Figure 7.

Tyrosine kinase, PI3K/Akt, and p38 MAPK's involvement in LTA-mediated increase in κB-luciferase activity in RAW 264.7 macrophages. In (a), RAW 264.7 macrophages were transiently transfected with 0·5 µg of pGL2-ELAM-Luc and 1 µg of pBK-CMV-Lac Z for 24 hr, and then cells were incubated with 0·3–10 µg/ml LTA for another 24 hr. Luciferase activities were determined as described in ‘Materials and methods’. The level of induction of luciferase activity was compared to that of cells without LTA treatment. Data represent the mean ± SEM of three experiments performed in duplicate. *P < 0·05 as compared to the control without LTA treatment. In (b), RAW 264.7 macrophages were transiently transfected with 0·5 µg of pGL2-ELAM-Luc and 1 µg of pBK-CMV-Lac Z for 24 hr. Cells were cotransfected with 1 µg of the Akt dominant negative mutant or pretreated with 20 µm tyrphostin AG126, 100 nm wortmannin, 30 µm LY 294002, or 10 µm SB 203580 for 30 min, and then stimulated with 10 µg/ml LTA for another 24 hr. Cells were harvested for the luciferase assay as described in ‘Materials and methods’. Data represent the mean ± SEM of three experiments performed in duplicate. *P < 0·05 as compared to the LTA-treatment group. AktDN, Akt dominant negative mutant; Tyrp, tyrphostin AG126; Wort, wortmannin; LY, LY 294002; SB, SB 203580.