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Xie Q, Chen X, Ma H, Zhu Y, Ma Y, Jalinous L, Cox GF, Weaver F, Yang J, Kennedy Z, Gruntman A, Du A, Su Q, He R, Tai PW, Gao G, Xie J. Improved gene therapy for spinal muscular atrophy in mice using codon-optimized hSMN1 transgene and hSMN1 gene-derived promotor. EMBO Mol Med 2024; 16:945-965. [PMID: 38413838 PMCID: PMC11018631 DOI: 10.1038/s44321-024-00037-x] [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: 11/02/2023] [Revised: 01/31/2024] [Accepted: 02/01/2024] [Indexed: 02/29/2024] Open
Abstract
Physiological regulation of transgene expression is a major challenge in gene therapy. Onasemnogene abeparvovec (Zolgensma®) is an approved adeno-associated virus (AAV) vector gene therapy for infants with spinal muscular atrophy (SMA), however, adverse events have been observed in both animals and patients following treatment. The construct contains a native human survival motor neuron 1 (hSMN1) transgene driven by a strong, cytomegalovirus enhancer/chicken β-actin (CMVen/CB) promoter providing high, ubiquitous tissue expression of SMN. We developed a second-generation AAV9 gene therapy expressing a codon-optimized hSMN1 transgene driven by a promoter derived from the native hSMN1 gene. This vector restored SMN expression close to physiological levels in the central nervous system and major systemic organs of a severe SMA mouse model. In a head-to-head comparison between the second-generation vector and a benchmark vector, identical in design to onasemnogene abeparvovec, the 2nd-generation vector showed better safety and improved efficacy in SMA mouse model.
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Affiliation(s)
- Qing Xie
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA, USA
| | - Xiupeng Chen
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA, USA
| | - Hong Ma
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA, USA
- Viral Vector Core, UMass Chan Medical School, Worcester, MA, USA
| | | | - Yijie Ma
- CANbridge Pharmaceuticals, Burlington, MA, USA
| | | | | | | | - Jun Yang
- CANbridge Pharmaceuticals, Burlington, MA, USA
| | | | - Alisha Gruntman
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA, USA
- Pediatrics, UMass Chan Medical School, Worcester, MA, USA
| | - Ailing Du
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA, USA
| | - Qin Su
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA, USA
- Viral Vector Core, UMass Chan Medical School, Worcester, MA, USA
| | - Ran He
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA, USA
- Viral Vector Core, UMass Chan Medical School, Worcester, MA, USA
| | - Phillip Wl Tai
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA, USA
- Li Weibo Institute for Rare Diseases Research, UMass Chan Medical School, Worcester, MA, USA
| | - Guangping Gao
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA, USA.
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA, USA.
- Li Weibo Institute for Rare Diseases Research, UMass Chan Medical School, Worcester, MA, USA.
| | - Jun Xie
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA, USA.
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA, USA.
- Viral Vector Core, UMass Chan Medical School, Worcester, MA, USA.
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He X, Li X, Yan M, Peng H, Zhang L, Liang Y, Tang W, Li S. Cardiac function evaluation in children with spinal muscular atrophy: A case-control study. Pediatr Int 2024; 66:e15769. [PMID: 38742693 DOI: 10.1111/ped.15769] [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: 10/28/2023] [Revised: 01/09/2024] [Accepted: 03/04/2024] [Indexed: 05/16/2024]
Abstract
BACKGROUND Spinal muscular atrophy (SMA) is an autosomal recessive disorder characterized by degeneration of lower motor neurons, resulting in progressive muscle weakness and atrophy. However, little is known regarding the cardiac function of children with SMA. METHODS We recruited SMA patients younger than 18 years of age from January 1, 2022, to April 1, 2022, in the First Affiliated Hospital of Sun Yat-sen University. All patients underwent a comprehensive cardiac evaluation before treatment, including history taking, physical examination, blood tests of cardiac biomarkers, assessment of echocardiography and electrocardiogram. Age/gender-matched healthy volunteers were recruited as controls. RESULTS A total of 36 SMA patients (26 with SMA type 2 and 10 with SMA type 3) and 40 controls were enrolled in the study. No patient was clinically diagnosed with heart failure. Blood tests showed elevated values of creatine kinase isoenzyme M and isoenzyme B (CK-MB) mass and high-sensitivity cardiac troponin T (hs-cTnT) in spinal muscular atrophy (SMA) patients. Regarding echocardiographic parameters, SMA children were detected with lower global left and right ventricular longitudinal strain, abnormal diastolic filling velocities of trans-mitral and trans-tricuspid flow. The results revealed no clinical heart dysfunction in SMA patients, but subclinical ventricular dysfunction was seen in SMA children including the diastolic function and myocardial performance. Some patients presented with elevated heart rate and abnormal echogenicity of aortic valve or wall. Among these SMA patients, seven patients (19.4%) had scoliosis. The Cobb's angles showed a significant negative correlation with LVEDd/BSA, but no correlation with other parameters, suggesting that mild scoliosis did not lead to significant cardiac dysfunction. CONCLUSIONS Our findings warrant increased attention to the cardiac status and highlight the need to investigate cardiac interventions in SMA children.
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Affiliation(s)
- Xiufang He
- Department of Pediatric Cardiology, Heart Center, The First Affiliated Hospital of Sun Yat-sen University, and NHC Key Laboratory of Assisted Circulation and Vascular Diseases (Sun Yat-sen University), Guangzhou, China
| | - Xuandi Li
- Department of Pediatric Cardiology, Heart Center, The First Affiliated Hospital of Sun Yat-sen University, and NHC Key Laboratory of Assisted Circulation and Vascular Diseases (Sun Yat-sen University), Guangzhou, China
| | - Mengzhen Yan
- Department of PICU, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Huimin Peng
- Department of Pediatric Cardiology, Heart Center, The First Affiliated Hospital of Sun Yat-sen University, and NHC Key Laboratory of Assisted Circulation and Vascular Diseases (Sun Yat-sen University), Guangzhou, China
| | - Lili Zhang
- Department of Pediatric Cardiology, Heart Center, The First Affiliated Hospital of Sun Yat-sen University, and NHC Key Laboratory of Assisted Circulation and Vascular Diseases (Sun Yat-sen University), Guangzhou, China
| | - Yujian Liang
- Department of PICU, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Wen Tang
- Department of PICU, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Shujuan Li
- Department of Pediatric Cardiology, Heart Center, The First Affiliated Hospital of Sun Yat-sen University, and NHC Key Laboratory of Assisted Circulation and Vascular Diseases (Sun Yat-sen University), Guangzhou, China
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Miller N, Xu Z, Quinlan KA, Ji A, McGivern JV, Feng Z, Shi H, Ko CP, Tsai LH, Heckman CJ, Ebert AD, Ma YC. Mitigating aberrant Cdk5 activation alleviates mitochondrial defects and motor neuron disease symptoms in spinal muscular atrophy. Proc Natl Acad Sci U S A 2023; 120:e2300308120. [PMID: 37976261 PMCID: PMC10666147 DOI: 10.1073/pnas.2300308120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 07/31/2023] [Indexed: 11/19/2023] Open
Abstract
Spinal muscular atrophy (SMA), the top genetic cause of infant mortality, is characterized by motor neuron degeneration. Mechanisms underlying SMA pathogenesis remain largely unknown. Here, we report that the activity of cyclin-dependent kinase 5 (Cdk5) and the conversion of its activating subunit p35 to the more potent activator p25 are significantly up-regulated in mouse models and human induced pluripotent stem cell (iPSC) models of SMA. The increase of Cdk5 activity occurs before the onset of SMA phenotypes, suggesting that it may be an initiator of the disease. Importantly, aberrant Cdk5 activation causes mitochondrial defects and motor neuron degeneration, as the genetic knockout of p35 in an SMA mouse model rescues mitochondrial transport and fragmentation defects, and alleviates SMA phenotypes including motor neuron hyperexcitability, loss of excitatory synapses, neuromuscular junction denervation, and motor neuron degeneration. Inhibition of the Cdk5 signaling pathway reduces the degeneration of motor neurons derived from SMA mice and human SMA iPSCs. Altogether, our studies reveal a critical role for the aberrant activation of Cdk5 in SMA pathogenesis and suggest a potential target for therapeutic intervention.
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Affiliation(s)
- Nimrod Miller
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL60611
- Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL60611
| | - Zhaofa Xu
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL60611
- Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL60611
| | - Katharina A. Quinlan
- Department of Neuroscience, Northwestern University Feinberg School of Medicine, Chicago, IL60611
- Department of Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, IL60611
- Department of Physical Therapy and Human Movement Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL60611
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI02881
| | - Amy Ji
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL60611
| | - Jered V. McGivern
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI53226
| | - Zhihua Feng
- Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA90089
| | - Han Shi
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL60611
- Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL60611
| | - Chien-Ping Ko
- Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA90089
| | - Li-Huei Tsai
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Charles J. Heckman
- Department of Neuroscience, Northwestern University Feinberg School of Medicine, Chicago, IL60611
- Department of Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, IL60611
- Department of Physical Therapy and Human Movement Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL60611
| | - Allison D. Ebert
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI53226
| | - Yongchao C. Ma
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL60611
- Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL60611
- Department of Neuroscience, Northwestern University Feinberg School of Medicine, Chicago, IL60611
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4
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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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5
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Brown SJ, Šoltić D, Synowsky SA, Shirran SL, Chilcott E, Shorrock HK, Gillingwater TH, Yáñez-Muñoz RJ, Schneider B, Bowerman M, Fuller HR. AAV9-mediated SMN gene therapy rescues cardiac desmin but not lamin A/C and elastin dysregulation in Smn2B/- spinal muscular atrophy mice. Hum Mol Genet 2023; 32:2950-2965. [PMID: 37498175 PMCID: PMC10549791 DOI: 10.1093/hmg/ddad121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 06/27/2023] [Accepted: 07/25/2023] [Indexed: 07/28/2023] Open
Abstract
Structural, functional and molecular cardiac defects have been reported in spinal muscular atrophy (SMA) patients and mouse models. Previous quantitative proteomics analyses demonstrated widespread molecular defects in the severe Taiwanese SMA mouse model. Whether such changes are conserved across different mouse models, including less severe forms of the disease, has yet to be established. Here, using the same high-resolution proteomics approach in the less-severe Smn2B/- SMA mouse model, 277 proteins were found to be differentially abundant at a symptomatic timepoint (post-natal day (P) 18), 50 of which were similarly dysregulated in severe Taiwanese SMA mice. Bioinformatics analysis linked many of the differentially abundant proteins to cardiovascular development and function, with intermediate filaments highlighted as an enriched cellular compartment in both datasets. Lamin A/C was increased in the cardiac tissue, whereas another intermediate filament protein, desmin, was reduced. The extracellular matrix (ECM) protein, elastin, was also robustly decreased in the heart of Smn2B/- mice. AAV9-SMN1-mediated gene therapy rectified low levels of survival motor neuron protein and restored desmin levels in heart tissues of Smn2B/- mice. In contrast, AAV9-SMN1 therapy failed to correct lamin A/C or elastin levels. Intermediate filament proteins and the ECM have key roles in cardiac function and their dysregulation may explain cardiac impairment in SMA, especially since mutations in genes encoding these proteins cause other diseases with cardiac aberration. Cardiac pathology may need to be considered in the long-term care of SMA patients, as it is unclear whether currently available treatments can fully rescue peripheral pathology in SMA.
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Affiliation(s)
- Sharon J Brown
- School of Pharmacy and Bioengineering, Keele University, Keele ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, TORCH Building, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
| | - Darija Šoltić
- School of Pharmacy and Bioengineering, Keele University, Keele ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, TORCH Building, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
| | - Silvia A Synowsky
- BSRC Mass Spectrometry and Proteomics Facility, University of St Andrews, St Andrews KY16 9ST, UK
| | - Sally L Shirran
- BSRC Mass Spectrometry and Proteomics Facility, University of St Andrews, St Andrews KY16 9ST, UK
| | - Ellie Chilcott
- AGCTlab.org, Centre of Gene and Cell Therapy, Centre for Biomedical Sciences, Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham Hill, Egham, Surrey TW20 0EX, UK
| | - Hannah K Shorrock
- Edinburgh Medical School: Biomedical Sciences, Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Thomas H Gillingwater
- Edinburgh Medical School: Biomedical Sciences, Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Rafael J Yáñez-Muñoz
- AGCTlab.org, Centre of Gene and Cell Therapy, Centre for Biomedical Sciences, Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham Hill, Egham, Surrey TW20 0EX, UK
| | - Bernard Schneider
- Bertarelli Platform for Gene Therapy, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Melissa Bowerman
- Wolfson Centre for Inherited Neuromuscular Disease, TORCH Building, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
- School of Medicine, Keele University, Keele ST5 5BG, UK
| | - Heidi R Fuller
- School of Pharmacy and Bioengineering, Keele University, Keele ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, TORCH Building, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
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6
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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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7
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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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8
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Dysfunctional mitochondria accumulate in a skeletal muscle knockout model of Smn1, the causal gene of spinal muscular atrophy. Cell Death Dis 2023; 14:162. [PMID: 36849544 PMCID: PMC9971247 DOI: 10.1038/s41419-023-05573-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 01/07/2023] [Accepted: 01/09/2023] [Indexed: 03/01/2023]
Abstract
The approved gene therapies for spinal muscular atrophy (SMA), caused by loss of survival motor neuron 1 (SMN1), greatly ameliorate SMA natural history but are not curative. These therapies primarily target motor neurons, but SMN1 loss has detrimental effects beyond motor neurons and especially in muscle. Here we show that SMN loss in mouse skeletal muscle leads to accumulation of dysfunctional mitochondria. Expression profiling of single myofibers from a muscle specific Smn1 knockout mouse model revealed down-regulation of mitochondrial and lysosomal genes. Albeit levels of proteins that mark mitochondria for mitophagy were increased, morphologically deranged mitochondria with impaired complex I and IV activity and respiration and that produced excess reactive oxygen species accumulated in Smn1 knockout muscles, because of the lysosomal dysfunction highlighted by the transcriptional profiling. Amniotic fluid stem cells transplantation that corrects the SMN knockout mouse myopathic phenotype restored mitochondrial morphology and expression of mitochondrial genes. Thus, targeting muscle mitochondrial dysfunction in SMA may complement the current gene therapy.
