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Updated: Oct 12, 2025
Multi-exon Skipping Using Cocktail Antisense Oligonucleotides in the Canine X-linked Muscular Dystrophy
Published on: May 24, 2016
Intramuscular Evaluation of Chimeric Locked Nucleic Acid/2'OMethyl-Modified Antisense Oligonucleotides for Targeted
Michaella Georgiadou1, Melina Christou1, Kleitos Sokratous2
1Molecular Genetics, Function & Therapy Department, The Cyprus Institute of Neurology & Genetics, Nicosia 2371, Cyprus.
Abstract:
Duchenne muscular dystrophy (DMD) is a fatal disorder characterised by progressive muscle wasting. It is caused by mutations in the dystrophin gene, which disrupt the open reading frame leading to the loss of functional dystrophin protein in muscle fibres. Antisense oligonucleotide (AON)-mediated skipping of the mutated exon, which allows production of a truncated but partially functional dystrophin protein, has been at the forefront of DMD therapeutic research for over two decades. Nonetheless, novel nucleic acid modifications and AON designs are continuously being developed to improve the clinical benefit profile of current drugs in the DMD pipeline. We herein designed a series of 15mer and 20mer AONs, consisting of 2'O-Methyl (2'OMe)- and locked nucleic acid (LNA)-modified nucleotides in different percentage compositions, and assessed their efficiency in inducing exon 23 skipping and dystrophin restoration in locally injected muscles of mdx mice. We demonstrate that LNA/2'OMe AONs with a 30% LNA composition were significantly more potent in inducing exon skipping and dystrophin restoration in treated mdx muscles, compared to a previously tested 2'OMe AON and LNA/2'OMe chimeras with lower or higher LNA compositions. These results underscore the therapeutic potential of LNA/2'OMe AONs, paving the way for further experimentation to evaluate their benefit-toxicity profile following systemic delivery.
Insights
Antisense oligonucleotides (AONs) modified with locked nucleic acids (LNAs) show promise for Duchenne muscular dystrophy (DMD) treatment. A 30% LNA composition in AONs significantly enhanced exon skipping and dystrophin restoration in mdx mouse models.
Area of Science:
- Biochemistry
- Genetics
- Molecular Biology
Background:
- Duchenne muscular dystrophy (DMD) results from dystrophin gene mutations, leading to muscle wasting.
- Antisense oligonucleotide (AON)-mediated exon skipping is a leading therapeutic strategy for DMD.
- Ongoing research focuses on novel nucleic acid modifications to enhance AON efficacy.
Purpose of the Study:
- To design and evaluate novel antisense oligonucleotides (AONs) with modified nucleotides for Duchenne muscular dystrophy (DMD) treatment.
- To assess the efficiency of LNA/2'OMethyl (2'OMe) AONs in inducing exon 23 skipping and dystrophin restoration in mdx mice.
Main Methods:
- Designed 15mer and 20mer AONs with varying percentages of 2'OMethyl and locked nucleic acid (LNA) modifications.
- Assessed exon skipping and dystrophin restoration in muscles of mdx mice injected with designed AONs.
Main Results:
- AONs with 30% LNA composition demonstrated significantly higher potency in inducing exon skipping and dystrophin restoration.
- These LNA/2'OMe AONs outperformed previously tested 2'OMe AONs and chimeras with different LNA percentages.
- Significant restoration of dystrophin protein was observed in treated mdx mouse muscles.
Conclusions:
- LNA/2'OMe AONs, particularly those with 30% LNA, represent a promising therapeutic approach for Duchenne muscular dystrophy.
- These findings support further investigation into the benefit-toxicity profile of LNA/2'OMe AONs for systemic delivery in DMD treatment.
