Figure 4

Effects of MAPK inhibitors on the level of p-GATA-4 and cardiac cTnI expression. H9c2 cells were incubated with SB203580 (25 mmol/L) or PD98059 (20 mmol/L) for 30 min before exposure to 30 mmol/L glucose. Then, nuclear fractions were isolated for Western blot analysis of GATA-4 phosphorylation (A) and cardiac troponin I expression (B). In another group, H9c2 cells were treated with 1 mmol/L phenylephrine (PE) in normal medium for 24 hr. Western blotting analysis was then used to estimate the effect of PD98059 on the expression of troponin I induced by PE (C). The results are presented as the mean ± SEM (n = 3-5 per group). *P < 0.05, **P < 0.01 as compared with the high glucose-treated group.