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9
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Faravelli I, Riboldi GM, Rinchetti P, Lotti F. The SMN Complex at the Crossroad between RNA Metabolism and Neurodegeneration. Int J Mol Sci 2023; 24:2247. [PMID: 36768569 PMCID: PMC9917330 DOI: 10.3390/ijms24032247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 01/17/2023] [Accepted: 01/20/2023] [Indexed: 01/24/2023] Open
Abstract
In the cell, RNA exists and functions in a complex with RNA binding proteins (RBPs) that regulate each step of the RNA life cycle from transcription to degradation. Central to this regulation is the role of several molecular chaperones that ensure the correct interactions between RNA and proteins, while aiding the biogenesis of large RNA-protein complexes (ribonucleoproteins or RNPs). Accurate formation of RNPs is fundamentally important to cellular development and function, and its impairment often leads to disease. The survival motor neuron (SMN) protein exemplifies this biological paradigm. SMN is part of a multi-protein complex essential for the biogenesis of various RNPs that function in RNA metabolism. Mutations leading to SMN deficiency cause the neurodegenerative disease spinal muscular atrophy (SMA). A fundamental question in SMA biology is how selective motor system dysfunction results from reduced levels of the ubiquitously expressed SMN protein. Recent clarification of the central role of the SMN complex in RNA metabolism and a thorough characterization of animal models of SMA have significantly advanced our knowledge of the molecular basis of the disease. Here we review the expanding role of SMN in the regulation of gene expression through its multiple functions in RNP biogenesis. We discuss developments in our understanding of SMN activity as a molecular chaperone of RNPs and how disruption of SMN-dependent RNA pathways can contribute to the SMA phenotype.
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Affiliation(s)
- Irene Faravelli
- Department of Stem Cell & Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
- Center for Motor Neuron Biology and Diseases, Departments of Pathology & Cell Biology, and Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Giulietta M. Riboldi
- Center for Motor Neuron Biology and Diseases, Departments of Pathology & Cell Biology, and Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
- The Marlene and Paolo Fresco Institute for Parkinson’s and Movement Disorders, NYU Langone Health, New York, NY 10017, USA
| | - Paola Rinchetti
- Center for Motor Neuron Biology and Diseases, Departments of Pathology & Cell Biology, and Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Francesco Lotti
- Center for Motor Neuron Biology and Diseases, Departments of Pathology & Cell Biology, and Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
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10
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Kray KM, McGovern VL, Chugh D, Arnold WD, Burghes AHM. Dual SMN inducing therapies can rescue survival and motor unit function in symptomatic ∆7SMA mice. Neurobiol Dis 2021; 159:105488. [PMID: 34425216 PMCID: PMC8502210 DOI: 10.1016/j.nbd.2021.105488] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 08/06/2021] [Accepted: 08/16/2021] [Indexed: 11/24/2022] Open
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by survival motor neuron (SMN) protein deficiency which results in motor neuron loss and muscle atrophy. SMA is caused by a mutation or deletion of the survival motor neuron 1 (SMN1) gene and retention of the nearly identical SMN2 gene. SMN2 contains a C to T change in exon 7 that results in exon 7 exclusion from 90% of transcripts. SMN protein lacking exon 7 is unstable and rapidly degraded. The remaining full-length transcripts from SMN2 are insufficient for normal motor neuron function leading to the development of SMA. Three different therapeutic approaches that increase full-length SMN (FL-SMN) protein production are approved for treatment of SMA patients. Studies in both animal models and humans have demonstrated increasing SMN levels prior to onset of symptoms provides the greatest therapeutic benefit. Treatment of SMA, after some motor neuron loss has occurred, is also effective but to a lesser degree. The SMN∆7 mouse model is a well characterized model of severe or type 1 SMA, dying at 14 days of age. Here we treated three groups of ∆7SMA mice starting before, roughly during, and after symptom onset to determine if combining two mechanistically distinct SMN inducing therapies could improve the therapeutic outcome both before and after motor neuron loss. We found, compared with individual therapies, that morpholino antisense oligonucleotide (ASO) directed against ISS-N1 combined with the small molecule compound RG7800 significantly increased FL-SMN transcript and protein production resulting in improved survival and weight of ∆7SMA mice. Moreover, when give late symptomatically, motor unit function was completely rescued with no loss in function at 100 days of age in the dual treatment group. We have therefore shown that this dual therapeutic approach successfully increases SMN protein and rescues motor function in symptomatic ∆7SMA mice.
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Affiliation(s)
- Kaitlyn M Kray
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, 1060 Carmack Road, Columbus, OH 43210, USA.
| | - Vicki L McGovern
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, 1060 Carmack Road, Columbus, OH 43210, USA.
| | - Deepti Chugh
- Department of Neurology, Neuromuscular Division, The Ohio State University Wexner Medical Center, 395 W. 12(th) Ave, Columbus, OH 43210, USA
| | - W David Arnold
- Department of Neurology, Neuromuscular Division, The Ohio State University Wexner Medical Center, 395 W. 12(th) Ave, Columbus, OH 43210, 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; Department of Neurology, Neuromuscular Division, The Ohio State University Wexner Medical Center, 395 W. 12(th) Ave, Columbus, OH 43210, USA.
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11
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Thomsen G, Burghes AHM, Hsieh C, Do J, Chu BTT, Perry S, Barkho B, Kaufmann P, Sproule DM, Feltner DE, Chung WK, McGovern VL, Hevner RF, Conces M, Pierson CR, Scoto M, Muntoni F, Mendell JR, Foust KD. Biodistribution of onasemnogene abeparvovec DNA, mRNA and SMN protein in human tissue. Nat Med 2021; 27:1701-1711. [PMID: 34608334 DOI: 10.1038/s41591-021-01483-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 07/27/2021] [Indexed: 02/08/2023]
Abstract
Spinal muscular atrophy type 1 (SMA1) is a debilitating neurodegenerative disease resulting from survival motor neuron 1 gene (SMN1) deletion/mutation. Onasemnogene abeparvovec (formerly AVXS-101) is a gene therapy that restores SMN production via one-time systemic administration. The present study demonstrates widespread biodistribution of vector genomes and transgenes throughout the central nervous system (CNS) and peripheral organs, after intravenous administration of an AAV9-mediated gene therapy. Two symptomatic infants with SMA1 enrolled in phase III studies received onasemnogene abeparvovec. Both patients died of respiratory complications unrelated to onasemnogene abeparvovec. One patient had improved motor function and the other died shortly after administration before appreciable clinical benefit could be observed. In both patients, onasemnogene abeparvovec DNA and messenger RNA distribution were widespread among peripheral organs and in the CNS. The greatest concentration of vector genomes was detected in the liver, with an increase over that detected in CNS tissues of 300-1,000-fold. SMN protein, which was low in an untreated SMA1 control, was clearly detectable in motor neurons, brain, skeletal muscle and multiple peripheral organs in treated patients. These data support the fact that onasemnogene abeparvovec has effective distribution, transduction and expression throughout the CNS after intravenous administration and restores SMN expression in humans.
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Affiliation(s)
| | - Arthur H M Burghes
- Department of Neurology, The Ohio State University, Columbus, OH, USA. .,Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA.
| | | | - Janet Do
- Novartis Gene Therapies, Bannockburn, IL, USA
| | | | | | | | | | | | | | - Wendy K Chung
- Departments of Pediatrics and Medicine, Columbia University, New York, NY, USA
| | - Vicki L McGovern
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA
| | - Robert F Hevner
- Department of Pathology, University of California, San Diego, CA, USA
| | - Miriam Conces
- Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pathology, The Ohio State University, Columbus, OH, USA
| | - Christopher R Pierson
- Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pathology, The Ohio State University, Columbus, OH, USA
| | - Mariacristina Scoto
- National Institute for Health Research, Great Ormond Street Institute of Child Health Biomedical Research Centre, University College London, London, UK.,Great Ormond Street Hospital Trust, London, UK
| | - Francesco Muntoni
- National Institute for Health Research, Great Ormond Street Institute of Child Health Biomedical Research Centre, University College London, London, UK.,Great Ormond Street Hospital Trust, London, UK
| | - Jerry R Mendell
- Department of Neurology, The Ohio State University, Columbus, OH, USA.,Center for Gene Therapy, Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pediatrics, The Ohio State University, Columbus, OH, USA
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12
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Metabolic Dysfunction in Spinal Muscular Atrophy. Int J Mol Sci 2021; 22:ijms22115913. [PMID: 34072857 PMCID: PMC8198411 DOI: 10.3390/ijms22115913] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 05/25/2021] [Accepted: 05/29/2021] [Indexed: 12/11/2022] Open
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive genetic disorder leading to paralysis, muscle atrophy, and death. Significant advances in antisense oligonucleotide treatment and gene therapy have made it possible for SMA patients to benefit from improvements in many aspects of the once devastating natural history of the disease. How the depletion of survival motor neuron (SMN) protein, the product of the gene implicated in the disease, leads to the consequent pathogenic changes remains unresolved. Over the past few years, evidence toward a potential contribution of gastrointestinal, metabolic, and endocrine defects to disease phenotype has surfaced. These findings ranged from disrupted body composition, gastrointestinal tract, fatty acid, glucose, amino acid, and hormonal regulation. Together, these changes could have a meaningful clinical impact on disease traits. However, it is currently unclear whether these findings are secondary to widespread denervation or unique to the SMA phenotype. This review provides an in-depth account of metabolism-related research available to date, with a discussion of unique features compared to other motor neuron and related disorders.
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13
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Servais L, Baranello G, Scoto M, Daron A, Oskoui M. Therapeutic interventions for spinal muscular atrophy: preclinical and early clinical development opportunities. Expert Opin Investig Drugs 2021; 30:519-527. [PMID: 33749510 DOI: 10.1080/13543784.2021.1904889] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative neuromuscular disease that presents primarily in children. Abnormalities in the SMN1 gene cause reduced levels of the survival motor neuron (SMN) protein, while a second gene, SMN2, produces low levels of functional SMN protein. Currently available drugs do not cure, so a significant unmet need remains for patients treated after symptom onset. AREAS COVERED Drugs available in the clinic, investigational agents and key questions for researchers are discussed. A pragmatic search of the literature was performed to identify therapies in late stages of preclinical, or in early stages of clinical development. This list was compared to the CureSMA pipeline for completeness. Drugs approved for indications that have potential for impact for SMA were included. These drugs target the primary deficiency in SMN protein or other pathways involved in SMA pathophysiology that are not SMN-protein dependent. EXPERT OPINION Children treated after the onset of symptoms continue to have significant disability. Given the heterogeneity of the population phenotype evidenced by variable response to initial therapy, age at treatment onset and the need to demonstrate added value beyond approved therapeutics, the clinical development of new drugs will be challenging.
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Affiliation(s)
- Laurent Servais
- MDUK Neuromuscular Center, Department of Paediatrics, University of Oxford, Oxford, UK.,Neuromuscular Reference Center Disease, Department of Paediatrics, Liege, Belgium and University of Liege, Liège, Belgium
| | - Giovanni Baranello
- Dubowitz Neuromuscular Centre, NIHR Great Ormond Street Hospital Biomedical Research Centre, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Mariacristina Scoto
- Dubowitz Neuromuscular Centre, NIHR Great Ormond Street Hospital Biomedical Research Centre, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Aurore Daron
- Neuromuscular Reference Center Disease, Department of Paediatrics, Liege, Belgium and University of Liege, Liège, Belgium
| | - Maryam Oskoui
- Departments of Pediatrics and Neurology & Neurosurgery, McGill University, Montreal, QC, Canada
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14
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Deguise MO, Beauvais A, Schneider BL, Kothary R. Blood Flow to the Spleen is Altered in a Mouse Model of Spinal Muscular Atrophy. J Neuromuscul Dis 2021; 7:315-322. [PMID: 32333548 DOI: 10.3233/jnd-200493] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular disorder affecting young children. While pre-clinical models of SMA show small spleens, the same is not true in humans. Here, we show by doppler ultrasonography decreased splenic blood flow in Smn2B/- mice. Further, AAV9-SMN gene therapy does not rescue the distal ear and tail necrosis nor the spleen size in these mice, suggesting that the latter may be linked to a cardiovascular defect. Absence of smaller spleens in human patients is likely due to differences in presentation of defects in SMA between pre-clinical mouse models and human patients, particularly the susceptibility to cardiovascular issues.
