Light-driven cone arrestin translocation in cones of postnatal guanylate cyclase-1 knockout mouse retina treated with AAV-GC1.
OBJECTIVE
Cone function and survival are compromised in the guanylate cyclase-1 (GC1) knockout mouse. Disruption of the light-driven translocation of cone arrestin is one of the phenotypes of cone cells in this retina: the cone arrestin in these cells is localized to the outer segments and synaptic terminals, regardless of the state of light adaptation. The purpose of this study was to determine whether the expression of GC1 restores cone arrestin translocation in the cone cells of postnatal GC1 knockout mouse retina.


METHODS
Subretinal injections of AAV-GC1 were performed on 3-week-old GC1 KO mice. Electroretinographic and immunohistochemical analyses of treated retinas were carried out 5 weeks after injection. GC1 and cone arrestin antibodies were used to identify photoreceptors transduced by the AAV vector and to localize cone arrestin within cone cells, respectively.


RESULTS
Treatment of GC1 knockout retinas with AAV-GC1 restored the light-driven translocation of cone arrestin in transduced cone cells. Staining patterns for cone arrestin in transduced and wild-type cone cells were indistinguishable after dark and light adaptation. In dark-adapted retinas, cone arrestin was distributed throughout the subcellular compartments of the cone cells. In light-adapted retinas, cone arrestin was concentrated in the cone outer segments. Successful restoration of cone arrestin translocation did not translate to a restoration of cone ERG responses, which remained undetectable in the treated retinas.


CONCLUSIONS
AAV-mediated expression of GC1 in a subpopulation of cone cells in postnatal GC1 knockout retina restores light-driven translocation of cone arrestin in these cells. These findings, which show that fully developed cone cells that have developed in the absence of GC1 can respond to viral-mediated expression of this enzyme, support further analysis of this animal model of Leber congenital amaurosis type 1 (LCA1), a disease that results from null mutations in the gene encoding this enzyme.
Haire
Shannon E
SE
Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0244, USA.
Pang
Jijing
J
Boye
Sanford L
SL
Sokal
Izabel
I
Craft
Cheryl M
CM
Palczewski
Krzysztof
K
Hauswirth
William W
WW
Semple-Rowland
Susan L
SL
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D019393:Arrestin / Q000737:chemistry / Q000378:metabolism*; D000229:Dependovirus / Q000235:genetics*; D004596:Electroretinography; D019084:Fluorescent Antibody Technique, Indirect; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006162:Guanylate Cyclase / Q000235:genetics*; D008027:Light; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology; D021381:Protein Transport / Q000528:radiation effects*; D011956:Receptors, Cell Surface / Q000235:genetics*; D012160:Retina / Q000502:physiology; D017949:Retinal Cone Photoreceptor Cells / Q000378:metabolism* / Q000528:radiation effects; D019076:Transgenes; D014785:Vision, Ocular
D000911:Antibodies, Monoclonal; D019393:Arrestin; D010446:Peptide Fragments; D011956:Receptors, Cell Surface; C110715:guanylate cyclase 1; D006162:Guanylate Cyclase