Figure 4. Rapamycin protected chondrocytes against the autophagy deficiency caused by IL-18 stimulation. Chondrocytes of the IL-18 + rapamycin treatment group were pre-treated with rapamycin (100 nM) for 1 h, followed with 24 h IL-18 stimulation (100 ng/ml). Chondrocytes of the IL-18 treatment group were treated with 100 ng/ml IL-18 for 24 h. Chondrocytes of the rapamycin treatment group were treated with 100 nM rapamycin for 24 h. Protein levels of Atg5 (B), Atg7 (C), Beclin1 (D), LC3B/LC3A (E), P62 (F), and GAPDH as an internal control, evaluated by Western blot (A). The values are expressed as mean ± standard deviation (SD). Significance was calculated by a one-way ANOVA with a post hoc Tukey's multiple comparisons test. *p<0.05 versus the IL-18 treatment group.