Figure 1.

FAIM-L protects Type II but not Type I cells from Fas ligand-induced apoptosis. A, PC12 cells were transfected with pcDNA3, 3xHA-Bcl-xL, 3xFLAG-FAIM-L, or 3xHA-c-FLIP-L expression plasmids and treated with sFasL (100 ng/ml) and AD (1 nm) for 24 h. The percentage of apoptotic cells was assessed by counting nuclei with apoptotic morphology. B, HEK293 cells were transfected and treated as in A for 8 h, and the percentage of apoptotic cells was determined. C, PC12 cells were transfected with pcDNA3, 3xHA-Bcl-xL, or 3xFLAG-FAIM-L expression plasmids and treated with sFasL and AD. Cleavage of caspases and their substrate PARP was assessed by Western blot. D, HEK293 cells were transfected and treated with sFasL prior Western blot analysis as in C. E, DEVDase activity was measured in PC12 cells that were treated with sFasL and AD for 24 h. F, DEVDase activity was measured in HEK293 cells that were treated with sFasL for 8 h. Error bars indicate SD. Student test was performed, comparing transfected cells treated with sFasL or sFasL+AD with their pcDNA3-transfected counterpart. * p ≤ 0.01. **p ≤ 0.001.