Fig. 3. Up-regulation of DR5 in HEK 293 cells treated with ISO and TRAIL. HEK 293 cells were treated with ISO (100 µM) and/or TRAIL (100 ng/mL) for 24 hours. DR5 expression was evaluated by immunoblotting, and the band intensity of DR5 was analyzed by densitometry. GAPDH was used as the housekeeping gene. Standard error was determined on the basis of three independent experiments; ^*p<0.05. DR: death receptor, HEK: human embryonic kidney, ISO: isoproterenol, TRAIL: tumor necrosis factor-related apoptosis-inducing ligand, GAPDH: glyceraldehydes-3-phosphate dehydrogenase.