title: Mislocalisation of BEST1 in iPSC-derived retinal pigment epithelial cells from a family with autosomal dominant vitreoretinochoroidopathy (ADVIRC).
abstract: Autosomal dominant vitreoretinochoroidopathy (ADVIRC) is a rare, early-onset retinal dystrophy characterised by distinct bands of circumferential pigmentary degeneration in the peripheral retina and developmental eye defects. ADVIRC is caused by mutations in the Bestrophin1 (BEST1) gene, which encodes a transmembrane protein thought to function as an ion channel in the basolateral membrane of retinal pigment epithelial (RPE) cells. Previous studies suggest that the distinct ADVIRC phenotype results from alternative splicing of BEST1 pre-mRNA. Here, we have used induced pluripotent stem cell (iPSC) technology to investigate the effects of an ADVIRC associated BEST1 mutation (c.704T > C, p.V235A) in patient-derived iPSC-RPE. We found no evidence of alternate splicing of the BEST1 transcript in ADVIRC iPSC-RPE, however in patient-derived iPSC-RPE, BEST1 was expressed at the basolateral membrane and the apical membrane. During human eye development we show that BEST1 is expressed more abundantly in peripheral RPE compared to central RPE and is also expressed in cells of the developing retina. These results suggest that higher levels of mislocalised BEST1 expression in the periphery, from an early developmental stage, could provide a mechanism that leads to the distinct clinical phenotype observed in ADVIRC patients.
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
authors.forename: David A
authors.initials: DA
authors.lastname: Carter
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
authors.forename: Matthew J K
authors.initials: MJ
authors.lastname: Smart
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
authors.forename: William V G
authors.initials: WV
authors.lastname: Letton
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.|Moorfields Eye Hospital, 162 City Road, London, EC1V 2PD, UK.
authors.forename: Conor M
authors.initials: CM
authors.lastname: Ramsden
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
authors.forename: Britta
authors.initials: B
authors.lastname: Nommiste
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
authors.forename: Li Li
authors.initials: LL
authors.lastname: Chen
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
authors.forename: Kate
authors.initials: K
authors.lastname: Fynes
authors.affiliation: Moorfields Eye Hospital, 162 City Road, London, EC1V 2PD, UK.
authors.forename: Manickam N
authors.initials: MN
authors.lastname: Muthiah
authors.affiliation: Research Department of Haematology, UCL Cancer Institute, 72 Huntley Street, London, WC1E 6DD, UK.
authors.forename: Pollyanna
authors.initials: P
authors.lastname: Goh
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
authors.forename: Amelia
authors.initials: A
authors.lastname: Lane
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Powner
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.|Moorfields Eye Hospital, 162 City Road, London, EC1V 2PD, UK.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Webster
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.|Moorfields Eye Hospital, 162 City Road, London, EC1V 2PD, UK.
authors.forename: Lyndon
authors.initials: L
authors.lastname: da Cruz
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.|Moorfields Eye Hospital, 162 City Road, London, EC1V 2PD, UK.|UCSF School of Medicine, Beckman Vision Center, 10 Koret Way, San Francisco, CA 94143, USA.
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Moore
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Coffey
authors.affiliation: Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
authors.forename: Amanda-Jayne F
authors.initials: AF
authors.lastname: Carr