Effect of overexpression of gelsolin on apoptosis of CTLL-20 cells induced by C2-ceramide.

Overexpression of gelsolin did not prevent apoptosis of CTLL-20 cells induced by C2-ceramide. Transfected CTLL-20 cells overexpressing gelsolin (solid bars) or vector alone (hatched bars) were incubated for 12.5 hours in the presence of 50 U/mL recombinant human IL-2 and in the presence of 100 μmol/L C2-ceramide (closed or dark gray bars), 50 μmol/L C2-ceramide (gray bars), or its vehicle, 0.05% Me₂SO (open bars). The percentage of apoptosis was determined by Annexin V-FITC staining as described in “Materials and methods.” Comparable results were obtained by trypan blue exclusion (data not shown). These results are representative of 3 independent experiments. Immunoblotting for gelsolin (inset) demonstrated that the gelsolin CTLL-20 transfectants were overexpressing gelsolin protein at the time of the experiment.