italy;
| | - Claudia Ricci
- Department of Medical, Surgical and Neurological Sciences, University of Siena, 53100 Siena, Italy;
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2
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Qu Y, Bai J, Jiao H, Qi H, Huang W, OuYang S, Peng X, Jin Y, Wang H, Song F. Variants located in intron 6 of SMN1 lead to misdiagnosis in genetic detection and screening for SMA. Heliyon 2024; 10:e28015. [PMID: 38515714 PMCID: PMC10955315 DOI: 10.1016/j.heliyon.2024.e28015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 02/28/2024] [Accepted: 03/11/2024] [Indexed: 03/23/2024] Open
Abstract
Accurate genetic diagnosis is necessary for guiding the treatment of spinal muscular atrophy (SMA). An updated consensus for the diagnosis and management of SMA was published in 2018. However, clinicians should remain alert to some pitfalls of genetic testing that can occur when following a routine diagnosis. In this study, we report the diagnosis of three unrelated individuals who were initially misdiagnosed as carrying a homozygous deletion of SMN1 exon 7. MLPA (P060 and P021) and qPCR were used to detect the copy number of SMN. SMN1 variants were identified by SMN1 clone and next-generation sequencing (NGS). Transcription of SMN1 variants was detected using qRT-PCR and ex vivo splicing analysis. Among the three individuals, one was identified as a patient with SMA carrying a heterozygous deletion and a pathogenic variant (c.835-17_835-14delCTTT) of SMN1, one was a healthy carrier only carrying a heterozygous deletion of SMN1 exon 7, and the third was a patient with nemaline myopathy 2 carrying a heterozygous deletion of SMN1 exon 7. The misdiagnosis of these individuals was attributed to the presence of the c.835-17_835-14delCTTT or c.835-17C > G variants in SMN1 intron 6, which affect the amplification of SMN1 exon 7 during MLPA-P060 and qPCR testing. However, MLPA-P021 and NGS analyses were unaffected by these variants. These results support that additional detection methods should be employed in cases where the SMN1 copy number is ambiguous to minimize the misdiagnosis of SMA.
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Affiliation(s)
- Yujin Qu
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Jinli Bai
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Hui Jiao
- Department of Neurology, Children’s Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China
| | - Hong Qi
- Prenatal Diagnosis Center, Beijing Haidian District Maternal and Child Health Care Hospital, Beijing, China
| | - Wenchen Huang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Shijia OuYang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Xiaoyin Peng
- Department of Neurology, Children’s Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China
| | - Yuwei Jin
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Hong Wang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Fang Song
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
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3
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Hoolachan JM, McCallion E, Sutton ER, Çetin Ö, Pacheco-Torres P, Dimitriadi M, Sari S, Miller GJ, Okoh M, Walter LM, Claus P, Wood MJA, Tonge DP, Bowerman M. A transcriptomics-based drug repositioning approach to identify drugs with similar activities for the treatment of muscle pathologies in spinal muscular atrophy (SMA) models. Hum Mol Genet 2024; 33:400-425. [PMID: 37947217 PMCID: PMC10877467 DOI: 10.1093/hmg/ddad192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 10/08/2023] [Accepted: 11/03/2023] [Indexed: 11/12/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder caused by the reduction of survival of motor neuron (SMN) protein levels. Although three SMN-augmentation therapies are clinically approved that significantly slow down disease progression, they are unfortunately not cures. Thus, complementary SMN-independent therapies that can target key SMA pathologies and that can support the clinically approved SMN-dependent drugs are the forefront of therapeutic development. We have previously demonstrated that prednisolone, a synthetic glucocorticoid (GC) improved muscle health and survival in severe Smn-/-;SMN2 and intermediate Smn2B/- SMA mice. However, long-term administration of prednisolone can promote myopathy. We thus wanted to identify genes and pathways targeted by prednisolone in skeletal muscle to discover clinically approved drugs that are predicted to emulate prednisolone's activities. Using an RNA-sequencing, bioinformatics, and drug repositioning pipeline on skeletal muscle from symptomatic prednisolone-treated and untreated Smn-/-; SMN2 SMA and Smn+/-; SMN2 healthy mice, we identified molecular targets linked to prednisolone's ameliorative effects and a list of 580 drug candidates with similar predicted activities. Two of these candidates, metformin and oxandrolone, were further investigated in SMA cellular and animal models, which highlighted that these compounds do not have the same ameliorative effects on SMA phenotypes as prednisolone; however, a number of other important drug targets remain. Overall, our work further supports the usefulness of prednisolone's potential as a second-generation therapy for SMA, identifies a list of potential SMA drug treatments and highlights improvements for future transcriptomic-based drug repositioning studies in SMA.
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Affiliation(s)
- Joseph M Hoolachan
- School of Medicine, David Weatherall Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Eve McCallion
- School of Medicine, David Weatherall Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Emma R Sutton
- School of Medicine, David Weatherall Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Özge Çetin
- School of Medicine, David Weatherall Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Paloma Pacheco-Torres
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield, Hertfordshire, AL910 9AB, United Kingdom
| | - Maria Dimitriadi
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield, Hertfordshire, AL910 9AB, United Kingdom
| | - Suat Sari
- Department of Pharmaceutical Chemistry, Hacettepe University, Ankara, 06100, Turkey
- School of Chemical and Physical Sciences, Lennard-Jones Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Gavin J Miller
- School of Chemical and Physical Sciences, Lennard-Jones Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
- Centre for Glycoscience, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Magnus Okoh
- School of Medicine, David Weatherall Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Lisa M Walter
- SMATHERIA gGmbH – Non-Profit Biomedical Research Institute, Feodor-Lynen-Straße 31, 30625, Hannover, Germany
- Centre of Systems Neuroscience (ZSN), Hannover Medical School, Bünteweg 2, 30559, Hannover, Germany
| | - Peter Claus
- SMATHERIA gGmbH – Non-Profit Biomedical Research Institute, Feodor-Lynen-Straße 31, 30625, Hannover, Germany
- Centre of Systems Neuroscience (ZSN), Hannover Medical School, Bünteweg 2, 30559, Hannover, Germany
| | - Matthew J A Wood
- Department of Paediatrics, University of Oxford, Level 2, Children's Hospital, John Radcliffe, Headington Oxford, OX3 9DU, United Kingdom
| | - Daniel P Tonge
- School of Life Sciences, Huxley Building, Keele University, Staffordshire ST5 5BG, United Kingdom
| | - Melissa Bowerman
- School of Medicine, David Weatherall Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, United Kingdom
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Pajuste FD, Remm M. GeneToCN: an alignment-free method for gene copy number estimation directly from next-generation sequencing reads. Sci Rep 2023; 13:17765. [PMID: 37853040 PMCID: PMC10584998 DOI: 10.1038/s41598-023-44636-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 10/10/2023] [Indexed: 10/20/2023] Open
Abstract
Genomes exhibit large regions with segmental copy number variation, many of which include entire genes and are multiallelic. We have developed a computational method GeneToCN that counts the frequencies of gene-specific k-mers in FASTQ files and uses this information to infer copy number of the gene. We validated the copy number predictions for amylase genes (AMY1, AMY2A, AMY2B) using experimental data from digital droplet PCR (ddPCR) on 39 individuals and observed a strong correlation (R = 0.99) between GeneToCN predictions and experimentally determined copy numbers. An additional validation on FCGR3 genes showed a higher concordance for FCGR3A compared to two other methods, but reduced accuracy for FCGR3B. We further tested the method on three different genomic regions (SMN, NPY4R, and LPA Kringle IV-2 domain). Predicted copy number distributions of these genes in a set of 500 individuals from the Estonian Biobank were in good agreement with the previously published studies. In addition, we investigated the possibility to use GeneToCN on sequencing data generated by different technologies by comparing copy number predictions from Illumina, PacBio, and Oxford Nanopore data of the same sample. Despite the differences in variability of k-mer frequencies, all three sequencing technologies give similar predictions with GeneToCN.
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Affiliation(s)
- Fanny-Dhelia Pajuste
- Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Str., 51010, Tartu, Estonia.
| | - Maido Remm
- Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Str., 51010, Tartu, Estonia
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Brown SJ, Šoltić D, Synowsky SA, Shirran SL, Chilcott E, Shorrock HK, Gillingwater TH, Yáñez-Muñoz RJ, Schneider B, Bowerman M, Fuller HR. AAV9-mediated SMN gene therapy rescues cardiac desmin but not lamin A/C and elastin dysregulation in Smn2B/- spinal muscular atrophy mice. Hum Mol Genet 2023; 32:2950-2965. [PMID: 37498175 PMCID: PMC10549791 DOI: 10.1093/hmg/ddad121] [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: 06/03/2023] [Revised: 06/27/2023] [Accepted: 07/25/2023] [Indexed: 07/28/2023] Open
Abstract
Structural, functional and molecular cardiac defects have been reported in spinal muscular atrophy (SMA) patients and mouse models. Previous quantitative proteomics analyses demonstrated widespread molecular defects in the severe Taiwanese SMA mouse model. Whether such changes are conserved across different mouse models, including less severe forms of the disease, has yet to be established. Here, using the same high-resolution proteomics approach in the less-severe Smn2B/- SMA mouse model, 277 proteins were found to be differentially abundant at a symptomatic timepoint (post-natal day (P) 18), 50 of which were similarly dysregulated in severe Taiwanese SMA mice. Bioinformatics analysis linked many of the differentially abundant proteins to cardiovascular development and function, with intermediate filaments highlighted as an enriched cellular compartment in both datasets. Lamin A/C was increased in the cardiac tissue, whereas another intermediate filament protein, desmin, was reduced. The extracellular matrix (ECM) protein, elastin, was also robustly decreased in the heart of Smn2B/- mice. AAV9-SMN1-mediated gene therapy rectified low levels of survival motor neuron protein and restored desmin levels in heart tissues of Smn2B/- mice. In contrast, AAV9-SMN1 therapy failed to correct lamin A/C or elastin levels. Intermediate filament proteins and the ECM have key roles in cardiac function and their dysregulation may explain cardiac impairment in SMA, especially since mutations in genes encoding these proteins cause other diseases with cardiac aberration. Cardiac pathology may need to be considered in the long-term care of SMA patients, as it is unclear whether currently available treatments can fully rescue peripheral pathology in SMA.
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Affiliation(s)
- Sharon J Brown
- School of Pharmacy and Bioengineering, Keele University, Keele ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, TORCH Building, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
| | - Darija Šoltić
- School of Pharmacy and Bioengineering, Keele University, Keele ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, TORCH Building, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
| | - Silvia A Synowsky
- BSRC Mass Spectrometry and Proteomics Facility, University of St Andrews, St Andrews KY16 9ST, UK
| | - Sally L Shirran
- BSRC Mass Spectrometry and Proteomics Facility, University of St Andrews, St Andrews KY16 9ST, UK
| | - Ellie Chilcott
- AGCTlab.org, Centre of Gene and Cell Therapy, Centre for Biomedical Sciences, Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham Hill, Egham, Surrey TW20 0EX, UK
| | - Hannah K Shorrock
- Edinburgh Medical School: Biomedical Sciences, Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Thomas H Gillingwater
- Edinburgh Medical School: Biomedical Sciences, Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Rafael J Yáñez-Muñoz
- AGCTlab.org, Centre of Gene and Cell Therapy, Centre for Biomedical Sciences, Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham Hill, Egham, Surrey TW20 0EX, UK
| | - Bernard Schneider
- Bertarelli Platform for Gene Therapy, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Melissa Bowerman
- Wolfson Centre for Inherited Neuromuscular Disease, TORCH Building, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
- School of Medicine, Keele University, Keele ST5 5BG, UK
| | - Heidi R Fuller
- School of Pharmacy and Bioengineering, Keele University, Keele ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, TORCH Building, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
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6
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Ponomarev AS, Chulpanova DS, Yanygina LM, Solovyeva VV, Rizvanov AA. Emerging Gene Therapy Approaches in the Management of Spinal Muscular Atrophy (SMA): An Overview of Clinical Trials and Patent Landscape. Int J Mol Sci 2023; 24:13743. [PMID: 37762045 PMCID: PMC10530942 DOI: 10.3390/ijms241813743] [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: 06/30/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a rare autosomal recessive neuromuscular disease that is characterized by progressive muscle atrophy (degeneration), including skeletal muscles in charge of the ability to move. SMA is caused by defects in the SMN1 gene (Survival of Motor Neuron 1) which encodes a protein crucial for the survival and functionality of neuron cells called motor neurons. Decreased level of functioning SMN protein leads to progressive degeneration of alpha-motor neurons performing muscular motility. Over the past decade, many strategies directed for SMN-level-restoration emerged, such as gene replacement therapy (GRT), CRISPR/Cas9-based gene editing, usage of antisense oligonucleotides and small-molecule modulators, and all have been showing their perspectives in SMA therapy. In this review, modern SMA therapy strategies are described, making it a valuable resource for researchers, clinicians and everyone interested in the progress of therapy of this serious disorder.
