Effect of JNK inhibition on c-Jun activity and LPS-induced KC release in neuronal cultures. Neuronal primary cultures were left untreated (UT), were treated with vehicle (DMSO), or were treated with LPS (10 ng/ml prepared in DMSO) for 30 min (for c-Jun activity, levels of phosphorylated (P-c-Jun) compared to total (T-c-Jun) c-Jun, a) or for 24 hours (for KC release, b) in the absence or the presence of increasing concentrations of a specific JNK inhibitor (SP600125, JNKi) added 30 min prior to treatment with LPS. Cell lysates were assayed for c-Jun activity by Western blot analysis. Image shown is representative of three experiments carried out on separate cultures (a). Culture supernatants were assayed for KC levels by ELISA (b). Data are presented as mean ± SD of at least three independent experiments carried out on separate cultures. **P <0.01, ***P <0.001, LPS + JNKi-treated versus LPS-treated cultures, using one-way ANOVA and Tukey’s multiple comparison post-hoc test. ANOVA, analysis of variance; DMSO, dimethyl sulfoxide; JNK, c-Jun-N-terminal kinase; KC, CXCL1; LPS, lipopolysaccharide.