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Bayoumy S, Verberk IMW, Vermunt L, Willemse E, den Dulk B, van der Ploeg AT, Pajkrt D, Nitz E, van den Hout JMP, van der Post J, Wolf NI, Beerepoot S, Groen EJN, Tüngler V, Teunissen CE. Neurofilament light protein as a biomarker for spinal muscular atrophy: a review and reference ranges. Clin Chem Lab Med 2024; 62:1252-1265. [PMID: 38215341 DOI: 10.1515/cclm-2023-1311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Accepted: 01/03/2024] [Indexed: 01/14/2024]
Abstract
Spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality, characterized by progressive neuromuscular degeneration resulting from mutations in the survival motor neuron (SMN1) gene. The availability of disease-modifying therapies for SMA therapies highlights the pressing need for easily accessible and cost-effective blood biomarkers to monitor treatment response and for better disease management. Additionally, the wide implementation of newborn genetic screening programs in Western countries enables presymptomatic diagnosis of SMA and immediate treatment administration. However, the absence of monitoring and prognostic blood biomarkers for neurodegeneration in SMA hinders effective disease management. Neurofilament light protein (NfL) is a promising biomarker of neuroaxonal damage in SMA and reflects disease progression in children with SMA undergoing treatment. Recently, the European Medicines Agency issued a letter of support endorsing the potential utilization of NfL as a biomarker of pediatric neurological diseases, including SMA. Within this review, we comprehensively assess the potential applications of NfL as a monitoring biomarker for disease severity and treatment response in pediatric-onset SMA. We provide reference ranges for normal levels of serum based NfL in neurologically healthy children aged 0-18 years. These reference ranges enable accurate interpretation of NfL levels in children and can accelerate the implementation of NfL into clinical practice.
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Affiliation(s)
- Sherif Bayoumy
- Neurochemistry Laboratory, Department of Laboratory Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Inge M W Verberk
- Neurochemistry Laboratory, Department of Laboratory Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Lisa Vermunt
- Neurochemistry Laboratory, Department of Laboratory Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Eline Willemse
- Neurochemistry Laboratory, Department of Laboratory Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Ben den Dulk
- Neurochemistry Laboratory, Department of Laboratory Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Ans T van der Ploeg
- Center for Lysosomal and Metabolic Diseases, Department of Pediatrics, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Dasja Pajkrt
- Organovir Labs, Department of Pediatric Infectious Diseases, Amsterdam University Medical Centers Location Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Elisa Nitz
- Department of Neuropediatrics, Medizinische Fakultät, Technische Universität Dresden, Dresden, Germany
| | - Johanna M P van den Hout
- Center for Lysosomal and Metabolic Diseases, Department of Pediatrics, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Julie van der Post
- Organovir Labs, Department of Pediatric Infectious Diseases, Amsterdam University Medical Centers Location Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Nicole I Wolf
- Amsterdam Leukodystrophy Center, Department of Child Neurology, Emma Children's Hospital, Amsterdam University Medical Center, VU University Amsterdam, and Amsterdam Neuroscience, Cellular & Molecular Mechanisms, Amsterdam, The Netherlands
| | - Shanice Beerepoot
- Amsterdam Leukodystrophy Center, Department of Child Neurology, Emma Children's Hospital, Amsterdam University Medical Center, VU University Amsterdam, and Amsterdam Neuroscience, Cellular & Molecular Mechanisms, Amsterdam, The Netherlands
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Ewout J N Groen
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Victoria Tüngler
- Department of Neuropediatrics, Medizinische Fakultät, Technische Universität Dresden, Dresden, Germany
- University Center for Rare Diseases, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Charlotte E Teunissen
- Neurochemistry Laboratory, Department of Laboratory Medicine, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
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2
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Steffens P, Weiss D, Perez A, Appel M, Weber P, Weiss C, Stoltenburg C, Ehinger U, von der Hagen M, Schallner J, Claussen B, Lode I, Hahn A, Schuler R, Ruß L, Ziegler A, Denecke J, Johannsen J. Cognitive function in SMA patients with 2 or 3 SMN2 copies treated with SMN-modifying or gene addition therapy during the first year of life. Eur J Paediatr Neurol 2024; 51:17-23. [PMID: 38772209 DOI: 10.1016/j.ejpn.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 04/15/2024] [Accepted: 05/07/2024] [Indexed: 05/23/2024]
Abstract
BACKGROUND Spinal muscular atrophy (SMA) is a neuromuscular disease, causing progressive muscle weakness due to loss of lower motoneurons. Since 2017, three therapies, two modifying gene transcription and one adding the defective gene, have been approved with comparable efficacy on motor outcome. Data on cognitive outcomes of treated SMA type 1 patients is limited. The aim of this study was to evaluate cognitive function in symptomatic and presymptomatic SMA type 1 patients with two or three SMN2 copies who received SMN-modifying or gene-addition therapy in the first year of life. METHODS Cognitive testing was performed in 20 patients, including 19 symptomatic SMA type 1 patients with up to three SMN2 copies and 1 pre-symptomatically treated patient. Children were tested using Bayley Scales of Infant Development (BSID-III) at the age of 2 or 3 years or the Wechsler Preschool and Primary Scale of Intelligence (WPSII-IV) at the of age of 5 years. RESULTS 11/20 patients showed subnormal cognitive development. Boys had significantly lower cognitive scores. Patients requiring assisted ventilation or feeding support were more likely to have cognitive deficits. Achieving more motor milestones was associated with a better cognitive outcome. CONCLUSION Treated patients with SMA type 1 have heterogeneous cognitive function with 55 % of patients showing deficits. Risk factors for cognitive impairment in our cohort were male gender and need for assisted ventilation or feeding support. Therefore, cognitive assessment should be included in the standard of care to allow early identification of deficits and potential therapeutic interventions.
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Affiliation(s)
- Paula Steffens
- University Medical Center Hamburg-Eppendorf, Department of Pediatrics, Hamburg, Germany.
| | - Deike Weiss
- University Medical Center Hamburg-Eppendorf, Department of Pediatrics, Hamburg, Germany
| | - Anna Perez
- University Medical Center Hamburg-Eppendorf, Department of Pediatrics, Hamburg, Germany
| | - Manuel Appel
- University Medical Center Hamburg-Eppendorf, Department of Pediatrics, Hamburg, Germany
| | - Philipp Weber
- University Medical Center Hamburg-Eppendorf, Institute of Medical Biometry and Epidemiology, Hamburg, Germany
| | - Claudia Weiss
- Charité Universitätsmedizin Berlin, Department of Pediatric Neurology, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Corinna Stoltenburg
- Charité Universitätsmedizin Berlin, Department of Pediatric Neurology, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Ute Ehinger
- Charité Universitätsmedizin Berlin, Department of Pediatric Neurology, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Maja von der Hagen
- Abteilung Neuropädiatrie, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Jens Schallner
- Abteilung Neuropädiatrie, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Birte Claussen
- Abteilung Neuropädiatrie, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Ilka Lode
- Abteilung Neuropädiatrie, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Andreas Hahn
- Department of General Pediatrics and Neonatology and Department of Child Neurology, University Hospital, Gießen, Germany
| | - Rahel Schuler
- Department of General Pediatrics and Neonatology and Department of Child Neurology, University Hospital, Gießen, Germany
| | - Lena Ruß
- Department of General Pediatrics and Neonatology and Department of Child Neurology, University Hospital, Gießen, Germany
| | - Andreas Ziegler
- Division of Child Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Jonas Denecke
- University Medical Center Hamburg-Eppendorf, Department of Pediatrics, Hamburg, Germany
| | - Jessika Johannsen
- University Medical Center Hamburg-Eppendorf, Department of Pediatrics, Hamburg, Germany
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3
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Luo D, Ottesen EW, Lee JH, Singh RN. Transcriptome- and proteome-wide effects of a circular RNA encompassing four early exons of the spinal muscular atrophy genes. Sci Rep 2024; 14:10442. [PMID: 38714739 PMCID: PMC11076517 DOI: 10.1038/s41598-024-60593-7] [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: 12/28/2023] [Accepted: 04/25/2024] [Indexed: 05/10/2024] Open
Abstract
Spinal muscular atrophy (SMA) genes, SMN1 and SMN2 (hereinafter referred to as SMN1/2), produce multiple circular RNAs (circRNAs), including C2A-2B-3-4 that encompasses early exons 2A, 2B, 3 and 4. C2A-2B-3-4 is a universally and abundantly expressed circRNA of SMN1/2. Here we report the transcriptome- and proteome-wide effects of overexpression of C2A-2B-3-4 in inducible HEK293 cells. Our RNA-Seq analysis revealed altered expression of ~ 15% genes (4172 genes) by C2A-2B-3-4. About half of the affected genes by C2A-2B-3-4 remained unaffected by L2A-2B-3-4, a linear transcript encompassing exons 2A, 2B, 3 and 4 of SMN1/2. These findings underscore the unique role of the structural context of C2A-2B-3-4 in gene regulation. A surprisingly high number of upregulated genes by C2A-2B-3-4 were located on chromosomes 4 and 7, whereas many of the downregulated genes were located on chromosomes 10 and X. Supporting a cross-regulation of SMN1/2 transcripts, C2A-2B-3-4 and L2A-2B-3-4 upregulated and downregulated SMN1/2 mRNAs, respectively. Proteome analysis revealed 61 upregulated and 57 downregulated proteins by C2A-2B-3-4 with very limited overlap with those affected by L2A-2B-3-4. Independent validations confirmed the effect of C2A-2B-3-4 on expression of genes associated with chromatin remodeling, transcription, spliceosome function, ribosome biogenesis, lipid metabolism, cytoskeletal formation, cell proliferation and neuromuscular junction formation. Our findings reveal a broad role of C2A-2B-3-4, and expands our understanding of functions of SMN1/2 genes.
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Affiliation(s)
- Diou Luo
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Eric W Ottesen
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Ji Heon Lee
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Ravindra N Singh
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA.
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Tapken I, Kuhn D, Hoffmann N, Detering NT, Schüning T, Billaud JN, Tugendreich S, Schlüter N, Green J, Krämer A, Claus P. From data to discovery: AI-guided analysis of disease-relevant molecules in spinal muscular atrophy (SMA). Hum Mol Genet 2024:ddae076. [PMID: 38704739 DOI: 10.1093/hmg/ddae076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 04/04/2024] [Accepted: 04/22/2024] [Indexed: 05/07/2024] Open
Abstract
Spinal Muscular Atrophy is caused by partial loss of survival of motoneuron (SMN) protein expression. The numerous interaction partners and mechanisms influenced by SMN loss result in a complex disease. Current treatments restore SMN protein levels to a certain extent, but do not cure all symptoms. The prolonged survival of patients creates an increasing need for a better understanding of SMA. Although many SMN-protein interactions, dysregulated pathways, and organ phenotypes are known, the connections among them remain largely unexplored. Monogenic diseases are ideal examples for the exploration of cause-and-effect relationships to create a network describing the disease-context. Machine learning tools can utilize such knowledge to analyze similarities between disease-relevant molecules and molecules not described in the disease so far. We used an artificial intelligence-based algorithm to predict new genes of interest. The transcriptional regulation of 8 out of 13 molecules selected from the predicted set were successfully validated in an SMA mouse model. This bioinformatic approach, using the given experimental knowledge for relevance predictions, enhances efficient targeted research in SMA and potentially in other disease settings.
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Affiliation(s)
- Ines Tapken
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Feodor-Lynen-Str. 31, Hannover 30625, Germany
- Center for Systems Neuroscience (ZSN), Bünteweg 2, Hannover 30559, Germany
| | - Daniela Kuhn
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Feodor-Lynen-Str. 31, Hannover 30625, Germany
- Hannover Medical School, Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Carl-Neuberg-Str. 1, Hannover 30625, Germany
| | - Nico Hoffmann
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Feodor-Lynen-Str. 31, Hannover 30625, Germany
| | - Nora T Detering
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Feodor-Lynen-Str. 31, Hannover 30625, Germany
- Center for Systems Neuroscience (ZSN), Bünteweg 2, Hannover 30559, Germany
| | - Tobias Schüning
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Feodor-Lynen-Str. 31, Hannover 30625, Germany
| | - Jean-Noël Billaud
- QIAGEN Digital Insights, 1001 Marshall Street,Redwood City, CA 94063, United States
| | - Stuart Tugendreich
- QIAGEN Digital Insights, 1001 Marshall Street,Redwood City, CA 94063, United States
| | - Nadine Schlüter
- Hannover Medical School, Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Carl-Neuberg-Str. 1, Hannover 30625, Germany
| | - Jeff Green
- QIAGEN Digital Insights, 1001 Marshall Street,Redwood City, CA 94063, United States
| | - Andreas Krämer
- QIAGEN Digital Insights, 1001 Marshall Street,Redwood City, CA 94063, United States
| | - Peter Claus
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Feodor-Lynen-Str. 31, Hannover 30625, Germany
- Center for Systems Neuroscience (ZSN), Bünteweg 2, Hannover 30559, Germany
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Ottesen EW, Seo J, Luo D, Singh NN, Singh RN. A super minigene with a short promoter and truncated introns recapitulates essential features of transcription and splicing regulation of the SMN1 and SMN2 genes. Nucleic Acids Res 2024; 52:3547-3571. [PMID: 38214229 DOI: 10.1093/nar/gkad1259] [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: 07/01/2022] [Revised: 12/19/2023] [Accepted: 12/30/2023] [Indexed: 01/13/2024] Open
Abstract
Here we report a Survival Motor Neuron 2 (SMN2) super minigene, SMN2Sup, encompassing its own promoter, all exons, their flanking intronic sequences and the entire 3'-untranslated region. We confirm that the pre-mRNA generated from SMN2Sup undergoes splicing to produce a translation-competent mRNA. We demonstrate that mRNA generated from SMN2Sup produces more SMN than an identical mRNA generated from a cDNA clone. We uncover that overexpression of SMN triggers skipping of exon 3 of SMN1/SMN2. We define the minimal promoter and regulatory elements associated with the initiation and elongation of transcription of SMN2. The shortened introns within SMN2Sup preserved the ability of camptothecin, a transcription elongation inhibitor, to induce skipping of exons 3 and 7 of SMN2. We show that intron 1-retained transcripts undergo nonsense-mediated decay. We demonstrate that splicing factor SRSF3 and DNA/RNA helicase DHX9 regulate splicing of multiple exons in the context of both SMN2Sup and endogenous SMN1/SMN2. Prevention of SMN2 exon 7 skipping has implications for the treatment of spinal muscular atrophy (SMA). We validate the utility of the super minigene in monitoring SMN levels upon splicing correction. Finally, we demonstrate how the super minigene could be employed to capture the cell type-specific effects of a pathogenic SMN1 mutation.
