Figure 7. The effect of light wavelength on photoreceptor cell death in retinal organoids.

(A) Retinal organoids were exposed to blue, green, or red LED light on day 180 for 24 hours. (B) The peak wavelengths of blue, green, and red lights were 454, 514, and 628 nm, respectively. (C) Representative immunofluorescence images of photoreceptor marker (ARR1) and cleaved caspase-3 (Cl. CASP3) in control and RD retinal organoids after exposure to each LED light. White arrowheads indicate cleaved caspase-3–positive cells. Scale bars: 50 μm. (D) Quantification of the data in C. The y axis indicates the number of cleaved caspase-3–positive cells per field. Data represent mean ± SEM from 3 retinal organoids. One-way ANOVA with Dunnett’s post hoc test was used for statistical comparison (*P < 0.05). (E) Schematic representation of putative mechanism of EYS-RD. EYS interacts with GRK7 and transports it from the IS to the OS. In control photoreceptor cells, EYS can localize at the CC and OS, whereas in RD, EYS with GRK7 cannot distribute to these regions. Light-induced damage via excessive reactive oxygen species production is caused by the mislocalization of mutant EYS with GRK7.