Angiotensin II stimulates p38MAPK phosphorylation and proliferation of macrophage cell line

Objective:To investigate the changes of p38 mitogen-activated protein kinase(p38MAPK) phosphorylation induced by angiotensin Ⅱ(AngⅡ) in RAW264.7 macrophages, and to determine the activation of p38MAPK signaling induced by AngⅡ with specific inhibitor of p38MAPK, SB202190, and also to investigate the effect of AngⅡ on RAW264.7 macrophage proliferation. Methods: Western blot was used for examining the p38MAPK phosphorylation, and the nuclear translocation of phosphorylated p38MAPK was detected by immunohis tochemical staining. MTT was used for examining the cell proliferation.Results:Following excitation by AngⅡ(1 μmol/L) in vitro, there was substantial up-regulation of p38MAPK phosphorylation in RAW264.7 macrophages with maximal activation at 15-30 min; and marked nuclear translocation of phosphorylated p38MAPK was also happened at 15-30 min. AngⅡ enhanced the expression of p38MAPK phosphorylation in RAW264.7 macrophages in a dose-dependent manner. Pre-treatment with SB202190(1,5 μmol/L) for 30 min in RAW264.7 macrophages before AngⅡ(1 μmol/L) used, the expression of p38MAPK phosphorylation was inhibited markedly in a dose-dependent manner. AngⅡ increased the cell proliferation in vitro, and pretreatment of SB202190 reduced the cell proliferation induced by AngⅡ.Conclusion: Angiotensin Ⅱ may induce phosphorylation of p38MAPK in RAW264.7 macrophages, and the activation of p38MAPK may regulate the proliferation of RAW264.7 macrophages.