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Affiliation(s)
- Eric W Ottesen
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Joonbae Seo
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Diou Luo
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Natalia N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Ravindra N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
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Kaur J, Sharma A, Mundlia P, Sood V, Pandey A, Singh G, Barnwal RP. RNA-Small-Molecule Interaction: Challenging the "Undruggable" Tag. J Med Chem 2024. [PMID: 38498010 DOI: 10.1021/acs.jmedchem.3c01354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
RNA targeting, specifically with small molecules, is a relatively new and rapidly emerging avenue with the promise to expand the target space in the drug discovery field. From being "disregarded" as an "undruggable" messenger molecule to FDA approval of an RNA-targeting small-molecule drug Risdiplam, a radical change in perspective toward RNA has been observed in the past decade. RNAs serve important regulatory functions beyond canonical protein synthesis, and their dysregulation has been reported in many diseases. A deeper understanding of RNA biology reveals that RNA molecules can adopt a variety of structures, carrying defined binding pockets that can accommodate small-molecule drugs. Due to its functional diversity and structural complexity, RNA can be perceived as a prospective target for therapeutic intervention. This perspective highlights the proof of concept of RNA-small-molecule interactions, exemplified by targeting of various transcripts with functional modulators. The advent of RNA-oriented knowledge would help expedite drug discovery.
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Affiliation(s)
- Jaskirat Kaur
- Department of Biophysics, Panjab University, Chandigarh 160014, India
| | - Akanksha Sharma
- Department of Biophysics, Panjab University, Chandigarh 160014, India
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh 160014, India
| | - Poonam Mundlia
- Department of Biophysics, Panjab University, Chandigarh 160014, India
| | - Vikas Sood
- Department of Biochemistry, Jamia Hamdard, New Delhi 110062, India
| | - Ankur Pandey
- Department of Chemistry, Panjab University, Chandigarh 160014, India
| | - Gurpal Singh
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh 160014, India
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7
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Luo D, Ottesen E, Lee JH, Singh R. Transcriptome- and proteome-wide effects of a circular RNA encompassing four early exons of the spinal muscular atrophy genes. RESEARCH SQUARE 2024:rs.3.rs-3818622. [PMID: 38464174 PMCID: PMC10925445 DOI: 10.21203/rs.3.rs-3818622/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Spinal muscular atrophy (SMA) genes, SMN1 and SMN2, produce multiple circular RNAs (circRNAs), including C2A-2B-3-4 that encompasses early exons 2A, 2B, 3 and 4. Here we report the transcriptome- and proteome-wide effects of overexpression of C2A-2B-3-4 in inducible HEK293 cells. Our RNA-Seq analysis revealed altered expression of ~ 15% genes (4,172 genes) by C2A-2B-3-4. About half of the affected genes by C2A-2B-3-4 remained unaffected by L2A-2B-3-4, a linear transcript encompassing exons 2A, 2B, 3 and 4 of SMN1/SMN2. These fifindings underscore the unique role of the structural context of C2A-2B-3-4 in gene regulation. A surprisingly high number of upregulated genes by C2A-2B-3-4 were located on chromosomes 4 and 7, whereas many of the downregulated genes were located on chromosomes 10 and X. Supporting a cross-regulation of SMN1/SMN2 transcripts, C2A-2B-3-4 and L2A-2B-3-4 upregulated and downregulated SMN1/SMN2 mRNAs, respectively. Proteome analysis revealed 61 upregulated and 57 downregulated proteins by C2A-2B-3-4 with very limited overlap with those affected by L2A-2B-3-4. Independent validations confirmed the effect of C2A-2B-3-4 on expression of genes associated with chromatin remodeling, transcription, spliceosome function, ribosome biogenesis, lipid metabolism, cytoskeletal formation, cell proliferation and neuromuscular junction formation. Our findings reveal a broad role of C2A-2B-3-4, a universally expressed circRNA produced by SMN1/SMN2.
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8
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Reilly A, Yaworski R, Beauvais A, Schneider BL, Kothary R. Long term peripheral AAV9-SMN gene therapy promotes survival in a mouse model of spinal muscular atrophy. Hum Mol Genet 2024; 33:510-519. [PMID: 38073249 PMCID: PMC10908349 DOI: 10.1093/hmg/ddad202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/24/2023] [Accepted: 11/27/2023] [Indexed: 03/03/2024] Open
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease characterized by motor neuron loss and skeletal muscle atrophy. SMA is caused by the loss of the SMN1 gene and low SMN protein levels. Current SMA therapies work by increasing SMN protein in the body. Although SMA is regarded as a motor neuron disorder, growing evidence shows that several peripheral organs contribute to SMA pathology. A gene therapy treatment, onasemnogene abeparvovec, is being explored in clinical trials via both systemic and central nervous system (CNS) specific delivery, but the ideal route of delivery as well as the long-term effectiveness is unclear. To investigate the impact of gene therapy long term, we assessed SMA mice at 6 months after treatment of either intravenous (IV) or intracerebroventricular (ICV) delivery of scAAV9-cba-SMN. Interestingly, we observed that SMN protein levels were restored in the peripheral tissues but not in the spinal cord at 6 months of age. However, ICV injections provided better motor neuron and motor function protection than IV injection, while IV-injected mice demonstrated better protection of neuromuscular junctions and muscle fiber size. Surprisingly, both delivery routes resulted in an equal rescue on survival, weight, and liver and pancreatic defects. These results demonstrate that continued peripheral AAV9-SMN gene therapy is beneficial for disease improvement even in the absence of SMN restoration in the spinal cord.
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Affiliation(s)
- Aoife Reilly
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501, Smyth Road, Ottawa K1H 8L6, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa K1H 8M5, Canada
- Centre for Neuromuscular Disease, University of Ottawa, 451 Smyth Road, Ottawa K1H 8M5, Canada
| | - Rebecca Yaworski
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501, Smyth Road, Ottawa K1H 8L6, Canada
| | - Ariane Beauvais
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501, Smyth Road, Ottawa K1H 8L6, Canada
| | - Bernard L Schneider
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
- Bertarelli Platform for Gene Therapy, Ecole Polytechnique Fédérale de Lausanne, 1202 Geneva, Switzerland
| | - Rashmi Kothary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501, Smyth Road, Ottawa K1H 8L6, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa K1H 8M5, Canada
- Centre for Neuromuscular Disease, University of Ottawa, 451 Smyth Road, Ottawa K1H 8M5, Canada
- Department of Medicine, University of Ottawa, 501 Smyth Road, Ottawa K1H 8L6, Canada
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9
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Ottesen EW, Singh RN. Synergistic Effect of an Antisense Oligonucleotide and Small Molecule on Splicing Correction of the Spinal Muscular Atrophy Gene. Neurosci Insights 2024; 19:26331055241233596. [PMID: 38379891 PMCID: PMC10878212 DOI: 10.1177/26331055241233596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 02/02/2024] [Indexed: 02/22/2024] Open
Abstract
Spinal muscular atrophy (SMA) is treated by increasing the level of Survival Motor Neuron (SMN) protein through correction of SMN2 exon 7 skipping or exogenous expression of SMN through gene therapy. Currently available therapies have multiple shortcomings, including poor body-wide distribution, invasive delivery, and potential negative consequences due to high doses needed for clinical efficacy. Here we test the effects of a combination treatment of a splice-correcting antisense oligonucleotide (ASO) Anti-N1 with the small compounds risdiplam and branaplam. We show that a low-dose treatment of Anti-N1 with either compound produces a synergistic effect on the inclusion of SMN2 exon 7 in SMA patient fibroblasts. Using RNA-Seq, we characterize the transcriptomes of cells treated with each compound as well as in combination. Although high doses of each individual treatment trigger widespread perturbations of the transcriptome, combination treatment of Anti-N1 with risdiplam and branaplam results in minimal disruption of gene expression. For individual genes targeted by the 3 compounds, we observe little to no additive effects of combination treatment. Overall, we conclude that the combination treatment of a splice-correcting ASO with small compounds represents a promising strategy for achieving a high level of SMN expression while minimizing the risk of off-target effects.
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Affiliation(s)
- Eric W Ottesen
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Ravindra N Singh
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
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10
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Cheung VCK, Ha SCW, Zhang-Lea JH, Chan ZYS, Teng Y, Yeung G, Wu L, Liang D, Cheung RTH. Motor patterns of patients with spinal muscular atrophy suggestive of sensory and corticospinal contributions to the development of locomotor muscle synergies. J Neurophysiol 2024; 131:338-359. [PMID: 38230872 DOI: 10.1152/jn.00513.2022] [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: 12/21/2022] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 01/18/2024] Open
Abstract
Complex locomotor patterns are generated by combination of muscle synergies. How genetic processes, early sensorimotor experiences, and the developmental dynamics of neuronal circuits contribute to the expression of muscle synergies remains elusive. We shed light on the factors that influence development of muscle synergies by studying subjects with spinal muscular atrophy (SMA, types II/IIIa), a disorder associated with degeneration and deafferentation of motoneurons and possibly motor cortical and cerebellar abnormalities, from which the afflicted would have atypical sensorimotor histories around typical walking onset. Muscle synergies of children with SMA were identified from electromyographic signals recorded during active-assisted leg motions or walking, and compared with those of age-matched controls. We found that the earlier the SMA onset age, the more different the SMA synergies were from the normative. These alterations could not just be explained by the different degrees of uneven motoneuronal losses across muscles. The SMA-specific synergies had activations in muscles from multiple limb compartments, a finding reminiscent of the neonatal synergies of typically developing infants. Overall, while the synergies shared between SMA and control subjects may reflect components of a core modular infrastructure determined early in life, the SMA-specific synergies may be developmentally immature synergies that arise from inadequate activity-dependent interneuronal sculpting due to abnormal sensorimotor experience and other factors. Other mechanisms including SMA-induced intraspinal changes and altered cortical-spinal interactions may also contribute to synergy changes. Our interpretation highlights the roles of the sensory and descending systems to the typical and abnormal development of locomotor modules.NEW & NOTEWORTHY This is likely the first report of locomotor muscle synergies of children with spinal muscular atrophy (SMA), a subject group with atypical developmental sensorimotor experience. We found that the earlier the SMA onset age, the more the subjects' synergies deviated from those of age-matched controls. This result suggests contributions of the sensory/corticospinal activities to the typical expression of locomotor modules, and how their disruptions during a critical period of development may lead to abnormal motor modules.
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Affiliation(s)
- Vincent C K Cheung
- School of Biomedical Sciences, and Gerald Choa Neuroscience Institute, The Chinese University of Hong Kong, Hong Kong, China
- Joint Laboratory of Bioresources and Molecular Research of Common Diseases, The Chinese University of Hong Kong and Kunming Institute of Zoology of the Chinese Academy of Sciences, Hong Kong, China
| | - Sophia C W Ha
- School of Biomedical Sciences, and Gerald Choa Neuroscience Institute, The Chinese University of Hong Kong, Hong Kong, China
- Department of Health and Physical Education, The Education University of Hong Kong, Hong Kong, China
| | - Janet H Zhang-Lea
- School of Nursing and Human Physiology, Gonzaga University, Spokane, Washington, United States
| | - Zoe Y S Chan
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Yanling Teng
- State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Geshi Yeung
- School of Biomedical Sciences, and Gerald Choa Neuroscience Institute, The Chinese University of Hong Kong, Hong Kong, China
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Lingqian Wu
- State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Desheng Liang
- State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Roy T H Cheung
- School of Health Sciences, Western Sydney University, Sydney, New South Wales, Australia
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11
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Kiselev A, Maretina M, Shtykalova S, Al-Hilal H, Maslyanyuk N, Plokhih M, Serebryakova E, Frolova M, Shved N, Krylova N, Il’ina A, Freund S, Osinovskaya N, Sultanov I, Egorova A, Lobenskaya A, Koroteev A, Sosnina I, Gorelik Y, Bespalova O, Baranov V, Kogan I, Glotov A. Establishment of a Pilot Newborn Screening Program for Spinal Muscular Atrophy in Saint Petersburg. Int J Neonatal Screen 2024; 10:9. [PMID: 38390973 PMCID: PMC10885106 DOI: 10.3390/ijns10010009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/16/2024] [Accepted: 01/22/2024] [Indexed: 02/24/2024] Open
Abstract
Spinal muscular atrophy 5q (SMA) is one of the most common neuromuscular inherited diseases and is the most common genetic cause of infant mortality. SMA is associated with homozygous deletion of exon 7 in the SMN1 gene. Recently developed drugs can improve the motor functions of infants with SMA when they are treated in the pre-symptomatic stage. With aim of providing an early diagnosis, newborn screening (NBS) for SMA using a real-time PCR assay with dried blood spots (DBS) was performed from January 2022 through November 2022 in Saint Petersburg, which is a representative Russian megapolis. Here, 36,140 newborns were screened by the GenomeX real-time PCR-based screening test, and three genotypes were identified: homozygous deletion carriers (4 newborns), heterozygous carriers (772 newborns), and wild-type individuals (35,364 newborns). The disease status of all four newborns that screened positive for the homozygous SMN1 deletion was confirmed by alternate methods. Two of the newborns had two copies of SMN2, and two of the newborns had three copies. We determined the incidence of spinal muscular atrophy in Saint Petersburg to be 1 in 9035 and the SMA carrier frequency to be 1 in 47. In conclusion, providing timely information regarding SMN1, confirmation of disease status, and SMN2 copy number as part of the SMA newborn-screening algorithm can significantly improve clinical follow-up, testing of family members, and treatment of patients with SMA.
