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PMID: 25986506 Published · ppublish English Journal Article Research Support, Non-U.S. Gov't Review

Spinal muscular atrophy--recent therapeutic advances for an old challenge.

Nature reviews. Neurology ·Vol. 11 ·No. 6 ·2015-06-00 ·Pages 351-9

Faravelli I, Nizzardo M, Comi GP, Corti S

Abstract

In the past decade, improved understanding of spinal muscular atrophy (SMA) aetiopathogenesis has brought us to a historical turning point: we are at the verge of development of disease-modifying treatments for this hitherto incurable disease. The increasingly precise delineation of molecular targets within the survival of motor neuron (SMN) gene locus has led to the development of promising therapeutic strategies. These novel avenues in treatment for SMA include gene therapy, molecular therapy with antisense oligonucleotides, and small molecules that aim to increase expression of SMN protein. Stem cell studies of SMA have provided an in vitro model for SMA, and stem cell transplantation could be used as a complementary strategy with a potential to treat the symptomatic phases of the disease. Here, we provide an overview of established data and novel insights into SMA pathogenesis, including discussion of the crucial function of the SMN protein. Preclinical evidence and recent advances from ongoing clinical trials are thoroughly reviewed. The final remarks are dedicated to future clinical perspectives in this rapidly evolving field, with a broad discussion on the comparison between the outlined therapeutic approaches and the remaining open questions.

MeSH Terms
Animals Clinical Trials as Topic Diagnosis, Differential Humans Motor Neurons Muscular Atrophy, Spinal/diagnosis,genetics,therapy Oligonucleotides, Antisense/genetics SMN Complex Proteins/genetics
Chemicals
Oligonucleotides, Antisense SMN Complex Proteins
Authors & Affiliations
4 authors, click to expand affiliations / ORCID
Faravelli Irene
Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation, Neurology Unit, IRCCS Foundation Ca'Granda Ospedale Maggiore Policlinico, University of Milan, via Francesco Sforza 35, 20122 Milan, Italy.
Nizzardo Monica
Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation, Neurology Unit, IRCCS Foundation Ca'Granda Ospedale Maggiore Policlinico, University of Milan, via Francesco Sforza 35, 20122 Milan, Italy.
Comi Giacomo P
Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation, Neurology Unit, IRCCS Foundation Ca'Granda Ospedale Maggiore Policlinico, University of Milan, via Francesco Sforza 35, 20122 Milan, Italy.
Corti Stefania
Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation, Neurology Unit, IRCCS Foundation Ca'Granda Ospedale Maggiore Policlinico, University of Milan, via Francesco Sforza 35, 20122 Milan, Italy.
References (109)
109 references, click to expand
  1. Spinal muscular atrophy.
    Orphanet J Rare Dis. 2011 Nov 02;6:71 PMID: 22047105
  2. SMN deficiency causes tissue-specific perturbations in the repertoire of snRNAs and widespread defects in splicing.
    Cell. 2008 May 16;133(4):585-600 PMID: 18485868
  3. A single nucleotide difference that alters splicing patterns distinguishes the SMA gene SMN1 from the copy gene SMN2.
    Hum Mol Genet. 1999 Jul;8(7):1177-83 PMID: 10369862
  4. Homozygous SMN1 deletions in unaffected family members and modification of the phenotype by SMN2.
    Am J Med Genet A. 2004 Oct 15;130A(3):307-10 PMID: 15378550
  5. Spinal muscular atrophy and a model for survival of motor neuron protein function in axonal ribonucleoprotein complexes.
    Results Probl Cell Differ. 2009;48:289-326 PMID: 19343312
  6. Bone health and associated metabolic complications in neuromuscular diseases.
    Phys Med Rehabil Clin N Am. 2012 Nov;23(4):773-99 PMID: 23137737
  7. Cardiac involvement in patients with spinal muscular atrophies.
    Acta Myol. 2011 Dec;30(3):175-8 PMID: 22616198
  8. Chaperoning ribonucleoprotein biogenesis in health and disease.
    EMBO Rep. 2007 Apr;8(4):340-5 PMID: 17401408
  9. Two early infantile hereditary cases of progressive muscular atrophy simulating dystrophy, but on a neural basis. 1891.
