Background:

BI-78D3 is a substrate competitive inhibitor of JNK inhibitor [2].

JNK is a member of the MAPK family. JNK is a stress-activated protein kinase that modulates pathways implicated in a variety of disease states. Non-motoric JNK functions may differ between cell types and organs. The JNK is involved in a1-adrenoceptor-mediated contraction of prostate smooth muscle. For non-malignant, epithelial human prostate cells, JNK activation not only has the function of pro-apoptotic and antiproliferative but also related with JNK-dependent survival.[1]

BI-78D3 is competitive with ATF2 for binding to JNK1 with an apparent Ki value of 200 nM. In addition, it has been reported that BI-78D3 does not inhibit the phosphorylation of a short peptide substrate lacking a D-domain. This confirms that BI-78D3 is substrate competitive.[2]

BI-78D3 inhibits both noradrenaline- and phenylephrine-induced contractions. Then it prevents α1-adrenoceptor-mediated contraction of prostate tissue. As an effective JNK inhibitor, BI-78D3 has the ability of abrogating ConA-induced liver damage and restoring insulin sensitivity. [1,2]

参考文献:
[1] Strittmatter F1, Walther S, Gratzke C, etal. , Inhibition of adrenergic human prostate smooth muscle contraction by the inhibitors of c-Jun N-terminal kinase, SP600125 and BI-78D3. Br J Pharmacol. 2012 Jul;166(6):1926-35.
[2] Stebbins JL, De SK, Machleidt T,etal.  , Identification of a new JNK inhibitor targeting the JNK-JIP interaction site. Proc Natl Acad Sci U S A. 2008 Oct 28;105(43):16809-13.