Figure 4

Tranilast restores PA-induced functional impairment. (A,B) INS-1 cells were treated with PA (500 μM) in the presence or absence of tranilast at the indicated concentrations for 8 h (real-time qPCR) or 24 h (western blotting). Expression of PDX-1, MafA, insulin, and DP-5 was determined by real-time qPCR (A), and by western blot analysis (B). Original scans of whole blots are shown in Supplementary information. Density analyses of western blots were shown in the lower panel. Data are expressed as mean ± SD of three independent experiments, each done in duplicate. #p < 0.05, ##p < 0.01, ###p < 0.005 versus control, *p < 0.05, **p < 0.01, ***p < 0.005 versus PA alone. (C upper) INS-1 cells were treated with PA (500 μM) in the presence or absence of tranilast at the indicated concentrations for 24 h, and further incubated in the same buffer containing 5.6 or 28 mM glucose for 30 min. Insulin level in the media was quantified using an insulin RIA kit. (C lower) Primary islets isolated from C57BL/6J mice were treated with various concentrations of tranilast for 24 h, and the insulin content in the media was measured using mouse insulin RIA kit. Data are expressed as mean ± SD of three independent experiments, each done in duplicate. #p < 0.05, ###p < 0.005 versus control, ***p < 0.005 versus PA alone.