    Arch Neurol. 1971 Sep;25(3):276-8 PMID: 4952838
  10. Enhancement of SMN protein levels in a mouse model of spinal muscular atrophy using novel drug-like compounds.
    EMBO Mol Med. 2013 Jul;5(7):1103-18 PMID: 23740718
  11. Survival motor neuron protein in motor neurons determines synaptic integrity in spinal muscular atrophy.
    J Neurosci. 2012 Jun 20;32(25):8703-15 PMID: 22723710
  12. Intravascular AAV9 preferentially targets neonatal neurons and adult astrocytes.
    Nat Biotechnol. 2009 Jan;27(1):59-65 PMID: 19098898
  13. Tetracyclines that promote SMN2 exon 7 splicing as therapeutics for spinal muscular atrophy.
    Sci Transl Med. 2009 Nov 4;1(5):5ra12 PMID: 20161659
  14. Induced pluripotent stem cells from a spinal muscular atrophy patient.
    Nature. 2009 Jan 15;457(7227):277-80 PMID: 19098894
  15. Sleep architecture in infants with spinal muscular atrophy type 1.
    Sleep Med. 2014 Oct;15(10):1246-50 PMID: 25132610
  16. Clinical utility gene card for: proximal spinal muscular atrophy.
    Eur J Hum Genet. 2012 Jun;20(6): PMID: 22510849
  17. Ribonucleoprotein assembly defects correlate with spinal muscular atrophy severity and preferentially affect a subset of spliceosomal snRNPs.
    PLoS One. 2007 Sep 26;2(9):e921 PMID: 17895963
  18. SMN-targeted therapeutics for spinal muscular atrophy: are we SMArt enough yet?
    J Clin Invest. 2014 Feb;124(2):487-90 PMID: 24463455
  19. Systemic delivery of scAAV9 expressing SMN prolongs survival in a model of spinal muscular atrophy.
    Sci Transl Med. 2010 Jun 9;2(35):35ra42 PMID: 20538619
  20. Effect of combined systemic and local morpholino treatment on the spinal muscular atrophy Δ7 mouse model phenotype.
    Clin Ther. 2014 Mar 1;36(3):340-56.e5 PMID: 24636820
  21. Inactivation of the survival motor neuron gene, a candidate gene for human spinal muscular atrophy, leads to massive cell death in early mouse embryos.
    Proc Natl Acad Sci U S A. 1997 Sep 2;94(18):9920-5 PMID: 9275227
  22. A large animal model of spinal muscular atrophy and correction of phenotype.
    Ann Neurol. 2015 Mar;77(3):399-414 PMID: 25516063
  23. International SMA consortium meeting. (26-28 June 1992, Bonn, Germany).
    Neuromuscul Disord. 1992;2(5-6):423-8 PMID: 1300191
  24. Genetic testing and risk assessment for spinal muscular atrophy (SMA).
    Hum Genet. 2002 Dec;111(6):477-500 PMID: 12436240
  25. Intravenous scAAV9 delivery of a codon-optimized SMN1 sequence rescues SMA mice.
    Hum Mol Genet. 2011 Feb 15;20(4):681-93 PMID: 21118896
  26. Genetic correction of human induced pluripotent stem cells from patients with spinal muscular atrophy.
    Sci Transl Med. 2012 Dec 19;4(165):165ra162 PMID: 23253609
  27. Skeletal muscle DNA damage precedes spinal motor neuron DNA damage in a mouse model of Spinal Muscular Atrophy (SMA).
