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

Figure 5 Urotensin II interferes with insulin signaling, and this effect is reversed by apocynin. HepG2 cells were exposed to 100 nmol/L urotensin II (UII) for 24 h prior to stimulation with insulin (100 nmol/L, 30 min), and pretreatment with 200 μmol/L apocynin for 30 min. Total cell lysates were analyzed by Western blot. UII increased JNK phosphorylation, and this effect was abolished by apocynin (A); Protein levels of IRS-1 and Glut 2 and phosphorylation of IRS-1, Akt and GSK-3β were all reversed by apocynin (B-D). Data from at least three independent experiments are presented as the mean ± SD. ^gP < 0.05 vs UII treatment alone; ^hP < 0.05 vs insulin + UII group.