Figure 2

Dependence on TRPM2 of migration towards neutrophil chemoattractants. (A) Effect of genetic deletion of TRPM2 on mouse neutrophil migration. Forward migration index (FMI) in response to gradient of lipopolysaccharide (LPS, 50 ng/ml), C5a (10 nM), CXCL2 (10 nM) and fMLP (1 µM), all over 1 mm. No significant difference in FMI of WT and TRPM2^−/− neutrophils in response to LPS, C5a or CXCL2, but neutrophil migration to fMLP was significantly inhibited by TRPM2 deletion. (B) Effect of pharmacological block of TRPM2 with ACA (N-(p-amylcinnamoyl)anthranilic acid, 10 µM) on mouse neutrophil migration. FMI in gradient of H₂O₂ (0.01 µM), ADPR (100 µM) and other chemoattractants as in (A). (C) Human blood neutrophil FMI in response to gradients of chemoattractants as follows, all over 1 mm: H₂O₂ (0.01 µM), ADPR (100 µM), IL8 (10 nM), C5a (10 nM), fMLP (1 µM) and LPS (50 ng/ml). (D) Inhibition of human blood neutrophil FMI by TRPM2 blocker ACA (10 µM). Gradients over 1 mm: H₂O₂ (0.01 µM), IL8 (10 nM). Statistical analysis: Mean ± SEM, independent samples from n = 3 mice or humans in each panel. (A, B, D): pairwise t-test comparing WT to TRPM2^−/− or ACA. (C) One-way ANOVA and Tukey–Kramer post-hoc test compared to DMEM. *, p < 0.05; **, p < 0.01; *** p < 0.001; ****, p < 0.0001, difference non-significant if not stated.