    PLoS One. 2014 Mar 25;9(3):e93329 PMID: 24667816
  28. Consensus statement for standard of care in spinal muscular atrophy.
    J Child Neurol. 2007 Aug;22(8):1027-49 PMID: 17761659
  29. SMN is required for sensory-motor circuit function in Drosophila.
    Cell. 2012 Oct 12;151(2):427-39 PMID: 23063130
  30. Early onset muscle weakness and disruption of muscle proteins in mouse models of spinal muscular atrophy.
    Skelet Muscle. 2013 Oct 11;3(1):24 PMID: 24119341
  31. A short antisense oligonucleotide ameliorates symptoms of severe mouse models of spinal muscular atrophy.
    Mol Ther Nucleic Acids. 2014 Jul 08;3:e174 PMID: 25004100
  32. Spinal muscular atrophy: why do low levels of survival motor neuron protein make motor neurons sick?
    Nat Rev Neurosci. 2009 Aug;10(8):597-609 PMID: 19584893
  33. Improved antisense oligonucleotide design to suppress aberrant SMN2 gene transcript processing: towards a treatment for spinal muscular atrophy.
    PLoS One. 2013 Apr 22;8(4):e62114 PMID: 23630626
  34. Specific interaction of Smn, the spinal muscular atrophy determining gene product, with hnRNP-R and gry-rbp/hnRNP-Q: a role for Smn in RNA processing in motor axons?
    Hum Mol Genet. 2002 Jan 1;11(1):93-105 PMID: 11773003
  35. Identification and characterization of a spinal muscular atrophy-determining gene.
    Cell. 1995 Jan 13;80(1):155-65 PMID: 7813012
  36. Genetic mapping of chronic childhood-onset spinal muscular atrophy to chromosome 5q11.2-13.3.
    Nature. 1990 Apr 5;344(6266):540-1 PMID: 2320125
  37. Molecular functions of the SMN complex.
    J Child Neurol. 2007 Aug;22(8):990-4 PMID: 17761654
  38. The activity of the spinal muscular atrophy protein is regulated during development and cellular differentiation.
    Hum Mol Genet. 2005 Dec 1;14(23):3629-42 PMID: 16236758
  39. The human centromeric survival motor neuron gene (SMN2) rescues embryonic lethality in Smn(-/-) mice and results in a mouse with spinal muscular atrophy.
    Hum Mol Genet. 2000 Feb 12;9(3):333-9 PMID: 10655541
  40. Global CNS gene delivery and evasion of anti-AAV-neutralizing antibodies by intrathecal AAV administration in non-human primates.
    Gene Ther. 2013 Apr;20(4):450-9 PMID: 23303281
  41. How genetic modifiers influence the phenotype of spinal muscular atrophy and suggest future therapeutic approaches.
    Curr Opin Genet Dev. 2013 Jun;23(3):330-8 PMID: 23602330
  42. Modern management of spinal muscular atrophy.
    J Child Neurol. 2007 Aug;22(8):974-8 PMID: 17761652
  43. Splicing of a critical exon of human Survival Motor Neuron is regulated by a unique silencer element located in the last intron.
    Mol Cell Biol. 2006 Feb;26(4):1333-46 PMID: 16449646
  44. Spinal muscular atrophy: therapeutic strategies.
    Curr Treat Options Neurol. 2014 Nov;16(11):316 PMID: 25245431
  45. At the "junction" of spinal muscular atrophy pathogenesis: the role of neuromuscular junction dysfunction in SMA disease progression.
    Curr Mol Med. 2013 Aug;13(7):1160-74 PMID: 23514457
  46. Rho-kinase inactivation prolongs survival of an intermediate SMA mouse model.
    Hum Mol Genet. 2010 Apr 15;19(8):1468-78 PMID: 20097679
  47. The SMN complex: an assembly machine for RNPs.
    Cold Spring Harb Symp Quant Biol. 2006;71:313-20 PMID: 17381311
  48. A natural history study of late onset spinal muscular atrophy types 3b and 4.
    J Neurol. 2008 Sep;255(9):1400-4 PMID: 18575920
  49. A degron created by SMN2 exon 7 skipping is a principal contributor to spinal muscular atrophy severity.
    Genes Dev. 2010 Mar 1;24(5):438-42 PMID: 20194437
  50. Improving single injection CSF delivery of AAV9-mediated gene therapy for SMA: a dose-response study in mice and nonhuman primates.
