Altered expression of retinal molecular markers in the canine RPE65 model of Leber congenital amaurosis.
OBJECTIVE
Leber congenital amaurosis (LCA) is a group of childhood-onset retinal diseases characterized by severe visual impairment or blindness. One form is caused by mutations in the RPE65 gene, which encodes the retinal pigment epithelium (RPE) isomerase. In this study, the retinal structure and expression of molecular markers for different retinal cell types were characterized, and differences between control and RPE65 mutant dogs during the temporal evolution of the disease were analyzed.


METHODS
Retinas from normal and mutant dogs of different ages were examined by immunofluorescence with a panel of 16 different antibodies.


RESULTS
Cones and rods were preserved in the mutant retinas, and the number of cones was normal. However, there was altered expression of cone arrestin and delocalization of rod opsin. The ON bipolar cells showed sprouting of the dendritic arbors toward the outer nuclear layer (ONL) and retraction of their axons in the inner nuclear layer (INL). A decreased expression of GABA, and an increased expression of intermediate filament glial markers was also found in the mutant retinas. These changes were more evident in the adult than the young mutant retinas.


CONCLUSIONS
The structure of the retina is well preserved in the mutant retina, but several molecular changes take place in photoreceptors and in bipolar and amacrine cells. Some of these changes are structural, whereas others reflect a change in localization of the examined proteins. This study provides new information that can be applied to the interpretation of outcomes of retinal gene therapy in animal models and humans.
Hernández
Maria
M
Department of Cell Biology and Histology, University of the Basque Country (UPV/EHU), Vizcaya, Spain.
Pearce-Kelling
Susan E
SE
Rodriguez
F David
FD
Aguirre
Gustavo D
GD
Vecino
Elena
E
D000818:Animals; D015415:Biomarkers / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics*; D004195:Disease Models, Animal; D004285:Dogs; D005136:Eye Proteins / Q000235:genetics*; D019084:Fluorescent Antibody Technique, Indirect; D057130:Leber Congenital Amaurosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018613:Microscopy, Confocal; D012162:Retinal Degeneration / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D055351:Retinal Neurons / Q000378:metabolism* / Q000473:pathology; D055213:Retinal Pigment Epithelium / Q000378:metabolism* / Q000473:pathology; D019745:cis-trans-Isomerases / Q000235:genetics*; D000099178:Retinoid Isomerohydrolase
D015415:Biomarkers; D002352:Carrier Proteins; D005136:Eye Proteins; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase