Figure 3. Oxidative stress upregulates the expression of sirtuins.

(A) Quantitative real-time RT-PCR analysis of sirtuin gene expression after H₂O₂ treatment (20 μM, 6 hours) in preimplantation embryos. Sirt3 mRNA levels were significantly increased in 4-cell embryos after exposure to H₂O₂. Data are derived from 3 independent experiments. Statistical assessments were performed by applying Mann-Whitney U test. *P < 0.05. (B and C) Western blotting analysis showing Sirt3 protein upregulation in 4-cell embryos (B) and NIH 3T3 cells (C) after H₂O₂ treatment (B, 20 and 100 μM, 18 hours; C, 20 μM, 24 hours) detected by Western blot. Blotting for α-tubulin served as an internal control.