Abstract:Aim To investigate the effect of advanced glycation end products (AGE) modified protein on morphological changes of actin cytoskeleton in endothelial cell and the role of receptor for AGE (RAGE) and oxidant stress in this pathological procedure. Methods Human umbilical vein endothelial cells (hUVEC)-derived cell line (ECV304) were incubated with AGE modified human serum albumin (AGE-HSA) of concentrations of 12.5, 25, 50, and 100 mg/L respectively, for 2, 4, 8, 12 and 24 h. As control, HSA of the same concentration was administrated to ECV304 cells. To visualize the morphological changes of actin cytoskeleton,the treated cells were incubated with rhodamine-phalloidin or Oregon Green-Dnase I to stain F-actin or G-actin. ECV304 were treated with anti-RAGE IgG before AGE-HSA applications or both together. Apocynin, a specific inhibitor of NADPH oxidase, was pre-administrated to the endothelial cells in concentrations of 10, 100, 250, and 500 μmol/L respectively, for 30 min, then the cells were rinsed with DMEM for three times and exposed to 50 mg/L AGE-HSA for 8 h. The morphological changes of actin cytoskeleton were observed after the above-mentioned procedure. Results Morphology of F-actin and G-actin in endothelial cells were changed greatly under the stimulation of AGE-HSA in a concentration and time-dependent manner. Exposure of ECs to AGE-HSA caused a shift in F-actin distribution from web-like structure to polymerized stress fiber. Cells subjected to higher-concentration and longer-time AGE-HSA exposure showed more and more stress fiber accumulation.Also the edge of G-actin became coarse and illegible and merged with each other, even formed tufts of flock extending all around nuclear area. And the changes can be inhibited by not only pretreatment with anti-RAGE IgG or NADPH oxidase inhibitor Apocynin, but also co-administrated with anti-RAGE IgG and AGE-HSA. The unmodified HSA,anti-RAGE IgG and Apocynin did not affect morphology of actin cytoskeleton. Conclusion AGE induced morphological changes of actin cytoskeleton in endothelial cells and it required receptor occupancy on cells surface and intracellular activation of NADPH oxidase.