Fructose Promotes Uptake and Activity of Oligonucleotides With Different Chemistries in a Context-dependent Manner in mdx Mice

Abstract

Antisense oligonucleotide (AO)-mediated exon-skipping therapeutics shows great promise in correcting frame-disrupting mutations in the DMD gene for Duchenne muscular dystrophy. However, insufficient systemic delivery limits clinical adoption. Previously, we showed that a glucose/fructose mixture augmented AO delivery to muscle in mdx mice. Here, we evaluated if fructose alone could enhance the activities of AOs with different chemistries in mdx mice. The results demonstrated that fructose improved the potency of AOs tested with the greatest effect on phosphorodiamidate morpholino oligomer (PMO), resulted in a 4.25-fold increase in the number of dystrophin-positive fibres, compared to PMO in saline in mdx mice. Systemic injection of lissamine-labeled PMO with fructose at 25 mg/kg led to increased uptake and elevated dystrophin expression in peripheral muscles, compared to PMO in saline, suggesting that fructose potentiates PMO by enhancing uptake. Repeated intravenous administration of PMO in fructose at 50 mg/kg/week for 3 weeks and 50 mg/kg/month for 5 months restored up to 20% of wild-type dystrophin levels in skeletal muscles with improved functions without detectable toxicity, compared to untreated mdx controls. Collectively, we show that fructose can potentiate AOs of different chemistries in vivo although the effect diminished over repeated administration.

Long-Term Morpholino Oligomers in Hexose Elicit Long-Lasting Therapeutic Improvements in mdx Mice

“…Recently, we identified a delivery formulation, the mixture of glucose and fructose (GF), which showed significant enhancement on the delivery of various AOs, particularly PMO, to muscle in energy-deficient mice such as dystrophin-deficient mdx mice. 11 , 12 …”

Saponins as Natural Adjuvant for Antisense Morpholino Oligonucleotides Delivery In Vitro and in mdx Mice

“…These include dantrolene-aided PMO delivery studied by Kendall et al. 24 and monosaccharide-formulated AONs reported by Yin’s group 25 , 26 ; (4) the amphiphilic polymer-mediated delivery strategy has been recently studied by us and demonstrated promising in vitro and in vivo in mdx mice. The amphiphilic nature has been verified as key, especially for the delivery of uncharged PMO.…”

Developments in reading frame restoring therapy approaches for Duchenne muscular dystrophy

“…It has also been shown feasible to increase muscle delivery of AONs by formulating them in hexose solutions [60,61] or glycine solutions [62]. This increase was observed for both PMOs and 2OMePS AONs for hexose and, the effect was shown to be related to the metabolic state of the mdx muscle, which due to active and continuous muscle regeneration has a very high demand for nutrients.…”