Figure 7. Protein expression of S6 and PS6 in rabbit AFSCs cultured in growth medium with five different conditions for 6 days and tested by western blot. (A) Protein levels for S6, PS6 and GAPDH; (B) semi-quantification of PS6; (C) semi-quantification of S6. To ensure that equal amount of total protein was loaded, GAPDH (glyceraldehyde-3-phosphate dehydrogenase) was used as a loading control for protein normalization. The results indicated that bleomycin did not cause the significant changes in S6 protein levels in AF cells (A, C), however, bleomycin increased PS6 protein expression in AF cells with a concentration-dependent manner (A, B). Adding rapamycin in bleomycin treated AF cells decreased PS6 levels in AF cells (A, B), but not S6 protein levels (A, C). *p<0.05 compared to control, #P<0.05 compared to bleomycin 50 μg/ml.