Figure 5: SB216763 protects retinal neurons from ischemic injury in vivo. (A) SB216763 pretreatment upregulated expression of p-CREB1 and ligase IV in the retinas of rats subjected to I/R injury. (B) Relative expression of p-CREB1 and ligase IV in rat retinas quantified by densitometry is presented as a histogram. (C) γ-H2AX foci labeled double-strand DNA breaks in rat retinas subjected to I/R injury. γ-H2AX-positive cells (red staining by Alexa Fluor 555) were primarily located in the ganglion cell layer of ischemic rat retinas. Scale bars: 40 μm. (D) SB216763 pretreatment significantly suppressed γ-H2AX foci formation at 1 day and 3 days following I/R surgery. Data are expressed mean ± SEM. n = 3 for each group. *P < 0.05, **P < 0.01, vs. control (Con) group (Student's t-test). DAPI: 4',6-Diamidino-2-phenylindole; I/R: ischemia/reperfusion; p-CREB1: phosphorylated CREB1; SB216763: a glycogen synthase kinase-3β inhibitor; γ-H2AX: γ-H2A histone family member X.