Figure 8.

JNK-specific inhibitor JNK–IN-8 alleviates light-induced photoreceptor degeneration and apoptosis in Abca4^−/−Rdh8^−/− mice. 48-h dark-adapted Abca4^−/−Rdh8^−/− mice at 4 weeks of age were intraperitoneally injected with JNK–IN-8 or DMSO (vehicle) (4 mg/kg body weight). One hour later, pupils of mice were dilated with 1% tropicamide, and the mice were exposed to LED light with the intensity of 10,000 lx for 2 h, followed by once-daily treatment with JNK–IN-8 or DMSO (vehicle) (4 mg/kg body weight) for 4 days. Eyeballs, 5 days after light illumination, were collected for subsequent studies. Control Abca4^−/−Rdh8^−/− mice were administered intraperitoneally with JNK–IN-8 or DMSO (vehicle) (4 mg/kg body weight) in the absence of light exposure. A, morphology of mouse retina was analyzed by H&E staining. Scale bars, 20 μm. B, apoptotic cells in mouse retina were examined by TUNEL staining. Scale bars, 20 μm. C and D, immunoblot analysis of p-c-Jun, c-Jun, cleaved caspase-3, and γH2AX in extracts from mouse neural retina. GAPDH served as a loading control. Molecular mass markers (kDa) are indicated to the left of the blots.