Fig. 2

The effect of TfR1 on cartilage ECM degradation and chondrocyte ferroptosis. (A-B) Chondrocytes were treated with 5ng/ml IL-1β with or without TfR1 siRNA, representative images for ferrous ions in the indicated group and statistical analysis of fluorescence intensity. Scale bars = 200 μm. (C-D) Chondrocytes were treated with 5ng/ml IL-1β for 12 h with or without TfR1 siRNA, then expressions of TfR1, MMP3, MMP13, SOX9 and COL2 were examined by western blotting. GAPDH was included as a loading control and semi-quantitative analysis of band density was conducted. Scale bars = 200 μm. (E) Representative images of IF staining for COL2 expression in chondrocytes treated with IL-1β for 12 h. Scale bars = 50 μm. (F) Chondrocytes were treated with 5ng/ml IL-1β for 12 h, representative fluorescence microscopy photomicrographs of intracellular ROS in chondrocytes. (G) Flow cytometric analysis was conducted to quantify the ROS production. (H) Representative images of IF staining for GPX4 expression in chondrocytes treated with IL-1β for 12 h. Scale bars = 50 μm. (I-J) Expressions of GPX4 and SLC7A11 were examined by western blotting. GAPDH was included as a loading control and semi-quantitative analysis of band density was conducted. Data are presented as mean ± SD from three independent experiments. **P < 0.01, **P < 0.01, ***P < 0.001, ****P < 0.0001