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Affiliation(s)
| | | | | | | | - Albert A. Rizvanov
- Institute of Fundamental Medicine and Biology, Kazan Federal University, 420008 Kazan, Russia; (A.S.P.); (D.S.C.); (L.M.Y.); (V.V.S.)
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7
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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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8
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Nishio H, Niba ETE, Saito T, Okamoto K, Takeshima Y, Awano H. Spinal Muscular Atrophy: The Past, Present, and Future of Diagnosis and Treatment. Int J Mol Sci 2023; 24:11939. [PMID: 37569314 PMCID: PMC10418635 DOI: 10.3390/ijms241511939] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/17/2023] [Accepted: 07/21/2023] [Indexed: 08/13/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a lower motor neuron disease with autosomal recessive inheritance. The first cases of SMA were reported by Werdnig in 1891. Although the phenotypic variation of SMA led to controversy regarding the clinical entity of the disease, the genetic homogeneity of SMA was proved in 1990. Five years later, in 1995, the gene responsible for SMA, SMN1, was identified. Genetic testing of SMN1 has enabled precise epidemiological studies, revealing that SMA occurs in 1 of 10,000 to 20,000 live births and that more than 95% of affected patients are homozygous for SMN1 deletion. In 2016, nusinersen was the first drug approved for treatment of SMA in the United States. Two other drugs were subsequently approved: onasemnogene abeparvovec and risdiplam. Clinical trials with these drugs targeting patients with pre-symptomatic SMA (those who were diagnosed by genetic testing but showed no symptoms) revealed that such patients could achieve the milestones of independent sitting and/or walking. Following the great success of these trials, population-based newborn screening programs for SMA (more precisely, SMN1-deleted SMA) have been increasingly implemented worldwide. Early detection by newborn screening and early treatment with new drugs are expected to soon become the standards in the field of SMA.
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Affiliation(s)
- Hisahide Nishio
- Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe 651-2180, Japan
| | - Emma Tabe Eko Niba
- Laboratory of Molecular and Biochemical Research, Biomedical Research Core Facilities, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan;
| | - Toshio Saito
- Department of Neurology, National Hospital Organization Osaka Toneyama Medical Center, 5-1-1 Toneyama, Toyonaka 560-8552, Japan;
| | - Kentaro Okamoto
- Department of Pediatrics, Ehime Prefectural Imabari Hospital, 4-5-5 Ishi-cho, Imabari 794-0006, Japan;
| | - Yasuhiro Takeshima
- Department of Pediatrics, Hyogo Medical University, 1-1 Mukogawacho, Nishinomiya 663-8501, Japan;
| | - Hiroyuki Awano
- Organization for Research Initiative and Promotion, Research Initiative Center, Tottori University, 86 Nishi-cho, Yonago 683-8503, Japan;
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Lakhina Y, Boulis NM, Donsante A. Current and emerging targeted therapies for spinal muscular atrophy. Expert Rev Neurother 2023; 23:1189-1199. [PMID: 37843301 DOI: 10.1080/14737175.2023.2268276] [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: 07/07/2023] [Accepted: 10/04/2023] [Indexed: 10/17/2023]
Abstract
INTRODUCTION Spinal muscular atrophy (SMA) is a progressive neurodegenerative disorder caused by insufficiency or total absence of the survival motor neuron protein due to a mutation in the SMN1 gene. The copy number of its paralog, SMN2, influences disease onset and phenotype severity. Current therapeutic approaches include viral and non-viral modalities affecting gene expression. Regulatory-approved drugs Spinraza (Nusinersen), Zolgensma (Onasemnogene abeparvovec), and Evrysdi (Risdiplam) are still being investigated during clinical trials and show benefits in the long-term for symptomatic and pre-symptomatic patients. However, some ongoing interventions require repeated drug administration. AREAS COVERED In this review, the authors describe the existing therapy based on point of application, focusing on recent clinical trials of antisense oligonucleotides, viral gene therapy, and splice modulators and thepotential routes for correcting the mutation to provide therapeutic levels of SMN protein. EXPERT OPINION In the opinion of the authors, multiple treatment options for patients with SMA shifted the treatment paradigm from palliative supportive care to improvedmotor function, increased survival, and greater quality of life for such patients. They further believe that the future in SMA treatment development lies incombining existing treatment options, targeting aspects of the disease refractory to these treatments, and using gene editing technologies.
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Affiliation(s)
- Yuliya Lakhina
- Department of Neurosurgery, Emory University, Atlanta, USA
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10
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Vaill M, Kawanishi K, Varki N, Gagneux P, Varki A. Comparative physiological anthropogeny: exploring molecular underpinnings of distinctly human phenotypes. Physiol Rev 2023; 103:2171-2229. [PMID: 36603157 PMCID: PMC10151058 DOI: 10.1152/physrev.00040.2021] [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: 11/05/2021] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 01/06/2023] Open
Abstract
Anthropogeny is a classic term encompassing transdisciplinary investigations of the origins of the human species. Comparative anthropogeny is a systematic comparison of humans and other living nonhuman hominids (so-called "great apes"), aiming to identify distinctly human features in health and disease, with the overall goal of explaining human origins. We begin with a historical perspective, briefly describing how the field progressed from the earliest evolutionary insights to the current emphasis on in-depth molecular and genomic investigations of "human-specific" biology and an increased appreciation for cultural impacts on human biology. While many such genetic differences between humans and other hominids have been revealed over the last two decades, this information remains insufficient to explain the most distinctive phenotypic traits distinguishing humans from other living hominids. Here we undertake a complementary approach of "comparative physiological anthropogeny," along the lines of the preclinical medical curriculum, i.e., beginning with anatomy and considering each physiological system and in each case considering genetic and molecular components that are relevant. What is ultimately needed is a systematic comparative approach at all levels from molecular to physiological to sociocultural, building networks of related information, drawing inferences, and generating testable hypotheses. The concluding section will touch on distinctive considerations in the study of human evolution, including the importance of gene-culture interactions.
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Affiliation(s)
- Michael Vaill
- Center for Academic Research and Training in Anthropogeny, University of California, San Diego, La Jolla, California
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, California
| | - Kunio Kawanishi
- Center for Academic Research and Training in Anthropogeny, University of California, San Diego, La Jolla, California
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California
- Department of Experimental Pathology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Nissi Varki
- Center for Academic Research and Training in Anthropogeny, University of California, San Diego, La Jolla, California
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, California
- Department of Pathology, University of California, San Diego, La Jolla, California
| | - Pascal Gagneux
- Center for Academic Research and Training in Anthropogeny, University of California, San Diego, La Jolla, California
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, California
- Department of Pathology, University of California, San Diego, La Jolla, California
| | - Ajit Varki
- Center for Academic Research and Training in Anthropogeny, University of California, San Diego, La Jolla, California
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, California
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11
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Barone C, Qi X. Altered Metabolism in Motor Neuron Diseases: Mechanism and Potential Therapeutic Target. Cells 2023; 12:1536. [PMID: 37296656 PMCID: PMC10252517 DOI: 10.3390/cells12111536] [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: 04/08/2023] [Revised: 05/21/2023] [Accepted: 05/31/2023] [Indexed: 06/12/2023] Open
Abstract
Motor Neuron Diseases (MND) are neurological disorders characterized by a loss of varying motor neurons resulting in decreased physical capabilities. Current research is focused on hindering disease progression by determining causes of motor neuron death. Metabolic malfunction has been proposed as a promising topic when targeting motor neuron loss. Alterations in metabolism have also been noted at the neuromuscular junction (NMJ) and skeletal muscle tissue, emphasizing the importance of a cohesive system. Finding metabolism changes consistent throughout both neurons and skeletal muscle tissue could pose as a target for therapeutic intervention. This review will focus on metabolic deficits reported in MNDs and propose potential therapeutic targets for future intervention.
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Affiliation(s)
| | - Xin Qi
- Department of Physiology and Biophysics, School of Medicine Case Western Reserve University, Cleveland, OH 44106-4970, USA;
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12
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Mikhalchuk K, Shchagina O, Chukhrova A, Zabnenkova V, Chausova P, Ryadninskaya N, Vlodavets D, Kutsev SI, Polyakov A. Pilot Program of Newborn Screening for 5q Spinal Muscular Atrophy in the Russian Federation. Int J Neonatal Screen 2023; 9:29. [PMID: 37218894 PMCID: PMC10204550 DOI: 10.3390/ijns9020029] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 05/02/2023] [Accepted: 05/11/2023] [Indexed: 05/24/2023] Open
Abstract
5q spinal muscular atrophy (5q SMA) is one of the most common autosomal recessive disorders in the Russian Federation. The first medication to treat 5q SMA was registered in the Russian Federation for treatment of all 5q SMA types in 2019, and the last of the three currently available in December 2021. We launched the pilot newborn screening (NBS) program for 5q SMA in Moscow, the Russian Federation, starting in 2019. During the pilot program, 23,405 neonates were tested for the deletion of exon 7 of the SMN1 gene, the most common cause of 5q SMA. We used the SALSA® MC002 SMA Newborn Screen Kit (MRC Holland) to specifically detect homozygous deletions of SMN1 exon 7. We used the restriction fragment length polymorphism (RFLP) approach to validate detected homozygous deletions and the SALSA MLPA Probemix P060 SMA Carrier Kit (MRC Holland) to determine the SMN2 exon 7 copy number to prescribe gene therapy for 5q SMA. Three newborns with a homozygous deletion of the SMN1 gene were detected. The calculated birth prevalence of 1:7801 appears to be similar to the results in other European countries. The children did not show any signs of respiratory involvement or bulbar weakness immediately after birth. Until now, no 5q SMA case missed by NBS has been detected.
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Affiliation(s)
- Kristina Mikhalchuk
- Research Centre for Medical Genetics, Moskvorechye St., 1, 115522 Moscow, Russia
| | - Olga Shchagina
- Research Centre for Medical Genetics, Moskvorechye St., 1, 115522 Moscow, Russia
| | - Alena Chukhrova
- Research Centre for Medical Genetics, Moskvorechye St., 1, 115522 Moscow, Russia
| | - Viktoria Zabnenkova
- Research Centre for Medical Genetics, Moskvorechye St., 1, 115522 Moscow, Russia
| | - Polina Chausova
- Research Centre for Medical Genetics, Moskvorechye St., 1, 115522 Moscow, Russia
| | - Nina Ryadninskaya
- Research Centre for Medical Genetics, Moskvorechye St., 1, 115522 Moscow, Russia
| | - Dmitry Vlodavets
- Russian Children Neuromuscular Center, Veltischev Clinical Pediatric Research Institute, Pirogov Russian National Research Medical University, Taldomskaya Str. 2, 125412 Moscow, Russia
| | - Sergei I. Kutsev
- Research Centre for Medical Genetics, Moskvorechye St., 1, 115522 Moscow, Russia
| | - Alexander Polyakov
- Research Centre for Medical Genetics, Moskvorechye St., 1, 115522 Moscow, Russia
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13
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Arbab M, Matuszek Z, Kray KM, Du A, Newby GA, Blatnik AJ, Raguram A, Richter MF, Zhao KT, Levy JM, Shen MW, Arnold WD, Wang D, Xie J, Gao G, Burghes AHM, Liu DR. Base editing rescue of spinal muscular atrophy in cells and in mice. Science 2023; 380:eadg6518. [PMID: 36996170 PMCID: PMC10270003 DOI: 10.1126/science.adg6518] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 03/21/2023] [Indexed: 04/01/2023]
Abstract
Spinal muscular atrophy (SMA), the leading genetic cause of infant mortality, arises from survival motor neuron (SMN) protein insufficiency resulting from SMN1 loss. Approved therapies circumvent endogenous SMN regulation and require repeated dosing or may wane. We describe genome editing of SMN2, an insufficient copy of SMN1 harboring a C6>T mutation, to permanently restore SMN protein levels and rescue SMA phenotypes. We used nucleases or base editors to modify five SMN2 regulatory regions. Base editing converted SMN2 T6>C, restoring SMN protein levels to wild type. Adeno-associated virus serotype 9-mediated base editor delivery in Δ7SMA mice yielded 87% average T6>C conversion, improved motor function, and extended average life span, which was enhanced by one-time base editor and nusinersen coadministration (111 versus 17 days untreated). These findings demonstrate the potential of a one-time base editing treatment for SMA.