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Affiliation(s)
- Marc-Olivier Deguise
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada.,Centre for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario, Canada
| | - Ariane Beauvais
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Bernard L Schneider
- Bertarelli Foundation Gene Therapy Platform, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland.,Brain Mind Institute, 27218 Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Rashmi Kothary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada.,Centre for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario, Canada.,Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, and Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
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15
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Ryan ÉB, Yan J, Miller N, Dayanidhi S, Ma YC, Deng HX, Siddique T. Early death of ALS-linked CHCHD10-R15L transgenic mice with central nervous system, skeletal muscle, and cardiac pathology. iScience 2021; 24:102061. [PMID: 33659869 PMCID: PMC7890413 DOI: 10.1016/j.isci.2021.102061] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 08/27/2020] [Accepted: 01/12/2021] [Indexed: 12/14/2022] Open
Abstract
Mutations in coiled-coil-helix-coiled-coil-helix domain containing 10 (CHCHD10) have been identified in patients suffering from various degenerative diseases including mitochondrial myopathy, spinal muscular atrophy Jokela type, frontotemporal dementia, and/or amyotrophic lateral sclerosis (ALS). The pathogenic mechanism underlying CHCHD10-linked divergent disorders remains largely unknown. Here we show that transgenic mice overexpressing an ALS-linked CHCHD10 p.R15L mutation leads to an abbreviated lifespan compared with CHCHD10-WT transgenic mice. The occurrence and severity of the phenotype correlates to transgene copy number. Central nervous system (CNS), skeletal muscle, and cardiac pathology is apparent in CHCHD10-R15L transgenic mice. Despite the pathology, CHCHD10-R15L transgenic mice perform comparably to control mice in motor behavioral tasks until very close to death. Although paralysis is not observed, these models provide insight into the pleiotropic nature of CHCHD10 and suggest a contribution of CNS, skeletal muscle, and cardiac pathology to CHCHD10 p.R15L-ALS pathogenesis.
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Affiliation(s)
- Éanna B. Ryan
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Tarry Building, Room 13-715, 303 East Chicago Avenue, Chicago, IL 60611, USA
- Northwestern University Interdepartmental Neuroscience Program, Chicago, IL, USA
| | - Jianhua Yan
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Tarry Building, Room 13-715, 303 East Chicago Avenue, Chicago, IL 60611, USA
| | - Nimrod Miller
- Ann and Robert H. Lurie Children's Hospital of Chicago and Departments of Pediatrics, Neurology and Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Sudarshan Dayanidhi
- Shirley Ryan AbilityLab and Department of Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Yongchao C. Ma
- Ann and Robert H. Lurie Children's Hospital of Chicago and Departments of Pediatrics, Neurology and Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Han-Xiang Deng
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Tarry Building, Room 13-715, 303 East Chicago Avenue, Chicago, IL 60611, USA
| | - Teepu Siddique
- The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Tarry Building, Room 13-715, 303 East Chicago Avenue, Chicago, IL 60611, USA
- Northwestern University Interdepartmental Neuroscience Program, Chicago, IL, USA
- Department of Cell and Developmental Biology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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16
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In Search of a Cure: The Development of Therapeutics to Alter the Progression of Spinal Muscular Atrophy. Brain Sci 2021; 11:brainsci11020194. [PMID: 33562482 PMCID: PMC7915832 DOI: 10.3390/brainsci11020194] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 12/19/2022] Open
Abstract
Until the recent development of disease-modifying therapeutics, spinal muscular atrophy (SMA) was considered a devastating neuromuscular disease with a poor prognosis for most affected individuals. Symptoms generally present during early childhood and manifest as muscle weakness and progressive paralysis, severely compromising the affected individual’s quality of life, independence, and lifespan. SMA is most commonly caused by the inheritance of homozygously deleted SMN1 alleles with retention of one or more copies of a paralog gene, SMN2, which inversely correlates with disease severity. The recent advent and use of genetically targeted therapies have transformed SMA into a prototype for monogenic disease treatment in the era of genetic medicine. Many SMA-affected individuals receiving these therapies achieve traditionally unobtainable motor milestones and survival rates as medicines drastically alter the natural progression of this disease. This review discusses historical SMA progression and underlying disease mechanisms, highlights advances made in therapeutic research, clinical trials, and FDA-approved medicines, and discusses possible second-generation and complementary medicines as well as optimal temporal intervention windows in order to optimize motor function and improve quality of life for all SMA-affected individuals.
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17
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Spinal muscular atrophy: Broad disease spectrum and sex-specific phenotypes. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166063. [PMID: 33412266 DOI: 10.1016/j.bbadis.2020.166063] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/14/2020] [Accepted: 12/21/2020] [Indexed: 12/17/2022]
Abstract
Spinal muscular atrophy (SMA) is one of the major genetic disorders associated with infant mortality. More than 90% of cases of SMA result from deletions of or mutations in the Survival Motor Neuron 1 (SMN1) gene. SMN2, a nearly identical copy of SMN1, does not compensate for the loss of SMN1 due to predominant skipping of exon 7. The spectrum of SMA is broad, ranging from prenatal death to infant mortality to survival into adulthood. All tissues, including brain, spinal cord, bone, skeletal muscle, heart, lung, liver, pancreas, gastrointestinal tract, kidney, spleen, ovary and testis, are directly and/or indirectly affected in SMA. Accumulating evidence on impaired mitochondrial biogenesis and defects in X chromosome-linked modifying factors, coupled with the sexual dimorphic nature of many tissues, point to sex-specific vulnerabilities in SMA. Here we review the role of sex in the pathogenesis of SMA.
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18
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Gollapalli K, Kim JK, Monani UR. Emerging concepts underlying selective neuromuscular dysfunction in infantile-onset spinal muscular atrophy. Neural Regen Res 2021; 16:1978-1984. [PMID: 33642371 PMCID: PMC8343306 DOI: 10.4103/1673-5374.308073] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Infantile-onset spinal muscular atrophy is the quintessential example of a disorder characterized by a predominantly neurodegenerative phenotype that nevertheless stems from perturbations in a housekeeping protein. Resulting from low levels of the Survival of Motor Neuron (SMN) protein, spinal muscular atrophy manifests mainly as a lower motor neuron disease. Why this is so and whether other cell types contribute to the classic spinal muscular atrophy phenotype continue to be the subject of intense investigation and are only now gaining appreciation. Yet, what is emerging is sometimes as puzzling as it is instructive, arguing for a careful re-examination of recent study outcomes, raising questions about established dogma in the field and making the case for a greater focus on milder spinal muscular atrophy models as tools to identify key mechanisms driving selective neuromuscular dysfunction in the disease. This review examines the evidence for novel molecular and cellular mechanisms that have recently been implicated in spinal muscular atrophy, highlights breakthroughs, points out caveats and poses questions that ought to serve as the basis of new investigations to better understand and treat this and other more common neurodegenerative disorders.
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Affiliation(s)
- Kishore Gollapalli
- Department of Neurology; Center for Motor Neuron Biology and Disease, Columbia University Medical Center, New York, NY, USA
| | - Jeong-Ki Kim
- Department of Neurology; Center for Motor Neuron Biology and Disease, Columbia University Medical Center, New York, NY, USA
| | - Umrao R Monani
- Department of Neurology; Department of Pathology & Cell Biology; Center for Motor Neuron Biology and Disease, Columbia University Medical Center, New York, NY, USA
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19
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Singh RN, Ottesen EW, Singh NN. The First Orally Deliverable Small Molecule for the Treatment of Spinal Muscular Atrophy. Neurosci Insights 2020; 15:2633105520973985. [PMID: 33283185 PMCID: PMC7691903 DOI: 10.1177/2633105520973985] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 10/27/2020] [Indexed: 12/12/2022] Open
Abstract
Spinal muscular atrophy (SMA) is 1 of the leading causes of infant mortality. SMA
is mostly caused by low levels of Survival Motor Neuron (SMN) protein due to
deletion of or mutation in the SMN1 gene. Its nearly identical
copy, SMN2, fails to compensate for the loss of
SMN1 due to predominant skipping of exon 7. Correction of
SMN2 exon 7 splicing by an antisense oligonucleotide (ASO),
nusinersen (Spinraza™), that targets the intronic splicing silencer N1 (ISS-N1)
became the first approved therapy for SMA. Restoration of SMN levels using gene
therapy was the next. Very recently, an orally deliverable small molecule,
risdiplam (Evrysdi™), became the third approved therapy for SMA. Here we discuss
how these therapies are positioned to meet the needs of the broad phenotypic
spectrum of SMA patients.
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Affiliation(s)
- Ravindra N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA, USA
| | - Eric W Ottesen
- Department of Biomedical Sciences, Iowa State University, Ames, IA, USA
| | - Natalia N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA, USA
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20
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Bennett CF, Krainer AR, Cleveland DW. Antisense Oligonucleotide Therapies for Neurodegenerative Diseases. Annu Rev Neurosci 2020; 42:385-406. [PMID: 31283897 DOI: 10.1146/annurev-neuro-070918-050501] [Citation(s) in RCA: 181] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Antisense oligonucleotides represent a novel therapeutic platform for the discovery of medicines that have the potential to treat most neurodegenerative diseases. Antisense drugs are currently in development for the treatment of amyotrophic lateral sclerosis, Huntington's disease, and Alzheimer's disease, and multiple research programs are underway for additional neurodegenerative diseases. One antisense drug, nusinersen, has been approved for the treatment of spinal muscular atrophy. Importantly, nusinersen improves disease symptoms when administered to symptomatic patients rather than just slowing the progression of the disease. In addition to the benefit to spinal muscular atrophy patients, there are discoveries from nusinersen that can be applied to other neurological diseases, including method of delivery, doses, tolerability of intrathecally delivered antisense drugs, and the biodistribution of intrathecal dosed antisense drugs. Based in part on the early success of nusinersen, antisense drugs hold great promise as a therapeutic platform for the treatment of neurological diseases.
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Affiliation(s)
| | - Adrian R Krainer
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Don W Cleveland
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, California 92093, USA
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21
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Hernandez-Gerez E, Dall'Angelo S, Collinson JM, Fleming IN, Parson SH. Widespread tissue hypoxia dysregulates cell and metabolic pathways in SMA. Ann Clin Transl Neurol 2020; 7:1580-1593. [PMID: 32790171 PMCID: PMC7480929 DOI: 10.1002/acn3.51134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 07/01/2020] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE The purpose of the study was to determine the extent and role of systemic hypoxia in the pathogenesis of spinal muscular atrophy (SMA). METHODS Hypoxia was assayed in vivo in early-symptomatic (postnatal day 5) SMA-model mice by pimonidazole and [18 F]-Fluoroazomycin arabinoside injections, which accumulate in hypoxic cells, followed by immunohistochemistry and tracer biodistribution evaluation. Glucose uptake in hypoxic cells was assayed by [18 F]-Fluorodeoxyglucose labeling. In vitro knockdown of Survival Motor Neuron (SMN) was performed on motor neurons and lactate metabolism measured biochemically, whereas cell cycle progression and cell death were assayed by flow cytometry. RESULTS All assays found significant levels of hypoxia in multiple organ systems in early symptomatic SMA mouse pups, except aerated tissues such as skin and lungs. This was accompanied by significantly increased glucose uptake in many affected organs, consistent with a metabolic hypoxia response. SMN protein levels were shown to vary widely between motor neuron precursors in vitro, and those with lower levels were most susceptible to cell death. In addition, SMA-model motor neurons were particularly sensitive to hypoxia, with reduced ability to transport lactate out of the cell in hypoxic culture, and a failure in normal cell cycle progression. INTERPRETATION Not only is there widespread tissue hypoxia and multi-organ cellular hypoxic response in SMA model mice, but SMA-model motor neurons are especially susceptible to that hypoxia. The data support the hypothesis that vascular defects leading to hypoxia are a significant contributor to disease progression in SMA, and offer a route for combinatorial, non-SMN related therapy.
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Affiliation(s)
- Elena Hernandez-Gerez
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.,Euan Macdonald Centre for Motor Neurone Disease Research, University of Edinburgh, Chancellor's Building, Edinburgh, EH16 4SB, UK
| | - Sergio Dall'Angelo
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.,John Mallard Scottish PET Centre, University of Aberdeen, Foresterhill, AB25 2ZD, UK
| | - Jon M Collinson
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Ian N Fleming
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Simon H Parson
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.,Euan Macdonald Centre for Motor Neurone Disease Research, University of Edinburgh, Chancellor's Building, Edinburgh, EH16 4SB, UK
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Yeo CJJ, Darras BT. Overturning the Paradigm of Spinal Muscular Atrophy as Just a Motor Neuron Disease. Pediatr Neurol 2020; 109:12-19. [PMID: 32409122 DOI: 10.1016/j.pediatrneurol.2020.01.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/23/2019] [Accepted: 01/05/2020] [Indexed: 12/31/2022]
Abstract
Spinal muscular atrophy is typically characterized as a motor neuron disease. Untreated patients with the most severe form, spinal muscular atrophy type 1, die early with infantile-onset progressive skeletal, bulbar, and respiratory muscle weakness. Such patients are now living longer due to new disease-modifying treatments such as gene replacement therapy (onasemnogene abeparvovec), recently approved by the US Food and Drug Administration, and nusinersen, a central nervous system-directed treatment which was approved by the US Food and Drug Administration three years ago. This has created an area of pressing clinical need: if spinal muscular atrophy is a multisystem disease, dysfunction of peripheral tissues and organs may become significant comorbidities as these patients survive into childhood and adulthood. In this review, we have compiled autopsy data, case reports, and cohort studies of peripheral tissue involvement in patients and animal models with spinal muscular atrophy. We have also evaluated preclinical studies addressing the question of whether peripheral expression of survival motor neuron is necessary and/or sufficient for motor neuron function and survival. Indeed, spinal muscular atrophy patient data suggest that spinal muscular atrophy is a multisystem disease with dysfunction in skeletal muscle, heart, kidney, liver, pancreas, spleen, bone, connective tissues, and immune systems. The peripheral requirement of SMN in each organ and how these contribute to motor neuron function and survival remains to be answered. A systemic (peripheral and central nervous system) approach to therapy during early development is most likely to effectively maximize positive clinical outcome.
