title: Bubble liposomes and ultrasound exposure improve localized morpholino oligomer delivery into the skeletal muscles of dystrophic mdx mice.
abstract: Duchenne muscular dystrophy (DMD) is a genetic disorder that is caused by mutations in the DMD gene that lead to an absence of functional protein. The mdx dystrophic mouse contains a nonsense mutation in exon 23 of the dystrophin gene; a phosphorodiamidate morpholino oligomer (PMO) designed to skip this mutated exon in the mRNA induces dystrophin expression. However, an efficient PMO delivery method is needed to improve treatment strategies for DMD. We previously developed polyethylene glycol (PEG)-modified liposomes (Bubble liposomes) that entrap ultrasound contrast gas and demonstrated that the combination of Bubble liposomes with ultrasound exposure is an effective gene delivery tool in vitro and in vivo. In this study, to evaluate the ability of Bubble liposomes as a PMO delivery tool, we tested the potency of the Bubble liposomes combined with ultrasound exposure to boost the delivery of PMO and increase the skipping of the mutated exon in the mdx mouse. The results indicated that the combination of Bubble liposomes and ultrasound exposure increased the uptake of the PMO targeting a nonsense mutation in exon 23 of the dystrophin gene and consequently increased the PMO-mediated exon-skipping efficiency compared with PMO injection alone, leading to significantly enhanced dystrophin expression. This increased efficiency indicated the potential of the combination of Bubble liposomes with ultrasound exposure to enhance PMO delivery for treating DMD. Thus, this ultrasound-mediated Bubble liposome technique may provide an effective, noninvasive, nonviral method for PMO therapy for DMD muscle as well as for other muscular dystrophies.
authors.affiliation: Department of Drug Delivery and Molecular Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences , 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Negishi
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ishii
authors.forename: Hitomi
authors.initials: H
authors.lastname: Shiono
authors.forename: Saki
authors.initials: S
authors.lastname: Akiyama
authors.forename: Shoko
authors.initials: S
authors.lastname: Sekine
authors.forename: Takuo
authors.initials: T
authors.lastname: Kojima
authors.forename: Sayaka
authors.initials: S
authors.lastname: Mayama
authors.forename: Taiki
authors.initials: T
authors.lastname: Kikuchi
authors.forename: Nobuhito
authors.initials: N
authors.lastname: Hamano
authors.forename: Yoko
authors.initials: Y
authors.lastname: Endo-Takahashi
authors.forename: Ryo
authors.initials: R
authors.lastname: Suzuki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Maruyama
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Aramaki
mesh_terms: D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D049109:Cell Proliferation; D002478:Cells, Cultured; D016189:Dystrophin / Q000037:antagonists & inhibitors* / Q000502:physiology; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D007124:Immunoenzyme Techniques; D008081:Liposomes; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D060172:Morpholinos / Q000008:administration & dosage* / Q000494:pharmacology; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology / Q000528:radiation effects; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics / Q000628:therapy*; D016376:Oligonucleotides, Antisense / Q000008:administration & dosage* / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014465:Ultrasonics
chemical_list: D016189:Dystrophin; D008081:Liposomes; D060172:Morpholinos; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger
keywords: Bubble liposomes; delivery of an antisense phosphorodiamidate morpholino oligomer (PMO); exon-skipping therapy; muscular dystrophy; ultrasound