Figure 2. Endogenous depletion or suppression of HO-1 promoted HUVEC senescence. (A) Screening of HO-1 interference sequences by Western blotting. Sequence-3 was used for the following experiments. *P < 0.05 vs. Control or NC-siRNA. n = 3. (B) SA-β-gal staining of HUVEC transfected with HO-1 siRNA (200 × magnification). *P < 0.05 vs. Control or NC-siRNA. n = 5. (C) SA-β-gal staining after treating with different concentration of ZnPP (0.1, 1 or 10 μM) (200 × magnification). *P < 0.05 vs. Control. n = 5. (D) Silencing of HO-1 increased the expression of p53 or p21. *P < 0.05 vs. Control or NC-siRNA. n = 5. (E) HO-1 inhibitor ZnPP increased the expression of p53 or p21. *P < 0.05 vs. Control. n = 5. (F) Silencing of HO-1 increased the expression of γH2A.X(Ser139). *P < 0.05 vs. Control or NC-siRNA. n = 5.