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Affiliation(s)
- Crystal Jing Jing Yeo
- Department of Neurology, Neuromuscular Center and SMA Program, Boston Children's Hospital, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts; Division of Neuromuscular Medicine, Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts; Division of Neuromuscular Medicine, Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts; Translational Neuromuscular Medicine Laboratory, Institute of Molecular and Cell Biology, Singapore; Experimental Drug Development Center, Singapore.
| | - Basil T Darras
- Department of Neurology, Neuromuscular Center and SMA Program, Boston Children's Hospital, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts.
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23
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Singh NN, Ottesen EW, Singh RN. A survey of transcripts generated by spinal muscular atrophy genes. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2020; 1863:194562. [PMID: 32387331 PMCID: PMC7302838 DOI: 10.1016/j.bbagrm.2020.194562] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/01/2020] [Accepted: 04/13/2020] [Indexed: 02/07/2023]
Abstract
Human Survival Motor Neuron (SMN) genes code for SMN, an essential multifunctional protein. Complete loss of SMN is embryonic lethal, while low levels of SMN lead to spinal muscular atrophy (SMA), a major genetic disease of children and infants. Reduced levels of SMN are associated with the abnormal development of heart, lung, muscle, gastro-intestinal system and testis. The SMN loci have been shown to generate a vast repertoire of transcripts, including linear, back- and trans-spliced RNAs as well as antisense long noncoding RNAs. However, functions of the majority of these transcripts remain unknown. Here we review the nature of RNAs generated from the SMN loci and discuss their potential functions in cellular metabolism.
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Affiliation(s)
- Natalia N Singh
- Department of Biomedical Science, Iowa State University, Ames, IA, 50011, United States of America
| | - Eric W Ottesen
- Department of Biomedical Science, Iowa State University, Ames, IA, 50011, United States of America
| | - Ravindra N Singh
- Department of Biomedical Science, Iowa State University, Ames, IA, 50011, United States of America.
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24
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Berciano MT, Castillo-Iglesias MS, Val-Bernal JF, Lafarga V, Rodriguez-Rey JC, Lafarga M, Tapia O. Mislocalization of SMN from the I-band and M-band in human skeletal myofibers in spinal muscular atrophy associates with primary structural alterations of the sarcomere. Cell Tissue Res 2020; 381:461-478. [PMID: 32676861 DOI: 10.1007/s00441-020-03236-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 06/05/2020] [Indexed: 12/22/2022]
Abstract
Spinal muscular atrophy (SMA) is caused by a deletion or mutation of the survival motor neuron 1 (SMN1) gene. Reduced SMN levels lead to motor neuron degeneration and muscular atrophy. SMN protein localizes to the cytoplasm and Cajal bodies. Moreover, in myofibrils from Drosophila and mice, SMN is a sarcomeric protein localized to the Z-disc. Although SMN participates in multiple functions, including the biogenesis of spliceosomal small nuclear ribonucleoproteins, its role in the sarcomere is unclear. Here, we analyzed the sarcomeric organization of SMN in human control and type I SMA skeletal myofibers. In control sarcomeres, we demonstrate that human SMN is localized to the titin-positive M-band and actin-positive I-band, and to SMN-positive granules that flanked the Z-discs. Co-immunoprecipitation assays revealed that SMN interacts with the sarcomeric protein actin, α-actinin, titin, and profilin2. In the type I SMA muscle, SMN levels were reduced, and atrophic (denervated) and hypertrophic (nondenervated) myofibers coexisted. The hypertrophied myofibers, which are potential primary targets of SMN deficiency, exhibited sites of focal or segmental alterations of the actin cytoskeleton, where the SMN immunostaining pattern was altered. Moreover, SMN was relocalized to the Z-disc in overcontracted minisarcomeres from hypertrophic myofibers. We propose that SMN could have an integrating role in the molecular components of the sarcomere. Consequently, low SMN levels might impact the normal sarcomeric architecture, resulting in the disruption of myofibrils found in SMA muscle. This primary effect might be independent of the neurogenic myopathy produced by denervation and contribute to pathophysiology of the SMA myopathy.
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Affiliation(s)
- María T Berciano
- Departamento de Biología Molecular, Universidad de Cantabria-IDIVAL, Santander, Spain
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL) and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Santander, Spain
| | | | - J Fernando Val-Bernal
- Unidad de Patología, Departamento de Ciencias Médicas y Quirúrgicas, Universidad de Cantabria-IDIVAL, Santander, Spain
| | - Vanesa Lafarga
- Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain
| | - José C Rodriguez-Rey
- Departamento de Biología Molecular, Universidad de Cantabria-IDIVAL, Santander, Spain
| | - Miguel Lafarga
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL) and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Santander, Spain.
- Departamento de Anatomía y Biología Celular, Universidad de Cantabria-IDIVAL, Santander, Spain.
| | - Olga Tapia
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL) and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Santander, Spain.
- Universidad Europea del Atlántico, Santander, Spain.
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25
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Zhong X, Song Z, Song X. Survival motor neuron protein protects H9c2 cardiomyocytes from hypoxia-induced cell injury by reducing apoptosis. Clin Exp Pharmacol Physiol 2020; 47:1808-1815. [PMID: 32603518 DOI: 10.1111/1440-1681.13369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 06/10/2020] [Accepted: 06/19/2020] [Indexed: 12/01/2022]
Abstract
BACKGROUND Hypoxia induces cell injury in cardiomyocytes and leads to the development of cardiovascular diseases. The survival motor neuron protein (SMN) is a crucial ubiquitous protein whose functional deficiency causes motor neuron loss seen in spinal muscular atrophy. SMN has shown protective effects on the cardiovascular system and the aim of the present study was to investigate the cardioprotective effects of SMN on hypoxia-induced cell injury. METHODS Cobalt chloride (CoCl2 ) was used to induce chemical hypoxia in H9c2 cardiomyocytes. Cell proliferation was determined by the MTT assay and the mRNA levels of SMN were evaluated by real-time polymerase chain reaction. The protein expression levels of SMN, hypoxia-inducible transcription factor 1α (HIF-1α), and apoptosis-related proteins, such as cytochrome c (Cyt c), B cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), and cleaved caspase-3 were evaluated by western blot analysis. Cell apoptosis was analysed using annexin V/propidium iodide (PI) staining. RESULTS Treatment with CoCl2 significantly reduced H9c2 cell viability; the level of HIF-1α, which is a hypoxia-related indicator increased whereas the expression of SMN protein decreased. Hypoxia also induced cardiomyocyte apoptosis, indicated by reduced Bcl-2 expression and elevated cleaved caspase-3, Bax, and cytochrome c levels. Interestingly, SMN, which is a neuron protection factor, ameliorated CoCl2 -induced cell damage by reducing cardiomyocyte apoptosis through upregulation of Bcl-2 and inhibition of cytochrome c, cleaved caspase-3, and Bax expression. CONCLUSION Survival motor neuron prevents hypoxia-induced cell apoptosis through inhibition of the mitochondrial apoptotic pathway, and thereby exerts a protective effect on H9c2 cardiomyocytes.
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Affiliation(s)
- Xiao Zhong
- Department of Cardiovascular Center, The Fourth Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Ziguang Song
- Department of Cardiovascular Center, The Fourth Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Xiang Song
- Department of Cardiovascular Center, The Fourth Affiliated Hospital, Harbin Medical University, Harbin, China
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26
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Besse A, Astord S, Marais T, Roda M, Giroux B, Lejeune FX, Relaix F, Smeriglio P, Barkats M, Biferi MG. AAV9-Mediated Expression of SMN Restricted to Neurons Does Not Rescue the Spinal Muscular Atrophy Phenotype in Mice. Mol Ther 2020; 28:1887-1901. [PMID: 32470325 PMCID: PMC7403319 DOI: 10.1016/j.ymthe.2020.05.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 03/30/2020] [Accepted: 05/12/2020] [Indexed: 01/13/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular disease mainly caused by mutations or deletions in the survival of motor neuron 1 (SMN1) gene and characterized by the degeneration of motor neurons and progressive muscle weakness. A viable therapeutic approach for SMA patients is a gene replacement strategy that restores functional SMN expression using adeno-associated virus serotype 9 (AAV9) vectors. Currently, systemic or intra-cerebrospinal fluid (CSF) delivery of AAV9-SMN is being explored in clinical trials. In this study, we show that the postnatal delivery of an AAV9 that expresses SMN under the control of the neuron-specific promoter synapsin selectively targets neurons without inducing re-expression in the peripheral organs of SMA mice. However, this approach is less efficient in restoring the survival and neuromuscular functions of SMA mice than the systemic or intra-CSF delivery of an AAV9 in which SMN is placed under the control of a ubiquitous promoter. This study suggests that further efforts are needed to understand the extent to which SMN is required in neurons and peripheral organs for a successful therapeutic effect.
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Affiliation(s)
- Aurore Besse
- Sorbonne Université, INSERM, Institute of Myology, Centre of Research in Myology, 75013 Paris, France
| | - Stephanie Astord
- Sorbonne Université, INSERM, Institute of Myology, Centre of Research in Myology, 75013 Paris, France
| | - Thibaut Marais
- Sorbonne Université, INSERM, Institute of Myology, Centre of Research in Myology, 75013 Paris, France
| | - Marianne Roda
- Sorbonne Université, INSERM, Institute of Myology, Centre of Research in Myology, 75013 Paris, France
| | - Benoit Giroux
- Sorbonne Université, INSERM, Institute of Myology, Centre of Research in Myology, 75013 Paris, France
| | - François-Xavier Lejeune
- Institut du Cerveau et de la Moelle épinière (ICM), Bioinformatics and Biostatistics Core Facility (iCONICS), Sorbonne Université, INSERM U1127, CNRS UMR 7225, GH Pitié-Salpêtrière, 75013 Paris, France
| | - Frederic Relaix
- Université Paris Est Créteil, INSERM, EnvA, AP-HP, 94000 Créteil, France
| | - Piera Smeriglio
- Sorbonne Université, INSERM, Institute of Myology, Centre of Research in Myology, 75013 Paris, France
| | - Martine Barkats
- Sorbonne Université, INSERM, Institute of Myology, Centre of Research in Myology, 75013 Paris, France
| | - Maria Grazia Biferi
- Sorbonne Université, INSERM, Institute of Myology, Centre of Research in Myology, 75013 Paris, France.
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27
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SMN-deficiency disrupts SERCA2 expression and intracellular Ca 2+ signaling in cardiomyocytes from SMA mice and patient-derived iPSCs. Skelet Muscle 2020; 10:16. [PMID: 32384912 PMCID: PMC7206821 DOI: 10.1186/s13395-020-00232-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 04/22/2020] [Indexed: 11/17/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by loss of alpha motor neurons and skeletal muscle atrophy. The disease is caused by mutations of the SMN1 gene that result in reduced functional expression of survival motor neuron (SMN) protein. SMN is ubiquitously expressed, and there have been reports of cardiovascular dysfunction in the most severe SMA patients and animal models of the disease. In this study, we directly assessed the function of cardiomyocytes isolated from a severe SMA model mouse and cardiomyocytes generated from patient-derived IPSCs. Consistent with impaired cardiovascular function at the very early disease stages in mice, heart failure markers such as brain natriuretic peptide were significantly elevated. Functionally, cardiomyocyte relaxation kinetics were markedly slowed and the T50 for Ca2+ sequestration increased to 146 ± 4 ms in SMN-deficient cardiomyocytes from 126 ± 4 ms in wild type cells. Reducing SMN levels in cardiomyocytes from control patient IPSCs slowed calcium reuptake similar to SMA patent-derived cardiac cells. Importantly, restoring SMN increased calcium reuptake rate. Taken together, these results indicate that SMN deficiency impairs cardiomyocyte function at least partially through intracellular Ca2+ cycling dysregulation.
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28
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Deguise MO, De Repentigny Y, Tierney A, Beauvais A, Michaud J, Chehade L, Thabet M, Paul B, Reilly A, Gagnon S, Renaud JM, Kothary R. Motor transmission defects with sex differences in a new mouse model of mild spinal muscular atrophy. EBioMedicine 2020; 55:102750. [PMID: 32339936 PMCID: PMC7184161 DOI: 10.1016/j.ebiom.2020.102750] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 02/25/2020] [Accepted: 03/19/2020] [Indexed: 12/31/2022] Open
Abstract
Background Mouse models of mild spinal muscular atrophy (SMA) have been extremely challenging to generate. This paucity of model systems has limited our understanding of pathophysiological events in milder forms of the disease and of the effect of SMN depletion during aging. Methods A mild mouse model of SMA, termed Smn2B/−;SMN2+/−, was generated by crossing Smn−/−;SMN2 and Smn2B/2B mice. This new model was characterized using behavioral testing, histology, western blot, muscle-nerve electrophysiology as well as ultrasonography to study classical SMA features and extra-neuronal involvement. Findings Smn2B/−;SMN2+/− mice have normal survival, mild but sustained motor weakness, denervation and neuronal/neuromuscular junction (NMJ) transmission defects, and neurogenic muscle atrophy that are more prominent in male mice. Increased centrally located nuclei, intrinsic contractile and relaxation muscle defects were also identified in both female and male mice, with some male predominance. There was an absence of extra-neuronal pathology. Interpretation The Smn2B/−;SMN2+/− mouse provides a model of mild SMA, displaying some hallmark features including reduced weight, sustained motor weakness, electrophysiological transmission deficit, NMJ defects, and muscle atrophy. Early and prominent increase central nucleation and intrinsic electrophysiological deficits demonstrate the potential role played by muscle in SMA disease. The use of this model will allow for the understanding of the most susceptible pathogenic molecular changes in motor neurons and muscles, investigation of the effects of SMN depletion in aging, sex differences and most importantly will provide guidance for the currently aging SMA patients treated with the recently approved genetic therapies. Funding : This work was supported by Cure SMA/Families of SMA Canada (grant numbers KOT-1819 and KOT-2021); Muscular Dystrophy Association (USA) (grant number 575466); and Canadian Institutes of Health Research (CIHR) (grant number PJT-156379).
