Preferential silencing of a common dominant rhodopsin mutation does not inhibit retinal degeneration in a transgenic model.
Autosomal dominant retinitis pigmentosa caused by the frequent rhodopsin P23H mutation is characterized by progressive photoreceptor cell death eventually leading to blindness and for which no therapies are available. Considering the gain-of-function effect exerted by the P23H mutation, strategies aimed at silencing the expression of the mutated allele, like RNA interference, are desirable. We have designed small interfering RNAs (siRNA) to silence specifically the P23H rhodopsin allele expressed by a transgenic rat model of the disease. We have selected in vitro one siRNA and generated an adeno-associated viral (AAV) vector expressing the short hairpin RNA (shRNA) based on the selected siRNA. In vitro the shRNA significantly inhibits the expression of the P23H but not the wild-type rhodopsin allele. Subretinal administration of the AAV2/5 vector encoding the shRNA in P23H transgenic rats results in inhibition of rhodopsin P23H expression that is not able to prevent or block photoreceptor degeneration. Since rhodopsin is the most abundant rod photoreceptor protein, systems resulting in more robust shRNA expression in the retina may be required to achieve therapeutic efficacy in vivo.
Tessitore
Alessandra
A
Telethon Institute of Genetics and Medicine, 80131 Naples, Italy.
Parisi
Fabiana
F
Denti
Michela Alessandra
MA
Allocca
Mariacarmela
M
Di Vicino
Umberto
U
Domenici
Luciano
L
Bozzoni
Irene
I
Auricchio
Alberto
A
D000483:Alleles; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D000229:Dependovirus / Q000235:genetics; D020868:Gene Silencing; D005822:Genetic Vectors / Q000235:genetics; D051379:Mice; D023421:Models, Animal; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D011392:Proline / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D012162:Retinal Degeneration / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D012243:Rhodopsin / Q000235:genetics* / Q000378:metabolism
D034741:RNA, Small Interfering; D012243:Rhodopsin; D011392:Proline