Fig. 5

Synergistic effect of dexamethasone and rapamycin against cytokine-induced cytotoxicity in A549. a Dose-response effect of dexamethasone (D) or rapamycin (R) against cytokine-induced cytotoxicity in A549. A549 cells were pretreated with dexamethasone or rapamycin at the indicated concentration for 1 h and then stimulated with CM. Forty-eight hours after CM stimulation, cytotoxicity was evaluated by monitoring the concentration of LDH in culture medium as described in the “Methods” section. Both dexamethasone (D) and rapamycin (R) significantly attenuated CM-induced cytotoxicity in A549 cells in a dose-dependent manner. Bar graph shows means ± SEM. *P < 0.05 vs. CM alone, ^# P < 0.01 vs. CM alone. b Synergistic effect of dexamethasone (D) and rapamycin (R) against cytokine-induced cytotoxicity and apoptosis in A549. Grey bar graph shows cytotoxicity evaluated by monitoring the concentration of released LDH in culture medium as described in the “Methods” section. Bar graph shows means ± SEM. Black bar graph shows caspase activation estimated by determining the concentration of cleaved cytokeratin 18 in culture medium using an M30 cytodeath ELISA kit as described in “Methods”. Bar graph shows means ± SEM. Upper pair of the graphs shows the effect of combined treatment compared with that of dexamethasone alone. *P<0.01 vs. D10/R0, D100/R0, ^#P < 0.05 vs. D10/R0, D100/R0. Lower pair of the graphs shows the effect of combined treatment compared with that of rapamycin alone. *P < 0.01 vs. R1/D0, R10/D0 #; P < 0.05 vs. R1/D0 ^##P <0.05 vs. R1/D0, R10/D0