Abstract 19242: Allele-Specific Silencing of MYH7 in Human iPSC-Derived Cardiomyocytes Using Antisense Oligonucleotides
Introduction: Hypertrophic cardiomyopathy (HCM) is an autosomal genetic disease which results in hypertrophy of the left ventricular wall and remains a leading cause of sudden death in young adults. Current standard of care treatments for HCM involve invasive procedures including myectomies and alcohol septal ablation.
Hypothesis: Often caused by heterozygous, dominant mutations, we hypothesize that HCM is an ideal target for allele-specific RNA silencing, and that we can enact that silencing using antisense oligonucleotides (ASOs). By reducing expression of a single, mutant allele, we may be able to relieve HCM disease phenotypes.
Methods: Here, we knockdown expression of a mutant version of MYH7 (beta-myosin heavy chain) in heterozygous iPSC-derived cardiomyocytes (iPSC-CMs) using short, 12-mer antisense oligonucleotides. These ASOs discriminate a single nucleotide change between wild-type and mutant alleles. Our iPSC-CM line contains one of the most common HCM causing mutations, R403Q in MYH7, which causes an arginine to glutamine change in the 403rd amino acid.
Results: Patient-derived iPSC-cardiomyocytes with a single version of this mutant allele show a 49% decrease in mutant allele expression (p=0.0013, t-test) after treatment with our silencing ASOs while showing no significant decrease in expression of the wild-type allele (p=0.1253, t-test), as compared to iPSC-CMs treated with a matched, scrambled control ASO. We additionally observe changes in hypertrophic biomarkers and contractile phenotypes of disease post-treatment.
Conclusions: Short, antisense oligonucleotides have the ability to discriminate between wild-type and disease-causing alleles in MYH7. By reducing expression of the mutant version of the gene, we may be able to ameliorate disease phenotypes. Allele-specific ASO silencing may prove to be an effective strategy for reducing deleterious-allele expression in hypertrophic cardiomyopathy and holds potential as a non-invasive therapeutic strategy.
Author Disclosures: A. Dainis: None. M. Wheeler: None. E. Ashley: None.
- © 2016 by American Heart Association, Inc.