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Affiliation(s)
- Mandana Arbab
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Zaneta Matuszek
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Kaitlyn M. Kray
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, 1060 Carmack Road, Columbus, OH 43210, USA
| | - Ailing Du
- Horae Gene Therapy Center, University of Massachusetts, Medical School, Worcester, MA 01605, USA
| | - Gregory A. Newby
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Anton J. Blatnik
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, 1060 Carmack Road, Columbus, OH 43210, USA
| | - Aditya Raguram
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Michelle F. Richter
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Kevin T. Zhao
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Jonathan M. Levy
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Max W. Shen
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
- Computational and Systems Biology Program, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - W. David Arnold
- Department of Neurology, The Ohio State University Wexner Medical Center, 1060 Carmack Road, Columbus, OH 43210, USA
- NextGen Precision Health, University of Missouri, Columbia, MO 65212, USA
| | - Dan Wang
- Horae Gene Therapy Center, University of Massachusetts, Medical School, Worcester, MA 01605, USA
- Horae Gene Therapy Center and RNA Therapeutics Institute, University of Massachusetts, Medical School, Worcester, MA 01605, USA
| | - Jun Xie
- Horae Gene Therapy Center, University of Massachusetts, Medical School, Worcester, MA 01605, USA
| | - Guangping Gao
- Horae Gene Therapy Center, University of Massachusetts, Medical School, Worcester, MA 01605, USA
- Microbiology and Physiological Systems, University of Massachusetts, Medical School, Worcester, MA 01605, USA
| | - Arthur H. M. Burghes
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, 1060 Carmack Road, Columbus, OH 43210, USA
| | - David R. Liu
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
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14
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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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15
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Sabuncu Gürses G, Erdem SS, Saçan MT. A QSAR study to predict the survival motor neuron promoter activity of candidate diaminoquinazoline derivatives for the potential treatment of spinal muscular atrophy. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2023; 34:247-266. [PMID: 37125536 DOI: 10.1080/1062936x.2023.2200975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Spinal Muscular Atrophy is a genetic neuromuscular disease that leads to muscle weakness and atrophy and it is characterized by the loss of α-motor neurons in the spinal cord's anterior horn cells. The disease appears due to low levels of the survival motor neuron protein. There are continuing clinical trials for the treatment of Spinal Muscular Atrophy. Quinazoline-based compounds are promising since they were tested on fibroblasts derived from the patients and found to increase the survival motor neuron protein levels. In this study, using multiple linear regression, we generated robust and valid quantitative structure- activity relationship models to predict the survival motor neuron-2 promoter activity of the new candidate compounds using the experimental survival motor neuron-2 promoter activity values of 2,4-diaminoquinazoline derivatives taken from the literature. The novel compounds designed by combining the pyrido[1,2-α]pyrimidin-4-one moeity of the known drug Risdiplam with that of 2,4 - diaminoquinazoline scaffold were predicted to exhibit strong promoter activities.
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Affiliation(s)
- G Sabuncu Gürses
- Chemistry Department, Faculty of Science, Marmara University, Istanbul, Turkey
| | - S S Erdem
- Chemistry Department, Faculty of Science, Marmara University, Istanbul, Turkey
| | - M T Saçan
- Institute of Environmental Sciences, Bogaziçi University, Istanbul, Turkey
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16
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Soto DC, Uribe-Salazar JM, Shew CJ, Sekar A, McGinty SP, Dennis MY. Genomic structural variation: A complex but important driver of human evolution. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2023. [PMID: 36794631 DOI: 10.1002/ajpa.24713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 01/21/2023] [Accepted: 02/05/2023] [Indexed: 02/17/2023]
Abstract
Structural variants (SVs)-including duplications, deletions, and inversions of DNA-can have significant genomic and functional impacts but are technically difficult to identify and assay compared with single-nucleotide variants. With the aid of new genomic technologies, it has become clear that SVs account for significant differences across and within species. This phenomenon is particularly well-documented for humans and other primates due to the wealth of sequence data available. In great apes, SVs affect a larger number of nucleotides than single-nucleotide variants, with many identified SVs exhibiting population and species specificity. In this review, we highlight the importance of SVs in human evolution by (1) how they have shaped great ape genomes resulting in sensitized regions associated with traits and diseases, (2) their impact on gene functions and regulation, which subsequently has played a role in natural selection, and (3) the role of gene duplications in human brain evolution. We further discuss how to incorporate SVs in research, including the strengths and limitations of various genomic approaches. Finally, we propose future considerations in integrating existing data and biospecimens with the ever-expanding SV compendium propelled by biotechnology advancements.
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Affiliation(s)
- Daniela C Soto
- Genome Center, MIND Institute, Department of Biochemstry & Molecular Medicine, University of California, Davis, California, USA.,Integrative Genetics and Genomics Graduate Group, University of California, Davis, California, USA
| | - José M Uribe-Salazar
- Genome Center, MIND Institute, Department of Biochemstry & Molecular Medicine, University of California, Davis, California, USA.,Integrative Genetics and Genomics Graduate Group, University of California, Davis, California, USA
| | - Colin J Shew
- Genome Center, MIND Institute, Department of Biochemstry & Molecular Medicine, University of California, Davis, California, USA.,Integrative Genetics and Genomics Graduate Group, University of California, Davis, California, USA
| | - Aarthi Sekar
- Genome Center, MIND Institute, Department of Biochemstry & Molecular Medicine, University of California, Davis, California, USA.,Integrative Genetics and Genomics Graduate Group, University of California, Davis, California, USA
| | - Sean P McGinty
- Genome Center, MIND Institute, Department of Biochemstry & Molecular Medicine, University of California, Davis, California, USA.,Integrative Genetics and Genomics Graduate Group, University of California, Davis, California, USA
| | - Megan Y Dennis
- Genome Center, MIND Institute, Department of Biochemstry & Molecular Medicine, University of California, Davis, California, USA.,Integrative Genetics and Genomics Graduate Group, University of California, Davis, California, USA
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17
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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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18
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Gadelha RB, Machado CB, Pessoa FMCDP, Pantoja LDC, Barreto IV, Ribeiro RM, de Moraes Filho MO, de Moraes MEA, Khayat AS, Moreira-Nunes CA. The Role of WRAP53 in Cell Homeostasis and Carcinogenesis Onset. Curr Issues Mol Biol 2022; 44:5498-5515. [PMID: 36354684 PMCID: PMC9688736 DOI: 10.3390/cimb44110372] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/30/2022] [Accepted: 09/29/2022] [Indexed: 11/07/2023] Open
Abstract
The WD repeat containing antisense to TP53 (WRAP53) gene codifies an antisense transcript for tumor protein p53 (TP53), stabilization (WRAP53α), and a functional protein (WRAP53β, WDR79, or TCAB1). The WRAP53β protein functions as a scaffolding protein that is important for telomerase localization, telomere assembly, Cajal body integrity, and DNA double-strand break repair. WRAP53β is one of many proteins known for containing WD40 domains, which are responsible for mediating a variety of cell interactions. Currently, WRAP53 overexpression is considered a biomarker for a diverse subset of cancer types, and in this study, we describe what is known about WRAP53β's multiple interactions in cell protein trafficking, Cajal body formation, and DNA double-strand break repair and its current perspectives as a biomarker for cancer.
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Affiliation(s)
- Renan Brito Gadelha
- Pharmacogenetics Laboratory, Department of Medicine, Drug Research and Development Center (NPDM), Federal University of Ceará, Fortaleza 60430-275, CE, Brazil
| | - Caio Bezerra Machado
- Pharmacogenetics Laboratory, Department of Medicine, Drug Research and Development Center (NPDM), Federal University of Ceará, Fortaleza 60430-275, CE, Brazil
| | - Flávia Melo Cunha de Pinho Pessoa
- Pharmacogenetics Laboratory, Department of Medicine, Drug Research and Development Center (NPDM), Federal University of Ceará, Fortaleza 60430-275, CE, Brazil
| | - Laudreísa da Costa Pantoja
- Department of Pediatrics, Octávio Lobo Children’s Hospital, Belém 60430-275, PA, Brazil
- Department of Biological Sciences, Oncology Research Center, Federal University of Pará, Belém 66073-005, PA, Brazil
| | - Igor Valentim Barreto
- Pharmacogenetics Laboratory, Department of Medicine, Drug Research and Development Center (NPDM), Federal University of Ceará, Fortaleza 60430-275, CE, Brazil
| | | | - Manoel Odorico de Moraes Filho
- Pharmacogenetics Laboratory, Department of Medicine, Drug Research and Development Center (NPDM), Federal University of Ceará, Fortaleza 60430-275, CE, Brazil
| | - Maria Elisabete Amaral de Moraes
- Pharmacogenetics Laboratory, Department of Medicine, Drug Research and Development Center (NPDM), Federal University of Ceará, Fortaleza 60430-275, CE, Brazil
| | - André Salim Khayat
- Department of Biological Sciences, Oncology Research Center, Federal University of Pará, Belém 66073-005, PA, Brazil
| | - Caroline Aquino Moreira-Nunes
- Pharmacogenetics Laboratory, Department of Medicine, Drug Research and Development Center (NPDM), Federal University of Ceará, Fortaleza 60430-275, CE, Brazil
- Department of Biological Sciences, Oncology Research Center, Federal University of Pará, Belém 66073-005, PA, Brazil
- Northeast Biotechnology Network (RENORBIO), Itaperi Campus, Ceará State University, Fortaleza 60740-903, CE, Brazil
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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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20
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Deep Molecular Characterization of Milder Spinal Muscular Atrophy Patients Carrying the c.859G>C Variant in SMN2. Int J Mol Sci 2022; 23:ijms23158289. [PMID: 35955418 PMCID: PMC9368089 DOI: 10.3390/ijms23158289] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 02/01/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a severe neuromuscular disorder caused by biallelic loss or pathogenic variants in the SMN1 gene. Copy number and modifier intragenic variants in SMN2, an almost identical paralog gene of SMN1, are known to influence the amount of complete SMN proteins. Therefore, SMN2 is considered the main phenotypic modifier of SMA, although genotype−phenotype correlation is not absolute. We present eleven unrelated SMA patients with milder phenotypes carrying the c.859G>C-positive modifier variant in SMN2. All were studied by a specific NGS method to allow a deep characterization of the entire SMN region. Analysis of two homozygous cases for the variant allowed us to identify a specific haplotype, Smn2-859C.1, in association with c.859G>C. Two other cases with the c.859G>C variant in their two SMN2 copies showed a second haplotype, Smn2-859C.2, in cis with Smn2-859C.1, assembling a more complex allele. We also identified a previously unreported variant in intron 2a exclusively linked to the Smn2-859C.1 haplotype (c.154-1141G>A), further suggesting that this region has been ancestrally conserved. The deep molecular characterization of SMN2 in our cohort highlights the importance of testing c.859G>C, as well as accurately assessing the SMN2 region in SMA patients to gain insight into the complex genotype−phenotype correlations and improve prognostic outcomes.
