LPS from P. gingivalis and Hypoxia Increases Oxidative Stress in Periodontal Ligament Fibroblasts and Contributes to Periodontitis

Figure 1

NOX4 in human primary periodontal ligament (PDL) cells. (a) PDL cells were cultured under normoxic or hypoxic condition and stimulated with or without LPS of Porphyromonas gingivalis (1 μg/mL). NOX4 mRNA expression was analyzed after 2, 4, 8, 24, and 48 h. Statistical differences were analyzed by one-way ANOVA and post hoc Dunnett and Tukey’s multiple comparison test; ^# difference to control; * difference between groups (means SD; ). (b) NOX4 protein was visualized by immunofluorescence as well as immunohistochemical staining in unstimulated PDL fibroblasts (1 : 50; antibody from Abcam). (c) Immunoblot data of NOX4 in PDL cells cultured under normoxic or hypoxic condition (Hox) and stimulated with or without LPS of Porphyromonas gingivalis (1 μg/mL). NOX4 protein levels were analyzed after 2 and 4 h. Statistical analysis of western blot data was performed using the freely available image-processing software ImageJ 1.43 (http://rsb.info.nih.gov/ij/). Statistical differences were analyzed by one-way ANOVA and post hoc Dunnett and Tukey’s multiple comparison test; ^# difference to control; * difference between groups (means SD; ). The scale bars indicate 200 μm in the bright field survey and 50 μm in the immunofluorescence image, respectively.