FIGURE 2.

Senescence-relevant alterations in oxidation/antioxidation capacity and measurement of Sirt3 and superoxide dismutase 2 (SOD2) expression and activity. (A) Intracellular reactive oxygen species (ROS) levels were determined using dihydroethidium (DHE) staining in young (Y), old (O), and H₂O₂ pretreated (Y + H) MSCs. (B) Quantitative analysis of DHE-fluorescent intensity. (C–E) DNA damage was detected by comet assays (C), quantitative analysis of comet cells ratio (D), and measurement of olive tail moments (OTMs) (E). (F) Intracellular malondialdehyde (MDA) contents. (G) Sirt3 mRNA expression was detected by real-time quantitative polymerase chain reaction (RT-qPCR). (H) Sirt3 protein expression was detected by western blotting. (I) SOD2 mRNA expression was examined by RT-qPCR. (J) SOD2 protein expression was examined by western blotting. (K) Assessment of SOD2 activity. Data are expressed as mean ± SD, n = 3. **P < 0.01 vs. young.