Figure 3

LL-37 blocks SAA-induced ERK and p38 MAPK activity in human neutrophils. Human neutrophils were preincubated with vehicle (DMSO), PD98059 (50 µM) for 60 min, or SB203580 (20 µM) for 15 min prior to treatment with SAA (2 µM) for 24 h (A). The amount of IL-8 secreted was measured by ELISA. The data represent the mean ± SE of three independent experiments performed in duplicate. Human neutrophils were stimulated with LL-37 (10 µM), SAA (2 µM), or LL-37 (10 µM) + SAA (2 µM) for 5 min. Samples (30 µg of protein) were subjected to 10% SDS-PAGE, and the phosphorylated ERK or phosphorylated p38 MAPK levels were determined by immunoblot analysis using anti-phospho-ERK antibody or anti-phospho-p38 MAPK antibody (B). The results shown are representative of at least three independent experiments (B).