FIGURE 6.

AICAR inhibits caveolin-1 phosphorylation under oxidative stress by suppressing the dissociation between Prdx1 and c-Abl. A, cells were transfected with siRNA against Prdx1. Three days after transfection cells were stimulated with 2 mm AICAR for 2 h followed by H₂O₂ (2 mm) stimulation for 30 min. The amounts of p-c-Abl, p-caveolin-1 were examined by Western blotting. B, densitometry of p-caveolin-1 in A is shown. C, densitometry of p-c-Abl in A is shown. D, cells were stimulated with 2 mm AICAR for 2 h followed by H₂O₂ (2 mm) stimulation for 30 min. After total cell lysates of each group were collected, the interaction between Prdx1 and c-Abl was examined by immunoprecipitation with anti-Prdx1 antibody. Immunoprecipitates were then subjected to immunoblotting using anti-c-Abl antibody. E, densitometry of p-c-Abl in D is shown. F, cells were transfected with siRNA against AMPKα1 or -α2. Three days after transfection cells were stimulated with 2 mm AICAR for 2 h followed by H₂O₂ (2 mm) stimulation for 30 min. After total cell lysates of each group were collected, the interaction between c-Abl and Prdx1 was examined by immunoprecipitation (IP) with anti-Prdx1 antibody. Immunoprecipitates were then subjected to immunoblotting using anti-c-Abl antibody. G, densitometry of c-Abl in F. H, cells were transfected with siRNA against AMPKα1 or -α2. Three days after transfection cells were stimulated with 2 mm AICAR for 2 h followed by H₂O₂ (2 mm) stimulation for 30 min. After total cell lysates of each group were collected, the interaction between total AMPK and Prdx1 or c-Abl was examined by immunoprecipitation with anti-total AMPK antibody. Immunoprecipitates were then subjected to immunoblotting using anti-c-Abl and Prdx1 antibody. A, D, and F, representative blots are shown. *, p < 0.01; NS, not significant.