Figure 5.

NR4A1 is involved in TNF-induced chondrocyte apoptosis. A. si-NR4A1 partly reduces the TNF-induced up-regulation of cleaved PARP1, as indicated by western blot. GAPDH is an internal reference. B. TUNEL assay shows that the apoptotic cell percent of each group exhibits similar apoptosis changes to western blot results. The experiments are repeated five times. Cells are first treated by TNF for 12 h and then transfected with si-NR4A1. Scramble si-NR4A1 is transfected as control. *P < 0.05. **P < 0.01. ***P < 0.001. NR4A1, nuclear receptor subfamily 4, group A, member 1. TNF, tumor necrosis factor. PARP1, poly (ADP-ribose) polymerase 1.