Figure 4

Effects of endocytosis and NADPH oxidase inhibitor on generation of ROS induced by silica particle treatment. HaCaT cells were pretreated with cytochalasin D or apocynin for 30 min prior to incubation with 270 mg/ml nSP70 for 3 h. ROS induced by silica particle treatment were expressed as relative fluorescence units, which means that ROS intensity of each silica particle alone and non-treatment is 100 and 0 respectively, in the DCFH assay. Data shown are means ± SD (n = 3). *P < 0.01, **P < 0.05.