Fig. 2From: Oxidative stress generated by polycyclic aromatic hydrocarbons from ambient particulate matter enhance vascular smooth muscle cell migration through MMP upregulation and actin reorganizationEffect of organic matters extracted from ambient PM on MMP expression and activity in VSMCs. a The expression levels of MMP2, 9, and 13 were analyzed by western blotting. Serum-starved VSMCs were treated with control (0.1% DMSO), PDGF-BB (20 ng/mL), SPM, or WPM at the indicated concentration for 24 h. The band densities were normalized to β-actin band density. The gel images shown are representative of those obtained from at least three independent experiments. b The mRNA levels of MMPs were quantified by qPCR. Gene expression was normalized to GAPDH. c The zymolytic activity of MMP2 was evaluated using gelatin zymography. Serum-starved VSMCs without or with NAC (1 mM) were pretreated with the designated concentrations of SPM or WPM for 24 h. PDGF treatment alone was used as a positive control. The media were then collected and used for this assay. The images shown are representative of those obtained from at least three independent experiments. d The effect of NAC on transcriptional activity of the MMP9 promoter in VSMCs was evaluated using a luciferase assay. e The expression levels of phosphorylated ERK1/2, Akt, FAK, and Src were analyzed by western blotting. Protein levels were normalized to their total levels. All values are represented as mean ± SD. *P < 0.05, **P < 0.01, and ***P < 0.001 versus control; #P < 0.05 WPM versus SPM; $P < 0.05 and $$$P < 0.001 PM with NAC versus PM alone; NS, no significanceBack to article page