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Affiliation(s)
- Marc-Olivier Deguise
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Centre for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Yves De Repentigny
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada
| | - Alexandra Tierney
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada
| | - Ariane Beauvais
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada
| | - Jean Michaud
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Lucia Chehade
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Centre for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Mohamed Thabet
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Brittany Paul
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada; Centre for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Aoife Reilly
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Centre for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Sabrina Gagnon
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada
| | - Jean-Marc Renaud
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Centre for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Rashmi Kothary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Centre for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada.
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29
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Glial cells involvement in spinal muscular atrophy: Could SMA be a neuroinflammatory disease? Neurobiol Dis 2020; 140:104870. [PMID: 32294521 DOI: 10.1016/j.nbd.2020.104870] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/16/2020] [Accepted: 04/10/2020] [Indexed: 01/11/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a severe, inherited disease characterized by the progressive degeneration and death of motor neurons of the anterior horns of the spinal cord, which results in muscular atrophy and weakness of variable severity. Its early-onset form is invariably fatal in early childhood, while milder forms lead to permanent disability, physical deformities and respiratory complications. Recently, two novel revolutionary therapies, antisense oligonucleotides and gene therapy, have been approved, and might prove successful in making long-term survival of these patients likely. In this perspective, a deep understanding of the pathogenic mechanisms and of their impact on the interactions between motor neurons and other cell types within the central nervous system (CNS) is crucial. Studies using SMA animal and cellular models have taught us that the survival and functionality of motor neurons is highly dependent on a whole range of other cell types, namely glial cells, which are responsible for a variety of different functions, such as neuronal trophic support, synaptic remodeling, and immune surveillance. Thus, it emerges that SMA is likely a non-cell autonomous, multifactorial disease in which the interaction of different cell types and disease mechanisms leads to motor neurons failure and loss. This review will introduce the different glial cell types in the CNS and provide an overview of the role of glial cells in motor neuron degeneration in SMA. Furthermore, we will discuss the relevance of these findings so far and the potential impact on the success of available therapies and on the development of novel ones.
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30
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Šoltić D, Shorrock HK, Allardyce H, Wilson EL, Holt I, Synowsky SA, Shirran SL, Parson SH, Gillingwater TH, Fuller HR. Lamin A/C dysregulation contributes to cardiac pathology in a mouse model of severe spinal muscular atrophy. Hum Mol Genet 2019; 28:3515-3527. [PMID: 31397869 PMCID: PMC6927462 DOI: 10.1093/hmg/ddz195] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 07/25/2019] [Accepted: 07/25/2019] [Indexed: 12/21/2022] Open
Abstract
Cardiac pathology is emerging as a prominent systemic feature of spinal muscular atrophy (SMA), but little is known about the underlying molecular pathways. Using quantitative proteomics analysis, we demonstrate widespread molecular defects in heart tissue from the Taiwanese mouse model of severe SMA. We identify increased levels of lamin A/C as a robust molecular phenotype in the heart of SMA mice and show that lamin A/C dysregulation is also apparent in SMA patient fibroblast cells and other tissues from SMA mice. Lamin A/C expression was regulated in vitro by knockdown of the E1 ubiquitination factor ubiquitin-like modifier activating enzyme 1, a key downstream mediator of SMN-dependent disease pathways, converging on β-catenin signaling. Increased levels of lamin A are known to increase the rigidity of nuclei, inevitably disrupting contractile activity in cardiomyocytes. The increased lamin A/C levels in the hearts of SMA mice therefore provide a likely mechanism explaining morphological and functional cardiac defects, leading to blood pooling. Therapeutic strategies directed at lamin A/C may therefore offer a new approach to target cardiac pathology in SMA.
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Affiliation(s)
- Darija Šoltić
- Institute for Science and Technology in Medicine, Keele University, Keele ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
| | - Hannah K Shorrock
- Edinburgh Medical School: Biomedical Sciences
- Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Hazel Allardyce
- Institute of Education for Medical and Dental Science, College of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen AB24 3FX, UK
| | - Emma L Wilson
- Chester Medical School, University of Chester, Chester CH1 4BJ, UK
| | - Ian Holt
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
| | - Silvia A Synowsky
- BSRC Mass Spectrometry and Proteomics Facility, University of St Andrews, St Andrews KY16 9ST, UK
| | - Sally L Shirran
- BSRC Mass Spectrometry and Proteomics Facility, University of St Andrews, St Andrews KY16 9ST, UK
| | - Simon H Parson
- Institute of Education for Medical and Dental Science, College of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen AB24 3FX, UK
| | - Thomas H Gillingwater
- Edinburgh Medical School: Biomedical Sciences
- Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Heidi R Fuller
- Institute for Science and Technology in Medicine, Keele University, Keele ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
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31
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Houdebine L, D'Amico D, Bastin J, Chali F, Desseille C, Rumeau V, Soukkari J, Oudot C, Rouquet T, Bariohay B, Roux J, Sapaly D, Weill L, Lopes P, Djouadi F, Bezier C, Charbonnier F, Biondi O. Low-Intensity Running and High-Intensity Swimming Exercises Differentially Improve Energy Metabolism in Mice With Mild Spinal Muscular Atrophy. Front Physiol 2019; 10:1258. [PMID: 31632295 PMCID: PMC6781613 DOI: 10.3389/fphys.2019.01258] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Accepted: 09/17/2019] [Indexed: 12/13/2022] Open
Abstract
Spinal Muscular Atrophy (SMA), an autosomal recessive neurodegenerative disease characterized by the loss of spinal-cord motor-neurons, is caused by mutations on Survival-of-Motor Neuron (SMN)-1 gene. The expression of SMN2, a SMN1 gene copy, partially compensates for SMN1 disruption due to exon-7 excision in 90% of transcripts subsequently explaining the strong clinical heterogeneity. Several alterations in energy metabolism, like glucose intolerance and hyperlipidemia, have been reported in SMA at both systemic and cellular level, prompting questions about the potential role of energy homeostasis and/or production involvement in disease progression. In this context, we have recently reported the tolerance of mild SMA-like mice (SmnΔ7/Δ7; huSMN2+/+) to 10 months of low-intensity running or high-intensity swimming exercise programs, respectively involving aerobic and a mix aerobic/anaerobic muscular metabolic pathways. Here, we investigated whether those exercise-induced benefits were associated with an improvement in metabolic status in mild SMA-like mice. We showed that untrained SMA-like mice exhibited a dysregulation of lipid metabolism with an enhancement of lipogenesis and adipocyte deposits when compared to control mice. Moreover, they displayed a high oxygen consumption and energy expenditure through β-oxidation increase yet for the same levels of spontaneous activity. Interestingly, both exercises significantly improved lipid metabolism and glucose homeostasis in SMA-like mice, and enhanced oxygen consumption efficiency with the maintenance of a high oxygen consumption for higher levels of spontaneous activity. Surprisingly, more significant effects were obtained with the high-intensity swimming protocol with the maintenance of high lipid oxidation. Finally, when combining electron microscopy, respiratory chain complexes expression and enzymatic activity measurements in muscle mitochondria, we found that (1) a muscle-specific decreased in enzymatic activity of respiratory chain I, II, and IV complexes for equal amount of mitochondria and complexes expression and (2) a significant decline in mitochondrial maximal oxygen consumption, were reduced by both exercise programs. Most of the beneficial effects were obtained with the high-intensity swimming protocol. Taking together, our data support the hypothesis that active physical exercise, including high-intensity protocols, induces metabolic adaptations at both systemic and cellular levels, providing further evidence for its use in association with SMN-overexpressing therapies, in the long-term care of SMA patients.
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Affiliation(s)
- Léo Houdebine
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
| | - Domenico D'Amico
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
| | - Jean Bastin
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
| | - Farah Chali
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
| | - Céline Desseille
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
| | - Valentin Rumeau
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
| | - Judy Soukkari
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
| | - Carole Oudot
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
| | - Thaïs Rouquet
- Biomeostasis CRO, Nutritional Behavior and Metabolic Disorders, La Penne-sur-Huveaune, France
| | - Bruno Bariohay
- Biomeostasis CRO, Nutritional Behavior and Metabolic Disorders, La Penne-sur-Huveaune, France
| | - Julien Roux
- Biomeostasis CRO, Nutritional Behavior and Metabolic Disorders, La Penne-sur-Huveaune, France
| | - Delphine Sapaly
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
| | - Laure Weill
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
| | - Philippe Lopes
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France.,UFR STAPS, Université d'Evry Val-d'Essonne, Evry, France
| | - Fatima Djouadi
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
| | - Cynthia Bezier
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France.,Biophytis, Sorbonne Université, Paris, France
| | - Frédéric Charbonnier
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
| | - Olivier Biondi
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, Paris, France
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Quinlan KA, Reedich EJ, Arnold WD, Puritz AC, Cavarsan CF, Heckman CJ, DiDonato CJ. Hyperexcitability precedes motoneuron loss in the Smn2B/- mouse model of spinal muscular atrophy. J Neurophysiol 2019; 122:1297-1311. [PMID: 31365319 DOI: 10.1152/jn.00652.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Spinal motoneuron dysfunction and loss are pathological hallmarks of the neuromuscular disease spinal muscular atrophy (SMA). Changes in motoneuron physiological function precede cell death, but how these alterations vary with disease severity and motoneuron maturational state is unknown. To address this question, we assessed the electrophysiology and morphology of spinal motoneurons of presymptomatic Smn2B/- mice older than 1 wk of age and tracked the timing of motor unit loss in this model using motor unit number estimation (MUNE). In contrast to other commonly used SMA mouse models, Smn2B/- mice exhibit more typical postnatal development until postnatal day (P)11 or 12 and have longer survival (~3 wk of age). We demonstrate that Smn2B/- motoneuron hyperexcitability, marked by hyperpolarization of the threshold voltage for action potential firing, was present at P9-10 and preceded the loss of motor units. Using MUNE studies, we determined that motor unit loss in this mouse model occurred 2 wk after birth. Smn2B/- motoneurons were also larger in size, which may reflect compensatory changes taking place during postnatal development. This work suggests that motoneuron hyperexcitability, marked by a reduced threshold for action potential firing, is a pathological change preceding motoneuron loss that is common to multiple models of severe SMA with different motoneuron maturational states. Our results indicate voltage-gated sodium channel activity may be altered in the disease process.NEW & NOTEWORTHY Changes in spinal motoneuron physiologic function precede cell death in spinal muscular atrophy (SMA), but how they vary with maturational state and disease severity remains unknown. This study characterized motoneuron and neuromuscular electrophysiology from the Smn2B/- model of SMA. Motoneurons were hyperexcitable at postnatal day (P)9-10, and specific electrophysiological changes in Smn2B/- motoneurons preceded functional motor unit loss at P14, as determined by motor unit number estimation studies.
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Affiliation(s)
- K A Quinlan
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, Rhode Island.,George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, Rhode Island.,Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - E J Reedich
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Human Molecular Genetics Program, Stanley Manne Children's Research Institute at Ann & Robert H. Lurie Children's Hospital, Chicago, Illinois
| | - W D Arnold
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, Ohio.,Department of Physical Medicine and Rehabilitation, The Ohio State University Wexner Medical Center, Columbus, Ohio.,Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio.,Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - A C Puritz
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - C F Cavarsan
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, Rhode Island.,George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, Rhode Island
| | - C J Heckman
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - C J DiDonato
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Human Molecular Genetics Program, Stanley Manne Children's Research Institute at Ann & Robert H. Lurie Children's Hospital, Chicago, Illinois
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Qian X, Du Y, Jiang G, Lin F, Yao L. Survival Motor Neuron (SMN) Protein Insufficiency Exacerbates Renal Ischemia/Reperfusion Injury. Front Physiol 2019; 10:559. [PMID: 31139093 PMCID: PMC6527877 DOI: 10.3389/fphys.2019.00559] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 04/24/2019] [Indexed: 12/14/2022] Open
Abstract
The survival of motor neuron (SMN) protein is ubiquitously involved in spliceosome assembly and ribonucleoprotein biogenesis. SMN protein is expressed in kidney and can affect cell death processes. However, the role of SMN in acute kidney injury (AKI) is largely unknown. In the current study, we found that the expression of SMN in the kidney was significantly reduced in both clinical ischemic AKI and a mouse model of renal ischemia-reperfusion injury (IRI). We then used SMN heterozygous knockout (SMN+/-) mice and found that the declines in renal function, tubular injury, and tubular cell apoptosis after experimental IRI were significantly more severe in SMN+/- mice than those in their wild-type littermates. Concomitantly, the canonical transcription factor nuclear factor-κb (NFκb) signaling was enhanced in ischemic SMN+/- mice. In vitro, cobalt dichloride (CoCl2) treatment reduced SMN expression in proximal tubular epithelial cells. In addition, CoCl2-induced apoptosis and activation of NFκb signaling pathway were enhanced by transient transfection of a small-interfering RNA (siRNA) against SMN while attenuated by transient transfection of a full-length SMN plasmid. Taken together, this study for the first time supported the protective role of SMN in ischemic AKI.