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Affiliation(s)
- Anton Kiselev
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Marianna Maretina
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Sofia Shtykalova
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Haya Al-Hilal
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Natalia Maslyanyuk
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Mariya Plokhih
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Elena Serebryakova
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
- Saint Petersburg State Medical Diagnostic Center (Genetic Medical Center), Tobolskaya Street 5, 353912 Saint Petersburg, Russia; (M.F.); (A.L.); (A.K.)
| | - Marina Frolova
- Saint Petersburg State Medical Diagnostic Center (Genetic Medical Center), Tobolskaya Street 5, 353912 Saint Petersburg, Russia; (M.F.); (A.L.); (A.K.)
| | - Natalia Shved
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Nadezhda Krylova
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Arina Il’ina
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Svetlana Freund
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Natalia Osinovskaya
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Iskender Sultanov
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Anna Egorova
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Anastasia Lobenskaya
- Saint Petersburg State Medical Diagnostic Center (Genetic Medical Center), Tobolskaya Street 5, 353912 Saint Petersburg, Russia; (M.F.); (A.L.); (A.K.)
| | - Alexander Koroteev
- Saint Petersburg State Medical Diagnostic Center (Genetic Medical Center), Tobolskaya Street 5, 353912 Saint Petersburg, Russia; (M.F.); (A.L.); (A.K.)
| | - Irina Sosnina
- Saint Petersburg State Budgetary Healthcare Institution “Consulting and Diagnostic Center for Children”, Aleksa Dundić Street 36/2, 192289 Saint Petersburg, Russia;
| | - Yulia Gorelik
- Children’s City Multidisciplinary Clinical Specialized Center of High Medical Technologies, Avangardnaya Street 14, 198205 Saint Petersburg, Russia;
| | - Olesya Bespalova
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Vladislav Baranov
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Igor Kogan
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
| | - Andrey Glotov
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (S.S.); (H.A.-H.); (N.M.); (M.P.); (E.S.); (N.S.); (N.K.); (A.I.); (S.F.); (I.S.); (A.E.); (O.B.); (I.K.); (A.G.)
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12
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Al-Hilal H, Maretina M, Egorova A, Glotov A, Kiselev A. Assessment of Nuclear Gem Quantity for Evaluating the Efficacy of Antisense Oligonucleotides in Spinal Muscular Atrophy Cells. Methods Protoc 2024; 7:9. [PMID: 38392683 PMCID: PMC10893389 DOI: 10.3390/mps7010009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/25/2023] [Accepted: 12/27/2023] [Indexed: 02/24/2024] Open
Abstract
Spinal muscular atrophy is a neuromuscular disorder caused by mutations in both copies of the survival motor neuron gene 1 (SMN1), which lead to reduction in the production of the SMN protein. Currently, there are several therapies that have been approved for SMA, with many more undergoing active research. While various biomarkers have been proposed for assessing the effectiveness of SMA treatment, a universally accepted one still has not been identified. This study aimed to describe a fast and reliable method using the number of gems in cell nuclei as a potential tool for assessment of splicing correction of oligonucleotide efficacy in SMA cells. To gain insight into whether the number of gems in cell nuclei varies based on their SMN genotype and whether the increase in gem number is associated with therapeutic response, we utilized fibroblast cell cultures obtained from a patient with SMA type II and from a healthy individual. We discovered a remarkable difference in the number of gems found in the nuclei of these cells, specifically when counting gems per 100 nuclei. The SMA fibroblasts treated with antisense oligonucleotide showed beneficial effects in correcting the abnormal splicing of SMN2 exon 7. It was observed that there was a significant increase in the number of gems in the treated cells compared to the intact SMA cells. The results obtained significantly correlate with an increase of full-length SMN transcript sharing. Based on our findings, we propose using the quantity of gems as a reliable biomarker for SMA drug development.
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Affiliation(s)
- Haya Al-Hilal
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint-Petersburg, Russia; (H.A.-H.); (M.M.); (A.E.); (A.G.)
- Faculty of Biology, Saint-Petersburg State University, Universitetskaya Embankment 7-9, 199034 Saint-Petersburg, Russia
| | - Marianna Maretina
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint-Petersburg, Russia; (H.A.-H.); (M.M.); (A.E.); (A.G.)
| | - Anna Egorova
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint-Petersburg, Russia; (H.A.-H.); (M.M.); (A.E.); (A.G.)
| | - Andrey Glotov
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint-Petersburg, Russia; (H.A.-H.); (M.M.); (A.E.); (A.G.)
| | - Anton Kiselev
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint-Petersburg, Russia; (H.A.-H.); (M.M.); (A.E.); (A.G.)
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13
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Rashid S, Dimitriadi M. Autophagy in spinal muscular atrophy: from pathogenic mechanisms to therapeutic approaches. Front Cell Neurosci 2024; 17:1307636. [PMID: 38259504 PMCID: PMC10801191 DOI: 10.3389/fncel.2023.1307636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 12/14/2023] [Indexed: 01/24/2024] Open
Abstract
Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder caused by the depletion of the ubiquitously expressed survival motor neuron (SMN) protein. While the genetic cause of SMA has been well documented, the exact mechanism(s) by which SMN depletion results in disease progression remain elusive. A wide body of evidence has highlighted the involvement and dysregulation of autophagy in SMA. Autophagy is a highly conserved lysosomal degradation process which is necessary for cellular homeostasis; defects in the autophagic machinery have been linked with a wide range of neurodegenerative disorders, including amyotrophic lateral sclerosis, Alzheimer's disease and Parkinson's disease. The pathway is particularly known to prevent neurodegeneration and has been suggested to act as a neuroprotective factor, thus presenting an attractive target for novel therapies for SMA patients. In this review, (a) we provide for the first time a comprehensive summary of the perturbations in the autophagic networks that characterize SMA development, (b) highlight the autophagic regulators which may play a key role in SMA pathogenesis and (c) propose decreased autophagic flux as the causative agent underlying the autophagic dysregulation observed in these patients.
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Affiliation(s)
| | - Maria Dimitriadi
- School of Life and Medical Science, University of Hertfordshire, Hatfield, United Kingdom
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Hainzl S, Trattner L, Liemberger B, Bischof J, Kocher T, Ablinger M, Nyström A, Obermayer A, Klausegger A, Guttmann-Gruber C, Wally V, Bauer JW, Hofbauer JP, Koller U. Splicing Modulation via Antisense Oligonucleotides in Recessive Dystrophic Epidermolysis Bullosa. Int J Mol Sci 2024; 25:761. [PMID: 38255836 PMCID: PMC10815346 DOI: 10.3390/ijms25020761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/30/2023] [Accepted: 01/03/2024] [Indexed: 01/24/2024] Open
Abstract
Antisense oligonucleotides (ASOs) represent an emerging therapeutic platform for targeting genetic diseases by influencing various aspects of (pre-)mRNA biology, such as splicing, stability, and translation. In this study, we investigated the potential of modulating the splicing pattern in recessive dystrophic epidermolysis bullosa (RDEB) patient cells carrying a frequent genomic variant (c.425A > G) that disrupts splicing in the COL7A1 gene by using short 2'-O-(2-Methoxyethyl) oligoribo-nucleotides (2'-MOE ASOs). COL7A1-encoded type VII collagen (C7) forms the anchoring fibrils within the skin that are essential for the attachment of the epidermis to the underlying dermis. As such, gene variants of COL7A1 leading to functionally impaired or absent C7 manifest in the form of extensive blistering and wounding. The severity of the disease pattern warrants the development of novel therapies for patients. The c.425A > G variant at the COL7A1 exon 3/intron 3 junction lowers the efficiency of splicing at this junction, resulting in non-functional C7 transcripts. However, we found that correct splicing still occurs, albeit at a very low level, highlighting an opportunity for intervention by modulating the splicing reaction. We therefore screened 2'-MOE ASOs that bind along the COL7A1 target region ranging from exon 3 to the intron 3/exon 4 junction for their ability to modulate splicing. We identified ASOs capable of increasing the relative levels of correctly spliced COL7A1 transcripts by RT-PCR, sqRT-PCR, and ddPCR. Furthermore, RDEB-derived skin equivalents treated with one of the most promising ASOs exhibited an increase in full-length C7 expression and its accurate deposition along the basement membrane zone (BMZ).
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Affiliation(s)
- Stefan Hainzl
- EB House Austria, Research Program for Molecular Therapy of Genodermatoses, Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.H.); (L.T.); (B.L.); (J.B.); (T.K.); (M.A.); (A.K.); (C.G.-G.); (V.W.); (J.P.H.)
| | - Lisa Trattner
- EB House Austria, Research Program for Molecular Therapy of Genodermatoses, Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.H.); (L.T.); (B.L.); (J.B.); (T.K.); (M.A.); (A.K.); (C.G.-G.); (V.W.); (J.P.H.)
| | - Bernadette Liemberger
- EB House Austria, Research Program for Molecular Therapy of Genodermatoses, Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.H.); (L.T.); (B.L.); (J.B.); (T.K.); (M.A.); (A.K.); (C.G.-G.); (V.W.); (J.P.H.)
| | - Johannes Bischof
- EB House Austria, Research Program for Molecular Therapy of Genodermatoses, Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.H.); (L.T.); (B.L.); (J.B.); (T.K.); (M.A.); (A.K.); (C.G.-G.); (V.W.); (J.P.H.)
| | - Thomas Kocher
- EB House Austria, Research Program for Molecular Therapy of Genodermatoses, Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.H.); (L.T.); (B.L.); (J.B.); (T.K.); (M.A.); (A.K.); (C.G.-G.); (V.W.); (J.P.H.)
| | - Michael Ablinger
- EB House Austria, Research Program for Molecular Therapy of Genodermatoses, Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.H.); (L.T.); (B.L.); (J.B.); (T.K.); (M.A.); (A.K.); (C.G.-G.); (V.W.); (J.P.H.)
| | - Alexander Nyström
- Department of Dermatology, Medical Faculty, Medical Center—University of Freiburg, 79110 Freiburg, Germany;
| | - Astrid Obermayer
- Core Facility of Electron Microscopy, Department of Environment & Biodiversity, Paris Lodron University Salzburg (PLUS Salzburg), 5020 Salzburg, Austria;
| | - Alfred Klausegger
- EB House Austria, Research Program for Molecular Therapy of Genodermatoses, Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.H.); (L.T.); (B.L.); (J.B.); (T.K.); (M.A.); (A.K.); (C.G.-G.); (V.W.); (J.P.H.)
| | - Christina Guttmann-Gruber
- EB House Austria, Research Program for Molecular Therapy of Genodermatoses, Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.H.); (L.T.); (B.L.); (J.B.); (T.K.); (M.A.); (A.K.); (C.G.-G.); (V.W.); (J.P.H.)
| | - Verena Wally
- EB House Austria, Research Program for Molecular Therapy of Genodermatoses, Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.H.); (L.T.); (B.L.); (J.B.); (T.K.); (M.A.); (A.K.); (C.G.-G.); (V.W.); (J.P.H.)
| | - Johann W. Bauer
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria;
| | - Josefina Piñón Hofbauer
- EB House Austria, Research Program for Molecular Therapy of Genodermatoses, Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.H.); (L.T.); (B.L.); (J.B.); (T.K.); (M.A.); (A.K.); (C.G.-G.); (V.W.); (J.P.H.)
| | - Ulrich Koller
- EB House Austria, Research Program for Molecular Therapy of Genodermatoses, Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria; (S.H.); (L.T.); (B.L.); (J.B.); (T.K.); (M.A.); (A.K.); (C.G.-G.); (V.W.); (J.P.H.)
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15
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Pascoe JE, Zygmunt A, Ehsan Z, Gurbani N. Sleep in pediatric neuromuscular disorders. Semin Pediatr Neurol 2023; 48:101092. [PMID: 38065635 DOI: 10.1016/j.spen.2023.101092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/06/2023] [Accepted: 10/09/2023] [Indexed: 12/18/2023]
Abstract
Sleep disordered breathing (SDB) is prevalent among children with neuromuscular disorders (NMD). The combination of respiratory muscle weakness, altered drive, and chest wall distortion due to scoliosis make sleep a stressful state in this population. Symptomatology can range from absent to snoring, nocturnal awakenings, morning headaches, and excessive daytime sleepiness. Sequelae of untreated SDB includes cardiovascular effects, metabolic derangements, and neurocognitive concerns which can be compounded by those innate to the NMD. The clinician should have a low threshold for obtaining polysomnography and recognize the nuances of individual disorders due to disproportionately impacted muscle groups such as hypoventilation in ambulating patients from diaphragm weakness. Non-invasive or invasive ventilation are the mainstay of treatment. In this review we explore the diagnosis and treatment of SDB in children with various NMD.
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Affiliation(s)
- John E Pascoe
- Division of Pulmonary and Sleep Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States.
| | - Alexander Zygmunt
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States; Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Zarmina Ehsan
- Division of Pulmonary and Sleep Medicine, Children's Mercy-Kansas City, Kansas City, MO, United States; Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, MO, United States
| | - Neepa Gurbani
- Division of Pulmonary and Sleep Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
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16
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Nafchi NAM, Chilcott EM, Brown S, Fuller HR, Bowerman M, Yáñez-Muñoz RJ. Enhanced expression of the human Survival motor neuron 1 gene from a codon-optimised cDNA transgene in vitro and in vivo. Gene Ther 2023; 30:812-825. [PMID: 37322133 DOI: 10.1038/s41434-023-00406-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 04/14/2023] [Accepted: 05/04/2023] [Indexed: 06/17/2023]
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular disease particularly characterised by degeneration of ventral motor neurons. Survival motor neuron (SMN) 1 gene mutations cause SMA, and gene addition strategies to replace the faulty SMN1 copy are a therapeutic option. We have developed a novel, codon-optimised hSMN1 transgene and produced integration-proficient and integration-deficient lentiviral vectors with cytomegalovirus (CMV), human synapsin (hSYN) or human phosphoglycerate kinase (hPGK) promoters to determine the optimal expression cassette configuration. Integrating, CMV-driven and codon-optimised hSMN1 lentiviral vectors resulted in the highest production of functional SMN protein in vitro. Integration-deficient lentiviral vectors also led to significant expression of the optimised transgene and are expected to be safer than integrating vectors. Lentiviral delivery in culture led to activation of the DNA damage response, in particular elevating levels of phosphorylated ataxia telangiectasia mutated (pATM) and γH2AX, but the optimised hSMN1 transgene showed some protective effects. Neonatal delivery of adeno-associated viral vector (AAV9) vector encoding the optimised transgene to the Smn2B/- mouse model of SMA resulted in a significant increase of SMN protein levels in liver and spinal cord. This work shows the potential of a novel codon-optimised hSMN1 transgene as a therapeutic strategy for SMA.
