Urotensin II-induced insulin resistance is mediated by NADPH oxidase-derived reactive oxygen species in HepG2 cells

Figure 3 Activation of JNK by urotensin II contributes to urotensin II-induced insulin resistance. HepG2 cells were incubated with 100 nmol/L urotensin II (UII) for 24 h and were pretreated with the JNK inhibitor SP600125 for 30 min. Total cell lysates were analyzed by Western blot analysis. UII increased JNK phosphorylation (A), and this effect was dose-dependently abolished by SP600125 (B). The effects of UII on IRS-1 protein and glycogen content and phosphorylation of IRS-1 and GSK-3β were all rescued by SP600125 (C, D). Data from at least three independent experiments are presented as the mean ± SD. ^aP < 0.05 vs control group; ^hP < 0.05, ⁱP < 0.001 vs insulin + UII group.