Figure 5.

SRT1720 activates SIRT1 and protected aged hMSCs from apoptosis. SIRT1 expression (b) was detected by western blot (a), and SIRT1 activity was evaluated by the ratio of acety-p53/p53 (c) detected by western blot (a). Western blot (d) was carried out to quantify the apoptosis-associated protein cleaved caspase-3 (e), cleaved caspase-8 (f) involved in extrinsic apoptosis pathway and Bcl-2/Bax (g) involved in intrinsic apoptosis pathway. The apoptosis was also examined by Hoechst 33258 staining (h and i). Ctrl refers to normal culture medium. The other stress groups are treated with serum deprivation plus H₂O₂ medium. The volume fraction of DMSO was the same in every groups. Data are expressed by mean±S.D. (three independent experiments, N=3). *P<0.05; **P<0.01