    Mol Ther. 2015 Mar;23(3):477-87 PMID: 25358252
  51. A novel morpholino oligomer targeting ISS-N1 improves rescue of severe spinal muscular atrophy transgenic mice.
    Hum Gene Ther. 2013 Mar;24(3):331-42 PMID: 23339722
  52. Refined characterization of the expression and stability of the SMN gene products.
    Am J Pathol. 2007 Oct;171(4):1269-80 PMID: 17717146
  53. Assays for the identification and prioritization of drug candidates for spinal muscular atrophy.
    Assay Drug Dev Technol. 2014 Aug;12(6):315-41 PMID: 25147906
  54. Inhibition of apoptosis blocks human motor neuron cell death in a stem cell model of spinal muscular atrophy.
    PLoS One. 2012;7(6):e39113 PMID: 22723941
  55. Requirement of enhanced Survival Motoneuron protein imposed during neuromuscular junction maturation.
    J Clin Invest. 2014 Feb;124(2):785-800 PMID: 24463453
  56. Essential role for the SMN complex in the specificity of snRNP assembly.
    Science. 2002 Nov 29;298(5599):1775-9 PMID: 12459587
  57. Observational study of spinal muscular atrophy type I and implications for clinical trials.
    Neurology. 2014 Aug 26;83(9):810-7 PMID: 25080519
  58. Newborn and carrier screening for spinal muscular atrophy.
    Am J Med Genet A. 2010 Jul;152A(7):1608-16 PMID: 20578137
  59. An analysis of disease severity based on SMN2 copy number in adults with spinal muscular atrophy.
    Muscle Nerve. 2009 Oct;40(4):652-6 PMID: 19760790
  60. Pharmacology of a central nervous system delivered 2'-O-methoxyethyl-modified survival of motor neuron splicing oligonucleotide in mice and nonhuman primates.
    J Pharmacol Exp Ther. 2014 Jul;350(1):46-55 PMID: 24784568
  61. Quantitative analyses of SMN1 and SMN2 based on real-time lightCycler PCR: fast and highly reliable carrier testing and prediction of severity of spinal muscular atrophy.
    Am J Hum Genet. 2002 Feb;70(2):358-68 PMID: 11791208
  62. Antisense oligonucleotides delivered to the mouse CNS ameliorate symptoms of severe spinal muscular atrophy.
    Sci Transl Med. 2011 Mar 2;3(72):72ra18 PMID: 21368223
  63. Cystic fibrosis newborn screening: a model for neuromuscular disease screening?
    Ann Neurol. 2015 Feb;77(2):189-97 PMID: 25425541
  64. Morpholino antisense oligonucleotides targeting intronic repressor Element1 improve phenotype in SMA mouse models.
    Hum Mol Genet. 2014 Sep 15;23(18):4832-45 PMID: 24781211
  65. Fasudil improves survival and promotes skeletal muscle development in a mouse model of spinal muscular atrophy.
    BMC Med. 2012 Mar 07;10:24 PMID: 22397316
  66. SMN control of RNP assembly: from post-transcriptional gene regulation to motor neuron disease.
    Semin Cell Dev Biol. 2014 Aug;32:22-9 PMID: 24769255
  67. Congenital heart disease is a feature of severe infantile spinal muscular atrophy.
    J Med Genet. 2008 Oct;45(10):635-8 PMID: 18662980
  68. Peripheral SMN restoration is essential for long-term rescue of a severe spinal muscular atrophy mouse model.
    Nature. 2011 Oct 05;478(7367):123-6 PMID: 21979052
  69. Spinal muscular atrophy: diagnosis and management in a new therapeutic era.
    Muscle Nerve. 2015 Feb;51(2):157-67 PMID: 25346245
  70. Plastin 3 is a protective modifier of autosomal recessive spinal muscular atrophy.
    Science. 2008 Apr 25;320(5875):524-7 PMID: 18440926
  71. Synthesis and biological evaluation of novel 2,4-diaminoquinazoline derivatives as SMN2 promoter activators for the potential treatment of spinal muscular atrophy.