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Affiliation(s)
- Neda A M Nafchi
- 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, TW20 0EX, UK
| | - Ellie M 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, TW20 0EX, UK
| | - Sharon Brown
- School of Pharmacy and Bioengineering, Keele University, Staffordshire, ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, TORCH Building, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, UK
| | - Heidi R Fuller
- School of Pharmacy and Bioengineering, Keele University, Staffordshire, ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, TORCH Building, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, UK
| | - Melissa Bowerman
- Wolfson Centre for Inherited Neuromuscular Disease, TORCH Building, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, UK
- School of Medicine, Keele University, Staffordshire, ST5 5BG, 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, TW20 0EX, UK.
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17
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Bouike Y, Sakima M, Taninishi Y, Matsutani T, Noguchi Y, Bo R, Awano H, Nishio H. Real-Time PCR-Based Screening for Homozygous SMN2 Deletion Using Residual Dried Blood Spots. Genes (Basel) 2023; 14:2159. [PMID: 38136980 PMCID: PMC10742981 DOI: 10.3390/genes14122159] [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: 11/09/2023] [Revised: 11/23/2023] [Accepted: 11/27/2023] [Indexed: 12/24/2023] Open
Abstract
The survival motor neuron 2 (SMN2) gene is a recognized modifier gene of spinal muscular atrophy (SMA). However, our knowledge about the role of SMN2-other than its modification of SMA phenotypes-is very limited. Discussions regarding the relationship between homozygous SMN2 deletion and motor neuron diseases, including amyotrophic lateral sclerosis, have been mainly based on retrospective epidemiological studies of the diseases, and the precise relationship remains inconclusive. In the present study, we first estimated that the frequency of homozygous SMN2 deletion was ~1 in 20 in Japan. We then established a real-time polymerase chain reaction (PCR)-based screening method using residual dried blood spots to identify infants with homozygous SMN2 deletion. This method can be applied to a future prospective cohort study to clarify the relationship between homozygous SMN2 deletion and motor neuron diseases. In our real-time PCR experiment, both PCR (low annealing temperatures) and blood (high hematocrit values and low white blood cell counts) conditions were associated with incorrect results (i.e., false negatives and positives). Together, our findings not only help to elucidate the role of SMN2, but also aid in our understanding of the pitfalls of current SMA newborn screening programs for detecting homozygous SMN1 deletions.
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Affiliation(s)
- Yoshihiro Bouike
- Faculty of Nutrition, Kobe Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe 651-2180, Japan; (Y.B.); (M.S.); (Y.T.)
| | - Makoto Sakima
- Faculty of Nutrition, Kobe Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe 651-2180, Japan; (Y.B.); (M.S.); (Y.T.)
| | - Yuya Taninishi
- Faculty of Nutrition, Kobe Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe 651-2180, Japan; (Y.B.); (M.S.); (Y.T.)
| | - Takanori Matsutani
- Division of Physiology, Shinko Hospital, 1-4-47 Wakinohama-cho, Chuo-ku, Kobe 651-0072, Japan;
| | - Yoriko Noguchi
- Department of Clinical Laboratory, Kobe University Hospital, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan;
| | - Ryosuke Bo
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan;
| | - Hiroyuki Awano
- Organization for Research Initiative and Promotion, Research Initiative Center, Tottori University, 86 Nishi-cho, Yonago 683-8503, Japan;
| | - Hisahide Nishio
- Department of Occupational Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe 651-2180, Japan
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18
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Wiedner HJ, Blue RE, Sadovsky M, Mills CA, Wehrens XH, Herring LE, Giudice J. RBFOX2 regulated EYA3 isoforms partner with SIX4 or ZBTB1 to control transcription during myogenesis. iScience 2023; 26:108258. [PMID: 38026174 PMCID: PMC10665822 DOI: 10.1016/j.isci.2023.108258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 08/14/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023] Open
Abstract
Alternative splicing is a prevalent gene-regulatory mechanism, with over 95% of multi-exon human genes estimated to be alternatively spliced. Here, we describe a tissue-specific, developmentally regulated, highly conserved, and disease-associated alternative splicing event in exon 7 of the eyes absent homolog 3 (Eya3) gene. We discovered that EYA3 expression is vital to the proliferation and differentiation of myoblasts. Genome-wide transcriptomic analysis and mass spectrometry-based proteomic studies identified SIX homeobox 4 (SIX4) and zinc finger and BTB-domain containing 1 (ZBTB1), as major transcription factors that interact with EYA3 to dictate gene expression. EYA3 isoforms differentially regulate transcription, indicating that splicing aids in temporal control of gene expression during muscle cell differentiation. Finally, we identified RNA-binding fox-1 homolog 2 (RBFOX2) as the main regulator of EYA3 splicing. Together, our findings illustrate the interplay between alternative splicing and transcription during myogenesis.
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Affiliation(s)
- Hannah J. Wiedner
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - R. Eric Blue
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Matheus Sadovsky
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - C. Allie Mills
- UNC Proteomics Core Facility, Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Xander H.T. Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Laura E. Herring
- UNC Proteomics Core Facility, Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jimena Giudice
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- McAllister Heart Institute, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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19
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Maretina M, Il’ina A, Egorova A, Glotov A, Kiselev A. Development of 2'-O-Methyl and LNA Antisense Oligonucleotides for SMN2 Splicing Correction in SMA Cells. Biomedicines 2023; 11:3071. [PMID: 38002071 PMCID: PMC10669464 DOI: 10.3390/biomedicines11113071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/07/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a devastating neurodegenerative disease caused by mutations in the SMN1 gene. Existing therapies demonstrate positive results on SMA patients but still might be ameliorated in efficacy and price. In the presented study we designed antisense oligonucleotides (AONs), targeting intronic splicing silencer sites, some were modified with 2'-O-methyl, others with LNA. The AONs have been extensively tested in different concentrations, both individually and combined, in order to effectively target the ISS-N1 and A+100G splicing silencer regions in intron 7 of the SMN2 gene. By treating SMA-cultured fibroblasts with certain AONs, we discovered a remarkable increase in the levels of full-length SMN transcripts and the number of nuclear gems. This increase was observed to be dose-dependent and reached levels comparable to those found in healthy cells. When added to cells together, most of the tested molecules showed a remarkable synergistic effect in correcting splicing. Through our research, we have discovered that the impact of oligonucleotides is greatly influenced by their length, sequence, and pattern of modification.
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Affiliation(s)
- Marianna Maretina
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (A.E.); (A.G.)
| | - Arina Il’ina
- Faculty of Biology, Saint Petersburg State University, Universitetskaya Embankment 7–9, 199034 Saint Petersburg, Russia;
| | - Anna Egorova
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (A.E.); (A.G.)
| | - Andrey Glotov
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (A.E.); (A.G.)
| | - Anton Kiselev
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (A.E.); (A.G.)
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20
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Kordala AJ, Stoodley J, Ahlskog N, Hanifi M, Garcia Guerra A, Bhomra A, Lim WF, Murray LM, Talbot K, Hammond SM, Wood MJA, Rinaldi C. PRMT inhibitor promotes SMN2 exon 7 inclusion and synergizes with nusinersen to rescue SMA mice. EMBO Mol Med 2023; 15:e17683. [PMID: 37724723 PMCID: PMC10630883 DOI: 10.15252/emmm.202317683] [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: 03/07/2023] [Revised: 08/31/2023] [Accepted: 09/01/2023] [Indexed: 09/21/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a leading genetic cause of infant mortality. The advent of approved treatments for this devastating condition has significantly changed SMA patients' life expectancy and quality of life. Nevertheless, these are not without limitations, and research efforts are underway to develop new approaches for improved and long-lasting benefits for patients. Protein arginine methyltransferases (PRMTs) are emerging as druggable epigenetic targets, with several small-molecule PRMT inhibitors already in clinical trials. From a screen of epigenetic molecules, we have identified MS023, a potent and selective type I PRMT inhibitor able to promote SMN2 exon 7 inclusion in preclinical SMA models. Treatment of SMA mice with MS023 results in amelioration of the disease phenotype, with strong synergistic amplification of the positive effect when delivered in combination with the antisense oligonucleotide nusinersen. Moreover, transcriptomic analysis revealed that MS023 treatment has minimal off-target effects, and the added benefit is mainly due to targeting neuroinflammation. Our study warrants further clinical investigation of PRMT inhibition both as a stand-alone and add-on therapy for SMA.
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Affiliation(s)
- Anna J Kordala
- Department of Physiology Anatomy and GeneticsUniversity of OxfordOxfordUK
- Department of PaediatricsUniversity of OxfordOxfordUK
- Institute of Developmental and Regenerative Medicine (IDRM)OxfordUK
| | - Jessica Stoodley
- Department of PaediatricsUniversity of OxfordOxfordUK
- Institute of Developmental and Regenerative Medicine (IDRM)OxfordUK
| | - Nina Ahlskog
- Department of PaediatricsUniversity of OxfordOxfordUK
- Institute of Developmental and Regenerative Medicine (IDRM)OxfordUK
| | | | - Antonio Garcia Guerra
- Department of PaediatricsUniversity of OxfordOxfordUK
- Institute of Developmental and Regenerative Medicine (IDRM)OxfordUK
| | - Amarjit Bhomra
- Department of PaediatricsUniversity of OxfordOxfordUK
- Institute of Developmental and Regenerative Medicine (IDRM)OxfordUK
| | - Wooi Fang Lim
- Department of PaediatricsUniversity of OxfordOxfordUK
- Institute of Developmental and Regenerative Medicine (IDRM)OxfordUK
| | - Lyndsay M Murray
- Centre for Discovery Brain Sciences, College of Medicine and Veterinary MedicineUniversity of EdinburghEdinburghUK
- Euan McDonald Centre for Motor Neuron Disease ResearchUniversity of EdinburghEdinburghUK
| | - Kevin Talbot
- Nuffield Department of Clinical Neurosciences, John Radcliffe HospitalUniversity of OxfordOxfordUK
- Kavli Institute for Nanoscience DiscoveryUniversity of OxfordOxfordUK
| | | | - Matthew JA Wood
- Department of PaediatricsUniversity of OxfordOxfordUK
- Institute of Developmental and Regenerative Medicine (IDRM)OxfordUK
- MDUK Oxford Neuromuscular CentreOxfordUK
| | - Carlo Rinaldi
- Department of PaediatricsUniversity of OxfordOxfordUK
- Institute of Developmental and Regenerative Medicine (IDRM)OxfordUK
- MDUK Oxford Neuromuscular CentreOxfordUK
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21
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Jiang T, Qu R, Liu X, Hou Y, Wang L, Hua Y. HnRNPR strongly represses splicing of a critical exon associated with spinal muscular atrophy through binding to an exonic AU-rich element. J Med Genet 2023; 60:1105-1115. [PMID: 37225410 DOI: 10.1136/jmg-2023-109186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 05/08/2023] [Indexed: 05/26/2023]
Abstract
BACKGROUND Spinal muscular atrophy (SMA) is a motor neuron disease caused by mutations of survival of motor neuron 1 (SMN1) gene, which encodes the SMN protein. SMN2, a nearly identical copy of SMN1, with several single-nucleotide substitutions leading to predominant skipping of its exon 7, is insufficient to compensate for loss of SMN1. Heterogeneous nuclear ribonucleoprotein R (hnRNPR) has been previously shown to interact with SMN in the 7SK complex in motoneuron axons and is implicated in the pathogenesis of SMA. Here, we show that hnRNPR also interacts with SMN1/2 pre-mRNAs and potently inhibits exon 7 inclusion. METHODS In this study, to examine the mechanism that hnRNPR regulates SMN1/2 splicing, deletion analysis in an SMN2 minigene system, RNA-affinity chromatography, co-overexpression analysis and tethering assay were performed. We screened antisense oligonucleotides (ASOs) in a minigene system and identified a few that markedly promoted SMN2 exon 7 splicing. RESULTS We pinpointed an AU-rich element located towards the 3' end of the exon that mediates splicing repression by hnRNPR. We uncovered that both hnRNPR and Sam68 bind to the element in a competitive manner, and the inhibitory effect of hnRNPR is much stronger than Sam68. Moreover, we found that, among the four hnRNPR splicing isoforms, the exon 5-skipped one has the minimal inhibitory effect, and ASOs inducing hnRNPR exon 5 skipping also promote SMN2 exon 7 inclusion. CONCLUSION We identified a novel mechanism that contributes to mis-splicing of SMN2 exon 7.
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Affiliation(s)
- Tao Jiang
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
- Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, China
| | - Ruobing Qu
- Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, China
- College of Chemistry Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, China
| | - Xuan Liu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, Nanjing Normal University College of Life Sciences, Nanjing, Jiangsu, China
| | - Yanjun Hou
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, Nanjing Normal University College of Life Sciences, Nanjing, Jiangsu, China
| | - Li Wang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, Nanjing Normal University College of Life Sciences, Nanjing, Jiangsu, China
| | - Yimin Hua
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, Nanjing Normal University College of Life Sciences, Nanjing, Jiangsu, China
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22
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Rani N, Alam MM, Jamal A, Bin Ghaffar U, Parvez S. Caenorhabditis elegans: A transgenic model for studying age-associated neurodegenerative diseases. Ageing Res Rev 2023; 91:102036. [PMID: 37598759 DOI: 10.1016/j.arr.2023.102036] [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: 05/09/2023] [Revised: 08/15/2023] [Accepted: 08/17/2023] [Indexed: 08/22/2023]
Abstract
Neurodegenerative diseases (NDs) are a heterogeneous group of aging-associated ailments characterized by interrupting cellular proteostasic machinery and the misfolding of distinct proteins to form toxic aggregates in neurons. Neurodegenerative diseases, which include Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and others, are becoming an increasing threat to human health worldwide. The degeneration and death of certain specific groups of neurons are the hallmarks of these diseases. Over the past decades, Caenorhabditis eleganshas beenwidely used as a transgenic model to investigate biological processes related to health and disease. The nematode Caenorhabditis elegans (C. elegans) has developed as a powerful tool for studying disease mechanisms due to its ease of genetic handling and instant cultivation while providing a whole-animal system amendable to several molecular and biochemical techniques. In this review, we elucidate the potential of C. elegans as a versatile platform for systematic dissection of the molecular basis of human disease, focusing on neurodegenerative disorders, and may help better our understanding of the disease mechanisms and search for new therapeutics for these devastating diseases.
