Fig. 5

The effects of mechanical force on macrophage polarization in the presence or absence of BG materials. Assessment of IL-1β and active-MMP-9 (M1 macrophages), as well as IL-4 (M2 macrophages) levels. A Concentrations of IL-1β in each group at 6 and 24 h. B Concentrations of IL-4 in each group at 6 and 24 h. C Gelatin zymography detection of MMP-9 activity. D Quantitative analysis of active-MMP-9 levels. C: Control. B: BG material. F: Force. F + B: Force + BG material. Each value represents the mean (n = 3/group) ± the standard error. * p < 0.05, ** p < 0.01, values were compared among group C and the other three groups (B, F, and F + B), respectively. ^# p < 0.05, ^### p < 0.001, values were compared among group B and the other two groups (F and F + B), respectively. ^† p < 0.05, ^†† p < 0.01, ^††† p < 0.001, values were compared between the F and F + B groups. E The proposed mechanism: the cAMP/PKA/RAC1 signaling pathway is involved in mechanical force-induced increase in phagocytosis and macrophage migration by promoting the polarization of M2 macrophages