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Arikan Y, Berker Karauzum S, Uysal H, Mihci E, Nur B, Duman O, Haspolat S, Altiok Clark O, Toylu A. Evaluation of exonic copy numbers of SMN1 and SMN2 genes in SMA. Gene X 2022; 823:146322. [PMID: 35219815 DOI: 10.1016/j.gene.2022.146322] [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: 10/06/2021] [Revised: 12/20/2021] [Accepted: 02/11/2022] [Indexed: 11/04/2022] Open
Abstract
SMA is a neuromuscular disease and occurs primarily through autosomal recessive inheritance. Identification of deletions in the SMN1 gene especially in the exon 7 and exon 8 regions (hot spot), are used in carrier testing. The exact copy numbers of those exons in the SMN1 and SMN2 genes in 113 patients who presented with a pre-diagnosis of SMA were determined using MLPA method. We aimed to reveal both the most common copy number profiles of different SMA types. It was found that the frequency of homozygous deletions in SMN1 was 15.9%, while heterozygous deletions was 16.9%. The most common SMN-MLPA profile was 0-0-3-3. In the cases with homozygous deletion, SMA type III diagnosis was observed most frequently (44%), and the rate of consanguineous marriage was found 33%. Two cases with the same exonic copy number profile but with different clinical subtypes were identified in a family. We also detected distinct exonic deletion and duplication MLPA profiles for the first time. We created "the SMA signature" that can be added to patient reports. Furthermore, our data are important for revealing potential local profiles of SMA and describing the disease in genetic reports in a way that is clear and comprehensive.
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Affiliation(s)
- Yunus Arikan
- Bozok University School of Medicine, Department of Medical Genetics, Yozgat, Turkey; Radboud University Medical Centre, Department of Human Genetics, Nijmegen, Netherland.
| | - Sibel Berker Karauzum
- Akdeniz University School of Medicine, Department of Medical Biology, Antalya, Turkey; Akdeniz University School of Medicine, Department of Medical Genetics, Antalya, Turkey.
| | - Hilmi Uysal
- Akdeniz University School of Medicine, Department of Neurology, Antalya, Turkey.
| | - Ercan Mihci
- Akdeniz University School of Medicine, Department of Medical Genetics, Antalya, Turkey; Akdeniz University School of Medicine, Department of Pediatry, Antalya, Turkey.
| | - Banu Nur
- Akdeniz University School of Medicine, Department of Medical Genetics, Antalya, Turkey; Akdeniz University School of Medicine, Department of Pediatry, Antalya, Turkey.
| | - Ozgur Duman
- Akdeniz University School of Medicine, Department of Neurology, Antalya, Turkey.
| | - Senay Haspolat
- Akdeniz University School of Medicine, Department of Pediatry, Antalya, Turkey.
| | - Ozden Altiok Clark
- Akdeniz University School of Medicine, Department of Medical Genetics, Antalya, Turkey.
| | - Asli Toylu
- Akdeniz University School of Medicine, Department of Medical Genetics, Antalya, Turkey.
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Restoring SMN Expression: An Overview of the Therapeutic Developments for the Treatment of Spinal Muscular Atrophy. Cells 2022; 11:cells11030417. [PMID: 35159227 PMCID: PMC8834523 DOI: 10.3390/cells11030417] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/14/2022] [Accepted: 01/24/2022] [Indexed: 02/06/2023] Open
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disorder and one of the most common genetic causes of infant death. It is characterized by progressive weakness of the muscles, loss of ambulation, and death from respiratory complications. SMA is caused by the homozygous deletion or mutations in the survival of the motor neuron 1 (SMN1) gene. Humans, however, have a nearly identical copy of SMN1 known as the SMN2 gene. The severity of the disease correlates inversely with the number of SMN2 copies present. SMN2 cannot completely compensate for the loss of SMN1 in SMA patients because it can produce only a fraction of functional SMN protein. SMN protein is ubiquitously expressed in the body and has a variety of roles ranging from assembling the spliceosomal machinery, autophagy, RNA metabolism, signal transduction, cellular homeostasis, DNA repair, and recombination. Motor neurons in the anterior horn of the spinal cord are extremely susceptible to the loss of SMN protein, with the reason still being unclear. Due to the ability of the SMN2 gene to produce small amounts of functional SMN, two FDA-approved treatment strategies, including an antisense oligonucleotide (AON) nusinersen and small-molecule risdiplam, target SMN2 to produce more functional SMN. On the other hand, Onasemnogene abeparvovec (brand name Zolgensma) is an FDA-approved adeno-associated vector 9-mediated gene replacement therapy that can deliver a copy of the human SMN1. In this review, we summarize the SMA etiology, the role of SMN, and discuss the challenges of the therapies that are approved for SMA treatment.
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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: 19] [Impact Index Per Article: 9.5] [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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24
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Zhang Y, Chen X, Wang Q, Du C, Lu W, Yuan H, Zhang Z, Li D, Ling X, Ren X, Zhao Y, Su Q, Xing Z, Qin Y, Yang X, Shen Y, Wu H, Qi Y. Hyper-SUMOylation of SMN induced by SENP2 deficiency decreases its stability and leads to spinal muscular atrophy-like pathology. J Mol Med (Berl) 2021; 99:1797-1813. [PMID: 34628513 DOI: 10.1007/s00109-021-02130-x] [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: 03/09/2021] [Revised: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 11/28/2022]
Abstract
Spinal muscular atrophy (SMA), a degenerative motor neuron disease and a leading cause of infant mortality, is caused by loss of functional survival motor neuron (SMN) protein due to SMN1 gene mutation. Here, using mouse and cell models for behavioral and histological studies, we found that SENP2 (SUMO/sentrin-specific protease 2)-deficient mice developed a notable SMA-like pathology phenotype with significantly decreased muscle fibers and motor neurons. At the molecular level, SENP2 deficiency in mice did not affect transcription but decreased SMN protein levels by promoting the SUMOylation of SMN. SMN was modified by SUMO2 with the E3 PIAS2α and deconjugated by SENP2. SUMOylation of SMN accelerated its degradation by the ubiquitin-proteasome degradation pathway with the ubiquitin E1 UBA1 (ubiquitin-like modifier activating enzyme 1) and E3 ITCH. SUMOylation of SMN increased its acetylation to inhibit the formation of Cajal bodies (CBs). These results showed that SENP2 deficiency induced hyper-SUMOylation of the SMN protein, which further affected the stability and functions of the SMN protein, eventually leading to the SMA-like phenotype. Thus, we uncovered the important roles for hyper-SUMOylation of SMN induced by SENP2 deficiency in motor neurons and provided a novel targeted therapeutic strategy for SMA. KEY MESSAGES: SENP2 deficiency enhanced the hyper-SUMOylation of SMN and promoted the degradation of SMN by the ubiquitin-proteasome pathway. SUMOylation increased the acetylation of SMN to inhibit CB formation. SENP2 deficiency caused hyper-SUMOylation of SMN protein, which further affected the stability and functions of SMN protein and eventually led to the occurrence of SMA-like pathology.
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Affiliation(s)
- Yuhong Zhang
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Xu Chen
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Qiqi Wang
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Congcong Du
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Wenbin Lu
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Hong Yuan
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Zhenzhen Zhang
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Danqing Li
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Xing Ling
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Xiang Ren
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Yang Zhao
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Qi Su
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Zhengcao Xing
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Yuanyuan Qin
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Xinyi Yang
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Yajie Shen
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China
| | - Hongmei Wu
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China.
| | - Yitao Qi
- Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China.
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25
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Chavali SS, Mali SM, Bonn R, Saseendran A, Bennett RP, Smith HC, Fasan R, Wedekind JE. Cyclic peptides with a distinct arginine-fork motif recognize the HIV trans-activation response RNA in vitro and in cells. J Biol Chem 2021; 297:101390. [PMID: 34767799 DOI: 10.1016/j.jbc.2021.101390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/02/2021] [Accepted: 11/04/2021] [Indexed: 12/21/2022] Open
Abstract
RNA represents a potential target for new antiviral therapies, which are urgently needed to address public health threats such as the human immunodeficiency virus (HIV). We showed previously that the interaction between the viral Tat protein and the HIV-1 trans-activation response (TAR) RNA was blocked by the cyclic peptide TB-CP-6.9a. This peptide was derived from a TAR-binding loop that emerged during lab-evolution of a TAR-binding protein (TBP) family. Here we synthesized and characterized a next-generation, cyclic-peptide library based on the TBP scaffold. We sought to identify conserved RNA-binding interactions, and the influence of cyclization linkers on RNA binding and antiviral activity. A diverse group of cyclization linkers, encompassing disulfide bonds to bicyclic aromatic staples, was used to restrain the cyclic peptide geometry. Thermodynamic profiling revealed specific arginine-rich sequences with low to sub-micromolar affinity driven by enthalpic and entropic contributions. The best compounds exhibited no appreciable off-target binding to related molecules, such as BIV TAR and human 7SK RNAs. A specific arginine-to-lysine change in the highest affinity cyclic peptide reduced TAR binding by 10-fold, suggesting that TBP-derived cyclic peptides use an arginine-fork motif to recognize the TAR major-groove while differentiating the mode of binding from other TAR-targeting molecules. Finally, we showed that HIV infectivity in cell culture was reduced in the presence of cyclic peptides constrained by methylene or naphthalene-based linkers. Our findings provide insight into the molecular determinants required for HIV-1 TAR recognition and antiviral activity. These findings are broadly relevant to the development of antivirals that target RNA molecules.
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Affiliation(s)
- Sai Shashank Chavali
- Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester NY 14642, USA
| | - Sachitanand M Mali
- Department of Chemistry, University of Rochester, Rochester NY 14627, USA
| | - Rachel Bonn
- Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester NY 14642, USA
| | | | | | - Harold C Smith
- Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester NY 14642, USA; OyaGen, Inc., Rochester NY 14623, USA
| | - Rudi Fasan
- Department of Chemistry, University of Rochester, Rochester NY 14627, USA
| | - Joseph E Wedekind
- Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester NY 14642, USA.
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Abstract
Autosomal-recessive spinal muscular atrophy (SMA) is characterized by the loss of specific motor neurons of the spinal cord and skeletal muscle atrophy. SMA is caused by mutations or deletions of the survival motor neuron 1 (SMN1) gene, and disease severity correlates with the expression levels of the nearly identical copy gene, SMN2. Both genes ubiquitously express SMN protein, but SMN2 generates only low levels of protein that do not fully compensate for the loss-of-function of SMN1. SMN protein forms a multiprotein complex essential for the cellular assembly of ribonucleoprotein particles involved in diverse aspects of RNA metabolism. Other studies using animal models revealed a spatio-temporal requirement of SMN that is high during the development of the neuromuscular system and later, in the general maintenance of cellular and tissues homeostasis. These observations define a period for maximum therapeutic efficiency of SMN restoration, and suggest that cells outside the central nervous system may also participate in the pathogenesis of SMA. Finally, recent innovative therapies have been shown to mitigate SMN deficiency and have been approved to treat SMA patients. We briefly review major findings from the past twenty-five years of SMA research. © 2020 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.
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Affiliation(s)
- S Lefebvre
- T3S INSERM UMR 1124, Toxicité Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, UFR des Sciences Fondamentales et Biomédicales, Campus Saint-Germain-des-prés, Université de Paris, Paris, France.
| | - C Sarret
- Centre de compétence maladies rares des pathologies neuromusculaires, service de génétique médicale, Hôpital Estaing, CHU Clermont-Ferrand, France.
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27
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The Importance of Digging into the Genetics of SMN Genes in the Therapeutic Scenario of Spinal Muscular Atrophy. Int J Mol Sci 2021; 22:ijms22169029. [PMID: 34445733 PMCID: PMC8396600 DOI: 10.3390/ijms22169029] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/13/2021] [Accepted: 08/19/2021] [Indexed: 12/12/2022] Open
Abstract
After 26 years of discovery of the determinant survival motor neuron 1 and the modifier survival motor neuron 2 genes (SMN1 and SMN2, respectively), three SMN-dependent specific therapies are already approved by FDA and EMA and, as a consequence, worldwide SMA patients are currently under clinical investigation and treatment. Bi-allelic pathogenic variants (mostly deletions) in SMN1 should be detected in SMA patients to confirm the disease. Determination of SMN2 copy number has been historically employed to correlate with the phenotype, predict disease evolution, stratify patients for clinical trials and to define those eligible for treatment. In view that discordant genotype-phenotype correlations are present in SMA, besides technical issues with detection of SMN2 copy number, we have hypothesized that copy number determination is only the tip of the iceberg and that more deepen studies of variants, sequencing and structures of the SMN2 genes are necessary for a better understanding of the disease as well as to investigate possible influences in treatment responses. Here, we highlight the importance of a comprehensive approach of SMN1 and SMN2 genetics with the perspective to apply for better prediction of SMA in positive neonatal screening cases and early diagnosis to start treatments.
