Send to

Choose Destination
Am J Hum Genet. 2008 Apr;82(4):834-48. doi: 10.1016/j.ajhg.2008.01.014. Epub 2008 Mar 27.

Antisense masking of an hnRNP A1/A2 intronic splicing silencer corrects SMN2 splicing in transgenic mice.

Author information

Cold Spring Harbor Laboratory, PO Box 100, Cold Spring Harbor, NY 11724, USA.


Survival of motor neuron 2, centromeric (SMN2) is a gene that modifies the severity of spinal muscular atrophy (SMA), a motor-neuron disease that is the leading genetic cause of infant mortality. Increasing inclusion of SMN2 exon 7, which is predominantly skipped, holds promise to treat or possibly cure SMA; one practical strategy is the disruption of splicing silencers that impair exon 7 recognition. By using an antisense oligonucleotide (ASO)-tiling method, we systematically screened the proximal intronic regions flanking exon 7 and identified two intronic splicing silencers (ISSs): one in intron 6 and a recently described one in intron 7. We analyzed the intron 7 ISS by mutagenesis, coupled with splicing assays, RNA-affinity chromatography, and protein overexpression, and found two tandem hnRNP A1/A2 motifs within the ISS that are responsible for its inhibitory character. Mutations in these two motifs, or ASOs that block them, promote very efficient exon 7 inclusion. We screened 31 ASOs in this region and selected two optimal ones to test in human SMN2 transgenic mice. Both ASOs strongly increased hSMN2 exon 7 inclusion in the liver and kidney of the transgenic animals. Our results show that the high-resolution ASO-tiling approach can identify cis-elements that modulate splicing positively or negatively. Most importantly, our results highlight the therapeutic potential of some of these ASOs in the context of SMA.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center