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Affiliation(s)
- Nisha Rani
- Department of Toxicology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Mohammad Mumtaz Alam
- Drug Design and Medicinal Chemistry Lab, Department of Pharmaceutical Chemistry, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Azfar Jamal
- Department of Biology, College of Science Al-Zulfi, Majmaah University, Al-Majmaah 11952, Saudi Arabia
| | - Usama Bin Ghaffar
- Department of Basic Science, College of Medicine, Majmaah University, Al-Majmaah 11952, Saudi Arabia
| | - Suhel Parvez
- Department of Toxicology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi 110062, India.
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23
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Eskandari S, Rezayof A, Asghari SM, Hashemizadeh S. Neurobiochemical characteristics of arginine-rich peptides explain their potential therapeutic efficacy in neurodegenerative diseases. Neuropeptides 2023; 101:102356. [PMID: 37390744 DOI: 10.1016/j.npep.2023.102356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/02/2023]
Abstract
Neurodegenerative diseases, including Alzheimer̕ s disease (AD), Parkinson̕ s disease (PD), Huntington̕ s disease (HD), and Amyotrophic Lateral Sclerosis (ALS) require special attention to find new potential treatment methods. This review aims to summarize the current knowledge of the relationship between the biochemical properties of arginine-rich peptides (ARPs) and their neuroprotective effects to deal with the harmful effects of risk factors. It seems that ARPs have portrayed a promising and fantastic landscape for treating neurodegeneration-associated disorders. With multimodal mechanisms of action, ARPs play various unprecedented roles, including as the novel delivery platforms for entering the central nervous system (CNS), the potent antagonists for calcium influx, the invader molecules for targeting mitochondria, and the protein stabilizers. Interestingly, these peptides inhibit the proteolytic enzymes and block protein aggregation to induce pro-survival signaling pathways. ARPs also serve as the scavengers of toxic molecules and the reducers of oxidative stress agents. They also have anti-inflammatory, antimicrobial, and anti-cancer properties. Moreover, by providing an efficient nucleic acid delivery system, ARPs can play an essential role in developing various fields, including gene vaccines, gene therapy, gene editing, and imaging. ARP agents and ARP/cargo therapeutics can be raised as an emergent class of neurotherapeutics for neurodegeneration. Part of the aim of this review is to present recent advances in treating neurodegenerative diseases using ARPs as an emerging and powerful therapeutic tool. The applications and progress of ARPs-based nucleic acid delivery systems have also been discussed to highlight their usefulness as a broad-acting class of drugs.
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Affiliation(s)
- Sedigheh Eskandari
- Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran, Iran; Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran
| | - Ameneh Rezayof
- Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran, Iran.
| | - S Mohsen Asghari
- Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran.
| | - Shiva Hashemizadeh
- School of Cognitive Sciences, Institute for Research in Fundamental Sciences, IPM, Tehran, Iran
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24
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Jiang T, Wang L, Tang L, Zeb A, Hou Y. Identification of two short peptide motifs from serine/arginine-rich protein ribonucleic acid recognition motif-1 domain acting as splicing regulators. PeerJ 2023; 11:e16103. [PMID: 37744237 PMCID: PMC10512959 DOI: 10.7717/peerj.16103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 08/25/2023] [Indexed: 09/26/2023] Open
Abstract
Background Serine/arginine-rich (SR) proteins regulate pre-mRNA splicing. However, structurally similar proteins often behave differently in splicing regulation and the underlying mechanisms are largely unknown. Here, using SMN1/2 minigenes we extensively analyzed four SR proteins, SRSF1/5/6/9. Methods In this study, the effects of these proteins on SMN1/2 exon 7 splicing when tethered at either intron 6 or 7 were evaluated using an MS2-tethering assay. Deletion analysis in four SR proteins and co-overexpression analysis were performed. Results Splicing outcomes varied among all four SR proteins, SRSF1 and SRSF5 function the same at the two sites, acting as repressor and stimulator, respectively; while SRSF6 and SRSF9 promote exon 7 inclusion at only one site. Further, the key domains of each SR proteins were investigated, which identified a potent inhibitory nonapeptide in the C-terminus of SRSF1/9 ribonucleic acid recognition motif-1 (RRM1) and a potent stimulatory heptapeptide at the N-terminus of SRSF5/6 RRM1. Conclusion The insight of the four SR proteins and their domains in affecting SMN gene splicing brings a new perspective on the modes of action of SR proteins; and the functional peptides obtained here offers new ideas for developing splice switching-related therapies.
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Affiliation(s)
- Tao Jiang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University Army Medical University, Chongqing, China
| | - Li Wang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
| | - Liang Tang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
| | - Azhar Zeb
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
| | - Yanjun Hou
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
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25
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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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Papaioannou I, Owen JS, Yáñez‐Muñoz RJ. Clinical applications of gene therapy for rare diseases: A review. Int J Exp Pathol 2023; 104:154-176. [PMID: 37177842 PMCID: PMC10349259 DOI: 10.1111/iep.12478] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 03/08/2023] [Accepted: 04/16/2023] [Indexed: 05/15/2023] Open
Abstract
Rare diseases collectively exact a high toll on society due to their sheer number and overall prevalence. Their heterogeneity, diversity, and nature pose daunting clinical challenges for both management and treatment. In this review, we discuss recent advances in clinical applications of gene therapy for rare diseases, focusing on a variety of viral and non-viral strategies. The use of adeno-associated virus (AAV) vectors is discussed in the context of Luxturna, licenced for the treatment of RPE65 deficiency in the retinal epithelium. Imlygic, a herpes virus vector licenced for the treatment of refractory metastatic melanoma, will be an example of oncolytic vectors developed against rare cancers. Yescarta and Kymriah will showcase the use of retrovirus and lentivirus vectors in the autologous ex vivo production of chimeric antigen receptor T cells (CAR-T), licenced for the treatment of refractory leukaemias and lymphomas. Similar retroviral and lentiviral technology can be applied to autologous haematopoietic stem cells, exemplified by Strimvelis and Zynteglo, licenced treatments for adenosine deaminase-severe combined immunodeficiency (ADA-SCID) and β-thalassaemia respectively. Antisense oligonucleotide technologies will be highlighted through Onpattro and Tegsedi, RNA interference drugs licenced for familial transthyretin (TTR) amyloidosis, and Spinraza, a splice-switching treatment for spinal muscular atrophy (SMA). An initial comparison of the effectiveness of AAV and oligonucleotide therapies in SMA is possible with Zolgensma, an AAV serotype 9 vector, and Spinraza. Through these examples of marketed gene therapies and gene cell therapies, we will discuss the expanding applications of such novel technologies to previously intractable rare diseases.
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Affiliation(s)
| | - James S. Owen
- Division of MedicineUniversity College LondonLondonUK
| | - Rafael J. Yáñez‐Muñoz
- AGCTlab.orgCentre of Gene and Cell TherapyCentre for Biomedical SciencesDepartment of Biological SciencesSchool of Life Sciences and the EnvironmentRoyal Holloway University of LondonEghamUK
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Tan J, Zhang J, Sun R, Jiang Z, Wang Y, Ma D, Jiao J, Chen H, Lin Y, Zhang Q, Xu Z, Hu P. Evaluating the performance of four assays for carrier screening of spinal muscular atrophy. Clin Chim Acta 2023; 548:117496. [PMID: 37479010 DOI: 10.1016/j.cca.2023.117496] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/19/2023] [Accepted: 07/18/2023] [Indexed: 07/23/2023]
Abstract
BACKGROUND AND AIMS Spinal muscular atrophy (SMA) is an autosomal recessive inherited neuromuscular condition caused by biallelic mutations in the survival of motor neuron 1 (SMN1) gene. A homozygous deletion of the SMN1 gene accounts for approximately 95-98% of SMA patients. A highly homologous gene survival motor neuron 2 (SMN2) can partially compensate for SMN1 deletion, and its copy number is associated with disease severity. Population-based carrier screening by simultaneous quantification of SMN1 and SMN2 copy numbers is the best method to prevent SMA. MATERIALS AND METHODS In this study, a total of 516 samples were re-tested for the SMN1 copy number by using quantitative polymerase chain reaction (qPCR), multiplex ligation probe amplification (MLPA), droplet digital PCR (ddPCR), high-resolution melting (HRM) analysis, and PCR-based capillary electrophoresis (PCR/CE) simultaneously. Then, the performance of these methods was compared by using MLPA results as the reference. RESULTS The results of qPCR, ddPCR, HRM, and PCR/CE in detecting heterozygous deletion of SMN1 exon 7 and the results of ddPCR, HRM, and PCR/CE in detecting ≥2 copies of SMN1 exon7 are totally consistent with those of MLPA. The sensitivity and specificity of qPCR for detection of 2 copies of SMN1 exon 7 were 99.7% and 98.8%, respectively. The sensitivity and specificity of qPCR for detection of >2 copies of SMN1 exon 7 were 96.3% and 99.8%, respectively. Compared with the MLPA results, the sensitivity and specificity of qPCR and HRM for detection of heterozygous deletion of SMN1 exon 8 were 100% and 100%, respectively. They were 99.4% and 100%, respectively for detection of 2 copies, and 100% and 100%, respectively for detection of >2 copies. The results of PCR/CE in detecting SMN1 exon 8 were consistent with those of MLPA. CONCLUSION All these four methods show excellent performance in detecting heterozygous deletion of SMN1 exon 7. All PCR/CE results are totally concordant with those of MLPA. As the most cost-effective method, qPCR also shows high sensitivity and specificity in detecting SMN1. Taken together, our study provides useful information to select appropriate methods for SMA carrier screening.
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Affiliation(s)
- Jianxin Tan
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Jingjing Zhang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Ruihong Sun
- Department of Laboratory Medicine, The First School of Clinical Medicine, Nanjing Medical University, Nanjing 210029, People's Republic of China
| | - Zhu Jiang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Yuguo Wang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Dingyuan Ma
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Jiao Jiao
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Hao Chen
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Yingchun Lin
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Qinxin Zhang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Zhengfeng Xu
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China.
| | - Ping Hu
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China.
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28
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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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Ottesen EW, Singh NN, Luo D, Kaas B, Gillette B, Seo J, Jorgensen H, Singh RN. Diverse targets of SMN2-directed splicing-modulating small molecule therapeutics for spinal muscular atrophy. Nucleic Acids Res 2023; 51:5948-5980. [PMID: 37026480 PMCID: PMC10325915 DOI: 10.1093/nar/gkad259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 03/13/2023] [Accepted: 03/28/2023] [Indexed: 04/08/2023] Open
Abstract
Designing an RNA-interacting molecule that displays high therapeutic efficacy while retaining specificity within a broad concentration range remains a challenging task. Risdiplam is an FDA-approved small molecule for the treatment of spinal muscular atrophy (SMA), the leading genetic cause of infant mortality. Branaplam is another small molecule which has undergone clinical trials. The therapeutic merit of both compounds is based on their ability to restore body-wide inclusion of Survival Motor Neuron 2 (SMN2) exon 7 upon oral administration. Here we compare the transcriptome-wide off-target effects of these compounds in SMA patient cells. We captured concentration-dependent compound-specific changes, including aberrant expression of genes associated with DNA replication, cell cycle, RNA metabolism, cell signaling and metabolic pathways. Both compounds triggered massive perturbations of splicing events, inducing off-target exon inclusion, exon skipping, intron retention, intron removal and alternative splice site usage. Our results of minigenes expressed in HeLa cells provide mechanistic insights into how these molecules targeted towards a single gene produce different off-target effects. We show the advantages of combined treatments with low doses of risdiplam and branaplam. Our findings are instructive for devising better dosing regimens as well as for developing the next generation of small molecule therapeutics aimed at splicing modulation.
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Affiliation(s)
- Eric W Ottesen
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Natalia N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Diou Luo
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Bailey Kaas
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Benjamin J Gillette
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Joonbae Seo
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Hannah J Jorgensen
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Ravindra N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
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30
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Balaji L, Farrar MA, D'Silva AM, Kariyawasam DS. Decision-making and challenges within the evolving treatment algorithm in spinal muscular atrophy: a clinical perspective. Expert Rev Neurother 2023; 23:571-586. [PMID: 37227306 DOI: 10.1080/14737175.2023.2218549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/23/2023] [Indexed: 05/26/2023]
Abstract
INTRODUCTION The clinical application of disease modifying therapies has dramatically changed the paradigm of the management of people with spinal muscular atrophy (SMA), from sole reliance on symptomatic care directed toward the downstream consequences of muscle weakness, to proactive intervention and even preventative care. AREAS COVERED In this perspective, the authors evaluate the contemporary therapeutic landscape of SMA and discuss the evolution of novel phenotypes and the treatment algorithm, including the key factors that define individual treatment choice and treatment response. The benefits achieved by early diagnosis and treatment through newborn screening are highlighted, alongside an appraisal of emerging prognostic methods and classification frameworks to inform clinicians, patients, and families about disease course, manage expectations, and improve care planning. A future perspective of unmet needs and challenges is provided, emphasizing the key role of research. EXPERT OPINION SMN-augmenting therapies have improved health outcomes for people with SMA and powered the practice of personalized medicine. Within this new proactive diagnostic and treatment paradigm, new phenotypes and different disease trajectories are emerging. Ongoing collaborative research efforts to understand the biology of SMA and define optimal response are critical to refining future approaches.
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Affiliation(s)
- Lakshmi Balaji
- Department of Neurology, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
- Discipline of Paediatrics and Child Health, School of Clinical Medicine, UNSW Medicine and Health UNSW, Sydney, Australia
| | - Michelle A Farrar
- Department of Neurology, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
- Discipline of Paediatrics and Child Health, School of Clinical Medicine, UNSW Medicine and Health UNSW, Sydney, Australia
- UNSW Kensington Campus, Sydney, Australia
| | - Arlene M D'Silva
- Department of Neurology, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
- Discipline of Paediatrics and Child Health, School of Clinical Medicine, UNSW Medicine and Health UNSW, Sydney, Australia
- UNSW Kensington Campus, Sydney, Australia
| | - Didu S Kariyawasam
- Department of Neurology, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
- Discipline of Paediatrics and Child Health, School of Clinical Medicine, UNSW Medicine and Health UNSW, Sydney, Australia
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31
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Aragon-Gawinska K, Mouraux C, Dangouloff T, Servais L. Spinal Muscular Atrophy Treatment in Patients Identified by Newborn Screening-A Systematic Review. Genes (Basel) 2023; 14:1377. [PMID: 37510282 PMCID: PMC10379202 DOI: 10.3390/genes14071377] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/16/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
BACKGROUND In spinal muscular atrophy, clinical trial results indicated that disease-modifying treatments are highly effective when given prior to symptom onset, which has prompted newborn screening programs in growing number of countries. However, prognosis of those patients cannot be inferred from clinical trials conducted in presymptomatic individuals, as in some cases disease presents very early. METHODS we conducted a systematic review of articles published up to January 2023. RESULTS Among 35 patients with three SMN2 copies treated before 42 days of age and followed-up for at least 18 months, all but one achieved autonomous ambulation. Of 41 patients with two SMN2 copies, who were non-symptomatic at treatment initiation, all achieved a sitting position independently and 31 were able to walk. Of 16 patients with two SMN2 copies followed-up for at least 18 months who presented with symptoms at treatment onset, 3 achieved the walking milestone and all but one were able to sit without support. CONCLUSIONS evaluation of data from 18 publications indicates that the results of early treatment depend on the number of SMN2 copies and the initial neurological status of the patient.
