Suppression of rds expression by siRNA and gene replacement strategies for gene therapy using rAAV vector

Abstract

Small interfering RNA (siRNA) is a promising tool for the treatment of dominant diseases. Autosomal dominant eye diseases like retinitis pigmentosa are a leading cause of blindness. Mutations in rds/peripherin lead to the degeneration of photoreceptors and are associated with several autosomal retinal diseases. Our goal is to develop a gene therapy for rds mutations. We describe an siRNA-based mutation-independent approach, targeting rds in which levels of endogenous mutant and wild-type mRNA were reduced, and an siRNA-resistant version of rds gene was supplied simultaneously. siRNAs and resistant rds were delivered to the photoreceptors by recombinant adeno-associated virus (rAAV) vector through subretinal injections. The retinal phenotype was examined, both structurally and functionally at different time points after rAAV delivery. We demonstrate suppression of rds transcript by up to 50% with concomitant expression of replacement transcript in the retina of mice in vivo. These results validate the concept of suppression of rds and replacement strategies of gene therapy with rAAV vectors containing siRNA. © 2012 Springer Science+Business Media, LLC.