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28
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Butchbach MER. Genomic Variability in the Survival Motor Neuron Genes ( SMN1 and SMN2): Implications for Spinal Muscular Atrophy Phenotype and Therapeutics Development. Int J Mol Sci 2021; 22:ijms22157896. [PMID: 34360669 PMCID: PMC8348669 DOI: 10.3390/ijms22157896] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/14/2021] [Accepted: 07/21/2021] [Indexed: 02/07/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a leading genetic cause of infant death worldwide that is characterized by loss of spinal motor neurons leading to muscle weakness and atrophy. SMA results from the loss of survival motor neuron 1 (SMN1) gene but retention of its paralog SMN2. The copy numbers of SMN1 and SMN2 are variable within the human population with SMN2 copy number inversely correlating with SMA severity. Current therapeutic options for SMA focus on increasing SMN2 expression and alternative splicing so as to increase the amount of SMN protein. Recent work has demonstrated that not all SMN2, or SMN1, genes are equivalent and there is a high degree of genomic heterogeneity with respect to the SMN genes. Because SMA is now an actionable disease with SMN2 being the primary target, it is imperative to have a comprehensive understanding of this genomic heterogeneity with respect to hybrid SMN1–SMN2 genes generated by gene conversion events as well as partial deletions of the SMN genes. This review will describe this genetic heterogeneity in SMA and its impact on disease phenotype as well as therapeutic efficacy.
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Affiliation(s)
- Matthew E. R. Butchbach
- Center for Applied Clinical Genomics, Nemours Children’s Health Delaware, Wilmington, DE 19803, USA;
- Center for Pediatric Research, Nemours Children’s Health Delaware, Wilmington, DE 19803, USA
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
- Department of Pediatrics, Thomas Jefferson University, Philadelphia, PA 19107, USA
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29
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Two Years of Improved Neurological Function With Nusinersen in a 48-Year-Old Patient With Spinal Muscular Atrophy Type 3. Neurologist 2021; 25:141-143. [PMID: 32925486 DOI: 10.1097/nrl.0000000000000284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Nusinersen antisense oligonucleotide infusions have been shown to be effective in the treatment spinal muscular atrophy. The majority of the evidence has been collected in young type 1 and type 2 patients, and evidence of efficacy in adult patients is limited. CASE REPORT A 48-year-old woman with spinal muscular atrophy type 3 who has received the loading dose and 8 maintenance infusions over an 8-month period. Grip and pinch strength, measured by hand-held dynamometry measured at baseline and in 6 to 12 months interval improved over a 24-month period. She also reported multiple other subjective improvements in function. CONCLUSIONS This is the first published case of nusinersen in a middle-aged adult with spinal muscular atrophy. Sustained clinically meaningful improvement may be possible with nusinersen initiation in mid adulthood.
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30
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Blasco-Pérez L, Paramonov I, Leno J, Bernal S, Alias L, Fuentes-Prior P, Cuscó I, Tizzano EF. Beyond copy number: A new, rapid, and versatile method for sequencing the entire SMN2 gene in SMA patients. Hum Mutat 2021; 42:787-795. [PMID: 33739559 PMCID: PMC8252042 DOI: 10.1002/humu.24200] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 01/13/2021] [Accepted: 03/11/2021] [Indexed: 01/16/2023]
Abstract
Spinal muscular atrophy (SMA) is caused by bi‐allelic loss or pathogenic variants in the SMN1 gene. SMN2, the highly homologous copy of SMN1, is considered the major phenotypic modifier of the disease. Determination of SMN2 copy number is essential to establish robust genotype–phenotype correlations and predict disease evolution, to stratify patients for clinical trials, as well as to define those eligible for treatment. Discordant genotype–phenotype correlations are not uncommon in SMA, some of which are due to intragenic SMN2 variants that may influence the amount of complete SMN transcripts and, therefore, of full‐length SMN protein. Detection of these variants is crucial to predict SMA phenotypes in the present scenario of therapeutic advances and with the perspective of SMA neonatal screening and early diagnosis to start treatments. Here, we present a novel, affordable, and versatile method for complete sequencing of the SMN2 gene based on long‐range polymerase chain reaction and next‐generation sequencing. The method was validated by analyzing samples from 53 SMA patients who lack SMN1, allowing to characterize paralogous, rare variants, and single‐nucleotide polymorphisms of SMN2 as well as SMN2–SMN1 hybrid genes. The method identifies partial deletions and can be adapted to determine rare pathogenic variants in patients with at least one SMN1 copy.
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Affiliation(s)
- Laura Blasco-Pérez
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain
| | - Ida Paramonov
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain
| | - Jordi Leno
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain
| | - Sara Bernal
- Genetics Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)
| | - Laura Alias
- Genetics Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)
| | - Pablo Fuentes-Prior
- Molecular Bases of Disease, Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Ivon Cuscó
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)
| | - Eduardo F Tizzano
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain
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31
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Moisse M, Zwamborn RAJ, van Vugt J, van der Spek R, van Rheenen W, Kenna B, Van Eijk K, Kenna K, Corcia P, Couratier P, Vourc'h P, Hardiman O, McLaughin R, Gotkine M, Drory V, Ticozzi N, Silani V, de Carvalho M, Mora Pardina JS, Povedano M, Andersen PM, Weber M, Başak NA, Chen X, Eberle MA, Al‐Chalabi A, Shaw C, Shaw PJ, Morrison KE, Landers JE, Glass JD, Robberecht W, van Es M, van den Berg L, Veldink J, Van Damme P. The Effect of SMN Gene Dosage on ALS Risk and Disease Severity. Ann Neurol 2021; 89:686-697. [PMID: 33389754 PMCID: PMC8048961 DOI: 10.1002/ana.26009] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/29/2020] [Accepted: 12/30/2020] [Indexed: 02/01/2023]
Abstract
OBJECTIVE The role of the survival of motor neuron (SMN) gene in amyotrophic lateral sclerosis (ALS) is unclear, with several conflicting reports. A decisive result on this topic is needed, given that treatment options are available now for SMN deficiency. METHODS In this largest multicenter case control study to evaluate the effect of SMN1 and SMN2 copy numbers in ALS, we used whole genome sequencing data from Project MinE data freeze 2. SMN copy numbers of 6,375 patients with ALS and 2,412 controls were called from whole genome sequencing data, and the reliability of the calls was tested with multiplex ligation-dependent probe amplification data. RESULTS The copy number distribution of SMN1 and SMN2 between cases and controls did not show any statistical differences (binomial multivariate logistic regression SMN1 p = 0.54 and SMN2 p = 0.49). In addition, the copy number of SMN did not associate with patient survival (Royston-Parmar; SMN1 p = 0.78 and SMN2 p = 0.23) or age at onset (Royston-Parmar; SMN1 p = 0.75 and SMN2 p = 0.63). INTERPRETATION In our well-powered study, there was no association of SMN1 or SMN2 copy numbers with the risk of ALS or ALS disease severity. This suggests that changing SMN protein levels in the physiological range may not modify ALS disease course. This is an important finding in the light of emerging therapies targeted at SMN deficiencies. ANN NEUROL 2021;89:686-697.
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Affiliation(s)
- Matthieu Moisse
- Departments of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI)KU Leuven – University of LeuvenLeuvenBelgium
- Laboratory of NeurobiologyVIB, Center for Brain and Disease ResearchLeuvenBelgium
| | - Ramona A. J. Zwamborn
- Department of NeurologyUMC Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
| | - Joke van Vugt
- Department of NeurologyUMC Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
| | - Rick van der Spek
- Department of NeurologyUMC Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
| | - Wouter van Rheenen
- Department of NeurologyUMC Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
| | - Brendan Kenna
- Department of NeurologyUMC Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
| | - Kristel Van Eijk
- Department of NeurologyUMC Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
| | - Kevin Kenna
- Department of NeurologyUMC Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
| | - Philippe Corcia
- Centre SLA, CHRU de ToursToursFrance
- UMR 1253, iBrain, Université de Tours, InsermToursFrance
| | | | | | - Orla Hardiman
- Academic Unit of NeurologyTrinity College Dublin, Trinity Biomedical Sciences InstituteDublinRepublic of Ireland
| | - Russell McLaughin
- Complex Trait Genomics LaboratorySmurfit Institute of Genetics, Trinity College DublinDublinRepublic of Ireland
| | - Marc Gotkine
- The Agnes Ginges Center for Human NeurogeneticsHadassah‐Hebrew University Medical CenterJerusalemIsrael
| | - Vivian Drory
- Department of NeurologyTel‐Aviv Sourasky Medical CentreTel AvivIsrael
| | - Nicola Ticozzi
- Department of Neurology, Stroke Unit and Laboratory of NeuroscienceIRCCS Istituto Auxologico ItalianoMilanoItaly
- Department of Pathophysiology and Transplantation“Dino Ferrari” Center, Università degli Studi di MilanoMilanItaly
| | - Vincenzo Silani
- Department of Neurology, Stroke Unit and Laboratory of NeuroscienceIRCCS Istituto Auxologico ItalianoMilanoItaly
- Department of Pathophysiology and Transplantation“Dino Ferrari” Center, Università degli Studi di MilanoMilanItaly
| | - Mamede de Carvalho
- Instituto de Fisiologia, Instituto de Medicina Molecular, Faculdade de MedicinaUniversidade de LisboaLisbonPortugal
| | | | | | - Peter M. Andersen
- Department of Clinical Science, NeurosciencesUmeå UniversityUmeåSweden
| | - Markus Weber
- Neuromuscular Diseases Unit/ALS ClinicSt. GallenSwitzerland
| | - Nazli A. Başak
- Koç University, School of Medicine, KUTTAM‐NDALIstanbulTurkey
| | | | | | - Ammar Al‐Chalabi
- Department of Basic and Clinical NeuroscienceMaurice Wohl Clinical Neuroscience Institute, King's College LondonLondonUK
| | - Chris Shaw
- Department of Basic and Clinical NeuroscienceMaurice Wohl Clinical Neuroscience Institute, King's College LondonLondonUK
| | - Pamela J. Shaw
- Sheffield Institute for Translational Neuroscience (SITraN)University of SheffieldSheffieldUK
| | - Karen E. Morrison
- School of Medicine, Dentistry, and Biomedical SciencesQueen's University BelfastBelfastUK
| | - John E. Landers
- Department of NeurologyUniversity of Massachusetts Medical SchoolWorcesterMA
| | | | - Wim Robberecht
- Departments of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI)KU Leuven – University of LeuvenLeuvenBelgium
- Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Michael van Es
- Department of NeurologyUMC Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
| | - Leonard van den Berg
- Department of NeurologyUMC Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
| | - Jan Veldink
- Department of NeurologyUMC Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
| | - Philip Van Damme
- Departments of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI)KU Leuven – University of LeuvenLeuvenBelgium
- Laboratory of NeurobiologyVIB, Center for Brain and Disease ResearchLeuvenBelgium
- Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
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32
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Bora G, Hensel N, Rademacher S, Koyunoğlu D, Sunguroğlu M, Aksu-Mengeş E, Balcı-Hayta B, Claus P, Erdem-Yurter H. Microtubule-associated protein 1B dysregulates microtubule dynamics and neuronal mitochondrial transport in spinal muscular atrophy. Hum Mol Genet 2021; 29:3935-3944. [PMID: 33410474 DOI: 10.1093/hmg/ddaa275] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 12/21/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a devastating childhood disease primarily affecting lower motoneurons in the spinal cord. SMA is caused by the loss of functional survival of motoneuron (SMN) protein, leading to structural and functional alterations of the cytoskeleton in motoneurons and other cells. Loss of SMN results in impairments of microtubule architecture, but the underlying mechanisms are not completely understood. In this study, we mechanistically analyzed the effects of SMN deficiency on microtubules, demonstrating a reduced stability together with a reduction in alpha tubulin detyrosination. This was caused by increased levels of microtubule-associated protein 1B and tubulin tyrosine ligase, resulting in mitochondrial mislocalization in SMA. Our findings suggest that altered tubulin post-translational modifications and microtubule-associated proteins are involved in the pathomechanisms of SMA, such as an impaired axonal transport of mitochondria.
