Targeted exon skipping in transgenic hDMD mice: A model for direct preclinical screening of human-specific antisense oligonucleotides.
The therapeutic potential of frame-restoring exon skipping by antisense oligonucleotides (AONs) has recently been demonstrated in cultured muscle cells from a series of Duchenne muscular dystrophy (DMD) patients. To facilitate clinical application, in vivo studies in animal models are required to develop safe and efficient AON-delivery methods. However, since exon skipping is a sequence-specific therapy, it is desirable to target the human DMD gene directly. We therefore set up human sequence-specific exon skipping in transgenic mice carrying the full-size human gene (hDMD). We initially compared the efficiency and toxicity of intramuscular AON injections using different delivery reagents in wild-type mice. At a dose of 3.6 nmol AON and using polyethylenimine, the skipping levels accumulated up to 3% in the second week postinjection and lasted for 4 weeks. We observed a correlation of this long-term effect with the intramuscular persistence of the AON. In regenerating myofibers higher efficiencies (up to 9%) could be obtained. Finally, using the optimized protocols in hDMD mice, we were able to induce the specific skipping of human DMD exons without affecting the endogenous mouse gene. These data highlight the high sequence specificity of this therapy and present the hDMD mouse as a unique model to optimize human-specific exon skipping in vivo.
Center for Human and Clinical Genetics, Leiden University Medical Center, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands.
Mattie
M
Bremmer-Bout
Annemieke
A
Aartsma-Rus
Emile J
EJ
de Meijer
Wendy E
WE
Kaman
Anneke A M
AA
Janson
Rolf H A M
RH
Vossen
Gert-Jan B
GJ
van Ommen
Johan T
JT
den Dunnen
Judith C T
JC
van Deutekom
D000818:Animals; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D016189:Dystrophin / Q000235:genetics* / Q000378:metabolism; D005091:Exons / Q000235:genetics*; D018390:Gene Targeting / Q000379:methods*; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D018482:Muscle, Skeletal / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D020388:Muscular Dystrophy, Duchenne / Q000188:drug therapy* / Q000235:genetics; D016376:Oligonucleotides, Antisense / Q000032:analysis / Q000235:genetics / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism
C484258:DMD protein, human; D016189:Dystrophin; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger