Phototoxicity avoidance is a potential therapeutic approach for retinal dystrophy caused by EYS dysfunction
Yuki Otsuka, Keiko Imamura, Akio Oishi, Kazuhide Asakawa, Takayuki Kondo, Risako Nakai, Mika Suga, Ikuyo Inoue, Yukako Sagara, Kayoko Tsukita, Kaori Teranaka, Yu Nishimura, Akira Watanabe, Kazuhiro Umeyama, Nanako Okushima, Kohnosuke Mitani, Hiroshi Nagashima, Koichi Kawakami, Keiko Muguruma, Akitaka Tsujikawa, Haruhisa Inoue
Yuki Otsuka, Keiko Imamura, Akio Oishi, Kazuhide Asakawa, Takayuki Kondo, Risako Nakai, Mika Suga, Ikuyo Inoue, Yukako Sagara, Kayoko Tsukita, Kaori Teranaka, Yu Nishimura, Akira Watanabe, Kazuhiro Umeyama, Nanako Okushima, Kohnosuke Mitani, Hiroshi Nagashima, Koichi Kawakami, Keiko Muguruma, Akitaka Tsujikawa, Haruhisa Inoue
View: Text | PDF
Research Article Ophthalmology Stem cells

Phototoxicity avoidance is a potential therapeutic approach for retinal dystrophy caused by EYS dysfunction

Abstract

Inherited retinal dystrophies (IRDs) are progressive diseases leading to vision loss. Mutation in the eyes shut homolog (EYS) gene is one of the most frequent causes of IRD. However, the mechanism of photoreceptor cell degeneration by mutant EYS has not been fully elucidated. Here, we generated retinal organoids from induced pluripotent stem cells (iPSCs) derived from patients with EYS-associated retinal dystrophy (EYS-RD). In photoreceptor cells of RD organoids, both EYS and G protein–coupled receptor kinase 7 (GRK7), one of the proteins handling phototoxicity, were not in the outer segment, where they are physiologically present. Furthermore, photoreceptor cells in RD organoids were vulnerable to light stimuli, and especially to blue light. Mislocalization of GRK7, which was also observed in eys-knockout zebrafish, was reversed by delivering control EYS into photoreceptor cells of RD organoids. These findings suggest that avoiding phototoxicity would be a potential therapeutic approach for EYS-RD.

Authors

Yuki Otsuka, Keiko Imamura, Akio Oishi, Kazuhide Asakawa, Takayuki Kondo, Risako Nakai, Mika Suga, Ikuyo Inoue, Yukako Sagara, Kayoko Tsukita, Kaori Teranaka, Yu Nishimura, Akira Watanabe, Kazuhiro Umeyama, Nanako Okushima, Kohnosuke Mitani, Hiroshi Nagashima, Koichi Kawakami, Keiko Muguruma, Akitaka Tsujikawa, Haruhisa Inoue

×

Figure 2

EYS localization in human retinal organoids, pig, and zebrafish.

Options: View larger image (or click on image) Download as PowerPoint
EYS localization in human retinal organoids, pig, and zebrafish. (A) Rep...
(A) Representative immunofluorescence images of control retinal organoids on day 100 and day 180 stained for EYS and acetylated α-tubulin (AcTub). Lower panels are higher-magnification images of the dotted boxes in the upper panels. White arrowheads indicate the CC, and white arrows indicate the nascent OS. ONL, outer nuclear layer. Scale bars: 10 μm. (B) Two representative immunostaining images of control retinal organoids on day 180, using orthogonal projections. EYS immunoreactivity colocalized with AcTub (white arrowheads). Scale bars: 10 μm. (C) Representative immunohistochemistry images of EYS and AcTub in WT pig retina. Lower panels are higher-magnification images of the dotted box in the upper panel. White arrowheads indicate the CC, and white arrows indicate the OS. RPE, retinal pigment epithelium. Scale bars: 10 μm. (D) Representative immunohistochemistry images of Eys and AcTub in WT zebrafish retina. Lower panels are higher-magnification images of the dotted box in the upper panel. White arrowheads indicate the CC. CC-C, cone CC; CC-R, rod CC; ONL-C, cone ONL; ONL-R, rod ONL; OS-DC, double cone outer segment; OS-LSC, long single cone outer segment; OS-R, rod outer segment. Scale bars: 10 μm. (E) Representative immunoelectron microscopy images of WT zebrafish retina. Upper panel shows staining with anti-Eys antibody. Negative control without the primary antibody is shown in the lower panel. AOS, accessory outer segment. Scale bars: 500 nm.