C<inf>2</inf>-ceramide mediates cerebellar granule cells apoptosis by activation of caspases-2, -9, and -3

Ceramide is able to induce the apoptotic death of cerebellar granule cells (CGC) in culture. However, previous reports did not agree on whether ceramide-induced apoptosis of CGC requires caspase activation. Here we have shown that addition of C2-ceramide is able to produce extensive death of cultured CGC, which is associated with chromatin condensation, ladder-like DNA fragmentation, and activation of caspases. Our results show that C 2-ceramide activates caspases-3, -9, and -2 but not caspases-1 and -8. Caspase-9 activation was associated with cytochrome c release from mitochondria toward the cytosol and was followed by activation of caspases-2 and -3. PARP proteolysis was also observed after caspase-3 and -2 activation. The involvement of caspases-9, -3, and -2 in ceramide-mediated apoptotic death of CGC was further supported by the use of specific inhibitors. © 2008 Wiley-Liss, Inc.