FIGURE 7.

Down-regulation of IQGAP1 with IQGAP1 siRNA blunts of hyperoxia-induced translocation of cortactin and phosphorylation of Src. A, HPAECs was transfected with scrambled or IQGAP1 siRNA prior to exposure to either normoxia or hyperoxia (3 h), probed with anti-cortactin antibody, and examined by immunofluorescence microscopy. Shown is a representative immunofluorescence micrograph from three independent experiments. The redistribution of cortactin to cell periphery was quantified using an image analyzer as described under “Experimental Procedures.” Values are mean± S.D. from three independent experiments and expressed as relative pixels. ^*, p < 0.01 compared with scrambled siRNA-transfected cells/normoxia; ^**, p < 0.05 compared with scrambled siRNA transfected cells/hyperoxia. B, in parallel experiments ECs were transfected with scrambled or IQGAP1 siRNA, cells exposed to either normoxia or hyperoxia (3 h), total cell lysates separated by SDS-PAGE 10% gels, and Western blotted with total Src, IQGAP1, and phospho-Src antibodies as described under “Experimental Procedures.” Shown is a representative blot from three independent experiments.