Figure 5.

DOX induced cardiomyocyte apoptosis through up-regulation of Bim. A, mice were sacrificed 24 h after DOX injection (5 mg/kg, i.p., n = 3/group), and Bim expression was examined by Western blotting. Results are mean ± S.D. and analyzed by two-tailed Student's t test. **, p < 0.01. B, NRCMs were treated with DOX (1 μm) for various periods of time (n = 3). Cell lysates were immunoblotted using the indicated antibodies, with β-actin as a loading control. One-way ANOVA with Tukey test; *, p < 0.05; **, p < 0.01 versus time 0. C and D, NRCMs were treated with DOX (1 μm) for 0, 4, or 24 h (n = 3–4/time point). Bim transcript levels were analyzed by semiquantitative RT-PCR (C) and qRT-PCR (D). One-way ANOVA with Tukey test; **, p < 0.01 versus Time 0. E, NRCMs were transfected with control or Bim siRNAs (100 nm) twice prior to treatment with DOX (1 μm) for 24 h (n = 3). **, p < 0.01 versus siControl.