J. Volk, Miriam Wessels, G. Leyhausen
Jan 25, 2016
Citations
0
Influential Citations
0
Citations
Quality indicators
Journal
Journal of the International Society of Antioxidants in Nutrition & Health
Abstract
Camphorquinone (CQ) is the most important photoinitiator used in dental resinousmaterials. Aim of this study was to investigate whether CQ induces Nuclearfactor erythroid-2 related factor 2 (Nrf2)-mediated defense mechanisms againstoxidative stress in immortalized human oral keratinocytes. OKF6/TERT2cells were treated with 0.5-2.5mM CQ. ROS-formation was assessed by means of fluorospectrophotometryusing 2´,7´-dichlorodihydrofluorescein diacetate. Immunofluorescence was usedto show nuclear translocation of Nrf2. Differences in mRNA expression levels ofdownstream genes (NAD(P)H:quinone oxidoreductase (NQO-1) and heme oxygenase-1(HO-1)) were assessed by quantitative realtime PCR. Protein level changes wereanalyzed by western blot. Statistics: Student´s t-test (p < 0.05). Incubationwith CQ resulted in significant ROS-generation in OKF6/TERT2 cells in aconcentration-dependent manner, amounting to an about 20-fold increase during 90minof incubation at 2.5mM CQ (1928%±293%), as compared to untreated controls. After1.5h CQ-exposure triggered translocation of Nrf2 into nucleus, resulting insignificant increases in HO-1 (9-fold) and NQO1 (3-fold) gene transcriptsobserved as early as 6h after exposure. After 24h increased levels of HO-1 (7-fold)and NQO1 (2-fold) proteins were observed.Our datareveal that the Nrf2 signaling pathway is activated by CQ, participates inresponses to mitigate ROS damage, and may influenceCQ toxicity.