FIGURE 3.

siRNA knockdown of PKA inhibited DHEA-stimulated phosphorylation of FoxO1. A, HAECs were transfected with scrambled control siRNA (lanes 1–3) or siRNA specifically targeting PKA (lanes 4–6). 48 h after transfection, cells were serum-starved for 6 h and treated with vehicle or DHEA (100 nm, 30 min) as indicated. Whole cell lysates were immunoblotted with antibodies against phospho-FoxO1, FoxO1, PKA, or β-actin. Representative immunoblots are shown for experiments that were repeated independently three times. B, immunoblots from three independent experiments were quantified by scanning densitometry, and the amounts of phospho-FoxO1 were normalized to total FoxO1. Results in the bar graph are the mean ± S.E.