BAR AND BAK PROTEINS REQUIRE CASPASE ACTIVITY TO TRIGGER APOPTOSIS INSYMPATHETIC NEURONS

WE show that the pro-apoptotic proteins Bar and Bak trigger apoptosis when over-expressed in sympathetic neurons cultured in the presence of NGF. This effect can be blocked with z-VAD-fmk, a peptide inhibitor o f caspases, but not with anti-apoptotic chemical compounds such as ant ioxidants or proteasome inhibitors. These results demonstrate that in sympathetic neurons Bar and Bak are sufficient to induce apoptosis in the absence of any other apparent cell death stimulus and that their e ffect is mediated by caspases but does not require reactive oxygen spe cies nor activity of the proteasome.