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Affiliation(s)
- Xiaoqian Qian
- Renal Division, Department of Internal Medicine, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Centre for Rare Disease, Shanghai, China
| | - Yichao Du
- Sichuan Provincial Academician (Expert) Workstation, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Gengru Jiang
- Renal Division, Department of Internal Medicine, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Centre for Rare Disease, Shanghai, China
| | - Fujun Lin
- Renal Division, Department of Internal Medicine, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Centre for Rare Disease, Shanghai, China
| | - Lei Yao
- Sichuan Provincial Academician (Expert) Workstation, The Affiliated Hospital of Southwest Medical University, Luzhou, China
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Lipnick SL, Agniel DM, Aggarwal R, Makhortova NR, Finlayson SG, Brocato A, Palmer N, Darras BT, Kohane I, Rubin LL. Systemic nature of spinal muscular atrophy revealed by studying insurance claims. PLoS One 2019; 14:e0213680. [PMID: 30870495 PMCID: PMC6417721 DOI: 10.1371/journal.pone.0213680] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/26/2019] [Indexed: 12/27/2022] Open
Abstract
Objective We investigated the presence of non-neuromuscular phenotypes in patients affected by Spinal Muscular Atrophy (SMA), a disorder caused by a mutation in the Survival of Motor Neuron (SMN) gene, and whether these phenotypes may be clinically detectable prior to clinical signs of neuromuscular degeneration and therefore independent of muscle weakness. Methods We utilized a de-identified database of insurance claims to explore the health of 1,038 SMA patients compared to controls. Two analyses were performed: (1) claims from the entire insurance coverage window; and (2) for SMA patients, claims prior to diagnosis of any neuromuscular disease or evidence of major neuromuscular degeneration to increase the chance that phenotypes could be attributed directly to reduced SMN levels. Logistic regression was used to determine whether phenotypes were diagnosed at significantly different rates between SMA patients and controls and to obtain covariate-adjusted odds ratios. Results Results from the entire coverage window revealed a broad spectrum of phenotypes that are differentially diagnosed in SMA subjects compared to controls. Moreover, data from SMA patients prior to their first clinical signs of neuromuscular degeneration revealed numerous non-neuromuscular phenotypes including defects within the cardiovascular, gastrointestinal, metabolic, reproductive, and skeletal systems. Furthermore, our data provide evidence of a potential ordering of disease progression beginning with these non-neuromuscular phenotypes. Conclusions Our data point to a direct relationship between early, detectable non-neuromuscular symptoms and SMN deficiency. Our findings are particularly important for evaluating the efficacy of SMN-increasing therapies for SMA, comparing the effectiveness of local versus systemically delivered therapeutics, and determining the optimal therapeutic treatment window prior to irreversible neuromuscular damage.
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Affiliation(s)
- Scott L. Lipnick
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, United States of America
- Center for Assessment Technology & Continuous Health (CATCH), Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Denis M. Agniel
- Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Rahul Aggarwal
- Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, United States of America
- Center for Assessment Technology & Continuous Health (CATCH), Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Nina R. Makhortova
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Samuel G. Finlayson
- Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Alexandra Brocato
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Nathan Palmer
- Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Basil T. Darras
- Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Isaac Kohane
- Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lee L. Rubin
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Harvard Stem Cell Institute, Cambridge, Massachusetts, United States of America
- * E-mail:
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Sheng L, Wan B, Feng P, Sun J, Rigo F, Bennett CF, Akerman M, Krainer AR, Hua Y. Downregulation of Survivin contributes to cell-cycle arrest during postnatal cardiac development in a severe spinal muscular atrophy mouse model. Hum Mol Genet 2019; 27:486-498. [PMID: 29220503 DOI: 10.1093/hmg/ddx418] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 11/28/2017] [Indexed: 11/13/2022] Open
Abstract
Spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality, characterized by progressive degeneration of spinal-cord motor neurons, leading to atrophy of skeletal muscles. However, accumulating evidence indicates that it is a multi-system disorder, particularly in its severe forms. Several studies delineated structural and functional cardiac abnormalities in SMA patients and mouse models, yet the abnormalities have been primarily attributed to autonomic dysfunction. Here, we show in a severe mouse model that its cardiomyocytes undergo G0/G1 cell-cycle arrest and enhanced apoptosis during postnatal development. Microarray and real-time RT-PCR analyses revealed that a set of genes associated with cell cycle and apoptosis were dysregulated in newborn pups. Of particular interest, the Birc5 gene, which encodes Survivin, an essential protein for heart development, was down-regulated even on pre-symptomatic postnatal day 0. Interestingly, cultured cardiomyocytes depleted of SMN recapitulated the gene expression changes including downregulation of Survivin and abnormal cell-cycle progression; and overexpression of Survivin rescued the cell-cycle defect. Finally, increasing SMN in SMA mice with a therapeutic antisense oligonucleotide improved heart pathology and recovered expression of deregulated genes. Collectively, our data demonstrate that the cardiac malfunction of the severe SMA mouse model is mainly a cell-autonomous defect, caused by widespread gene deregulation in heart tissue, particularly of Birc5, resulting in developmental abnormalities through cell-cycle arrest and apoptosis.
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Affiliation(s)
- Lei Sheng
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, China.,Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215123, China
| | - Bo Wan
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, China.,Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215123, China
| | - Pengchao Feng
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, China.,Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215123, China
| | - Junjie Sun
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, China.,Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215123, China
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA 92010, USA
| | | | - Martin Akerman
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY 11724, USA.,Envisagenics, Inc., New York, NY 10017, USA
| | - Adrian R Krainer
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY 11724, USA
| | - Yimin Hua
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, China.,Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215123, China
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Using Systems Biology and Mathematical Modeling Approaches in the Discovery of Therapeutic Targets for Spinal Muscular Atrophy. ADVANCES IN NEUROBIOLOGY 2018. [PMID: 30334226 DOI: 10.1007/978-3-319-94593-4_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Systems biology uses a combination of experimental and mathematical approaches to investigate the complex and dynamic interactions with a given system or biological process. Systems biology integrates genetics, signal transduction, biochemistry and cell biology with mathematical modeling. It can be used to identify novel pathways implicated in diseases as well as to understand the mechanisms by which a specific gene is regulated. This review describes the development of mathematical models for the regulation of an endogenous modifier gene, SMN2, in spinal muscular atrophy-an early-onset motor neuron disease that is a leading genetic cause of infant mortality worldwide-by cAMP signaling. These mathematical models not only can aid in understanding how SMN2 expression is regulated but they can also be used to examine the best ways to manipulate cAMP signaling to maximally increase SMN2 expression. These models will lead to the development of therapeutic strategies for treating SMA. This systems biology approach can also be applied to other neurological diseases, particularly those in which a disease-causing gene or a modifier gene has been identified.
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Schellino R, Boido M, Borsello T, Vercelli A. Pharmacological c-Jun NH 2-Terminal Kinase (JNK) Pathway Inhibition Reduces Severity of Spinal Muscular Atrophy Disease in Mice. Front Mol Neurosci 2018; 11:308. [PMID: 30233310 PMCID: PMC6131195 DOI: 10.3389/fnmol.2018.00308] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/14/2018] [Indexed: 12/20/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a severe neurodegenerative disorder that occurs in early childhood. The disease is caused by the deletion/mutation of the survival motor neuron 1 (SMN1) gene resulting in progressive skeletal muscle atrophy and paralysis, due to the degeneration of spinal motor neurons (MNs). Currently, the cellular and molecular mechanisms underlying MN death are only partly known, although recently it has been shown that the c-Jun NH2-terminal kinase (JNK)-signaling pathway might be involved in the SMA pathogenesis. After confirming the activation of JNK in our SMA mouse model (SMN2+/+; SMNΔ7+/+; Smn−/−), we tested a specific JNK-inhibitor peptide (D-JNKI1) on these mice, by chronic administration from postnatal day 1 to 10, and histologically analyzed the spinal cord and quadriceps muscle at age P12. We observed that D-JNKI1 administration delayed MN death and decreased inflammation in spinal cord. Moreover, the inhibition of JNK pathway improved the trophism of SMA muscular fibers and the size of the neuromuscular junctions (NMJs), leading to an ameliorated innervation of the muscles that resulted in improved motor performances and hind-limb muscular tone. Finally, D-JNKI1 treatment slightly, but significantly increased lifespan in SMA mice. Thus, our results identify JNK as a promising target to reduce MN cell death and progressive skeletal muscle atrophy, providing insight into the role of JNK-pathway for developing alternative pharmacological strategies for the treatment of SMA.
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Affiliation(s)
- Roberta Schellino
- Department of Neuroscience Rita Levi Montalcini, Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Turin, Italy
| | - Marina Boido
- Department of Neuroscience Rita Levi Montalcini, Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Turin, Italy.,National Institute of Neuroscience (INN), Turin, Italy
| | - Tiziana Borsello
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy.,Department of Neuroscience, IRCCS-Mario Negri Institute for Pharmacological Research, Milan, Italy
| | - Alessandro Vercelli
- Department of Neuroscience Rita Levi Montalcini, Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Turin, Italy.,National Institute of Neuroscience (INN), Turin, Italy
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Shababi M, Villalón E, Kaifer KA, DeMarco V, Lorson CL. A Direct Comparison of IV and ICV Delivery Methods for Gene Replacement Therapy in a Mouse Model of SMARD1. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2018; 10:348-360. [PMID: 30202772 PMCID: PMC6127875 DOI: 10.1016/j.omtm.2018.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 08/13/2018] [Indexed: 01/22/2023]
Abstract
Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is an infantile autosomal recessive disease caused by the loss of the ubiquitously expressed IGHMBP2 gene. SMARD1 causes degeneration of alpha-motor neurons, resulting in distal muscle weakness, diaphragm paralysis, and respiratory malfunction. We have reported that delivery of a low dose of AAV9-IGHMBP2 to the CNS results in a significant rescue of the SMARD1 mouse model (nmd). To examine how a delivery route can impact efficacy, a direct comparison of intravenous (IV) and intracerebroventricular (ICV) delivery of AAV9-IGHMBP2 was performed. Using a low-dose, both IV and ICV delivery routes led to a significant extension in survival and increased body weight. Conversely, only ICV-treated animals demonstrated improvements in the hindlimb muscle, neuromuscular junction, and motor function. The hindlimb phenotype of IV-treated mice resembled the untreated nmd mice. We investigated whether the increased survival of IV-treated nmd mice was the result of a positive impact on the cardiac function. Our results revealed that cardiac function and pathology were similarly improved in IV- and ICV-treated mice. We concluded that while IV delivery of a low dose does not improve the hindlimb phenotype and motor function, partial restoration of cardiac performance is sufficient to significantly extend survival.
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Affiliation(s)
- Monir Shababi
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.,Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Eric Villalón
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.,Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Kevin A Kaifer
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.,Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Vince DeMarco
- Department of Medicine, Division of Endocrinology, Diabetes and Cardiovascular Center, University of Missouri, Columbia, MO, USA.,Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, USA.,Research Service, Harry S. Truman Memorial Veterans Hospital, University of Missouri, Columbia, MO, USA
| | - Christian L Lorson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.,Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
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Pletto D, Capra S, Finardi A, Colciaghi F, Nobili P, Battaglia GS, Locatelli D, Cagnoli C. Axon outgrowth and neuronal differentiation defects after a-SMN and FL-SMN silencing in primary hippocampal cultures. PLoS One 2018; 13:e0199105. [PMID: 29902268 PMCID: PMC6001960 DOI: 10.1371/journal.pone.0199105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 05/31/2018] [Indexed: 12/30/2022] Open
Abstract
Spinal Muscular Atrophy (SMA) is a severe autosomal recessive disease characterized by selective motor neuron degeneration, caused by disruptions of the Survival of Motor Neuron 1 (Smn1) gene. The main product of SMN1 is the full-length SMN protein (FL-SMN), that plays an established role in mRNA splicing. FL-SMN is also involved in neurite outgrowth and axonal transport. A shorter SMN isoform, axonal-SMN or a-SMN, displays a more specific axonal localization and has remarkable axonogenic properties in NSC-34. Introduction of known SMA mutations into the a-SMN transcript leads to impairment of axon growth and morphological defects similar to those observed in SMA patients and animal models. Although there is increasing evidence for the relevance of SMN axonal functions in SMA pathogenesis, the specific contributions of FL-SMN and a-SMN are not known yet. This work aimed to analyze the differential roles of FL-SMN and a-SMN in axon outgrowth and in neuronal homeostasis during differentiation of neurons into a mature phenotype. We employed primary cultures of hippocampal neurons as a well-defined model of polarization and differentiation. By analyzing subcellular localization, we showed that a-SMN is preferentially localized in the growing axonal compartment. By specifically silencing FL-SMN or a-SMN proteins, we demonstrated that both proteins play a role in axon growth, as their selective down-regulation reduces axon length without affecting dendritic arborization. a-SMN silencing, and in minor extent FL-SMN silencing, resulted in the growth of multi-neuritic neurons, impaired in the differentiation process of selecting a single axon out of multiple neurites. In these neurons, neurites often display mixed axonal and dendritic markers and abnormal distribution of the axonal initial segment protein Ankirin G, suggesting loss of neuronal polarity. Our results indicate that a-SMN and FL-SMN are needed for neuronal polarization and organization of axonal and dendritic compartments, processes that are fundamental for neuronal function and survival.
