Figure 2. EC-Exos decreased the anti-oxidative stress response of mouse chondrocytes stimulated with inflammation and increased the ratio of apoptotic cells. ATDC5 cells and primary chondrocytes were exposed to IL-1β or IL-1β and EC-Exos at different concentrations (50 and 100 μg). (A) Comparison of ROS content in ATDC5 cells after specific experimental treatments. (B) Apoptosis was detected with TUNEL assays in ATDC5 cells under different treatments. (C) Flow cytometry was used to monitor apoptosis in dyed ATDC5 cells under different treatments. (D, E) Protein level of Keap-1, Nrf-2, NQO-1, HO-1, Bax, Bcl-2, C-caspase3 and β-actin in ATDC5 cells and primary chondrocytes under different treatments. ***p<0.001, **p<0.01, *p<0.05 (n = 3).