    J Med Chem. 2008 Feb 14;51(3):449-69 PMID: 18205293
  72. Knockdown of the survival motor neuron (Smn) protein in zebrafish causes defects in motor axon outgrowth and pathfinding.
    J Cell Biol. 2003 Sep 1;162(5):919-31 PMID: 12952942
  73. A screen for regulators of survival of motor neuron protein levels.
    Nat Chem Biol. 2011 Jun 19;7(8):544-52 PMID: 21685895
  74. Technical standards and guidelines for spinal muscular atrophy testing.
    Genet Med. 2011 Jul;13(7):686-94 PMID: 21673580
  75. Early heart failure in the SMNDelta7 model of spinal muscular atrophy and correction by postnatal scAAV9-SMN delivery.
    Hum Mol Genet. 2010 Oct 15;19(20):3895-905 PMID: 20639395
  76. A cell system with targeted disruption of the SMN gene: functional conservation of the SMN protein and dependence of Gemin2 on SMN.
    J Biol Chem. 2001 Mar 30;276(13):9599-605 PMID: 11121410
  77. Phenotypic and molecular insights into spinal muscular atrophy due to mutations in BICD2.
    Brain. 2015 Feb;138(Pt 2):293-310 PMID: 25497877
  78. Rescue of the spinal muscular atrophy phenotype in a mouse model by early postnatal delivery of SMN.
    Nat Biotechnol. 2010 Mar;28(3):271-4 PMID: 20190738
  79. Cardiac defects contribute to the pathology of spinal muscular atrophy models.
    Hum Mol Genet. 2010 Oct 15;19(20):4059-71 PMID: 20696672
  80. A novel function for SMN, the spinal muscular atrophy disease gene product, in pre-mRNA splicing.
    Cell. 1998 Nov 25;95(5):615-24 PMID: 9845364
  81. HuD interacts with survival motor neuron protein and can rescue spinal muscular atrophy-like neuronal defects.
    Hum Mol Genet. 2011 Feb 1;20(3):553-79 PMID: 21088113
  82. A placebo-controlled trial of gabapentin in spinal muscular atrophy.
    J Neurol Sci. 2001 Oct 15;191(1-2):127-31 PMID: 11677003
  83. Childhood spinal muscular atrophy: controversies and challenges.
    Lancet Neurol. 2012 May;11(5):443-52 PMID: 22516079
  84. Natural history of denervation in SMA: relation to age, SMN2 copy number, and function.
    Ann Neurol. 2005 May;57(5):704-12 PMID: 15852397
  85. CNS-targeted gene therapy improves survival and motor function in a mouse model of spinal muscular atrophy.
    J Clin Invest. 2010 Apr;120(4):1253-64 PMID: 20234094
  86. Systemic gene delivery in large species for targeting spinal cord, brain, and peripheral tissues for pediatric disorders.
    Mol Ther. 2011 Nov;19(11):1971-80 PMID: 21811247
  87. The AAV vector toolkit: poised at the clinical crossroads.
    Mol Ther. 2012 Apr;20(4):699-708 PMID: 22273577
  88. SMN-inducing compounds for the treatment of spinal muscular atrophy.
    Future Med Chem. 2012 Oct;4(16):2067-84 PMID: 23157239
  89. Non-5q spinal muscular atrophies: the alphanumeric soup thickens.
    Neurology. 2011 Jul 26;77(4):312-4 PMID: 21715708
  90. Motor neuron disease. SMN2 splicing modifiers improve motor function and longevity in mice with spinal muscular atrophy.
    Science. 2014 Aug 8;345(6197):688-93 PMID: 25104390
  91. The high frequency of genetic diseases in hypotonic infants referred by neuropediatrics.
    Am J Med Genet A. 2014 Jul;164A(7):1702-5 PMID: 24715477
  92. Antisense correction of SMN2 splicing in the CNS rescues necrosis in a type III SMA mouse model.
    Genes Dev. 2010 Aug 1;24(15):1634-44 PMID: 20624852
  93. A single nucleotide in the SMN gene regulates splicing and is responsible for spinal muscular atrophy.
    Proc Natl Acad Sci U S A. 1999 May 25;96(11):6307-11 PMID: 10339583
  94. Pan-ethnic carrier screening and prenatal diagnosis for spinal muscular atrophy: clinical laboratory analysis of >72,400 specimens.
    Eur J Hum Genet. 2012 Jan;20(1):27-32 PMID: 21811307
  95. Clinical characteristics of three subtypes of spinal muscular atrophy in children.
    Brain Dev. 2015 May;37(5):537-41 PMID: 25199871
  96. An assembly chaperone collaborates with the SMN complex to generate spliceosomal SnRNPs.
    Cell. 2008 Oct 31;135(3):497-509 PMID: 18984161
  97. Early laparoscopic fundoplication and gastrostomy in infants with spinal muscular atrophy type I.
    J Pediatr Surg. 2008 Nov;43(11):2031-7 PMID: 18970936
  98. Impaired minor tri-snRNP assembly generates differential splicing defects of U12-type introns in lymphoblasts derived from a type I SMA patient.
    Hum Mol Genet. 2011 Feb 15;20(4):641-8 PMID: 21098506
  99. 5-(N-ethyl-N-isopropyl)-amiloride enhances SMN2 exon 7 inclusion and protein expression in spinal muscular atrophy cells.
    Ann Neurol. 2008 Jan;63(1):26-34 PMID: 17924536
  100. NeuroNEXT SMA biomarkers study.
    Ann Neurol. 2013 Aug;74(2):A8 PMID: 24902530
  101. SMN-dependent intrinsic defects in Schwann cells in mouse models of spinal muscular atrophy.
    Hum Mol Genet. 2014 May 1;23(9):2235-50 PMID: 24301677
  102. Diverse small-molecule modulators of SMN expression found by high-throughput compound screening: early leads towards a therapeutic for spinal muscular atrophy.
    Hum Mol Genet. 2005 Jul 15;14(14):2003-18 PMID: 15944201
  103. SMNDelta7, the major product of the centromeric survival motor neuron (SMN2) gene, extends survival in mice with spinal muscular atrophy and associates with full-length SMN.
    Hum Mol Genet. 2005 Mar 15;14(6):845-57 PMID: 15703193
  104. Oligonucleotide-mediated survival of motor neuron protein expression in CNS improves phenotype in a mouse model of spinal muscular atrophy.
    J Neurosci. 2009 Jun 17;29(24):7633-8 PMID: 19535574
  105. Regulation of SMN protein stability.
    Mol Cell Biol. 2009 Mar;29(5):1107-15 PMID: 19103745
  106. A positive modifier of spinal muscular atrophy in the SMN2 gene.
    Am J Hum Genet. 2009 Sep;85(3):408-13 PMID: 19716110
  107. A novel method for oral delivery of drug compounds to the neonatal SMNDelta7 mouse model of spinal muscular atrophy.
    J Neurosci Methods. 2007 Apr 15;161(2):285-90 PMID: 17161463
  108. Observational study of spinal muscular atrophy type 2 and 3: functional outcomes over 1 year.
    Arch Neurol. 2011 Jun;68(6):779-86 PMID: 21320981
  109. Spinal muscular atrophy: the RNP connection.
    Trends Mol Med. 2006 Mar;12(3):113-21 PMID: 16473550
Article Info
Journal
Nature reviews. Neurology
Abbr.
Nat Rev Neurol
ISSN
1759-4766
Published
2015-06-00
Epub
2015-00-19
Pages
351-9
Language
English
Region
England
NLM ID
101500072
Subset
IM
Grants
Telethon · GGP14025 · Italy
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