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Affiliation(s)
| | - Charlotte Mouraux
- Neuromuscular Reference Center, Department of Pediatrics, University Hospital Liège, University of Liège, 4000 Liège, Belgium
| | - Tamara Dangouloff
- Neuromuscular Reference Center, Department of Pediatrics, University Hospital Liège, University of Liège, 4000 Liège, Belgium
| | - Laurent Servais
- Neuromuscular Reference Center, Department of Pediatrics, University Hospital Liège, University of Liège, 4000 Liège, Belgium
- MDUK Oxford Neuromuscular Centre & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 0ER, UK
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32
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Lumpkin CJ, Harris AW, Connell AJ, Kirk RW, Whiting JA, Saieva L, Pellizzoni L, Burghes AHM, Butchbach MER. Evaluation of the orally bioavailable 4-phenylbutyrate-tethered trichostatin A analogue AR42 in models of spinal muscular atrophy. Sci Rep 2023; 13:10374. [PMID: 37365234 PMCID: PMC10293174 DOI: 10.1038/s41598-023-37496-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 06/22/2023] [Indexed: 06/28/2023] Open
Abstract
Proximal spinal muscular atrophy (SMA) is a leading genetic cause for infant death in the world and results from the selective loss of motor neurons in the spinal cord. SMA is a consequence of low levels of SMN protein and small molecules that can increase SMN expression are of considerable interest as potential therapeutics. Previous studies have shown that both 4-phenylbutyrate (4PBA) and trichostatin A (TSA) increase SMN expression in dermal fibroblasts derived from SMA patients. AR42 is a 4PBA-tethered TSA derivative that is a very potent histone deacetylase inhibitor. SMA patient fibroblasts were treated with either AR42, AR19 (a related analogue), 4PBA, TSA or vehicle for 5 days and then immunostained for SMN localization. AR42 as well as 4PBA and TSA increased the number of SMN-positive nuclear gems in a dose-dependent manner while AR19 did not show marked changes in gem numbers. While gem number was increased in AR42-treated SMA fibroblasts, there were no significant changes in FL-SMN mRNA or SMN protein. The neuroprotective effect of this compound was then assessed in SMNΔ7 SMA (SMN2+/+;SMNΔ7+/+;mSmn-/-) mice. Oral administration of AR42 prior to disease onset increased the average lifespan of SMNΔ7 SMA mice by ~ 27% (20.1 ± 1.6 days for AR42-treated mice vs. 15.8 ± 0.4 days for vehicle-treated mice). AR42 treatment also improved motor function in these mice. AR42 treatment inhibited histone deacetylase (HDAC) activity in treated spinal cord although it did not affect SMN protein expression in these mice. AKT and GSK3β phosphorylation were both significantly increased in SMNΔ7 SMA mouse spinal cords. In conclusion, presymptomatic administration of the HDAC inhibitor AR42 ameliorates the disease phenotype in SMNΔ7 SMA mice in a SMN-independent manner possibly by increasing AKT neuroprotective signaling.
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Affiliation(s)
- Casey J Lumpkin
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Ashlee W Harris
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Andrew J Connell
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Ryan W Kirk
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Joshua A Whiting
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Luciano Saieva
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Livio Pellizzoni
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
- Department of Neurology, Columbia University, New York, NY, USA
- Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, USA
| | - Arthur H M Burghes
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Matthew E R Butchbach
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA.
- Department of Biological Sciences, University of Delaware, Newark, DE, USA.
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
- Department of Pediatrics, Thomas Jefferson University, Philadelphia, PA, USA.
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René CA, Parks RJ. Expanding the Availability of Onasemnogene Abeparvovec to Older Patients: The Evolving Treatment Landscape for Spinal Muscular Atrophy. Pharmaceutics 2023; 15:1764. [PMID: 37376212 DOI: 10.3390/pharmaceutics15061764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 06/06/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder caused by mutations in the survival of motor neuron 1 (SMN1) gene, which leads to a reduced level in the SMN protein within cells. Patients with SMA suffer from a loss of alpha motor neurons in the spinal cord leading to skeletal muscle atrophy in addition to deficits in other tissues and organs. Patients with severe forms of the disease require ventilator assistance and typically succumb to the disease due to respiratory failure. Onasemnogene abeparvovec is an adeno-associated virus (AAV)-based gene therapeutic that has been approved for infants and young children with SMA, and it is delivered through intravenous administration using a dose based on the weight of the patient. While excellent outcomes have been observed in treated patients, the greater viral dose necessary to treat older children and adults raises legitimate safety concerns. Recently, onasemnogene abeparvovec use was investigated in older children through a fixed dose and intrathecal administration, a route that provides a more direct delivery to affected cells in the spinal cord and central nervous system. The promising results observed in the STRONG trial may support approval of onasemnogene abeparvovec for a greater proportion of patients with SMA.
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Affiliation(s)
- Charlotte A René
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Centre for Neuromuscular Disease, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Robin J Parks
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Centre for Neuromuscular Disease, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Department of Medicine, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada
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34
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Zeng W, Kong X, Alamana C, Liu Y, Guzman J, Pang PD, Day JW, Wu JC. Generation of two induced pluripotent stem cell lines from spinal muscular atrophy type 1 patients carrying no functional copies of SMN1 gene. Stem Cell Res 2023; 69:103095. [PMID: 37087898 PMCID: PMC11068589 DOI: 10.1016/j.scr.2023.103095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/10/2023] [Accepted: 04/12/2023] [Indexed: 04/25/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a severe neurodegenerative muscular disease caused by the homozygous loss of survival of motor neuron 1 (SMN1) genes. SMA patients exhibit marked skeletal muscle (SKM) loss, eventually leading to death. Here we generated two iPSC lines from two SMA type I patients with homozygous SMN1 mutations and validated the pluripotency and the ability to differentiate into three germ layers. The iPSC lines can be applied to generate skeletal muscles to model muscle atrophy of SMA that persists after treatment of motor neurons and will serve as a complementary platform for drug screening in vitro.
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Affiliation(s)
- Wenshu Zeng
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA 94305, USA; Department of Medicine, Division of Cardiology, Stanford University, Stanford, CA 94305, USA
| | - Xiaohui Kong
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA 94305, USA; Department of Medicine, Division of Cardiology, Stanford University, Stanford, CA 94305, USA
| | - Christina Alamana
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA 94305, USA; Department of Medicine, Division of Cardiology, Stanford University, Stanford, CA 94305, USA
| | - Yu Liu
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA 94305, USA; Department of Medicine, Division of Cardiology, Stanford University, Stanford, CA 94305, USA
| | - Jessica Guzman
- Department of Neurology, Stanford University, Stanford, CA 94305, USA
| | - Paul D Pang
- Greenstone Biosciences, Palo Alto, CA 94304, USA
| | - John W Day
- Department of Neurology, Stanford University, Stanford, CA 94305, USA
| | - Joseph C Wu
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA 94305, USA; Department of Medicine, Division of Cardiology, Stanford University, Stanford, CA 94305, USA; Greenstone Biosciences, Palo Alto, CA 94304, USA.
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35
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Buchner F, Dokuzluoglu Z, Grass T, Rodriguez-Muela N. Spinal Cord Organoids to Study Motor Neuron Development and Disease. Life (Basel) 2023; 13:1254. [PMID: 37374039 DOI: 10.3390/life13061254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 05/18/2023] [Indexed: 06/29/2023] Open
Abstract
Motor neuron diseases (MNDs) are a heterogeneous group of disorders that affect the cranial and/or spinal motor neurons (spMNs), spinal sensory neurons and the muscular system. Although they have been investigated for decades, we still lack a comprehensive understanding of the underlying molecular mechanisms; and therefore, efficacious therapies are scarce. Model organisms and relatively simple two-dimensional cell culture systems have been instrumental in our current knowledge of neuromuscular disease pathology; however, in the recent years, human 3D in vitro models have transformed the disease-modeling landscape. While cerebral organoids have been pursued the most, interest in spinal cord organoids (SCOs) is now also increasing. Pluripotent stem cell (PSC)-based protocols to generate SpC-like structures, sometimes including the adjacent mesoderm and derived skeletal muscle, are constantly being refined and applied to study early human neuromuscular development and disease. In this review, we outline the evolution of human PSC-derived models for generating spMN and recapitulating SpC development. We also discuss how these models have been applied to exploring the basis of human neurodevelopmental and neurodegenerative diseases. Finally, we provide an overview of the main challenges to overcome in order to generate more physiologically relevant human SpC models and propose some exciting new perspectives.
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Affiliation(s)
- Felix Buchner
- German Center for Neurodegenerative Diseases, 01307 Dresden, Germany
| | | | - Tobias Grass
- German Center for Neurodegenerative Diseases, 01307 Dresden, Germany
| | - Natalia Rodriguez-Muela
- German Center for Neurodegenerative Diseases, 01307 Dresden, Germany
- Center for Regenerative Therapies Dresden, Technische Universität Dresden, 01307 Dresden, Germany
- Max Planck Institute for Molecular Cell Biology and Genetics, 01307 Dresden, Germany
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36
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Kim JK, Jha NN, Awano T, Caine C, Gollapalli K, Welby E, Kim SS, Fuentes-Moliz A, Wang X, Feng Z, Sera F, Takeda T, Homma S, Ko CP, Tabares L, Ebert AD, Rich MM, Monani UR. A spinal muscular atrophy modifier implicates the SMN protein in SNARE complex assembly at neuromuscular synapses. Neuron 2023; 111:1423-1439.e4. [PMID: 36863345 PMCID: PMC10164130 DOI: 10.1016/j.neuron.2023.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 12/11/2022] [Accepted: 02/02/2023] [Indexed: 03/04/2023]
Abstract
Reduced survival motor neuron (SMN) protein triggers the motor neuron disease, spinal muscular atrophy (SMA). Restoring SMN prevents disease, but it is not known how neuromuscular function is preserved. We used model mice to map and identify an Hspa8G470R synaptic chaperone variant, which suppressed SMA. Expression of the variant in the severely affected mutant mice increased lifespan >10-fold, improved motor performance, and mitigated neuromuscular pathology. Mechanistically, Hspa8G470R altered SMN2 splicing and simultaneously stimulated formation of a tripartite chaperone complex, critical for synaptic homeostasis, by augmenting its interaction with other complex members. Concomitantly, synaptic vesicular SNARE complex formation, which relies on chaperone activity for sustained neuromuscular synaptic transmission, was found perturbed in SMA mice and patient-derived motor neurons and was restored in modified mutants. Identification of the Hspa8G470R SMA modifier implicates SMN in SNARE complex assembly and casts new light on how deficiency of the ubiquitous protein causes motor neuron disease.
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Affiliation(s)
- Jeong-Ki Kim
- Department of Neurology, New York, NY, USA; Center for Motor Neuron Biology & Disease, New York, NY, USA
| | - Narendra N Jha
- Department of Neurology, New York, NY, USA; Center for Motor Neuron Biology & Disease, New York, NY, USA
| | - Tomoyuki Awano
- Department of Neurology, New York, NY, USA; Center for Motor Neuron Biology & Disease, New York, NY, USA
| | - Charlotte Caine
- Department of Neurology, New York, NY, USA; Center for Motor Neuron Biology & Disease, New York, NY, USA
| | - Kishore Gollapalli
- Department of Neurology, New York, NY, USA; Center for Motor Neuron Biology & Disease, New York, NY, USA
| | - Emily Welby
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Seung-Soo Kim
- Department of Obstetrics and Gynecology, New York, NY, USA
| | - Andrea Fuentes-Moliz
- Department of Medical Physiology and Biophysics, University of Seville School of Medicine, 41009, Seville, Spain
| | - Xueyong Wang
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH 45435, USA
| | - Zhihua Feng
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Fusako Sera
- Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Taishi Takeda
- Department of Neurology, New York, NY, USA; Center for Motor Neuron Biology & Disease, New York, NY, USA
| | - Shunichi Homma
- Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Chien-Ping Ko
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Lucia Tabares
- Department of Medical Physiology and Biophysics, University of Seville School of Medicine, 41009, Seville, Spain
| | - Allison D Ebert
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Mark M Rich
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH 45435, USA
| | - Umrao R Monani
- Department of Neurology, New York, NY, USA; Department of Pathology & Cell Biology, New York, NY, USA; Center for Motor Neuron Biology & Disease, New York, NY, USA; Colleen Giblin Research Laboratory, Columbia University Irving Medical Center, New York, NY 10032, USA.
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37
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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: 38] [Impact Index Per Article: 38.0] [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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38
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Nadal M, Anton R, Dorca‐Arévalo J, Estébanez‐Perpiñá E, Tizzano EF, Fuentes‐Prior P. Structure and function analysis of Sam68 and hnRNP A1 synergy in the exclusion of exon 7 from SMN2 transcripts. Protein Sci 2023; 32:e4553. [PMID: 36560896 PMCID: PMC10031812 DOI: 10.1002/pro.4553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 12/13/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022]
Abstract
Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by the absence of a functional copy of the Survival of Motor Neuron 1 gene (SMN1). The nearly identical paralog, SMN2, cannot compensate for the loss of SMN1 because exon 7 is aberrantly skipped from most SMN2 transcripts, a process mediated by synergistic activities of Src-associated during mitosis, 68 kDa (Sam68/KHDRBS1) and heterogeneous nuclear ribonucleoprotein (hnRNP) A1. This results in the production of a truncated, nonfunctional protein that is rapidly degraded. Here, we present several crystal structures of Sam68 RNA-binding domain (RBD). Sam68-RBD forms stable symmetric homodimers by antiparallel association of helices α3 from two monomers. However, the details of domain organization and the dimerization interface differ significantly from previously characterized homologs. We demonstrate that Sam68 and hnRNP A1 can simultaneously bind proximal motifs within the central region of SMN2 (ex7). Furthermore, we show that the RNA-binding pockets of the two proteins are close to each other in their heterodimeric complex and identify contact residues using crosslinking-mass spectrometry. We present a model of the ternary Sam68·SMN2 (ex7)·hnRNP A1 complex that reconciles all available information on SMN1/2 splicing. Our findings have important implications for the etiology of SMA and open new avenues for the design of novel therapeutics to treat splicing diseases.