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Affiliation(s)
- Gamze Bora
- Department of Medical Biology, Faculty of Medicine, Hacettepe University, Ankara 06100, Turkey
| | - Niko Hensel
- Institute of Neuroanatomy and Cell Biology, OE 4140, Hannover Medical School, Hannover 30625, Germany.,Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Sebastian Rademacher
- Institute of Neuroanatomy and Cell Biology, OE 4140, Hannover Medical School, Hannover 30625, Germany
| | - Dila Koyunoğlu
- Department of Medical Biology, Faculty of Medicine, Hacettepe University, Ankara 06100, Turkey
| | - Merve Sunguroğlu
- Department of Medical Biology, Faculty of Medicine, Hacettepe University, Ankara 06100, Turkey
| | - Evrim Aksu-Mengeş
- Department of Medical Biology, Faculty of Medicine, Hacettepe University, Ankara 06100, Turkey
| | - Burcu Balcı-Hayta
- Department of Medical Biology, Faculty of Medicine, Hacettepe University, Ankara 06100, Turkey
| | - Peter Claus
- Institute of Neuroanatomy and Cell Biology, OE 4140, Hannover Medical School, Hannover 30625, Germany.,Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Hayat Erdem-Yurter
- Department of Medical Biology, Faculty of Medicine, Hacettepe University, Ankara 06100, Turkey
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Meyer SM, Williams CC, Akahori Y, Tanaka T, Aikawa H, Tong Y, Childs-Disney JL, Disney MD. Small molecule recognition of disease-relevant RNA structures. Chem Soc Rev 2020; 49:7167-7199. [PMID: 32975549 PMCID: PMC7717589 DOI: 10.1039/d0cs00560f] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Targeting RNAs with small molecules represents a new frontier in drug discovery and development. The rich structural diversity of folded RNAs offers a nearly unlimited reservoir of targets for small molecules to bind, similar to small molecule occupancy of protein binding pockets, thus creating the potential to modulate human biology. Although the bacterial ribosome has historically been the most well exploited RNA target, advances in RNA sequencing technologies and a growing understanding of RNA structure have led to an explosion of interest in the direct targeting of human pathological RNAs. This review highlights recent advances in this area, with a focus on the design of small molecule probes that selectively engage structures within disease-causing RNAs, with micromolar to nanomolar affinity. Additionally, we explore emerging RNA-target strategies, such as bleomycin A5 conjugates and ribonuclease targeting chimeras (RIBOTACs), that allow for the targeted degradation of RNAs with impressive potency and selectivity. The compounds discussed in this review have proven efficacious in human cell lines, patient-derived cells, and pre-clinical animal models, with one compound currently undergoing a Phase II clinical trial and another that recently garnerd FDA-approval, indicating a bright future for targeted small molecule therapeutics that affect RNA function.
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Affiliation(s)
- Samantha M Meyer
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
| | - Christopher C Williams
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
| | - Yoshihiro Akahori
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
| | - Toru Tanaka
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
| | - Haruo Aikawa
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
| | - Yuquan Tong
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
| | - Jessica L Childs-Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
| | - Matthew D Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
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Bennett CF, Krainer AR, Cleveland DW. Antisense Oligonucleotide Therapies for Neurodegenerative Diseases. Annu Rev Neurosci 2020; 42:385-406. [PMID: 31283897 DOI: 10.1146/annurev-neuro-070918-050501] [Citation(s) in RCA: 181] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Antisense oligonucleotides represent a novel therapeutic platform for the discovery of medicines that have the potential to treat most neurodegenerative diseases. Antisense drugs are currently in development for the treatment of amyotrophic lateral sclerosis, Huntington's disease, and Alzheimer's disease, and multiple research programs are underway for additional neurodegenerative diseases. One antisense drug, nusinersen, has been approved for the treatment of spinal muscular atrophy. Importantly, nusinersen improves disease symptoms when administered to symptomatic patients rather than just slowing the progression of the disease. In addition to the benefit to spinal muscular atrophy patients, there are discoveries from nusinersen that can be applied to other neurological diseases, including method of delivery, doses, tolerability of intrathecally delivered antisense drugs, and the biodistribution of intrathecal dosed antisense drugs. Based in part on the early success of nusinersen, antisense drugs hold great promise as a therapeutic platform for the treatment of neurological diseases.
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Affiliation(s)
| | - Adrian R Krainer
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Don W Cleveland
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, California 92093, USA
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35
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Adami R, Bottai D. Spinal Muscular Atrophy Modeling and Treatment Advances by Induced Pluripotent Stem Cells Studies. Stem Cell Rev Rep 2020; 15:795-813. [PMID: 31863335 DOI: 10.1007/s12015-019-09910-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Spinal Muscular Atrophy (SMA) is a neurodegenerative disease characterized by specific and predominantly lower motor neuron (MN) loss. SMA is the main reason for infant death, while about one in 40 children born is a healthy carrier. SMA is caused by decreased levels of production of a ubiquitously expressed gene: the survival motor neuron (SMN). All SMA patients present mutations of the telomeric SMN1 gene, but many copies of a centromeric, partially functional paralog gene, SMN2, can somewhat compensate for the SMN1 deficiency, scaling inversely with phenotypic harshness. Because the study of neural tissue in and from patients presents too many challenges and is very often not feasible; the use of animal models, such as the mouse, had a pivotal impact in our understanding of SMA pathology but could not portray totally satisfactorily the elaborate regulatory mechanisms that are present in higher animals, particularly in humans. And while recent therapeutic achievements have been substantial, especially for very young infants, some issues should be considered for the treatment of older patients. An alternative way to study SMA, and other neurological pathologies, is the use of induced pluripotent stem cells (iPSCs) derived from patients. In this work, we will present a wide analysis of the uses of iPSCs in SMA pathology, starting from basic science to their possible roles as therapeutic tools.
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Affiliation(s)
- Raffaella Adami
- Department of Health Sciences, University of Milan, via A. di Rudinì 8, 20142, Milan, Italy
| | - Daniele Bottai
- Department of Health Sciences, University of Milan, via A. di Rudinì 8, 20142, Milan, Italy.
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36
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Berciano MT, Castillo-Iglesias MS, Val-Bernal JF, Lafarga V, Rodriguez-Rey JC, Lafarga M, Tapia O. Mislocalization of SMN from the I-band and M-band in human skeletal myofibers in spinal muscular atrophy associates with primary structural alterations of the sarcomere. Cell Tissue Res 2020; 381:461-478. [PMID: 32676861 DOI: 10.1007/s00441-020-03236-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 06/05/2020] [Indexed: 12/22/2022]
Abstract
Spinal muscular atrophy (SMA) is caused by a deletion or mutation of the survival motor neuron 1 (SMN1) gene. Reduced SMN levels lead to motor neuron degeneration and muscular atrophy. SMN protein localizes to the cytoplasm and Cajal bodies. Moreover, in myofibrils from Drosophila and mice, SMN is a sarcomeric protein localized to the Z-disc. Although SMN participates in multiple functions, including the biogenesis of spliceosomal small nuclear ribonucleoproteins, its role in the sarcomere is unclear. Here, we analyzed the sarcomeric organization of SMN in human control and type I SMA skeletal myofibers. In control sarcomeres, we demonstrate that human SMN is localized to the titin-positive M-band and actin-positive I-band, and to SMN-positive granules that flanked the Z-discs. Co-immunoprecipitation assays revealed that SMN interacts with the sarcomeric protein actin, α-actinin, titin, and profilin2. In the type I SMA muscle, SMN levels were reduced, and atrophic (denervated) and hypertrophic (nondenervated) myofibers coexisted. The hypertrophied myofibers, which are potential primary targets of SMN deficiency, exhibited sites of focal or segmental alterations of the actin cytoskeleton, where the SMN immunostaining pattern was altered. Moreover, SMN was relocalized to the Z-disc in overcontracted minisarcomeres from hypertrophic myofibers. We propose that SMN could have an integrating role in the molecular components of the sarcomere. Consequently, low SMN levels might impact the normal sarcomeric architecture, resulting in the disruption of myofibrils found in SMA muscle. This primary effect might be independent of the neurogenic myopathy produced by denervation and contribute to pathophysiology of the SMA myopathy.
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Affiliation(s)
- María T Berciano
- Departamento de Biología Molecular, Universidad de Cantabria-IDIVAL, Santander, Spain
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL) and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Santander, Spain
| | | | - J Fernando Val-Bernal
- Unidad de Patología, Departamento de Ciencias Médicas y Quirúrgicas, Universidad de Cantabria-IDIVAL, Santander, Spain
| | - Vanesa Lafarga
- Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain
| | - José C Rodriguez-Rey
- Departamento de Biología Molecular, Universidad de Cantabria-IDIVAL, Santander, Spain
| | - Miguel Lafarga
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL) and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Santander, Spain.
- Departamento de Anatomía y Biología Celular, Universidad de Cantabria-IDIVAL, Santander, Spain.
| | - Olga Tapia
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL) and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Santander, Spain.
- Universidad Europea del Atlántico, Santander, Spain.
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Wadman RI, Jansen MD, Stam M, Wijngaarde CA, Curial CAD, Medic J, Sodaar P, Schouten J, Vijzelaar R, Lemmink HH, van den Berg LH, Groen EJN, van der Pol WL. Intragenic and structural variation in the SMN locus and clinical variability in spinal muscular atrophy. Brain Commun 2020; 2:fcaa075. [PMID: 32954327 PMCID: PMC7425299 DOI: 10.1093/braincomms/fcaa075] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/17/2020] [Accepted: 04/22/2020] [Indexed: 11/15/2022] Open
Abstract
Clinical severity and treatment response vary significantly between patients with spinal muscular atrophy. The approval of therapies and the emergence of neonatal screening programmes urgently require a more detailed understanding of the genetic variants that underlie this clinical heterogeneity. We systematically investigated genetic variation other than SMN2 copy number in the SMN locus. Data were collected through our single-centre, population-based study on spinal muscular atrophy in the Netherlands, including 286 children and adults with spinal muscular atrophy Types 1–4, including 56 patients from 25 families with multiple siblings with spinal muscular atrophy. We combined multiplex ligation-dependent probe amplification, Sanger sequencing, multiplexed targeted resequencing and digital droplet polymerase chain reaction to determine sequence and expression variation in the SMN locus. SMN1, SMN2 and NAIP gene copy number were determined by multiplex ligation-dependent probe amplification. SMN2 gene variant analysis was performed using Sanger sequencing and RNA expression analysis of SMN by droplet digital polymerase chain reaction. We identified SMN1–SMN2 hybrid genes in 10% of spinal muscular atrophy patients, including partial gene deletions, duplications or conversions within SMN1 and SMN2 genes. This indicates that SMN2 copies can vary structurally between patients, implicating an important novel level of genetic variability in spinal muscular atrophy. Sequence analysis revealed six exonic and four intronic SMN2 variants, which were associated with disease severity in individual cases. There are no indications that NAIP1 gene copy number or sequence variants add value in addition to SMN2 copies in predicting the clinical phenotype in individual patients with spinal muscular atrophy. Importantly, 95% of spinal muscular atrophy siblings in our study had equal SMN2 copy numbers and structural changes (e.g. hybrid genes), but 60% presented with a different spinal muscular atrophy type, indicating the likely presence of further inter- and intragenic variabilities inside as well as outside the SMN locus. SMN2 gene copies can be structurally different, resulting in inter- and intra-individual differences in the composition of SMN1 and SMN2 gene copies. This adds another layer of complexity to the genetics that underlie spinal muscular atrophy and should be considered in current genetic diagnosis and counselling practices.
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Affiliation(s)
- Renske I Wadman
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Marc D Jansen
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Marloes Stam
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Camiel A Wijngaarde
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Chantall A D Curial
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Jelena Medic
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Peter Sodaar
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Jan Schouten
- MRC Holland BV, 1057 DL Amsterdam, the Netherlands
| | | | - Henny H Lemmink
- Department of Genetics, University Medical Center Groningen, 9713 GZ Groningen, the Netherlands
| | - Leonard H van den Berg
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Ewout J N Groen
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - W Ludo van der Pol
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
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38
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Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease caused by deletions or mutations in the survival motor neuron (SMN1) gene. SMA is characterized by loss of lower motor neurons (anterior horn cells) in the spinal cord and brainstem nuclei, leading to progressive symmetrical muscle weakness and atrophy. It affects approximately 1 in 6,000 to 1 in 10,000 individuals and is the most common inherited cause of childhood mortality, but this may soon change given recent developments. In December 2016, nusinersen, an antisense oligonucleotide drug, was approved by the United States Food and Drug Administration for the treatment of SMA, and in July 2018, SMA was added to the recommended uniform screening panel, a list of conditions that all states are encouraged to include in their newborn screening (NBS) panels. In this review, we begin with a brief clinical history of the diagnosis of SMA, discuss the current SMA clinical classification system, describe the current treatment, and discuss evolving treatment guidelines. We then discuss the path to include SMA in NBS programs as well as the controversies it engenders because the variability in age at symptom onset means early identification of asymptomatic patients who will not require therapy for years or decades. We also consider alternate population screening opportunities. Next, we consider experimental treatments. We conclude by supporting NBS for SMA with the caveat that a long-term follow-up registry is ethically essential to ensure that the benefits outweigh the harms for all screened infants, including those with milder and/or later-onset forms of SMA.
