Abstract
Purpose :
To demonstrate the allele-selective knockdown of human P23H rhodopsin mRNA using the GAPmer antisense oligonucleotide (ASO) QR-1123 and that, when dosed intravitreally, QR-1123 reduces the rate of retinal loss in a humanized P23H rhodopsin knock-in mouse model of adRP
Methods :
HEK293 cells stably expressing human rhodopsin mini-genes with mutation (P23H) or without (WT), were used to determine the selectivity of QR-1123 for the rhodopsin mRNA containing the C-A transversion (P23H). Human P23H/WT transgenic mice (hP23HTg) were created and used to determine the ability of QR-1123 to selectively target the P23H mutant mRNA in vivo following intravitreal delivery, and its ability to limit the retinal degeneration in the P23H rhodopsin expressing mouse
Results :
QR-1123 was demonstrated to selectively target the human P23H mutant rhodopsin mRNA, whilst sparing the human WT rhodopsin sequence using an RNAase H1-dependent mechanism in transfected cell lines containing either human rhodopsin mini-gene. When unilaterally dosed by intravitreal injection into humanized rhodopsin knock-in mice expressing either WT or mutated rhodopsin, QR-1123 selectively reduced the P23H human rhodopsin mRNA whilst having little impact in the human WT rhodopsin expressing mice. QR-1123 also showed a capacity to dramatically slow the retinal degeneration in the P23H humanized knock-in model in both inferior and superior retina, when compared to either control non-dosed animals, or in PBS injected contralateral eyes from the same animals
Conclusions :
Selective, allele-specific ASO mediated knockdown of human P23H rhodopsin expression by QR-1123 was demonstrated in cell lines containing human rhodopsin sequences and in transgenic human rhodopsin knock-in mice. QR-1123 when dosed intravitreally also slowed the rate of photoreceptor degeneration in the humanized P23H rhodopsin knock-in mouse. These data indicate that ASO treatment is a potentially effective therapy for adRP, arising from P23H mutation in rhodopsin
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.