FIGURE 2:

Inhibition of Akt does not inhibit capillary-like network formation. Cocultures of HUVECs and PaSMCs were treated with the Akt inhibitor AktVIII at time zero and days 1 and 3 and imaged at day 5. Inhibitor-treated cocultures were morphologically similar to control cells (A), and the tube total length was not significantly different from controls (B). Akt isoform expression levels of HUVECs were examined by Western blot. Akt1 was the predominantly expressed isoform, whereas only small amounts of Akt2 and Akt3 were detected (C). All Akt isoforms were knocked down by siRNA (D) and grown in coculture with PaSMCs for 5 d. Western blot exposures were optimized to show relative differences from control. Cultures were imaged with fluorescence microscopy (E), and network formation was quantified. Tube total length (F) and number of branch points (G) were significantly higher in networks formed by Akt1, 2 (except siAkt2_6), and 3 knockouts than with control. Asterisk indicates statistically significant differences from control (set to 100%). *p < 0.05, min n = 9, max n = 10.