Ang1 induced HGF production independently of Akt, MAPK, and p38 MAPK activation. (A) Total RNAs were extracted from corresponding adenoviral vector–infected HUVECs at 16, 24, and 48 hours, respectively. HGF mRNA was analyzed by Northern blot. 18S rRNA, visualized with ethidium bromide and UV, was used as a loading control. Images are representative of 3 separate experiments. (B) Inactivation of dominant-negative Akt was confirmed by Akt kinase assay using cells treated in the same manner as in panel A. (C) HUVECs were treated with PD98059 at 20 μM for 30 minutes before adenoviral-Ang1* infection for 16, 24, and 48 hours, respectively. Northern blot analysis was performed using total RNAs. Images are representative of 3 separate experiments. (D) Effectiveness of PD98059 was tested in the cells treated as in panel C. As a positive control, FGF was used. Extracted protein was analyzed by Western blot. (E) HUVECs were treated with SB203580 at 10 μM for 30 minutes before adenoviral-Ang1* infection for 16, 24, and 48 hours, and Northern blot was performed.