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Affiliation(s)
- Marta Nadal
- Molecular Bases of DiseaseBiomedical Research Institute Sant Pau (IIB Sant Pau)BarcelonaSpain
| | - Rosa Anton
- Molecular Bases of DiseaseBiomedical Research Institute Sant Pau (IIB Sant Pau)BarcelonaSpain
| | - Jonatan Dorca‐Arévalo
- Molecular Bases of DiseaseBiomedical Research Institute Sant Pau (IIB Sant Pau)BarcelonaSpain
- Present address:
Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Campus of BellvitgeHospitalet de Llobregat, University of BarcelonaBarcelonaSpain
| | - Eva Estébanez‐Perpiñá
- Structural Biology of Nuclear Receptors, Department of Biochemistry and Molecular Biomedicine, Faculty of BiologyInstitute of Biomedicine (IBUB) of the University of Barcelona (UB)BarcelonaSpain
| | - Eduardo F. Tizzano
- Medicine Genetics GroupVall d'Hebron Research Institute (VHIR)BarcelonaSpain
- Department of Clinical and Molecular GeneticsHospital Vall d'HebronBarcelonaSpain
| | - Pablo Fuentes‐Prior
- Molecular Bases of DiseaseBiomedical Research Institute Sant Pau (IIB Sant Pau)BarcelonaSpain
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39
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How does precursor RNA structure influence RNA processing and gene expression? Biosci Rep 2023; 43:232489. [PMID: 36689327 PMCID: PMC9977717 DOI: 10.1042/bsr20220149] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 01/17/2023] [Accepted: 01/23/2023] [Indexed: 01/24/2023] Open
Abstract
RNA is a fundamental biomolecule that has many purposes within cells. Due to its single-stranded and flexible nature, RNA naturally folds into complex and dynamic structures. Recent technological and computational advances have produced an explosion of RNA structural data. Many RNA structures have regulatory and functional properties. Studying the structure of nascent RNAs is particularly challenging due to their low abundance and long length, but their structures are important because they can influence RNA processing. Precursor RNA processing is a nexus of pathways that determines mature isoform composition and that controls gene expression. In this review, we examine what is known about human nascent RNA structure and the influence of RNA structure on processing of precursor RNAs. These known structures provide examples of how other nascent RNAs may be structured and show how novel RNA structures may influence RNA processing including splicing and polyadenylation. RNA structures can be targeted therapeutically to treat disease.
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40
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Ishibashi Y, Sung CYW, Grati M, Chien W. Immune responses in the mammalian inner ear and their implications for AAV-mediated inner ear gene therapy. Hear Res 2023; 432:108735. [PMID: 36965335 DOI: 10.1016/j.heares.2023.108735] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 02/17/2023] [Accepted: 03/04/2023] [Indexed: 03/13/2023]
Abstract
Adeno-associated virus (AAV)-mediated inner ear gene therapy is a promising treatment option for hearing loss and dizziness. Several studies have shown that AAV-mediated inner ear gene therapy can be applied to various mouse models of hereditary hearing loss to improve their auditory function. Despite the increase in AAV-based animal and clinical studies aiming to rescue auditory and vestibular functions, little is currently known about the host immune responses to AAV in the mammalian inner ear. It has been reported that the host immune response plays an important role in the safety and efficacy of viral-mediated gene therapy. Therefore, in order for AAV-mediated gene therapy to be successfully and safely translated into patients with hearing loss and dizziness, a better understanding of the host immune responses to AAV in the inner ear is critical. In this review, we summarize the current knowledge on host immune responses to AAV-mediated gene therapy in the mammalian inner ear and other organ systems. We also outline the areas of research that are critical for ensuring the safety and efficacy of AAV-mediated inner ear gene therapy in future clinical and translational studies.
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Affiliation(s)
- Yasuko Ishibashi
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, 35A 1F220, 35A Covent Dr., Bethesda, MD 20892, USA; Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, Bethesda, MD, USA
| | - Cathy Yea Won Sung
- Laboratory of Hearing Biology and Therapeutics, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, Bethesda, MD, USA
| | - Mhamed Grati
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, 35A 1F220, 35A Covent Dr., Bethesda, MD 20892, USA
| | - Wade Chien
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, 35A 1F220, 35A Covent Dr., Bethesda, MD 20892, USA; Department of Otolaryngology-Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA.
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41
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Aslesh T, Erkut E, Ren J, Lim KRQ, Woo S, Hatlevig S, Moulton HM, Gosgnach S, Greer J, Maruyama R, Yokota T. DG9-conjugated morpholino rescues phenotype in SMA mice by reaching the CNS via a subcutaneous administration. JCI Insight 2023; 8:160516. [PMID: 36719755 PMCID: PMC10077475 DOI: 10.1172/jci.insight.160516] [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: 04/05/2022] [Accepted: 01/25/2023] [Indexed: 02/01/2023] Open
Abstract
Antisense oligonucleotide-mediated (AO-mediated) therapy is a promising strategy to treat several neurological diseases, including spinal muscular atrophy (SMA). However, limited delivery to the CNS with AOs administered intravenously or subcutaneously is a major challenge. Here, we demonstrate a single subcutaneous administration of cell-penetrating peptide DG9 conjugated to an AO called phosphorodiamidate morpholino oligomer (PMO) reached the CNS and significantly prolonged the median survival compared with unconjugated PMO and R6G-PMO in a severe SMA mouse model. Treated mice exhibited substantially higher expression of full-length survival of motor neuron 2 in both the CNS and systemic tissues compared with nontreated and unmodified AO-treated mice. The treatment ameliorated the atrophic musculature and improved breathing function accompanied by improved muscle strength and innervation at the neuromuscular junction with no signs of apparent toxicity. We also demonstrated DG9-conjugated PMO localized in nuclei in the spinal cord and brain after subcutaneous injections. Our data identify DG9 peptide conjugation as a powerful way to improve the efficacy of AO-mediated splice modulation. Finally, DG9-PMO is a promising therapeutic option to treat SMA and other neurological diseases, overcoming the necessity for intrathecal injections and treating body-wide tissues without apparent toxicity.
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Affiliation(s)
| | | | - Jun Ren
- Neuroscience and Mental Health Institute.,Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | | | | | - Susan Hatlevig
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
| | - Hong M Moulton
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
| | - Simon Gosgnach
- Neuroscience and Mental Health Institute.,Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - John Greer
- Neuroscience and Mental Health Institute.,Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | | | - Toshifumi Yokota
- Neuroscience and Mental Health Institute.,Department of Medical Genetics, and
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42
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Wang L, Ji Y, Chen Y, Bai J, Gao P, Feng P. A splicing silencer in SMN2 intron 6 is critical in spinal muscular atrophy. Hum Mol Genet 2023; 32:971-983. [PMID: 36255739 DOI: 10.1093/hmg/ddac260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/10/2022] [Accepted: 10/14/2022] [Indexed: 11/14/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a fatal neuromuscular disease caused by homozygous deletions or mutations of the SMN1 gene. SMN2 is a paralogous gene of SMN1 and a modifying gene of SMA. A better understanding of how SMN2 exon 7 splicing is regulated helps discover new therapeutic targets for SMA therapy. Based on an antisense walk method to map exonic and intronic splicing silencers (ESSs and ISSs) in SMN2 exon 7 and the proximal regions of its flanking introns, we identified one ISS (ISS6-KH) at upstream of the branch point site in intron 6. By using mutagenesis-coupled RT-PCR with SMN1/2 minigenes, immunochromatography, overexpression and siRNA-knockdown, we found this ISS consists of a bipartite hnRNP A1 binding cis-element and a poly-U sequence located between the proximal hnRNP A1 binding site (UAGCUA) and the branch site. Both HuR and hnRNP C1 proteins promote exon 7 skipping through the poly-U stretch. Mutations or deletions of these motifs lead to efficient SMN2 exon 7 inclusion comparable to SMN1 gene. Furthermore, we identified an optimal antisense oligonucleotide that binds the intron six ISS and causes striking exon 7 inclusion in the SMN2 gene in patient fibroblasts and SMA mouse model. Our findings demonstrate that this novel ISS plays an important role in SMN2 exon 7 skipping and highlight a new therapeutic target for SMA therapy.
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Affiliation(s)
- Li Wang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Yinfeng Ji
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Yuqing Chen
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Jialin Bai
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Peng Gao
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Pengchao Feng
- Nanjing Antisense Biopharmaceutical Co., Ltd, Nanjing 210046, China
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43
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Krosschell KJ, Brown L, Hoffman K, Zumpf KB, Munson H, Bidwell J, Schulte DP, Schwaede AN, Buehner AN, DiDonato CJ, Kuntz NL, Rao VK. Longitudinal Assessment of Timed Function Tests Over Time in Ambulatory Individuals with SMA Treated with Nusinersen. J Neuromuscul Dis 2023; 10:337-348. [PMID: 36872785 DOI: 10.3233/jnd-221519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
BACKGROUND Ambulatory individuals with spinal muscular atrophy experience weakness and impairments of speed and endurance. This leads to decreased motor skill performance required for daily living including transitioning from floor to stand, climbing stairs, and traversing short and community distances. Motor function improvements have been reported in individuals receiving nusinersen, but changes in timed functional tests (TFTs) which assess shorter distance walking and transitions have not been well documented. OBJECTIVE To evaluate changes in TFT performance over the course of nusinersen treatment in ambulatory individuals with SMA and identify potential factors [age, SMN2 copy number, BMI, Hammersmith Functional Motor Scale expanded (HFMSE score), Peroneal Compound Motor Action Potential (CMAP) amplitude] associated with TFT performance. METHODS Nineteen ambulatory participants receiving nusinersen were followed from 2017 through 2019 (range: 0-900 days, mean 624.7 days, median 780 days); thirteen of 19 (mean age = 11.5 years) completed TFTs. The 10-meter walk/run test, time-to-rise from supine, time-to-rise from sitting, 4-stair climb, 6-minute walk test (6MWT), Hammersmith-Expanded and peroneal CMAP were assessed at each visit. Linear mixed-effects models were used to evaluate unadjusted and adjusted changes in these outcomes over time. RESULTS Apart from time to rise from sitting and from supine, all TFTs were found to improve over the course of treatment after adjusting for baseline age and BMI. CONCLUSIONS Improvement in TFTs over time in patients with SMA treated with nusinersen suggests that shorter TFTs may have value to assess individuals with SMA who have or later gain ambulatory function during treatment.
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Affiliation(s)
- Kristin J Krosschell
- Department of Physical Therapy and Human Movement Sciences, Northwestern University Feinberg School of Medicine, USA.,Department of Pediatrics, Northwestern University Feinberg School of Medicine, USA
| | - Laurey Brown
- Department of Rehabilitation Services, Ann and Robert H. Lurie Children's Hospital of Chicago, USA.,Division of Neurology, Ann and Robert H. Lurie Children's Hospital of Chicago, USA
| | - Katie Hoffman
- Department of Rehabilitation Services, Ann and Robert H. Lurie Children's Hospital of Chicago, USA.,Division of Neurology, Ann and Robert H. Lurie Children's Hospital of Chicago, USA
| | - Katelyn B Zumpf
- Biostatistics Collaboration Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA- sponsor.,Statistical Consulting, OSF Healthcare, Chicago, IL, USA
| | - Hannah Munson
- Chicago College of Osteopathic Medicine, Midwestern University Downers Grove, IL, USA
| | - Jessa Bidwell
- Graduate Program of Genetic Engineering, Northwestern University, Chicago, IL, USA
| | - Duncan P Schulte
- Division of Neurology, Ann and Robert H. Lurie Children's Hospital of Chicago, USA
| | - Abigail N Schwaede
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, USA.,Division of Neurology, Ann and Robert H. Lurie Children's Hospital of Chicago, USA
| | | | - Christine J DiDonato
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, USA.,Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, USA
| | - Nancy L Kuntz
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, USA.,Division of Neurology, Ann and Robert H. Lurie Children's Hospital of Chicago, USA
| | - Vamshi K Rao
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, USA.,Division of Neurology, Ann and Robert H. Lurie Children's Hospital of Chicago, USA.,Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, USA
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44
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Bai J, Qu Y, OuYang S, Jiao H, Wang Y, Li J, Huang W, Zhao Y, Peng X, Wang D, Jin Y, Wang H, Song F. Novel Alu-mediated deletions of the SMN1 gene were identified by ultra-long read sequencing technology in patients with spinal muscular atrophy. Neuromuscul Disord 2023; 33:382-390. [PMID: 37023488 DOI: 10.1016/j.nmd.2023.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 02/20/2023] [Accepted: 03/01/2023] [Indexed: 03/11/2023]
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular disease caused by biallelic variants of the survival motor neuron 1 (SMN1) gene. In this study, our aim was to make a molecular diagnosis in two patients with SMA carrying only one SMN1 copy number. Using ultra-long read sequencing (Ultra-LRS), 1415 bp deletion and 3348 bp deletion of the SMN1 gene were identified in patient 1 and the father of patient 2, respectively. Ultra-LRS revealed two novel deletions, starting from the SMN1 promoter to intron 1. It also accurately provided the location of the deletion breakpoints in the SMN1 gene: chr5 g.70,924,798-70,926,212 for a 1415 bp deletion; chr5 g.70,922,695-70,926,042 for a 3348 bp deletion. By analyzing the breakpoint junctions, we identified that these genomic sequences were composed of Alu sequences, including AluJb, AluYm1, AluSq, and AluYm1, indicating that Alu-mediated rearrangements are a mechanism of SMN1 deletion events. In addition, full-length SMN1 transcripts and SMN protein in patient 1 were significantly decreased (p < 0.01), suggesting that a 1415 bp deletion that included the transcription and translation initiation sites of the SMN1 gene had severe consequences for SMN expression. Ultra-LRS can easily distinguish highly homozygous genes compared to other detection technologies, which is useful for detecting SMN1 intragenic mutations, to quickly discover structural rearrangements and to precisely present the breakpoint positions.