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Affiliation(s)
- Daniela Pletto
- Molecular Neuroanatomy and Pathogenesis Unit, Neurology VII—Clinical and Experimental Epileptology Unit, Foundation IRCCS Neurological Institute “C. Besta”, Milano, Italy
| | - Silvia Capra
- Molecular Neuroanatomy and Pathogenesis Unit, Neurology VII—Clinical and Experimental Epileptology Unit, Foundation IRCCS Neurological Institute “C. Besta”, Milano, Italy
| | - Adele Finardi
- Molecular Neuroanatomy and Pathogenesis Unit, Neurology VII—Clinical and Experimental Epileptology Unit, Foundation IRCCS Neurological Institute “C. Besta”, Milano, Italy
| | - Francesca Colciaghi
- Molecular Neuroanatomy and Pathogenesis Unit, Neurology VII—Clinical and Experimental Epileptology Unit, Foundation IRCCS Neurological Institute “C. Besta”, Milano, Italy
| | - Paola Nobili
- Molecular Neuroanatomy and Pathogenesis Unit, Neurology VII—Clinical and Experimental Epileptology Unit, Foundation IRCCS Neurological Institute “C. Besta”, Milano, Italy
| | - Giorgio Stefano Battaglia
- Molecular Neuroanatomy and Pathogenesis Unit, Neurology VII—Clinical and Experimental Epileptology Unit, Foundation IRCCS Neurological Institute “C. Besta”, Milano, Italy
| | - Denise Locatelli
- Molecular Neuroanatomy and Pathogenesis Unit, Neurology VII—Clinical and Experimental Epileptology Unit, Foundation IRCCS Neurological Institute “C. Besta”, Milano, Italy
| | - Cinzia Cagnoli
- Molecular Neuroanatomy and Pathogenesis Unit, Neurology VII—Clinical and Experimental Epileptology Unit, Foundation IRCCS Neurological Institute “C. Besta”, Milano, Italy
- * E-mail:
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40
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Maxwell GK, Szunyogova E, Shorrock HK, Gillingwater TH, Parson SH. Developmental and degenerative cardiac defects in the Taiwanese mouse model of severe spinal muscular atrophy. J Anat 2018; 232:965-978. [PMID: 29473159 PMCID: PMC5978979 DOI: 10.1111/joa.12793] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2018] [Indexed: 12/31/2022] Open
Abstract
Spinal muscular atrophy (SMA), an autosomal recessive disease caused by a decrease in levels of the survival motor neuron (SMN) protein, is the most common genetic cause of infant mortality. Although neuromuscular pathology is the most severe feature of SMA, other organs and tissues, including the heart, are also known to be affected in both patients and animal models. Here, we provide new insights into changes occurring in the heart, predominantly at pre- and early symptomatic ages, in the Taiwanese mouse model of severe SMA. Thinning of the interventricular septum and dilation of the ventricles occurred at pre- and early symptomatic ages. However, the left ventricular wall was significantly thinner in SMA mice from birth, occurring prior to any overt neuromuscular symptoms. Alterations in collagen IV protein from birth indicated changes to the basement membrane and contributed to the abnormal arrangement of cardiomyocytes in SMA hearts. This raises the possibility that developmental defects, occurring prenatally, may contribute to cardiac pathology in SMA. In addition, cardiomyocytes in SMA hearts exhibited oxidative stress at pre-symptomatic ages and increased apoptosis during early symptomatic stages of disease. Heart microvasculature was similarly decreased at an early symptomatic age, likely contributing to the oxidative stress and apoptosis phenotypes observed. Finally, an increased incidence of blood retention in SMA hearts post-fixation suggests the likelihood of functional defects, resulting in blood pooling. These pathologies mirror dilated cardiomyopathy, with clear consequences for heart function that would likely contribute to potential heart failure. Our findings add significant additional experimental evidence in support of the requirement to develop systemic therapies for SMA capable of treating non-neuromuscular pathologies.
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Affiliation(s)
| | - Eva Szunyogova
- Institute for Medical ScienceUniversity of AberdeenAberdeenUK
- Euan MacDonald Centre for Motor Neurone Disease ResearchUniversity of EdinburghEdinburghUK
| | - Hannah K. Shorrock
- Euan MacDonald Centre for Motor Neurone Disease ResearchUniversity of EdinburghEdinburghUK
- Edinburgh Medical School: Biomedical SciencesUniversity of EdinburghEdinburghUK
| | - Thomas H. Gillingwater
- Euan MacDonald Centre for Motor Neurone Disease ResearchUniversity of EdinburghEdinburghUK
- Edinburgh Medical School: Biomedical SciencesUniversity of EdinburghEdinburghUK
| | - Simon H. Parson
- Institute for Medical ScienceUniversity of AberdeenAberdeenUK
- Euan MacDonald Centre for Motor Neurone Disease ResearchUniversity of EdinburghEdinburghUK
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Falsaperla R, Vitaliti G, Collotta AD, Fiorillo C, Pulvirenti A, Alaimo S, Romano C, Ruggieri M. Electrocardiographic Evaluation in Patients With Spinal Muscular Atrophy: A Case-Control Study. J Child Neurol 2018; 33:487-492. [PMID: 29687752 DOI: 10.1177/0883073818767170] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND This study aimed to show the impairment of autonomic cardiac conduction causing bradycardia and/or electrocardiographic alterations in children affected by spinal muscular atrophy type 1 and 2 (SMA 1 and 2). METHODS We included 25 spinal muscular atrophy patients, admitted from November 2016 to May 2017. All patients underwent an electrocardiographic examination and we studied PR and QRS intervals, P-waves and QRS amplitudes, and heart rate in spinal muscular atrophy patients compared to a control group. RESULTS In all patients, we found longer PRi and QRSi ( P < .05), lower P-wave and QRS complex amplitudes ( P < .01), and a decreased heart rate ( P < .01) with respect to controls. When we divided our patients into SMA1 and SMA2 subgroups, we found that statistical differences were maintained for P-wave and QRS complex amplitudes and heart rate, but not for PRi and QRSi with respect to controls. CONCLUSION We suggest the hypothesis of SMN expression on cardiac tissue condition and/or autonomic cardiac conduction.
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Affiliation(s)
- Raffaele Falsaperla
- 1 General Pediatrics and Pediatric Acute and Emergency Complex Unit, Policlinico-Vittorio-Emanuele University Hospital, University of Catania, Italy
| | - Giovanna Vitaliti
- 1 General Pediatrics and Pediatric Acute and Emergency Complex Unit, Policlinico-Vittorio-Emanuele University Hospital, University of Catania, Italy
| | - Ausilia Desiree Collotta
- 1 General Pediatrics and Pediatric Acute and Emergency Complex Unit, Policlinico-Vittorio-Emanuele University Hospital, University of Catania, Italy
| | - Chiara Fiorillo
- 2 Unit of Paediatric Neurology and Muscle Diseases, G. Gaslini Institute, Genoa, Italy
| | - Alfredo Pulvirenti
- 3 Department of Clinical and Experimental Medicine, Section of Bioinformatics, University of Catania, Italy
| | - Salvatore Alaimo
- 3 Department of Clinical and Experimental Medicine, Section of Bioinformatics, University of Catania, Italy
| | - Catia Romano
- 1 General Pediatrics and Pediatric Acute and Emergency Complex Unit, Policlinico-Vittorio-Emanuele University Hospital, University of Catania, Italy
| | - Martino Ruggieri
- 4 Unit of Rare Diseases of the Nervous System in Childhood, Policlinico-Vittorio-Emanuele University Hospital, University of Catania, Italy
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Bowerman M, Becker CG, Yáñez-Muñoz RJ, Ning K, Wood MJA, Gillingwater TH, Talbot K. Therapeutic strategies for spinal muscular atrophy: SMN and beyond. Dis Model Mech 2018; 10:943-954. [PMID: 28768735 PMCID: PMC5560066 DOI: 10.1242/dmm.030148] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder characterized by loss of motor neurons and muscle atrophy, generally presenting in childhood. SMA is caused by low levels of the survival motor neuron protein (SMN) due to inactivating mutations in the encoding gene SMN1. A second duplicated gene, SMN2, produces very little but sufficient functional protein for survival. Therapeutic strategies to increase SMN are in clinical trials, and the first SMN2-directed antisense oligonucleotide (ASO) therapy has recently been licensed. However, several factors suggest that complementary strategies may be needed for the long-term maintenance of neuromuscular and other functions in SMA patients. Pre-clinical SMA models demonstrate that the requirement for SMN protein is highest when the structural connections of the neuromuscular system are being established, from late fetal life throughout infancy. Augmenting SMN may not address the slow neurodegenerative process underlying progressive functional decline beyond childhood in less severe types of SMA. Furthermore, individuals receiving SMN-based treatments may be vulnerable to delayed symptoms if rescue of the neuromuscular system is incomplete. Finally, a large number of older patients living with SMA do not fulfill the present criteria for inclusion in gene therapy and ASO clinical trials, and may not benefit from SMN-inducing treatments. Therefore, a comprehensive whole-lifespan approach to SMA therapy is required that includes both SMN-dependent and SMN-independent strategies that treat the CNS and periphery. Here, we review the range of non-SMN pathways implicated in SMA pathophysiology and discuss how various model systems can serve as valuable tools for SMA drug discovery. Summary: Translational research for spinal muscular atrophy (SMA) should address the development of non-CNS and survival motor neuron (SMN)-independent therapeutic approaches to complement and enhance the benefits of CNS-directed and SMN-dependent therapies.
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Affiliation(s)
- Melissa Bowerman
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, UK
| | - Catherina G Becker
- Euan MacDonald Centre for Motor Neurone Disease Research and Centre for Neuroregeneration, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Rafael J Yáñez-Muñoz
- AGCTlab.org, Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway, University of London, Egham Hill, Egham, Surrey TW20 0EX, UK
| | - Ke Ning
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, UK
| | - Matthew J A Wood
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, UK
| | - Thomas H Gillingwater
- Euan MacDonald Centre for Motor Neurone Disease Research and Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Kevin Talbot
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
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43
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Wood MJA, Talbot K, Bowerman M. Spinal muscular atrophy: antisense oligonucleotide therapy opens the door to an integrated therapeutic landscape. Hum Mol Genet 2018; 26:R151-R159. [PMID: 28977438 DOI: 10.1093/hmg/ddx215] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 06/02/2017] [Indexed: 01/03/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder characterized by loss of spinal cord motor neurons, muscle atrophy and infantile death or severe disability. It is caused by severe reduction of the ubiquitously expressed survival motor neuron (SMN) protein, owing to loss of the SMN1 gene. This would be completely incompatible with survival without the presence of a quasi-identical duplicated gene, SMN2, specific to humans. SMN2 harbours a silent point mutation that favours the production of transcripts lacking exon 7 and a rapidly degraded non-functional SMNΔ7 protein, but from which functional full length SMN protein is produced at very low levels (∼10%). Since the seminal discovery of the SMA-causing gene in 1995, research has focused on the development of various SMN replacement strategies culminating, in December 2016, in the approval of the first precise molecularly targeted therapy for SMA (nusinersen), and a pivotal proof of principle that therapeutic antisense oligonucleotide (ASO) treatment can effectively target the central nervous system (CNS) to treat neurological and neuromuscular disease. Nusinersen is a steric block ASO that binds the SMN2 messenger RNA and promotes exon 7 inclusion and thus increases full length SMN expression. Here, we consider the implications of this therapeutic landmark for SMA therapeutics and discuss how future developments will need to address the challenges of delivering ASO therapies to the CNS, with appropriate efficiency and activity, and how SMN-based therapy should be used in combination with complementary strategies to provide an integrated approach to treat CNS and peripheral pathologies in SMA.
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Affiliation(s)
- Matthew J A Wood
- Department of Physiology, Anatomy and Genetics, University of Oxford OX1 3QX, Oxford, UK
| | - Kevin Talbot
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
| | - Melissa Bowerman
- Department of Physiology, Anatomy and Genetics, University of Oxford OX1 3QX, Oxford, UK
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44
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Krosschell KJ, Kissel JT, Townsend EL, Simeone SD, Zhang RZ, Reyna SP, Crawford TO, Schroth MK, Acsadi G, Kishnani PS, Von Kleist-Retzow JC, Hero B, D'Anjou G, Smith EC, Elsheikh B, Simard LR, Prior TW, Scott CB, Lasalle B, Sakonju A, Wirth B, Swoboda KJ. Clinical trial of L-Carnitine and valproic acid in spinal muscular atrophy type I. Muscle Nerve 2017; 57:193-199. [PMID: 28833236 DOI: 10.1002/mus.25776] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 08/10/2017] [Accepted: 08/12/2017] [Indexed: 12/21/2022]
Abstract
INTRODUCTION The aim of this study was to determine the safety and therapeutic potential of L-carnitine and valproic acid (VPA) in infants with spinal muscular atrophy (SMA). METHODS Our investigation was an open-label phase 2 multicenter trial of L-carnitine and VPA in infants with SMA type I with retrospective comparison to an untreated, matched cohort. Primary outcomes were: safety and adverse events; secondary outcomes were survival, time to death/>16 hours/day of ventilator support; motor outcomes; and maximum ulnar compound motor action potential amplitude. RESULTS A total of 245 AEs were observed in 35 of the 37 treated subjects (95%). Respiratory events accounted for 49% of all adverse events, resulting in 14 deaths. Survival was not significantly different between treated and untreated cohorts. DISCUSSION This trial provides evidence that, in infants with SMA type I, L-carnitine/VPA is ineffective at altering survival. The substantial proportion of infants reaching end-points within 6 months of enrollment underscores the urgent need for pre-symptomatic treatment in SMA type I. Muscle Nerve 57: 193-199, 2018.
