Fig 1: IL-8 promotes activation of ERK1/2 and p38MAPK mediated by CXCR2. (A) CXCR2 relative expression in Akata and Ramos cells in basal conditions. (B) CXCR1 and CXCR2 relative gene expression in Akata cells. Graphs represent the mean ± SEM of the relative gene or fold-change expression of three independent experiments. Expression values were normalized to GAPDH, and unpaired t-test was used to assess statistical significance between groups. (C) Heatmap of invading Akata cells chemoattracted by either the conditioned media from AGS cells infected with H. pylori CagA(-) and CagA(+) ABD strains or rIL-8 (2200 pg/mL), with or without pretreatment with CXCR2 inhibitors (SB225002 and reparixin). Bar scale indicates the number of invading cells. Statistical differences were assessed comparing inhibitors versus vehicle (DMSO). A two-way ANOVA was used for multiple comparisons and a Tukey’s post hoc test. (D,E) Western blot analysis of phosphorylated p-ERK1/2, ERK1/2, p-p38MAPK, p38MAPK and ß-Actin in Akata and Ramos cells treated or untreated (UT, control) with rIL-8 (2200 pg/mL), with or without pretreatment with the inhibitors. The images show one representative experiment of three independent assays (uncropped membranes are presented in Supplementary Figure S7A,B). * p < 0.05, ** p < 0.01 and **** p < 0.0001.