title: AAV-Mediated Clarin-1 Expression in the Mouse Retina: Implications for USH3A Gene Therapy.
abstract: Usher syndrome type III (USH3A) is an autosomal recessive disorder caused by mutations in clarin-1 (CLRN1) gene, leading to progressive retinal degeneration and sensorineural deafness. Efforts to develop therapies for preventing photoreceptor cell loss are hampered by the lack of a retinal phenotype in the existing USH3 mouse models and by conflicting reports regarding the endogenous retinal localization of clarin-1, a transmembrane protein of unknown function. In this study, we used an AAV-based approach to express CLRN1 in the mouse retina in order to determine the pattern of its subcellular localization in different cell types. We found that all major classes of retinal cells express AAV-delivered CLRN1 driven by the ubiquitous, constitutive small chicken β-actin promoter, which has important implications for the design of future USH3 gene therapy studies. Within photoreceptor cells, AAV-expressed CLRN1 is mainly localized at the inner segment region and outer plexiform layer, similar to the endogenous expression of other usher proteins. Subretinal delivery using a full strength viral titer led to significant loss of retinal function as evidenced by ERG analysis, suggesting that there is a critical limit for CLRN1 expression in photoreceptor cells. Taken together, these results suggest that CLRN1 expression is potentially supported by a variety of retinal cells, and the right combination of AAV vector dose, promoter, and delivery method needs to be selected to develop safe therapies for USH3 disorder.
authors.affiliation: Ophthalmology, University of Florida, Gainesville, FL, United States of America.
authors.forename: Astra
authors.initials: A
authors.lastname: Dinculescu
authors.affiliation: Ophthalmology, University of Florida, Gainesville, FL, United States of America.
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Stupay
authors.affiliation: Ophthalmology, University of Florida, Gainesville, FL, United States of America.
authors.forename: Wen-Tao
authors.initials: WT
authors.lastname: Deng
authors.affiliation: Ophthalmology, University of Florida, Gainesville, FL, United States of America.
authors.forename: Frank M
authors.initials: FM
authors.lastname: Dyka
authors.affiliation: Ophthalmology, University of Florida, Gainesville, FL, United States of America.
authors.forename: Seok-Hong
authors.initials: SH
authors.lastname: Min
authors.affiliation: Ophthalmology, University of Florida, Gainesville, FL, United States of America.
authors.forename: Sanford L
authors.initials: SL
authors.lastname: Boye
authors.affiliation: Ophthalmology, University of Florida, Gainesville, FL, United States of America.
authors.forename: Vince A
authors.initials: VA
authors.lastname: Chiodo
authors.affiliation: Ophthalmology, University of Florida, Gainesville, FL, United States of America.
authors.forename: Carolina E
authors.initials: CE
authors.lastname: Abrahan
authors.affiliation: Ophthalmology, University of Florida, Gainesville, FL, United States of America.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
authors.affiliation: Ophthalmology, University of Florida, Gainesville, FL, United States of America.
authors.forename: Qiuhong
authors.initials: Q
authors.lastname: Li
authors.affiliation: CNR Neuroscience Institute, Pisa, Italy.
authors.forename: Enrica
authors.initials: E
authors.lastname: Strettoi
authors.affiliation: CNR Neuroscience Institute, Pisa, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Novelli
authors.affiliation: Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg-University of Mainz, Mainz, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Nagel-Wolfrum
authors.affiliation: Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg-University of Mainz, Mainz, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Wolfrum
authors.affiliation: Ophthalmology, University of Florida, Gainesville, FL, United States of America.
authors.forename: W Clay
authors.initials: WC
authors.lastname: Smith
authors.affiliation: Ophthalmology, University of Florida, Gainesville, FL, United States of America.
authors.forename: William W
authors.initials: WW
authors.lastname: Hauswirth
mesh_terms: D000818:Animals; D000229:Dependovirus / Q000235:genetics; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D015316:Genetic Therapy; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D012160:Retina / Q000378:metabolism / Q000473:pathology; D012162:Retinal Degeneration / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D052245:Usher Syndromes / Q000235:genetics* / Q000473:pathology / Q000628:therapy
chemical_list: C512668:Clrn1 protein, mouse; D008565:Membrane Proteins