FIG. 4.

Oxidative-stress-induced changes in the total akt activity and also expression levels of Akt1, Akt2, and Akt3. (A) Oxidative stress differentially regulates Akt activity in the mock and Akt1 shRNA plasmid-transfected HLECs. Both mock and Akt1 shRNA plasmid-transfected HLECs were either mocked treated (by H₂O) or treated with 50 μM H₂O₂ for 2 h. After treatment, the cells were harvested for analysis of total Akt activity, total Akt protein, total Akt1 protein, and β-actin (as a loading reference) using the method as described in the Materials and Methods section. Note that in Akt1 knockdown cells, Akt activity was significantly upregulated. (B) Quantitative results of the Akt activity as reflected by S-473 phosphorylation against total Akt. (C) Oxidative stress differentially regulates the Akt2 level in the mock and Akt1 shRNA plasmid-transfected HLECs. Both mock and Akt1 shRNA plasmid-transfected HLECs were treated as described in (A). Note that in Akt1 knockdown cells, the Akt2 protein level was significantly upregulated in both mock- and H₂O₂-treated HLECs. (D) Quantitative results of the Akt2 level. (E) Oxidative stress does not significantly change the Akt3 level in the mock and Akt1 shRNA plasmid-transfected HLECs. Both mock and Akt1 shRNA plasmid-transfected HLECs were treated as described in (A). (F) Quantitative results of the Akt3 level. Data were analyzed with analyzed with the SNK test.