Figure 5.

Activation of p53 signaling in response to Nutlin-3. (A) Primary RPE cells were treated with DMSO or Nutlin-3 (60 μM) for 4 hours, and monolayers were photographed under a phase-contrast microscope equipped with a charge-coupled device camera using ImageJ software. (B) DNA fragmentation was measured by ELISA (mean ± SEM). *P < 0.05; significantly different compared with DMSO. (C) Primary RPE cells were treated with DMSO or 60 μM Nutlin-3, and lysates were analyzed for phospho-p53 (Ser15, Ser46), total p53, and Mdm2. (D) Cell extracts were analyzed to determine the levels of Bcl-xL, Bcl-2, PUMA, Noxa, Siva-1, and active caspase-3 by Western blot analysis. Actin was used as a loading control.