title: Caspase-2 (Nedd-2) processing and death of trophic factor-deprived PC12 cells and sympathetic neurons occur independently of caspase-3 (CPP32)-like activity.
abstract: We have previously shown that caspase-2 (Nedd-2) is required for apoptosis induced by withdrawal of trophic support from PC12 cells and sympathetic neurons. Here, we examine the relationship of caspase-2 processing and cell death to induction of caspase-3 (CPP32)-like activity in PC12 cells. Caspase-2 processing, at a site tentatively identified as D333, led to the formation of an N-terminal 37 kDa product. This processing correlated temporally with induction of caspase-3-like activity. Agents previously shown to inhibit caspase-3-like activation, such as bcl-2 and the Cdk inhibitor flavopiridol, also acted upstream of caspase-2 processing. The general caspase inhibitors BAF and zVAD-FMK inhibited N-terminal caspase-2 processing. In contrast, the more selective caspase inhibitor DEVD-FMK inhibited the induction of caspase-3-like activity but did not affect caspase-2 processing or significantly suppress death in PC12 cells or sympathetic neurons. This indicates that caspase-3-like activity is not required for either caspase-2 processing or apoptosis in this paradigm. An antisense oligonucleotide to caspase-2 inhibited cell death but did not affect caspase-3-like activity, indicating that caspase-2 is not upstream of this activity and that activation of caspase-3-like caspases is not sufficient for death. Thus, in our paradigm, caspase-2 processing and caspase-3-like activity are induced independently of each other. Moreover, although death requires caspase-2, caspase-3-like activity is neither necessary nor sufficient for death.
authors.affiliation: Department of Pathology, Taub Center for Alzheimer's Disease Research and Center for Neurobiology and Behavior, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
authors.forename: L
authors.initials: L
authors.lastname: Stefanis
authors.forename: C M
authors.initials: CM
authors.lastname: Troy
authors.forename: H
authors.initials: H
authors.lastname: Qi
authors.forename: M L
authors.initials: ML
authors.lastname: Shelanski
authors.forename: L A
authors.initials: LA
authors.lastname: Greene
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D053143:Caspase 2; D053148:Caspase 3; D020169:Caspases / Q000032:analysis / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004792:Enzyme Precursors / Q000032:analysis / Q000378:metabolism; D009414:Nerve Growth Factors / Q000494:pharmacology; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D009842:Oligopeptides / Q000494:pharmacology; D016716:PC12 Cells; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D011506:Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000494:pharmacology; D051381:Rats; D013564:Sympathetic Nervous System / Q000166:cytology
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D015853:Cysteine Proteinase Inhibitors; D004792:Enzyme Precursors; C098738:N-acetyl-tyrosyl-valyl-alanyl-aspartyl chloromethyl ketone; D009414:Nerve Growth Factors; D009842:Oligopeptides; D011506:Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C499322:Parp1 protein, rat; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; C505410:Casp3 protein, rat; D053143:Caspase 2; D053148:Caspase 3; D020169:Caspases