Figure 1

Release of HMGB1 from R28 retinal neuronal cells exposed to excessive oxidative stress. (a) Immunofluorescence was performed with anti-HMGB1 antibody (red) and DAPI (blue). HMGB1 is predominantly present in the nuclei of unstimulated R28 cells (left column). Some cells present robust upregulation of HMGB1 in the nuclei, as well as relocation into the cytoplasm (middle column; arrows) on 1 h exposure to a toxic dose of hydrogen peroxide (1 mM). In the other cells, the nuclear HMGB1 is found to be diminished or released into the cytoplasm (right column; arrowheads). Scale bars: 20 μm. (b) After 24 h exposure to 1 mM hydrogen peroxide, the cell viability analyzed by MTT assay is decreased to about 10% compared with the control. (c) Massive HMGB1 release into the culture supernatant was determined by ELISA after the same treatment as (b). The data represent the mean±s.d. (n=3). Similar results were obtained from three independent experiments.