AAV-mediated gene therapy for retinal degeneration in the rd10 mouse containing a recessive PDEbeta mutation.
OBJECTIVE
To test AAV-mediated gene therapy in the rd10 mouse, a natural model of recessive RP caused by mutation of the beta-subunit of rod photoreceptor cGMP phosphodiesterase.


METHODS
One eye of a cohort of rd10 mice kept in a dark environment was subretinally injected at postnatal day (P) 14 with 1 microL AAV5-smCBA-PDEbeta. The contralateral eye was not injected. The animals were then maintained for 2 weeks in the dark before they were moved to a normal 12-hour light/12-hour dark cycling light environment for visually guided behavioral training. Three weeks after injection, treated rd10 mice were examined by scotopic and photopic electroretinography and then killed for biochemical and morphologic examination.


RESULTS
Substantial scotopic ERG signals were maintained in treated rd10 eyes, whereas untreated eyes in the same animals showed minimal signals. Treated eyes showed photopic ERG b-wave amplitudes similar to those of the normal eyes; in untreated partner eyes, only half the normal amplitudes remained. Strong PDEbeta expression was observed in photoreceptor outer segments only in treated eyes. Light microscopy showed a substantial preservation of the outer nuclear layer in most parts of the treated retina only. Electron microscopy showed good outer segment preservation only in treated eyes. A visually guided water maze behavioral test under dim light showed significantly improved performance in one eye-treated rd10 mice compared with untreated mice.


CONCLUSIONS
These data demonstrate that P14 administration of AAV5-smCBA-PDEbeta can prevent retinal degeneration in rd10 mice, as reflected by significant structural, biochemical, electrophysiological, and behavioral preservation/restoration. These results serve as a baseline for studying long-term retinal rescue in rd10 mice.
Pang
Ji-Jing
JJ
Departments of Ophthalmology, University of Florida, Gainesville, Florida 32610, USA. jpang@eye.ufl.edu
Boye
Sanford L
SL
Kumar
Ashok
A
Dinculescu
Astra
A
Deng
Wentao
W
Li
Jie
J
Li
Qiuhong
Q
Rani
Asha
A
Foster
Thomas C
TC
Chang
Bo
B
Hawes
Norman L
NL
Boatright
Jeffrey H
JH
Hauswirth
William W
WW
D000818:Animals; D020296:Animals, Congenic; D000831:Animals, Newborn; D015153:Blotting, Western; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6 / Q000235:genetics* / Q000378:metabolism; D000229:Dependovirus / Q000235:genetics*; D004195:Disease Models, Animal; D004596:Electroretinography; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D005808:Genes, Recessive; D015316:Genetic Therapy; D051379:Mice; D008810:Mice, Inbred C57BL; D009154:Mutation; D011247:Pregnancy; D011597:Psychomotor Performance / Q000502:physiology; D012160:Retina / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D012174:Retinitis Pigmentosa / Q000235:genetics* / Q000503:physiopathology / Q000517:prevention & control*
D054707:Cyclic Nucleotide Phosphodiesterases, Type 6; C517438:Pde6b protein, mouse