Effects of JNK inhibition on insulin signaling pathway in HepG2 cells

Objective To investigate the effects of JNK inhibition on insulin signaling pathway. Methods HepG2 cells were treated with different kinds of JNK inhibitors for 12 h, and then the cells were treated with 10 nmol/L insulin for 5 min to stimulate insulin signaling pathway. Mitogen-activated protein kinases(MAPK)and insulin signaling pathways were analyzed by Western blot using the total cell lysates. Results JNK activity was significantly inhibited by JNK inhibitor JNKi-Ⅷ and results showed that JNKi-Ⅷ treatment could reduce insulin signaling pathway in a dose-dependent manner. Furthermore, other JNK inhibitors including JNKi-Ⅴ, JNKi-Ⅲ, and SP600125 blocked JNK activity in HepG2 cells. Similar to JNKi-Ⅷ, these JNK inhibitors also impaired insulin signaling transduction in a dose-dependent manner. Conclusion In HepG2 hepatocytes, JNK activity inhibition blocks insulin signaling transduction. (Chin J Endocrinol Metab, 2017, 33: 129-134) Key words: JNK; JNK inhibitors; MAPK signaling pathway; Insulin signaling pathway; HepG2 hepatocytes