Talk abstracts

Talk on Saturday 10:55-11:10am submitted by Fran Jodelka

Antisense oligonucleotide correction of splicing in a mouse model of Usher syndrome

Francine M. Jodelka (Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA), Anthony Hinrich (Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA), Kate McCaffrey (Department of Biological Sciences, DePaul University, Chicago, IL, USA), Jennifer J. Lentz (Neuroscience Center, LSU Health Sciences Center, New Orleans, LA, USA), Dominik M. Duelli (Department of Pathology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA), Michelle L. Hastings (Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA)

Abstract:
Usher syndrome is the leading genetic cause of combined blindness and deafness. Until recently, an obstacle to developing treatment strategies for the disease has been the lack of animal models that develop both auditory and visual defects. One mouse model for Usher syndrome that exhibits both phenotypes is based on a mutation in the USH1C gene, USH1C/G216A. This mutation causes the activation of a cryptic 5’ splice site that is used preferentially over the normal site. Splicing from the cryptic site produces a truncated mRNA and protein product. This mouse model provides a valuable tool to investigate therapeutic strategies for Usher syndrome. We used antisense oligonucleotides (ASO) targeted to the cryptic 5’ splice site to correct splicing of Ush1C pre-mRNA and restore proper USH1C expression. ASOs were first tested in a cell-free splicing assay and further validated using an USH1C/G216A minigene expression system. Optimized ASOs were then tested on the endogenous USH2C/G216A transcript and were found to completely correct splicing in cell lines derived from Usher syndrome patients as well as in cell lines derived from USH1C/G216A mouse tissues. The most effective ASO also corrected splicing in multiple tissues when injected into USH1C/G216A mice. Our results suggest therapeutic potential of ASOs in Usher syndrome and other diseases caused by mutations that disrupt splicing.

Keywords: Usher syndrome, Splicing, RNA and disease