title: Correction of SMN2 Pre-mRNA splicing by antisense U7 small nuclear RNAs.
abstract: Mutations in one of the duplicated survival of motor neuron (SMN) genes lead to the progressive loss of motor neurons and subsequent development of spinal muscular atrophy (SMA), a common, and usually fatal, hereditary disease. Homozygous absence of the telomeric copy (SMN1) correlates with development of SMA because differential splicing of the centromeric copy (SMN2) leads to exon 7 skipping and predominantly produces a biologically inactive protein isoform. To increase exon 7 inclusion of SMN2, we have designed a series of vectors that express modified U7 snRNAs containing antisense sequences complementary to the 3' splice site of SMN exon 8. Over 20 anti-SMN U7 snRNAs were tested for their ability to promote exon 7 inclusion in the SMN2 gene. Transient expression of anti-SMN U7 snRNAs in HeLa cells modulated SMN2 splicing to approximately 70% exon 7 inclusion in a sequence-specific and dose-dependent manner. Significantly, the administration of anti-SMN U7 snRNPs results in an increase in the concentration of SMN protein. These results suggest that modulation of SMN2 pre-mRNA splicing by modified U7 snRNAs provides a promising form of gene therapy for the treatment of SMA.
authors.affiliation: Department of Microbiology and Molecular Genetics, College of Medicine, University of California at Irvine, Irvine, CA 92697-4025, USA.
authors.forename: Csilla
authors.initials: C
authors.lastname: Madocsai
authors.forename: Sharlene R
authors.initials: SR
authors.lastname: Lim
authors.forename: Till
authors.initials: T
authors.lastname: Geib
authors.forename: Bianca J
authors.initials: BJ
authors.lastname: Lam
authors.forename: Klemens J
authors.initials: KJ
authors.lastname: Hertel
mesh_terms: D015153:Blotting, Western; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics*; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D005091:Exons; D005821:Genetic Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006367:HeLa Cells; D006720:Homozygote; D006801:Humans; D008957:Models, Genetic; D009134:Muscular Atrophy, Spinal / Q000235:genetics / Q000628:therapy*; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics*; D016376:Oligonucleotides, Antisense / Q000737:chemistry; D020033:Protein Isoforms; D012326:RNA Splicing; D012342:RNA, Small Nuclear / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics*; D055532:SMN Complex Proteins; D055533:Survival of Motor Neuron 1 Protein; D055540:Survival of Motor Neuron 2 Protein; D014162:Transfection
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein; D009419:Nerve Tissue Proteins; D016376:Oligonucleotides, Antisense; D020033:Protein Isoforms; D012342:RNA, Small Nuclear; D016601:RNA-Binding Proteins; D055532:SMN Complex Proteins; C526471:SMN1 protein, human; C526477:SMN2 protein, human; D055533:Survival of Motor Neuron 1 Protein; D055540:Survival of Motor Neuron 2 Protein; C405487:U7 small nuclear RNA; D004247:DNA