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Affiliation(s)
- Lainie Friedman Ross
- Departments of Pediatrics, Medicine, Surgery and the College; MacLean Center for Clinical Medical Ethics, University of Chicago, Chicago, IL
| | - Jennifer M Kwon
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI
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39
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Autophagy in motor neuron diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 172:157-202. [PMID: 32620242 DOI: 10.1016/bs.pmbts.2020.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Motor neuron diseases (MNDs) are a wide group of neurodegenerative disorders characterized by the degeneration of a specific neuronal type located in the central nervous system, the motor neuron (MN). There are two main types of MNs, spinal and cortical MNs and depending on the type of MND, one or both types are affected. Cortical MNs innervate spinal MNs and these control a variety of cellular targets, being skeletal muscle their main one which is also affected in MNDs. A correct functionality of autophagy is necessary for the survival of all cellular types and it is particularly crucial for neurons, given their postmitotic and highly specialized nature. Numerous studies have identified alterations of autophagy activity in multiple MNDs. The scientific community has been particularly prolific in reporting the role that autophagy plays in the most common adult MND, amyotrophic lateral sclerosis, although many studies have started to identify physiological and pathological functions of this catabolic system in other MNDs, such as spinal muscular atrophy and spinal and bulbar muscular atrophy. The degradation of selective cargo by autophagy and how this process is altered upon the presence of MND-causing mutations is currently also a matter of intense investigation, particularly regarding the selective autophagic clearance of mitochondria. Thorough reviews on this field have been recently published. This chapter will cover the current knowledge on the functionality of autophagy and lysosomal homeostasis in the main MNDs and other autophagy-related topics in the MND field that have risen special interest in the research community.
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40
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Chen X, Sanchis-Juan A, French CE, Connell AJ, Delon I, Kingsbury Z, Chawla A, Halpern AL, Taft RJ, Bentley DR, Butchbach MER, Raymond FL, Eberle MA. Spinal muscular atrophy diagnosis and carrier screening from genome sequencing data. Genet Med 2020; 22:945-953. [PMID: 32066871 PMCID: PMC7200598 DOI: 10.1038/s41436-020-0754-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 01/22/2020] [Accepted: 01/24/2020] [Indexed: 11/21/2022] Open
Abstract
Purpose Spinal muscular atrophy (SMA), caused by loss of the SMN1 gene, is a leading cause of early childhood death. Due to the near identical sequences of SMN1 and SMN2, analysis of this region is challenging. Population-wide SMA screening to quantify the SMN1 copy number (CN) is recommended by the American College of Medical Genetics and Genomics. Methods We developed a method that accurately identifies the CN of SMN1 and SMN2 using genome sequencing (GS) data by analyzing read depth and eight informative reference genome differences between SMN1/2. Results We characterized SMN1/2 in 12,747 genomes, identified 1568 samples with SMN1 gains or losses and 6615 samples with SMN2 gains or losses, and calculated a pan-ethnic carrier frequency of 2%, consistent with previous studies. Additionally, 99.8% of our SMN1 and 99.7% of SMN2 CN calls agreed with orthogonal methods, with a recall of 100% for SMA and 97.8% for carriers, and a precision of 100% for both SMA and carriers. Conclusion This SMN copy-number caller can be used to identify both carrier and affected status of SMA, enabling SMA testing to be offered as a comprehensive test in neonatal care and an accurate carrier screening tool in GS sequencing projects.
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Affiliation(s)
| | - Alba Sanchis-Juan
- Department of Haematology, University of Cambridge, NHS Blood and Transplant Centre, Cambridge, UK.,NIHR BioResource, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, UK
| | - Courtney E French
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Andrew J Connell
- Center for Applied Clinical Genomics, Nemours Biomedical Research, Nemours Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Isabelle Delon
- East Midlands and East of England NHS Genomic Laboratory Hub, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | | | | | | | | | | | | | - Matthew E R Butchbach
- Center for Applied Clinical Genomics, Nemours Biomedical Research, Nemours Alfred I. duPont Hospital for Children, Wilmington, DE, USA.,Center for Pediatric Research, Nemours Biomedical Research, Nemours Alfred I. duPont Hospital for Children, Wilmington, DE, USA.,Department of Pediatrics, Sidney Kimmel College of Medicine, Thomas Jefferson University, Philadelphia, PA, USA.,Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - F Lucy Raymond
- NIHR BioResource, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, UK.,Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
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Wirth B, Karakaya M, Kye MJ, Mendoza-Ferreira N. Twenty-Five Years of Spinal Muscular Atrophy Research: From Phenotype to Genotype to Therapy, and What Comes Next. Annu Rev Genomics Hum Genet 2020; 21:231-261. [PMID: 32004094 DOI: 10.1146/annurev-genom-102319-103602] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Twenty-five years ago, the underlying genetic cause for one of the most common and devastating inherited diseases in humans, spinal muscular atrophy (SMA), was identified. Homozygous deletions or, rarely, subtle mutations of SMN1 cause SMA, and the copy number of the nearly identical copy gene SMN2 inversely correlates with disease severity. SMA has become a paradigm and a prime example of a monogenic neurological disorder that can be efficiently ameliorated or nearly cured by novel therapeutic strategies, such as antisense oligonucleotide or gene replacement therapy. These therapies enable infants to survive who might otherwise have died before the age of two and allow individuals who have never been able to sit or walk to do both. The major milestones on the road to these therapies were to understand the genetic cause and splice regulation of SMN genes, the disease's phenotype-genotype variability, the function of the protein and the main affected cellular pathways and tissues, the disease's pathophysiology through research on animal models, the windows of opportunity for efficient treatment, and how and when to treat patients most effectively.This review aims to bridge our knowledge from phenotype to genotype to therapy, not only highlighting the significant advances so far but also speculating about the future of SMA screening and treatment.
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Affiliation(s)
- Brunhilde Wirth
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany;
| | - Mert Karakaya
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany;
| | - Min Jeong Kye
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany;
| | - Natalia Mendoza-Ferreira
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany;
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Campagne S, Boigner S, Rüdisser S, Moursy A, Gillioz L, Knörlein A, Hall J, Ratni H, Cléry A, Allain FHT. Structural basis of a small molecule targeting RNA for a specific splicing correction. Nat Chem Biol 2019; 15:1191-1198. [DOI: 10.1038/s41589-019-0384-5] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 09/07/2019] [Indexed: 12/24/2022]
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AAV9 Vector: a Novel modality in gene therapy for spinal muscular atrophy. Gene Ther 2019; 26:287-295. [PMID: 31243392 DOI: 10.1038/s41434-019-0085-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 05/03/2019] [Accepted: 05/20/2019] [Indexed: 12/30/2022]
Abstract
Spinal muscular atrophy (SMA), the leading genetic cause of infant mortality, is characterized by the deterioration of alpha motor neurons in the brainstem and spinal cord. Currently, there is no cure for SMA, which calls for an urgent need to explore affordable and effective therapies and to maximize patients' independence and quality of life. Adeno-associated virus (AAV) vector, one of the most promising and well-investigated vehicles for delivering transgenes, is a compelling candidate for gene therapy. Some of the hallmarks of AAVs are their nonpathogenicity, inability to incur an immune response, potential to achieve robust transgene expression, and varied tropism for several tissues of the body. Recently, these features were harnessed in a clinical trial conducted by AveXis in SMA patients, where AAV9 was employed as a vehicle for one-time administration of the SMN gene, the causative gene in SMA. The trial demonstrated remarkable improvements in motor milestones and rates of survival in the patients. This review focuses on the advent of SMA gene therapy and summarizes different preclinical studies that were conducted leading up to the AAV9-SMA trial in SMA patients.
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Ando S, Funato M, Ohuchi K, Inagaki S, Sato A, Seki J, Kawase C, Saito T, Nishio H, Nakamura S, Shimazawa M, Kaneko H, Hara H. The Protective Effects of Levetiracetam on a Human iPSCs-Derived Spinal Muscular Atrophy Model. Neurochem Res 2019; 44:1773-1779. [PMID: 31102025 DOI: 10.1007/s11064-019-02814-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 04/04/2019] [Accepted: 05/09/2019] [Indexed: 12/30/2022]
Abstract
Spinal muscular atrophy (SMA) is an inherited disease characterized by progressive motor neuron death and subsequent muscle weakness and is caused by deletion or mutation of survival motor neuron (SMN) 1 gene. Protecting spinal motor neuron is an effective clinical strategy for SMA. The purpose of this study was to investigate the potential effect of an anti-epileptic drug levetiracetam on SMA. In the present study, we used differentiated spinal motor neurons (MNs) from SMA patient-derived induced pluripotent stem cells (SMA-iPSCs) to investigate the effect of levetiracetam. Levetiracetam promoted neurite elongation in SMA-iPSCs-MNs. TUNEL-positive spinal motor neurons were significantly reduced by levetiracetam in SMA-iPSCs-MNs. In addition, the expression level of cleaved-caspase 3 was decreased by levetiracetam in SMA-iPSCs-MNs. Furthermore, levetiracetam improved impaired mitochondrial function in SMA-iPSCs-MNs. On the other hand, levetiracetam did not affect the expression level of SMN protein in SMA-iPSCs-MNs. These findings indicate that levetiracetam has a neuroprotective effect for SMA.
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Affiliation(s)
- Shiori Ando
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
- Department of Clinical Research, National Hospital Organization, Nagara Medical Center, Gifu, Japan
| | - Michinori Funato
- Department of Clinical Research, National Hospital Organization, Nagara Medical Center, Gifu, Japan
| | - Kazuki Ohuchi
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
- Department of Clinical Research, National Hospital Organization, Nagara Medical Center, Gifu, Japan
| | - Satoshi Inagaki
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
- Department of Clinical Research, National Hospital Organization, Nagara Medical Center, Gifu, Japan
| | - Arisu Sato
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
- Department of Clinical Research, National Hospital Organization, Nagara Medical Center, Gifu, Japan
| | - Junko Seki
- Department of Clinical Research, National Hospital Organization, Nagara Medical Center, Gifu, Japan
| | - Chizuru Kawase
- Department of Clinical Research, National Hospital Organization, Nagara Medical Center, Gifu, Japan
| | - Toshio Saito
- Division of Child Neurology, Department of Neurology, National Hospital Organization, Toneyama National Hospital, Toyonaka, Osaka, Japan
| | - Hisahide Nishio
- Department of Occupational Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Hyogo, Japan
| | - Shinsuke Nakamura
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Masamitsu Shimazawa
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Hideo Kaneko
- Department of Clinical Research, National Hospital Organization, Nagara Medical Center, Gifu, Japan
| | - Hideaki Hara
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan.
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Aslesh T, Maruyama R, Yokota T. Systemic and ICV Injections of Antisense Oligos into SMA Mice and Evaluation. Methods Mol Biol 2019; 1828:455-465. [PMID: 30171559 DOI: 10.1007/978-1-4939-8651-4_28] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Spinal muscular atrophy (SMA) is the most common genetic cause of infantile death caused by mutations in the SMN1 gene. Nusinersen (Spinraza), an antisense therapy-based drug with the 2'-methoxyethoxy (2'MOE) chemistry approved by the FDA in 2016, brought antisense drugs into the spotlight. Antisense-mediated exon inclusion targeting SMN2 leads to SMN protein expression. Although effective, 2'MOE has weaknesses such as the inability to cross the blood-brain barrier and the high cost of treatment. To investigate new chemistries of antisense oligonucleotides (ASOs), SMA mouse models can serve as an important source. Here we describe methods to test the efficacy of ASOs, such as phosphorodiamidate morpholino oligomers (PMOs), in a severe SMA mouse model.
