FIG. 3.

A1 partially inhibits TNF-induced cytochrome c release from mitochondria and inhibits caspase 3 processing. HT1080IA1 and HT1080I cells were treated with TNF (20 ng/ml) for the indicated times. To detect the release of cytochrome c, cytosolic proteins were extracted and separated by SDS–15% polyacrylamide gel electrophoresis. The blot was probed with monoclonal antibody to cytochrome c (1:1,000). For detecting caspase 8 and caspase 3 processing, whole-cell extracts were prepared and immunoblotted with monoclonal antibodies to caspase 8 (1:1,000) and caspase 3 (1:500). For the internal control, the blots were stripped and reprobed with antibody to α-tubulin (1:2,000).