PCB126 induces apoptosis of chondrocytes via ROS-dependent pathways H.-G. Lee, J.-H. Yang  Osteoarthritis and Cartilage  Volume 20, Issue 10, Pages 1179-1185 (October 2012) DOI: 10.1016/j.joca.2012.06.004 Copyright © 2012 Osteoarthritis Research Society International Terms and Conditions

Fig. 1 Cell viability of chondrocyte following PCB126 exposure. Chondrocytes plated on 96-well plate were treated with different concentrations of PCB126 for 12 h, 24 h and 36 h. Cell viabilities were measured with MTT assay as described in the text. All values are relative to the control cells (the viability of chondrocyte with DMSO; 100%) and represent mean and 95% CI (error bar) from three independent experiments. Statistical difference from DMSO control (*) was set to P < 0.05. Osteoarthritis and Cartilage 2012 20, 1179-1185DOI: (10.1016/j.joca.2012.06.004) Copyright © 2012 Osteoarthritis Research Society International Terms and Conditions

Fig. 2 Effects of PCB126 and TCDD on ROS generation. Cells were treated with 0.1% DMSO, TCDD (0.001, 0.01, 0.1 μM) or PCB126 (0.01, 0.1, 1 μM) for 15 min, respectively (A). Cells were treated with PCB126 only or in the presence of antioxidants (100 μM trolox; 10 mM NAC) or AhR blocker (10 μM α-NF) (B). Relative fluorescence was measured as described in method section. All unit values represent mean and 95% CI (error bar) of three independent experiments. Statistical difference from DMSO control (*) and PCB126 only-treated cells (#), respectively, was set to P < 0.05. Osteoarthritis and Cartilage 2012 20, 1179-1185DOI: (10.1016/j.joca.2012.06.004) Copyright © 2012 Osteoarthritis Research Society International Terms and Conditions

Fig. 3 Effects of PCB126 on NO generation. Cells were treated with 0.01, 0.1 and 1 μM PCB126 in the presence or absence of 0.5 mM l-NMMA. NO production was measured as described in method section. Unit values are mean and 95% CI (error bar) from three independent experiments. Statistical difference from DMSO control (*) and PCB126 only-treated cells (#), respectively, was set to P < 0.05. Osteoarthritis and Cartilage 2012 20, 1179-1185DOI: (10.1016/j.joca.2012.06.004) Copyright © 2012 Osteoarthritis Research Society International Terms and Conditions

Fig. 4 Effects of PCB126 on NF-κB binding activity. Cells were treated with 0.01, 0.1 and 1 μM PCB126 in the presence or absence of 0.5 mM l-NMMA. NF-κB binding activity was measured as described in method section. Unit values are mean and 95% CI (error bar) from three independent experiments. Statistical difference from DMSO control (*) and PCB126 only-treated cells (#), respectively, was set to P < 0.05. Osteoarthritis and Cartilage 2012 20, 1179-1185DOI: (10.1016/j.joca.2012.06.004) Copyright © 2012 Osteoarthritis Research Society International Terms and Conditions

Fig. 5 Effects of PCB126 on apoptosis induction. Apoptosis of chondrocyte was quantified by caspase-3 activity (A) and ELISA (B), as described in method section. Cells were exposed to 0.01, 0.1, 1 μM PCB126 for 24 h in the presence or absence of 10 mM NAC or 0.5 mM l-NMMA. All the values represent mean and 95% CI (error bar) of three independent experiments. Statistical difference from DMSO control (*) and PCB126 only-treated cells (#), respectively, was set to P < 0.05. Osteoarthritis and Cartilage 2012 20, 1179-1185DOI: (10.1016/j.joca.2012.06.004) Copyright © 2012 Osteoarthritis Research Society International Terms and Conditions

Fig. 6 Fluorescence microscopic image of TUNEL staining. Representative images from three independent experiments are presented. Magnification 400×. Osteoarthritis and Cartilage 2012 20, 1179-1185DOI: (10.1016/j.joca.2012.06.004) Copyright © 2012 Osteoarthritis Research Society International Terms and Conditions