Fig. 3

Roles of rottlerin in PMA-induced MMP-9 expression via Nox-mediated ROS production. a, b The Nox/ROS system inhibitor concentration dependently blocked PMA-induced MMP-9 expression, and cells were pretreated with a NAC (0.1, 1, and 5 mM) or (b) apocynin (Apo, 0.1, 1, 10 μM) and then incubated with PMA (1 μM) for 24 h. c, d PMA stimulates ROS generation. Cells were incubated with the DCF-DA (5 μM) for 45 min, followed by stimulation with PMA (1 μM) for the indicated times (c), or pretreatment with NAC (5 mM), Apo (10 μM), and Rott (1 μM) for 1 h and then stimulation with PMA (1 μM) for 10 min (d). The conditioned media were collected and assayed for MMP-9 expression by gelatin zymography (a, b). The fluorescence intensity (ROS generation) and images of cells (c, d) were determined as described in the “Methods” sectopn. Data are expressed as the mean ± SEM (N = 3). ^#P < 0.01, as compared with the respective values of untreated control. *P < 0.05; **P < 0.01, as compared with the respective values of untreated cells (c) or cells stimulated with PMA only (a, b, d). The image represents one of three individual experiments