FIGURE 1.

Effects of altered osmotic stresses on DNA DSBs and H2AX phosphorylation. A, increases in γH2AX following increased sorbitol concentrations in various human corneal epithelial cells. B, effects of high concentrations of extracellular solutes: sorbitol (300 mm), glucose (300 mm), sucrose (300 mm), and NaCl (300 mm) on increases in γH2AX in HCE cells. C, high concentration sorbitol-induced γH2AX following a time course in HCE cells. D, localization of hyperosmotic stress-induced γH2AX in nuclei of HCE cells. E, hyperosmotic stress-induced DNA DSBs in HCE cells. DNA DSBs were detected with Comet assays in sorbitol (250 mm)-treated cells, and the anti-tumor drug etoposide (20 μg/ml)-treated cells served as positive controls.