title: Gene Therapy Fully Restores Vision to the All-Cone Nrl(-/-) Gucy2e(-/-) Mouse Model of Leber Congenital Amaurosis-1.
abstract: Mutations in GUCY2D are the cause of Leber congenital amaurosis type 1 (LCA1). GUCY2D encodes retinal guanylate cyclase-1 (retGC1), a protein expressed exclusively in outer segments of photoreceptors and essential for timely recovery from photoexcitation. Recent clinical data show that, despite a high degree of visual disturbance stemming from a loss of cone function, LCA1 patients retain normal photoreceptor architecture, except for foveal cone outer segment abnormalities and, in some patients, foveal cone loss. These results point to the cone-rich central retina as a target for GUCY2D replacement. LCA1 gene replacement studies thus far have been conducted in rod-dominant models (mouse) or with vectors and organisms lacking clinical translatability. Here we investigate gene replacement in the Nrl(-/-) Gucy2e(-/-) mouse, an all-cone model deficient in retGC1. We show that AAV-retGC1 treatment fully restores cone function, cone-mediated visual behavior, and guanylate cyclase activity, and preserves cones in treated Nrl(-/-) Gucy2e(-/-) mice over the long-term. A novel finding was that retinal function could be restored to levels above that in Nrl(-/-) controls, contrasting results in other models of retGC1 deficiency. We attribute this to increased cyclase activity in treated Nrl(-/-) Gucy2e(-/-) mice relative to Nrl(-/-) controls. Thus, Nrl(-/-) Gucy2e(-/-) mice possess an expanded dynamic range in ERG response to gene replacement relative to other models. Lastly, we show that a candidate clinical vector, AAV5-GRK1-GUCY2D, when delivered to adult Nrl(-/-) Gucy2e(-/-) mice, restores retinal function that persists for at least 6 months. Our results provide strong support for clinical application of a gene therapy targeted to the cone-rich, central retina of LCA1 patients.
authors.affiliation: 1 Department of Ophthalmology, College of Medicine, University of Florida , Gainesville, Florida.
authors.forename: Sanford L
authors.initials: SL
authors.lastname: Boye
authors.affiliation: 1 Department of Ophthalmology, College of Medicine, University of Florida , Gainesville, Florida.
authors.forename: James J
authors.initials: JJ
authors.lastname: Peterson
authors.affiliation: 1 Department of Ophthalmology, College of Medicine, University of Florida , Gainesville, Florida.
authors.forename: Shreyasi
authors.initials: S
authors.lastname: Choudhury
authors.affiliation: 1 Department of Ophthalmology, College of Medicine, University of Florida , Gainesville, Florida.
authors.forename: Seok Hong
authors.initials: SH
authors.lastname: Min
authors.affiliation: 1 Department of Ophthalmology, College of Medicine, University of Florida , Gainesville, Florida.
authors.forename: Qing
authors.initials: Q
authors.lastname: Ruan
authors.affiliation: 1 Department of Ophthalmology, College of Medicine, University of Florida , Gainesville, Florida.
authors.forename: K Tyler
authors.initials: KT
authors.lastname: McCullough
authors.affiliation: 1 Department of Ophthalmology, College of Medicine, University of Florida , Gainesville, Florida.
authors.forename: Zhonghong
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: 2 Department of Basic Sciences Research, Salus University , Elkins Park, Pennsylvania.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Olshevskaya
authors.affiliation: 2 Department of Basic Sciences Research, Salus University , Elkins Park, Pennsylvania.
authors.forename: Igor V
authors.initials: IV
authors.lastname: Peshenko
authors.affiliation: 1 Department of Ophthalmology, College of Medicine, University of Florida , Gainesville, Florida.
authors.forename: William W
authors.initials: WW
authors.lastname: Hauswirth
authors.affiliation: 3 Department of Cell Biology, College of Medicine, University of Oklahoma , Oklahoma City, Oklahoma.
authors.forename: Xi-Qin
authors.initials: XQ
authors.lastname: Ding
authors.affiliation: 2 Department of Basic Sciences Research, Salus University , Elkins Park, Pennsylvania.
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Dizhoor
authors.affiliation: 1 Department of Ophthalmology, College of Medicine, University of Florida , Gainesville, Florida.
authors.forename: Shannon E
authors.initials: SE
authors.lastname: Boye
mesh_terms: D000818:Animals; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics*; D000229:Dependovirus / Q000235:genetics; D004195:Disease Models, Animal; D005136:Eye Proteins / Q000235:genetics*; D015316:Genetic Therapy; D005822:Genetic Vectors; D006162:Guanylate Cyclase / Q000235:genetics* / Q000378:metabolism; D056965:Injections, Intraocular; D057130:Leber Congenital Amaurosis / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D055355:Opsins / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism; D017949:Retinal Cone Photoreceptor Cells / Q000473:pathology; D016896:Treatment Outcome; D014785:Vision, Ocular
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D005136:Eye Proteins; C084884:Nrl protein, mouse; D055355:Opsins; D011956:Receptors, Cell Surface; D006162:Guanylate Cyclase; C484774:Gucy2d protein, mouse; C484780:Gucy2e protein, mouse