Figure 2.

Facilitation of TNF-α-mediated chondrocyte death by oxidized low density lipoprotein (ox-LDL). After 30 min preincubation with or without anti-LOX-1 antibody (10 μg/ml), Chondrocytes were co-treated with TNF-α (50 ng/ml) and ox-LDL (20 μg/ml), and harvested at 24 or 48 h for (A) cell death, (B) DNA fragmentation assay, (C) Flow cytometry analysis of the chrondrocyte apoptosis by Annexin V/PI staining and (D) western blot analysis of apoptosis related proteins. (A, B and C) Ox-LDL co-treatment could facilitate TNF-α-mediated chondrocyte death and this process could be blocked by Lox-1 monoclonal antibody pretreatment. (D) Western-blot analysis revealed that increased level of cleaved caspase-8 and caspase-3 in TNF-α and ox-LDL co-treated chondrocytes, and that this effect could be blocked by Lox-1 antibody pretreatment.*P<0.05 compared to control. ox-LDL, oxidized low density lipoprotein; Lox-1, lectin-like ox-LDL receptor-1; TNF-α, tumor necrosis factor α; Ab, antibody; PI, propidium iodide.