Effects of R406 on the protein phosphorylation in SAA-stimulated neutrophils.

<p><b>A</b> Quiescent neutrophils pretreated or untreated with the indicated concentrations of R406 for 1(5 µg/ml) for 20 min. Cellular lysates were subjected to western blotting using phosphotyrosine-specific antibody, 4G10. Three experiments were performed using different neutrophils and a representative result is shown. <b>B</b> Quiescent neutrophils pretreated or untreated with the indicated concentrations of R406 for 1 hr. The cells were stimulated with SAA (5 µg/ml) for 20 min. Syk was immunoprecipitated from each lysates and the immunoprecipitates were subjected to western blotting using phosphotyrosine-specific antibody, 4G10 or anti-Syk antibody. Each lane shows Syk precipitated from 10⁷ cells. Three experiments were performed using different neutrophils and a representative result is shown. <b>C</b> Quiescent neutrophils pretreated or untreated with the indicated concentrations of R406 for 1 hr. The cells were stimulated with SAA (5 µg/ml). Cellular lysates were subjected to western blotting using phospho-specific or pan antibodies against ERK1/2, p38 and JNK1. Three experiments were performed using different neutrophils and a representative result is shown.