Click on image to view larger version.
Figure 2. Inhibition of Jak signaling prevents retinal degeneration after bright light exposure. A) Immediately before light exposure, BALB/c mice received a single injection of 800 µg AG-490 (ag) or carrier DMSO (dm) or were not injected. Mice were subsequently exposed for 1 h to 5'000 lux or not (dark) and phosphorylation of proteins was tested 18 h postexposure. Retinal proteins from separate animals were loaded in each lane. B) Retinas of animals not exposed to light (dark) or of animals pretreated with AG-490 (ag) of DMSO (dm) and exposed for 1 h to 5'000 lux were used to quantify apoptosis by ELISA. *P = 0.003, 2-tailed t test; n = 10 mice for each condition. C) Light microscopy 18 h after light exposure. Retinas of dark control mice showed regular photoreceptors (upper panel). Retinas of AG-490 (ag)-treated mice exhibited few apoptotic photoreceptor nuclei (arrowheads, middle panel); retinas of carrier (DMSO, dm)-treated mice had significantly more dying photoreceptors (arrowheads, lower panel). RPE: retinal pigment epithelium; reactive oxygen species (ROS): rod outer segments; RIS: rod inner segments; ONL outer nuclear layer.
