Effect of LPS on KC expression and release in neuronal cultures. Neuronal primary cultures were left untreated (UT) or were treated with LPS (0.1 to 100 ng/ml) for 24 hours (a). Neuronal cultures were left untreated (UT) or were treated with LPS (10 ng/ml) for 24 hours, in the absence or the presence of the TLR4 antagonist VIPER or control peptide CP7 (2 μM) (b). Cell lysates and culture supernatants were assayed for KC levels by ELISA. Data are presented as mean ± SD of at least three independent experiments carried out on separate cultures. *P <0.05, **P <0.01, ***P <0.001, LPS-treated versus untreated cultures, ##P <0.01 LPS + VIPER versus. LPS alone, using one-way ANOVA and Tukey’s multiple comparison post-hoc test. ANOVA, analysis of variance; KC, CXCL1; LPS, lipopolysaccharide; TLR4, Toll-like receptor 4.