c-Jun amino terminal kinases (JNKs) are MAP kinase family members that become highly activated after cells are exposed to stress conditions and are poorly activated by exposure to growth factors or mitogens. They have been implicated in neurodegeneration, rheumatoid arthritis, inflammation, cancer, and diabetes. JNK1 and JNK2 are widely expressed throughout the body whereas JNK3 is predominantly distributed in the brain. JNK Inhibitor VIII is an aminopyridine compound that inhibits JNK1, JNK2, and JNK3 with Ki values of 2, 4, and 52 nM, respectively. It has been reported to inhibit the phosphorylation of the JNK substrate c-Jun in HepG2 cells (EC50 = 920 nM) without affecting the expression of IL-6, IL-8, or COX-2.
