title: AAV-mediated gene therapy in the guanylate cyclase (RetGC1/RetGC2) double knockout mouse model of Leber congenital amaurosis.
abstract: Mutations in GUCY2D are associated with recessive Leber congenital amaurosis-1 (LCA1). GUCY2D encodes photoreceptor-specific, retinal guanylate cyclase-1 (RetGC1). Reports of retinal degeneration in LCA1 are conflicting; some describe no obvious degeneration and others report loss of both rods and cones. Proof of concept studies in models representing the spectrum of phenotypes is warranted. We have previously demonstrated adeno-associated virus (AAV)-mediated RetGC1 is therapeutic in GC1ko mice, a model exhibiting loss of cones only. The purpose of this study was to characterize AAV-mediated gene therapy in the RetGC1/RetGC2 double knockout (GCdko) mouse, a model lacking rod and cone function and exhibiting progressive loss of both photoreceptor subclasses. Use of this model also allowed for the evaluation of the functional efficiency of transgenic RetGC1 isozyme. Subretinal delivery of AAV8(Y733F) vector containing the human rhodopsin kinase (hGRK1) promoter driving murine Gucy2e was performed in GCdko mice at various postnatal time points. Treatment resulted in restoration of rod and cone function at all treatment ages and preservation of retinal structure in GCdko mice treated as late as 7 weeks of age. Functional gains and structural preservation were stable for at least 1 year. Treatment also conferred cortical- and subcortical-based visually-guided behavior. Functional efficiency of transgenic RetGC1 was indistinguishable from that of endogenous isozyme in congenic wild-type (WT) mice. This study clearly demonstrates AAV-mediated RetGC1 expression restores function to and preserves structure of rod and cone photoreceptors in a degenerative model of retinal guanylate cyclase deficiency, further supporting development of an AAV-based vector for treatment of LCA1.
authors.affiliation: Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL 32610, USA.
authors.forename: Sanford L
authors.initials: SL
authors.lastname: Boye
authors.forename: Igor V
authors.initials: IV
authors.lastname: Peshenko
authors.forename: Wei Chieh
authors.initials: WC
authors.lastname: Huang
authors.forename: Seok Hong
authors.initials: SH
authors.lastname: Min
authors.forename: Issam
authors.initials: I
authors.lastname: McDoom
authors.forename: Christine N
authors.initials: CN
authors.lastname: Kay
authors.forename: Xuan
authors.initials: X
authors.lastname: Liu
authors.forename: Frank M
authors.initials: FM
authors.lastname: Dyka
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Foster
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Umino
authors.forename: Sukanya
authors.initials: S
authors.lastname: Karan
authors.forename: Samuel G
authors.initials: SG
authors.lastname: Jacobson
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Baehr
authors.forename: Alexander
authors.initials: A
authors.lastname: Dizhoor
authors.forename: William W
authors.initials: WW
authors.lastname: Hauswirth
authors.forename: Shannon E
authors.initials: SE
authors.lastname: Boye
mesh_terms: D000818:Animals; D000229:Dependovirus / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation; D051606:G-Protein-Coupled Receptor Kinase 1 / Q000235:genetics / Q000378:metabolism; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage; D006162:Guanylate Cyclase / Q000008:administration & dosage* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D057130:Leber Congenital Amaurosis / Q000473:pathology / Q000628:therapy*; D018782:Maze Learning; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011401:Promoter Regions, Genetic; D011956:Receptors, Cell Surface / Q000008:administration & dosage* / Q000235:genetics / Q000378:metabolism; D012160:Retina / Q000201:enzymology / Q000473:pathology; D017949:Retinal Cone Photoreceptor Cells / Q000201:enzymology / Q000473:pathology; D017948:Retinal Rod Photoreceptor Cells / Q000201:enzymology / Q000473:pathology; D041623:Tomography, Optical Coherence
chemical_list: D011956:Receptors, Cell Surface; D051606:G-Protein-Coupled Receptor Kinase 1; C496764:GRK1 protein, human; D006162:Guanylate Cyclase; C484774:Gucy2d protein, mouse; C484780:Gucy2e protein, mouse