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Affiliation(s)
- Kristin J Krosschell
- Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - John T Kissel
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Elise L Townsend
- Department of Physical Therapy, Institute of Health Professions, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Sarah D Simeone
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital, 185 Cambridge Street, Simches 5-240, Boston, Massachusetts, 02114, USA
| | - Ren Zhe Zhang
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital, 185 Cambridge Street, Simches 5-240, Boston, Massachusetts, 02114, USA
| | - Sandra P Reyna
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Thomas O Crawford
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Mary K Schroth
- Department of Pediatrics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA
| | - Gyula Acsadi
- Connecticut Children's Medical Center, Hartford, Connecticut, USA
| | - Priya S Kishnani
- Department of Pediatrics, Duke University, Durham, North Carolina, USA
| | | | - Barbara Hero
- Department of Pediatrics, Hospital of the University of Cologne, Cologne, Germany
| | - Guy D'Anjou
- Department of Pediatrics, Saint-Justine Hospital, Montreal, Quebec, Canada
| | - Edward C Smith
- Department of Pediatrics, Duke University, Durham, North Carolina, USA
| | - Bakri Elsheikh
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Louise R Simard
- Biochemistry and Medical Genetics, University of Manitoba, Winnepeg, Manitoba, Canada
| | - Thomas W Prior
- Department of Molecular Pathology, The Ohio State University, Columbus, Ohio, USA
| | | | - Bernard Lasalle
- Department of Bioinformatics, University of Utah, Salt Lake City, Utah, USA
| | - Ai Sakonju
- Department of Neurology, State University of New York, Syracuse, New York
| | - Brunhilde Wirth
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Center for Rare Diseases Cologne.,Institute of Genetics, University of Cologne, Cologne, Germany
| | - Kathryn J Swoboda
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital, 185 Cambridge Street, Simches 5-240, Boston, Massachusetts, 02114, USA
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Godena VK, Ning K. Phosphatase and tensin homologue: a therapeutic target for SMA. Signal Transduct Target Ther 2017; 2:17038. [PMID: 29263925 PMCID: PMC5661640 DOI: 10.1038/sigtrans.2017.38] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 05/09/2017] [Accepted: 06/01/2017] [Indexed: 01/15/2023] Open
Abstract
Spinal muscular atrophy (SMA) is one of the most common juvenile neurodegenerative diseases, which can be associated with child mortality. SMA is caused by a mutation of ubiquitously expressed gene, Survival Motor Neuron1 (SMN1), leading to reduced SMN protein and the motor neuron death. The disease is incurable and the only therapeutic strategy to follow is to improve the expression of SMN protein levels in motor neurons. Significant numbers of motor neurons in SMA mice and SMA cultures are caspase positive with condensed nuclei, suggesting that these cells are prone to a process of cell death called apoptosis. Searching for other potential molecules or signaling pathways that are neuroprotective for central nervous system (CNS) insults is essential for widening the scope of developmental medicine. PTEN, a Phosphatase and Tensin homologue, is a tumor suppressor, which is widely expressed in CNS. PTEN depletion activates anti-apoptotic factors and it is evident that the pathway plays an important protective role in many neurodegenerative disorders. It functions as a negative regulator of PIP3/AKT pathway and thereby modulates its downstream cellular functions through lipid phosphatase activity. Moreover, previous reports from our group demonstrated that, PTEN depletion using viral vector delivery system in SMN delta7 mice reduces disease pathology, with significant rescue on survival rate and the body weight of the SMA mice. Thus knockdown/depletion/mutation of PTEN and manipulation of PTEN medicated Akt/PKB signaling pathway may represent an important therapeutic strategy to promote motor neuron survival in SMA.
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Affiliation(s)
- Vinay K Godena
- Department of Neuroscience, Sheffield Institute of Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - Ke Ning
- Department of Neuroscience, Sheffield Institute of Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
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46
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Howell MD, Ottesen EW, Singh NN, Anderson RL, Seo J, Sivanesan S, Whitley EM, Singh RN. TIA1 is a gender-specific disease modifier of a mild mouse model of spinal muscular atrophy. Sci Rep 2017; 7:7183. [PMID: 28775379 PMCID: PMC5543135 DOI: 10.1038/s41598-017-07468-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 06/26/2017] [Indexed: 02/08/2023] Open
Abstract
Spinal muscular atrophy (SMA) is caused by deletions or mutations of Survival Motor Neuron 1 (SMN1) gene. The nearly identical SMN2 cannot compensate for SMN1 loss due to exon 7 skipping. The allele C (C +/+) mouse recapitulates a mild SMA-like phenotype and offers an ideal system to monitor the role of disease-modifying factors over a long time. T-cell-restricted intracellular antigen 1 (TIA1) regulates SMN exon 7 splicing. TIA1 is reported to be downregulated in obese patients, although it is not known if the effect is gender-specific. We show that female Tia1-knockout (Tia1 -/-) mice gain significant body weight (BW) during early postnatal development. We next examined the effect of Tia1 deletion in novel C +/+/Tia1 -/- mice. Underscoring the opposing effects of Tia1 deletion and low SMN level on BW gain, both C +/+ and C +/+/Tia1 -/- females showed similar BW gain trajectory at all time points during our study. We observed early tail necrosis in C +/+/Tia1 -/- females but not in males. We show enhanced impairment of male reproductive organ development and exacerbation of the C +/+/Tia1 -/- testis transcriptome. Our findings implicate a protein factor as a gender-specific modifier of a mild mouse model of SMA.
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Affiliation(s)
- Matthew D Howell
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, 50011, USA
| | - Eric W Ottesen
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, 50011, USA
| | - Natalia N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, 50011, USA
| | - Rachel L Anderson
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, 50011, USA
| | - Joonbae Seo
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, 50011, USA
- Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | | | - Elizabeth M Whitley
- Department of Veterinary Pathology, Iowa State University, Ames, IA, 50011-1250, USA
- Pathogenesis, LLC, Gainesville, Florida, 32614, USA
| | - Ravindra N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, 50011, USA.
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47
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Deguise MO, De Repentigny Y, McFall E, Auclair N, Sad S, Kothary R. Immune dysregulation may contribute to disease pathogenesis in spinal muscular atrophy mice. Hum Mol Genet 2017; 26:801-819. [PMID: 28108555 PMCID: PMC5409095 DOI: 10.1093/hmg/ddw434] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 12/16/2016] [Indexed: 01/21/2023] Open
Abstract
Spinal muscular atrophy (SMA) has long been solely considered a neurodegenerative disorder. However, recent work has highlighted defects in many other cell types that could contribute to disease aetiology. Interestingly, the immune system has never been extensively studied in SMA. Defects in lymphoid organs could exacerbate disease progression by neuroinflammation or immunodeficiency. Smn depletion led to severe alterations in the thymus and spleen of two different mouse models of SMA. The spleen from Smn depleted mice was dramatically smaller at a very young age and its histological architecture was marked by mislocalization of immune cells in the Smn2B/- model mice. In comparison, the thymus was relatively spared in gross morphology but showed many histological alterations including cortex thinning in both mouse models at symptomatic ages. Thymocyte development was also impaired as evidenced by abnormal population frequencies in the Smn2B/- thymus. Cytokine profiling revealed major changes in different tissues of both mouse models. Consistent with our observations, we found that survival motor neuron (Smn) protein levels were relatively high in lymphoid organs compared to skeletal muscle and spinal cord during postnatal development in wild type mice. Genetic introduction of one copy of the human SMN2 transgene was enough to rescue splenic and thymic defects in Smn2B/- mice. Thus, Smn is required for the normal development of lymphoid organs, and altered immune function may contribute to SMA disease pathogenesis.
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Affiliation(s)
- Marc-Olivier Deguise
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6.,Department of Cellular and Molecular Medicine.,Centre for Neuromuscular Disease, University of Ottawa
| | - Yves De Repentigny
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6.,Centre for Neuromuscular Disease, University of Ottawa
| | - Emily McFall
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6.,Centre for Neuromuscular Disease, University of Ottawa
| | - Nicole Auclair
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6.,Faculty of Science, University of Ottawa, Ottawa, Ontario, Canada, K1N 9B4
| | - Subash Sad
- Department of Biochemistry, Microbiology, and Immunology
| | - Rashmi Kothary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6.,Department of Cellular and Molecular Medicine.,Centre for Neuromuscular Disease, University of Ottawa.,Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
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48
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Deguise M, Kothary R. New insights into SMA pathogenesis: immune dysfunction and neuroinflammation. Ann Clin Transl Neurol 2017; 4:522-530. [PMID: 28695153 PMCID: PMC5497530 DOI: 10.1002/acn3.423] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 04/25/2017] [Indexed: 12/13/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by motor neuron degeneration, although defects in multiple cell types and tissues have also been implicated. Three independent laboratories recently identified immune organ defects in SMA. We therefore propose a novel pathogenic mechanism contributory to SMA, resulting in higher susceptibility to infection and exacerbated disease progression caused by neuroinflammation. Overall, compromised immune function could significantly affect survival and quality of life of SMA patients. We highlight the recent findings in immune organ defects, their potential consequences on patients, our understanding of neuroinflammation in SMA, and new research hypotheses in SMA pathogenesis.
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Affiliation(s)
- Marc‐Olivier Deguise
- Regenerative Medicine ProgramOttawa Hospital Research InstituteOttawaOntarioK1H 8L6Canada
- Department of Cellular and Molecular MedicineUniversity of OttawaOttawaOntarioK1H 8M5Canada
- Centre for Neuromuscular DiseaseUniversity of OttawaOttawaOntarioK1H 8M5Canada
| | - Rashmi Kothary
- Regenerative Medicine ProgramOttawa Hospital Research InstituteOttawaOntarioK1H 8L6Canada
- Department of Cellular and Molecular MedicineUniversity of OttawaOttawaOntarioK1H 8M5Canada
- Centre for Neuromuscular DiseaseUniversity of OttawaOttawaOntarioK1H 8M5Canada
- Department of MedicineUniversity of OttawaOttawaOntarioK1H 8M5Canada
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49
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Singh NN, Howell MD, Androphy EJ, Singh RN. How the discovery of ISS-N1 led to the first medical therapy for spinal muscular atrophy. Gene Ther 2017; 24:520-526. [PMID: 28485722 DOI: 10.1038/gt.2017.34] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 04/14/2017] [Accepted: 04/26/2017] [Indexed: 12/14/2022]
Abstract
Spinal muscular atrophy (SMA), a prominent genetic disease of infant mortality, is caused by low levels of survival motor neuron (SMN) protein owing to deletions or mutations of the SMN1 gene. SMN2, a nearly identical copy of SMN1 present in humans, cannot compensate for the loss of SMN1 because of predominant skipping of exon 7 during pre-mRNA splicing. With the recent US Food and Drug Administration approval of nusinersen (Spinraza), the potential for correction of SMN2 exon 7 splicing as an SMA therapy has been affirmed. Nusinersen is an antisense oligonucleotide that targets intronic splicing silencer N1 (ISS-N1) discovered in 2004 at the University of Massachusetts Medical School. ISS-N1 has emerged as the model target for testing the therapeutic efficacy of antisense oligonucleotides using different chemistries as well as different mouse models of SMA. Here, we provide a historical account of events that led to the discovery of ISS-N1 and describe the impact of independent validations that raised the profile of ISS-N1 as one of the most potent antisense targets for the treatment of a genetic disease. Recent approval of nusinersen provides a much-needed boost for antisense technology that is just beginning to realize its potential. Beyond treating SMA, the ISS-N1 target offers myriad potentials for perfecting various aspects of the nucleic-acid-based technology for the amelioration of the countless number of pathological conditions.
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Affiliation(s)
- N N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA, USA
| | - M D Howell
- Department of Biomedical Sciences, Iowa State University, Ames, IA, USA
| | - E J Androphy
- Department of Dermatology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - R N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA, USA
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50
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Gender-Specific Amelioration of SMA Phenotype upon Disruption of a Deep Intronic Structure by an Oligonucleotide. Mol Ther 2017; 25:1328-1341. [PMID: 28412171 DOI: 10.1016/j.ymthe.2017.03.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 03/18/2017] [Accepted: 03/28/2017] [Indexed: 01/01/2023] Open
Abstract
Spinal muscular atrophy (SMA), the leading genetic disease of children, is caused by low levels of survival motor neuron (SMN) protein. Here, we employ A15/283, an antisense oligonucleotide targeting a deep intronic sequence/structure, to examine the impact of restoration of SMN in a mild SMA mouse model. We show gender-specific amelioration of tail necrosis upon subcutaneous administrations of A15/283 into SMA mice at postnatal days 1 and 3. We also demonstrate that a modest increase in SMN due to early administrations of A15/283 dramatically improves testicular development and spermatogenesis. Our results reveal near total correction of expression of several genes in adult testis upon temporary increase in SMN during early postnatal development. This is the first demonstration of in vivo efficacy of an antisense oligonucleotide targeting a deep intronic sequence/structure. This is also the first report of gender-specific amelioration of SMA pathology upon a modest peripheral increase of SMN.
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