Figure 1.

TGFβ induces the caspase-dependent loss of ΔΨm. (A) BL41 cells were cultured for 48 h without (−) or with TGFβ (1 ng/ml). Apoptotic cells were selected as shrunken cells with high side-scatter (SSC) and low forward-scatter (FSC) properties as assessed by flow cytometry. Apoptotic cells were counted and their number expressed as a percentage of the total cells. After staining with DiOC₆(3), ΔΨm was assessed by flow cytometry, and cells with low ΔΨm were counted and their number expressed as a percentage of the total population. (B) BL41 cells were cultured for 48 h without (−) or with TGFβ (1 ng/ml) alone (TGFβ), or in combination with 100 μM zVAD-fmk (TGFβ + zVAD), or in the presence of ionomycin (10 μg/ml) alone (iono), or in combination with 100 μM zVAD-fmk (iono + zVAD). After staining with DiOC₆(3) cells with a low ΔΨm were counted as described above. The results are representative of at least three independent experiments.