Fig. 2

Danthron reduces HO-1/CPR BRET signal without affecting cell viability. a Structure of danthron. b HEK293T cells were co-transfected with the constant amount of Luc-HO-1 construct and increasing amounts of GFP or CPR-GFP construct as indicated. After 24 h, cells were reseeded in 96-well plates in triplicate for 18 h, followed by treatment with 20 μM danthron for 6 h. Luciferase substrate was then added into each well and the BRET signal was monitored. Data shown are the mean ± SE of three independent experiments. c HEK293T cells were treated with indicated concentration of danthron in culture for 6 h. Cell viability was then assessed by trypan blue exclusion method. Data shown are the mean ± SE of three independent experiments. d HEK293T cells were cotransfected with increasing ratio of CPR-GFP/Luc-HO-1 constructs for 24 h as described above, followed by treatment without (DMSO) or with 20 μM danthron for 6 h. Cell lysates were prepared and Western blot analysis was performed using antibodies against HO-1, CPR and GAPDH as indicated