Fig. 2.
EPO inhibits the release of cytochrome c, the decrease in mitochondrial membrane potential, and the activation of caspases associated with p53-dependent apoptosis.
(A) Cytosolic protein extracts were prepared from the DP16.1/p53ts cells that were cultured at 32°C for the time periods indicated with or without EPO. Proteins (30 μg) were fractionated by SDS-PAGE, immunoblotted separately with antibodies against cytochromec and β-actin, and visualized by enhanced chemiluminescence. (B) The mitochondrial membrane potential (ΔΨm) and free calcium content of DP16.1/p53ts cells cultured at 32°C in the presence or absence of EPO were measured by flow cytometry. (C) DP16.1/p53ts cells were cultured at 32°C in the presence or absence of EPO for the times indicated. Protein extracts were prepared and analyzed by SDS-PAGE and immunoblotting with anti-PARP antibodies. (D) The generation of ROS and glutathione content of DP16.1/p53ts cells cultured at 37°C or 32°C were measured by flow cytometry (i-iii). ROS production in DP16.1/p53ts cells in response to treatment with Tert-butyl-hydroperoxide is shown in panel iv (tBHP, 70 μM). Panel v represents an overlay of panels ii and iv.