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Affiliation(s)
- Tejal Aslesh
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Rika Maruyama
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada. .,The Friends of Garrett Cumming Research and Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair, Edmonton, AB, Canada.
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46
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Touznik A, Maruyama R, Yokota T. In Vitro Evaluation of Antisense-Mediated Exon Inclusion for Spinal Muscular Atrophy. Methods Mol Biol 2019; 1828:439-454. [PMID: 30171558 DOI: 10.1007/978-1-4939-8651-4_27] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Spinal muscular atrophy (SMA), the most common gentic cause of infantile death caused by mutations in the SMN1 gene, presents a unique case in the field of splice modulation therapy, where a gene (or lack of) is responsible for causing the disease phenotype but treatment is not focused around it. Antisense therapy targeting SMN2 which leads to SMN protein expression has been at the forefront of research when it comes to developing a feasible therapy for treating SMA. Recent FDA approval of an antisense-based drug with the 2'-methoxyethoxy (2'MOE) chemistry, called nusinersen (Spinraza), brought antisense drugs into the spotlight. The 2'MOE, although effective, has weaknesses such as the inability to cross the blood-brain barrier and the high cost of treatment. This propelled the research community to investigate new chemistries of antisense oligonucleotides (ASOs) that may be better in both treatment and cost efficiency. Here we describe two types of ASOs, phosphorodiamidate morpholino oligomers (PMOs) and locked nucleic acids (LNA)-DNA mixmers, being investigated as potential treatments for SMA, and methods used to test their efficacy, including quantitative RT-PCR, Western blotting, and immunofluorescence staining to detect SMN in nuclear gems/Cajal bodies, in type I SMA patient fibroblast cell lines.
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Affiliation(s)
- Aleksander Touznik
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Rika Maruyama
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada. .,The Friends of Garrett Cumming Research and Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair, Edmonton, AB, Canada.
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47
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Wang Y, Xu C, Ma L, Mou Y, Zhang B, Zhou S, Tian Y, Trinh J, Zhang X, Li XJ. Drug screening with human SMN2 reporter identifies SMN protein stabilizers to correct SMA pathology. Life Sci Alliance 2019; 2:2/2/e201800268. [PMID: 30910806 PMCID: PMC6435041 DOI: 10.26508/lsa.201800268] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 03/12/2019] [Accepted: 03/12/2019] [Indexed: 01/14/2023] Open
Abstract
Spinal muscular atrophy (SMA), the leading genetic cause of infant mortality, is caused by reduced levels of functional survival motor neuron (SMN) protein. To identify therapeutic agents for SMA, we established a versatile SMN2-GFP reporter line by targeting the human SMN2 gene. We then screened a compound library and identified Z-FA-FMK as a potent candidate. Z-FA-FMK, a cysteine protease inhibitor, increased functional SMN through inhibiting the protease-mediated degradation of both full-length and exon 7-deleted forms of SMN. Further studies reveal that CAPN1, CAPN7, CTSB, and CTSL mediate the degradation of SMN proteins, providing novel targets for SMA. Notably, Z-FA-FMK mitigated mitochondriopathy and neuropathy in SMA patient-derived motor neurons and showed protective effects in SMA animal model after intracerebroventricular injection. E64d, another cysteine protease inhibitor which can pass through the blood-brain barrier, showed even more potent therapeutic effects after subcutaneous delivery to SMA mice. Taken together, we have successfully established a human SMN2 reporter for future drug discovery and identified the potential therapeutic value of cysteine protease inhibitors in treating SMA via stabilizing SMN proteins.
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Affiliation(s)
- Yiran Wang
- Brain and Spinal Cord Innovative Research Center, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Chongchong Xu
- Department of Biomedical Sciences, University of Illinois College of Medicine Rockford, Rockford, IL, USA.,Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Lin Ma
- Brain and Spinal Cord Innovative Research Center, Tongji Hospital, Tongji University School of Medicine, Shanghai, China.,Key Laboratory of Reconstruction and Regeneration of Spine and Spinal Cord Injury, Ministry of Education, Shanghai, China.,Key Laboratory of Neuroregeneration of Shanghai Universities, Tongji University, School of Medicine, Shanghai, China
| | - Yongchao Mou
- Department of Biomedical Sciences, University of Illinois College of Medicine Rockford, Rockford, IL, USA.,Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Bowen Zhang
- Brain and Spinal Cord Innovative Research Center, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Shanshan Zhou
- Brain and Spinal Cord Innovative Research Center, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yue Tian
- Brain and Spinal Cord Innovative Research Center, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Jessica Trinh
- Department of Biomedical Sciences, University of Illinois College of Medicine Rockford, Rockford, IL, USA
| | - Xiaoqing Zhang
- Brain and Spinal Cord Innovative Research Center, Tongji Hospital, Tongji University School of Medicine, Shanghai, China .,Key Laboratory of Reconstruction and Regeneration of Spine and Spinal Cord Injury, Ministry of Education, Shanghai, China.,Key Laboratory of Neuroregeneration of Shanghai Universities, Tongji University, School of Medicine, Shanghai, China.,Tsingtao Advanced Research Institute, Tongji University, Shanghai, China.,Shanghai Institute of Stem Cell Research and Clinical Translation, Shanghai, China.,Translational Medical Center for Stem Cell Therapy, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xue-Jun Li
- Department of Biomedical Sciences, University of Illinois College of Medicine Rockford, Rockford, IL, USA .,Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA
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48
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Nik S, Bowman TV. Splicing and neurodegeneration: Insights and mechanisms. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1532. [PMID: 30895702 DOI: 10.1002/wrna.1532] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 02/17/2019] [Accepted: 02/20/2019] [Indexed: 12/13/2022]
Abstract
Splicing is the global cellular process whereby intervening sequences (introns) in precursor messenger RNA (pre-mRNA) are removed and expressed regions (exons) are ligated together, resulting in a mature mRNA transcript that is exported and translated in the cytoplasm. The tightly regulated splicing cycle is also flexible allowing for the inclusion or exclusion of some sequences depending on the specific cellular context. Alternative splicing allows for the generation of many transcripts from a single gene, thereby expanding the proteome. Although all cells require the function of the spliceosome, neurons are highly sensitive to splicing perturbations with numerous neurological diseases linked to splicing defects. The sensitivity of neurons to splicing alterations is largely due to the complex neuronal cell types and functions in the nervous system that require specific splice isoforms to maintain cellular homeostasis. In the past several years, the relationship between RNA splicing and the nervous system has been the source of significant investigation. Here, we review the current knowledge on RNA splicing in neurobiology and discuss its potential role and impact in neurodegenerative diseases. We will examine the impact of alternative splicing and the role of splicing regulatory proteins on neurodegeneration, highlighting novel animal models including mouse and zebrafish. We will also examine emerging technologies and therapeutic interventions that aim to "drug" the spliceosome. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing RNA in Disease and Development > RNA in Development.
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Affiliation(s)
- Sara Nik
- Department of Developmental and Molecular Biology and Gottesman Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, New York
| | - Teresa V Bowman
- Department of Developmental and Molecular Biology, Department of Medicine (Oncology), and Gottesman Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, New York
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49
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Sun J, Harrington MA. The Alteration of Intrinsic Excitability and Synaptic Transmission in Lumbar Spinal Motor Neurons and Interneurons of Severe Spinal Muscular Atrophy Mice. Front Cell Neurosci 2019; 13:15. [PMID: 30792629 PMCID: PMC6374350 DOI: 10.3389/fncel.2019.00015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 01/16/2019] [Indexed: 01/22/2023] Open
Abstract
Spinal muscular atrophy (SMA) is the leading genetic cause of death in infants. Studies with mouse models have demonstrated increased excitability and loss of afferent proprioceptive synapses on motor neurons (MNs). To further understand functional changes in the motor neural network occurring in SMA, we studied the intrinsic excitability and synaptic transmission of both MNs and interneurons (INs) from ventral horn in the lumbar spinal cord in the survival motor neuron (SMN)Δ7 mouse model. We found significant differences in the membrane properties of MNs in SMA mice compared to littermate controls, including hyperpolarized resting membrane potential, increased input resistance and decreased membrane capacitance. Action potential (AP) properties in MNs from SMA mice were also different from controls, including decreased rheobase current, increased amplitude and an increased afterdepolarization (ADP) potential. The relationship between AP firing frequency and injected current was reduced in MNs, as was the threshold current, while the percentage of MNs showing long-lasting potentiation (LLP) in the intrinsic excitability was higher in SMA mice. INs showed a high rate of spontaneous firing, and those from SMA mice fired at higher frequency. INs from SMA mice showed little difference in their input-output relationship, threshold current, and plasticity in intrinsic excitability. The changes observed in both passive membrane and AP properties suggest greater overall excitability in both MNs and INs in SMA mice, with MNs showing more differences. There were also changes of synaptic currents in SMA mice. The average charge transfer per post-synaptic current of spontaneous excitatory and inhibitory synaptic currents (sEPSCs/sIPSCs) were lower in SMA MNs, while in INs sIPSC frequency was higher. Strikingly in light of the known loss of excitatory synapses on MNs, there was no difference in sEPSC frequency in MNs from SMA mice compared to controls. For miniature synaptic currents, mEPSC frequency was higher in SMA MNs, while for SMA INs, both mEPSC and mIPSC frequencies were higher. In SMA-affected mice we observed alterations of intrinsic and synaptic properties in both MNs and INs in the spinal motor network that may contribute to the pathophysiology, or alternatively, may be a compensatory response to preserve network function.
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Affiliation(s)
- Jianli Sun
- Delaware Center for Neuroscience Research, Delaware State University, Dover, DE, United States.,Department of Biological Science, Delaware State University, Dover, DE, United States
| | - Melissa A Harrington
- Delaware Center for Neuroscience Research, Delaware State University, Dover, DE, United States.,Department of Biological Science, Delaware State University, Dover, DE, United States
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50
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Sheng L, Wan B, Feng P, Sun J, Rigo F, Bennett CF, Akerman M, Krainer AR, Hua Y. Downregulation of Survivin contributes to cell-cycle arrest during postnatal cardiac development in a severe spinal muscular atrophy mouse model. Hum Mol Genet 2019; 27:486-498. [PMID: 29220503 DOI: 10.1093/hmg/ddx418] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 11/28/2017] [Indexed: 11/13/2022] Open
Abstract
Spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality, characterized by progressive degeneration of spinal-cord motor neurons, leading to atrophy of skeletal muscles. However, accumulating evidence indicates that it is a multi-system disorder, particularly in its severe forms. Several studies delineated structural and functional cardiac abnormalities in SMA patients and mouse models, yet the abnormalities have been primarily attributed to autonomic dysfunction. Here, we show in a severe mouse model that its cardiomyocytes undergo G0/G1 cell-cycle arrest and enhanced apoptosis during postnatal development. Microarray and real-time RT-PCR analyses revealed that a set of genes associated with cell cycle and apoptosis were dysregulated in newborn pups. Of particular interest, the Birc5 gene, which encodes Survivin, an essential protein for heart development, was down-regulated even on pre-symptomatic postnatal day 0. Interestingly, cultured cardiomyocytes depleted of SMN recapitulated the gene expression changes including downregulation of Survivin and abnormal cell-cycle progression; and overexpression of Survivin rescued the cell-cycle defect. Finally, increasing SMN in SMA mice with a therapeutic antisense oligonucleotide improved heart pathology and recovered expression of deregulated genes. Collectively, our data demonstrate that the cardiac malfunction of the severe SMA mouse model is mainly a cell-autonomous defect, caused by widespread gene deregulation in heart tissue, particularly of Birc5, resulting in developmental abnormalities through cell-cycle arrest and apoptosis.
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Affiliation(s)
- Lei Sheng
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, China.,Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215123, China
| | - Bo Wan
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, China.,Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215123, China
| | - Pengchao Feng
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, China.,Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215123, China
| | - Junjie Sun
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, China.,Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215123, China
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA 92010, USA
| | | | - Martin Akerman
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY 11724, USA.,Envisagenics, Inc., New York, NY 10017, USA
| | - Adrian R Krainer
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY 11724, USA
| | - Yimin Hua
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, China.,Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215123, China
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