Figure 6
Shear stress and hydrogen peroxide induce HO-1 expression via a PI3K-dependent pathway. (A) Shear stress increased HO-1 protein expression. HUVECs were exposed to laminar shear stress (12 dyne/cm2) for the indicated times. After cell lysis, total cell lysates were prepared and subjected to Western blotting with anti-HO-1 and anti-tubulin (internal control) antibodies. (B) PI3K is involved in shear-induced HO-1 protein expression. HUVECs were pretreated with LY294002, a PI3K inhibitor (50 μM) for 60 min and then kept as static controls or exposed to shear stress in the presence of LY294002 for 4 h. Total cell lysates were subjected to Western blotting with anti-HO-1, anti-phospho-Akt, and anti-Akt (internal control) antibodies. (C) Hydrogen peroxide (H2O2) increased HO-1 protein expression. HUVECs were incubated with H2O2 (200 μM) for the indicated times. Total cell lysates were subjected to Western blotting with anti-HO-1 and anti-tubulin (internal control) antibodies. (D) PI3K is involved in H2O2-induced HO-1 protein expression. HUVECs were either kept as a static control or treated with H2O2 (200 μM) for 4 h or pretreated with LY294002, a PI3K inhibitor (50 μM), for 60 min. Total cell lysates were subjected to Western blotting with anti-HO-1, anti-phospho-Akt, and anti-tubulin (internal control) antibodies. Results are representative of duplicate experiments with similar results.