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Reilly A, Chehade L, Kothary R. Curing SMA: Are we there yet? Gene Ther 2023; 30:8-17. [PMID: 35614235 DOI: 10.1038/s41434-022-00349-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/04/2022] [Accepted: 05/12/2022] [Indexed: 11/09/2022]
Abstract
Loss or deletion of survival motor neuron 1 gene (SMN1) is causative for a severe and devastating neuromuscular disease, Spinal Muscular Atrophy (SMA). SMN1 produces SMN, a ubiquitously expressed protein, that is essential for the development and survival of motor neurons. Major advances and developments in SMA therapeutics are shifting the natural history of the disease. With three relatively new available therapies, nusinersen (Spinraza), onasemnogene abeparvovec (Zolgensma), and risdiplam (Evrysdi), patients survive longer and have improved outcomes. However, patients and families continue to face many challenges associated with use of these therapies, including poor treatment response and a variability in the benefits to those that do respond, suggesting that the quest for the SMA cure is not over. In this review, we discuss the current therapies, their limitations, and highlight necessary gaps that need to be addressed to guarantee the best outcomes for SMA patients.
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Affiliation(s)
- Aoife Reilly
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Centre for Neuromuscular Disease, University of Ottawa, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Lucia Chehade
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Centre for Neuromuscular Disease, University of Ottawa, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Rashmi Kothary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada. .,Centre for Neuromuscular Disease, University of Ottawa, Ottawa, ON, Canada. .,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada. .,Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON, Canada. .,Department of Medicine, University of Ottawa, Ottawa, ON, Canada.
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Torroba B, Macabuag N, Haisma EM, O'Neill A, Herva ME, Redis RS, Templin MV, Black LE, Fischer DF. RNA-based drug discovery for spinal muscular atrophy: a story of small molecules and antisense oligonucleotides. Expert Opin Drug Discov 2023; 18:181-192. [PMID: 36408582 DOI: 10.1080/17460441.2022.2149733] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Spinal Muscular Atrophy (SMA), the second most prevalent autosomal genetic disease affecting infants, is caused by the lack of SMN1, which encodes a neuron functioning vital protein, SMN. Improving exon 7 splicing in the paralogous gene SMN2, also coding for SMN protein, increases protein production efficiency from SMN2 to overcome the genetic deficit in SMN1. Several molecular mechanisms have been investigated to improve SMN2 functional splicing. AREAS COVERED This manuscript will cover two of the three mechanistically distinct available treatment options for SMA, both targeting the SMN2 splicing mechanism. The first therapeutic, nusinersen (Spinraza®, 2017), is an antisense oligonucleotide (ASO) targeting the splicing inhibitory sequence in the intron downstream of exon 7 from SMN2, thus increasing exon 7 inclusion. The second drug is a small molecule, risdiplam (Evrysdi®, 2021), that enhances the binding of splice factors and also promotes exon 7 inclusion. Both therapies, albeit through different mechanisms, increase full-length SMN protein expression. EXPERT OPINION Nusinersen and risdiplam have directly helped SMA patients and families, but they also herald a sea change in drug development for genetic diseases. This piece aims to draw parallels between both development histories; this may help chart the course for future targeted agents.
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Affiliation(s)
| | | | | | - Amy O'Neill
- Charles River Laboratories, Saffron Walden, UK
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Mouchet J, Roumpanis S, Gaki E, Lipnick S, Oskoui M, Scalco RS, Darras BT. Disease Burden of Spinal Muscular Atrophy: A Comparative Cohort Study Using Insurance Claims Data in the USA. J Neuromuscul Dis 2023; 10:41-53. [PMID: 36314213 PMCID: PMC9881018 DOI: 10.3233/jnd-210764] [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] [Indexed: 01/11/2023]
Abstract
BACKGROUND Spinal muscular atrophy (SMA) is a neuromuscular disease caused by homozygous deletion or loss-of-function mutations of the survival of motor neuron 1 (SMN1) gene, resulting in reduced levels of SMN protein throughout the body. Patients with SMA may have multiple tissue defects, which could present prior to neuromuscular symptoms. OBJECTIVE To assess the signs, comorbidities and potential extraneural manifestations associated with SMA in treatment-naïve patients. METHODS This observational, retrospective and matched-cohort study used secondary insurance claims data from the US IBM® MarketScan® Commercial, Medicaid and Medicare Supplemental databases between 01/01/2000 and 12/31/2013. Treatment-naïve individuals aged≤65 years with≥2 International Classification of Diseases, Ninth Revision (ICD-9) SMA codes were stratified into four groups (A-D), according to age at index (date of first SMA code recorded) and type of ICD-9 code used, and matched with non-SMA controls. The occurrence of ICD-9 codes, which were converted to various classifications (phecodes and system classes), were compared between groups in pre- and post-index periods. RESULTS A total of 1,457 individuals with SMA were included and matched to 13,362 controls. Increasing numbers of SMA-associated phecodes and system classes were generally observed from pre- to post-index across all groups. The strongest associations were observed in the post-index period for the youngest age groups. Endocrine/metabolic disorders were associated with SMA in almost all groups and across time periods. CONCLUSIONS This exploratory study confirmed the considerable disease burden in patients with SMA and identified 305 unique phecodes associated with SMA, providing a rationale for further research into the natural history and progression of SMA, including extraneural manifestations of the disease.
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Affiliation(s)
- Julie Mouchet
- F. Hoffmann-La Roche Ltd, Basel, Switzerland,Correspondence to: Julie Mouchet, PhD, F. Hoffmann-La Roche Ltd., Grenzacherstrasse 124, 4070 Basel, Real World Data (RWD) Enabling Platform, Global PD Data Sciences, Tel.: +41 79 968 50 85; E-mail:
| | | | - Eleni Gaki
- Roche Products Ltd, Welwyn Garden City, UK
| | - Scott Lipnick
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA,
Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA,Center for Assessment Technology & Continuous Health (CATCH), Massachusetts General Hospital, Boston, MA, USA
| | - Maryam Oskoui
- Departments of Pediatrics and Neurology Neurosurgery, McGill University, Montreal, QC, Canada
| | | | - Basil T. Darras
- Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
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48
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Vezain M, Thauvin-Robinet C, Vial Y, Coutant S, Drunat S, Urtizberea JA, Rolland A, Jacquin-Piques A, Fehrenbach S, Nicolas G, Lecoquierre F, Saugier-Veber P. Retrotransposon insertion as a novel mutational cause of spinal muscular atrophy. Hum Genet 2023; 142:125-138. [PMID: 36138164 DOI: 10.1007/s00439-022-02473-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/15/2022] [Indexed: 01/18/2023]
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder resulting from biallelic alterations of the SMN1 gene: deletion, gene conversion or, in rare cases, intragenic variants. The disease severity is mainly influenced by the copy number of SMN2, a nearly identical gene, which produces only low amounts of full-length (FL) mRNA. Here we describe the first example of retrotransposon insertion as a pathogenic SMN1 mutational event. The 50-year-old patient is clinically affected by SMA type III with a diagnostic odyssey spanning nearly 30 years. Despite a mild disease course, he carries a single SMN2 copy. Using Exome Sequencing and Sanger sequencing, we characterized a SINE-VNTR-Alu (SVA) type F retrotransposon inserted in SMN1 intron 7. Using RT-PCR and RNASeq experiments on lymphoblastoid cell lines, we documented the dramatic decrease of FL transcript production in the patient compared to subjects with the same SMN1 and SMN2 copy number, thus validating the pathogenicity of this SVA insertion. We described the mutant FL-SMN1-SVA transcript characterized by exon extension and showed that it is subject to degradation by nonsense-mediated mRNA decay. The stability of the SMN-SVA protein may explain the mild course of the disease. This observation exemplifies the role of retrotransposons in human genetic disorders.
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Affiliation(s)
- Myriam Vezain
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - Christel Thauvin-Robinet
- INSERM UMR1231 GAD-Génétique des Anomalies du Développement, Bourgogne Franche-Comté University, F-21000 , Dijon, France.,Genetics Center, Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD), Dijon-Burgundy University Hospital, F-21000, Dijon, France
| | - Yoann Vial
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France.,Genetics Department, AP-HP, Robert-Debré University Hospital, 48 boulevard Sérurier, 75019 , Paris, France
| | - Sophie Coutant
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - Séverine Drunat
- INSERM UMR 1141, PROTECT, Paris University, F-75019, Paris, France.,Genetics Department, AP-HP, Robert-Debré University Hospital, F-75019, Paris, France
| | - Jon Andoni Urtizberea
- Myology Institute, AP-HP Pitié-Salpêtrière University Hospital, F-75013, Paris, France
| | - Anne Rolland
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Pediatrics Department, Valence Hospital, 179 boulevard du Maréchal Juin, 26000, Valence, France
| | - Agnès Jacquin-Piques
- Department of Neurology, Clinical Neurophysiology, Competence Center of Neuromuscular Diseases, Dijon-Burgundy University Hospital, F-21000, Dijon, France
| | - Séverine Fehrenbach
- Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - Gaël Nicolas
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - François Lecoquierre
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - Pascale Saugier-Veber
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France. .,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France. .,Laboratoire de Génétique Moléculaire, UFR-Santé, 22 boulevard Gambetta, 76183, Rouen, France.
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Scheijmans FEV, Cuppen I, Zwartkruis MM, Signoria I, van Ekris C, Asselman F, Wadman RI, Knol EF, van der Pol WL, Groen EJN. Inflammatory markers in cerebrospinal fluid of paediatric spinal muscular atrophy patients receiving nusinersen treatment. Eur J Paediatr Neurol 2023; 42:34-41. [PMID: 36525882 DOI: 10.1016/j.ejpn.2022.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 11/01/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022]
Abstract
Spinal muscular atrophy (SMA) is a progressive motor neuron disease with onset during infancy or early childhood. Recent therapeutic advances targeting the genetic defect that underlies SMA improved survival in patients with infantile onset SMA (type 1) and improved motor function in SMA type 1-3. The most commonly used therapy for SMA, the antisense oligonucleotide nusinersen, is delivered by repeated intrathecal injections. The long-term safety effects of this procedure, however, have not yet been investigated in detail. We here present case reports of three children with SMA in which routine laboratory investigation revealed increased leukocyte counts in cerebrospinal fluid (CSF) collected during the course of nusinersen treatment. To further characterize this observation, we used a multiplex method to analyse a broad spectrum of inflammatory markers in the CSF of these patients. We found that interleukin-10 (IL10) was consistently elevated in CSF with increased leukocyte counts, but other inflammatory markers were not. Based on this analysis we selected 7 markers for further analysis in a cohort of 38 children with SMA and determined their expression during the course of nusinersen therapy. No consistent association was found between levels of inflammatory markers and the duration of nusinersen therapy in individual patients. However, monocyte chemoactive protein 1 (MCP1/CCL2) -a neuroprotective protein secreted by astrocytes and previously associated with SMA- levels increased over the course of nusinersen treatment, indicating a possible neuroprotective mechanism associated with nusinersen therapy. In summary, our findings confirm that repeated intrathecal injections are safe and do not trigger unwanted immune responses.
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Affiliation(s)
- F E V Scheijmans
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands
| | - I Cuppen
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands
| | - M M Zwartkruis
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands; Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - I Signoria
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands
| | - C van Ekris
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands
| | - F Asselman
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands
| | - R I Wadman
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands
| | - E F Knol
- Department of Dermatology and Allergology, Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - W L van der Pol
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.
| | - E J N Groen
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.
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50
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Sun J, Harrington MA, Porter B. Sex Difference in Spinal Muscular Atrophy Patients - are Males More Vulnerable? J Neuromuscul Dis 2023; 10:847-867. [PMID: 37393514 PMCID: PMC10578261 DOI: 10.3233/jnd-230011] [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] [Accepted: 06/12/2023] [Indexed: 07/03/2023]
Abstract
BACKGROUND Sex is a significant risk factor in many neurodegenerative disorders. A better understanding of the molecular mechanisms behind sex differences could help develop more targeted therapies that would lead to better outcomes. Untreated spinal muscular atrophy (SMA) is the leading genetic motor disorder causing infant mortality. SMA has a broad spectrum of severity ranging from prenatal death to infant mortality to normal lifespan with some disability. Scattered evidence points to a sex-specific vulnerability in SMA. However, the role of sex as a risk factor in SMA pathology and treatment has received limited attention. OBJECTIVE Systematically investigate sex differences in the incidence, symptom severity, motor function of patients with different types of SMA, and in the development of SMA1 patients. METHODS Aggregated data of SMA patients were obtained from the TREAT-NMD Global SMA Registry and the Cure SMA membership database by data enquiries. Data were analyzed and compared with publicly available standard data and data from published literature. RESULTS The analysis of the aggregated results from the TREAT-NMD dataset revealed that the male/female ratio was correlated to the incidence and prevalence of SMA from different countries; and for SMA patients, more of their male family members were affected by SMA. However, there was no significant difference of sex ratio in the Cure SMA membership dataset. As quantified by the clinician severity scores, symptoms were more severe in males than females in SMA types 2 and 3b. Motor function scores measured higher in females than males in SMA types 1, 3a and 3b. The head circumference was more strongly affected in male SMA type 1 patients. CONCLUSIONS The data in certain registry datasets suggest that males may be more vulnerable to SMA than females. The variability observed indicates that more investigation is necessary to fully understand the role of sex differences in SMA epidemiology, and to guide development of more targeted treatments.
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Affiliation(s)
- Jianli Sun
- Delaware Center for Neuroscience Research, Delaware State University, Dover, DE, USA
- Department of Biological Sciences, Delaware State University, Dover, DE, USA
| | - Melissa A. Harrington
- Delaware Center for Neuroscience Research, Delaware State University, Dover, DE, USA
| | - Ben Porter
- TREAT-NMD Services Limited, Newcastle upon Tyne, UK
| | - on behalf of the TREAT-NMD Global Registry Network for SMA
- Delaware Center for Neuroscience Research, Delaware State University, Dover, DE, USA
- Department of Biological Sciences, Delaware State University, Dover, DE, USA
- TREAT-NMD Services Limited, Newcastle upon Tyne, UK
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