Specific expression of CPP32 in sensory neurons of mouse embryos and activation of CPP32 in the apoptosis induced by a withdrawal of NGF.

We isolated mouse CPP32/apopain cDNA, a mammalian homologue most closely related to Ced-3 in C. elegans, and examined the involvement of CPP32 in the apoptosis of nervous system during development. CPP32 is specifically expressed in the trigeminal (V) ganglia, facio-acoustic (VII-VIII) ganglion complex, and dorsal root ganglia (DRGs) of mouse 10.5-day embryos. CPP32-like proteases are activated during apoptosis of DRG neurons induced by deprivation of NGF and serum. Ac-DEVD-CHO, an inhibitor for CPP32-like proteases, prevents apoptosis of DRG neurons, but Ac-YVAD-CHO, an inhibitor for ICE-like proteases, does not. These results suggest that CPP32 or CPP32-like proteases play a role as central mediator in the apoptosis of DRG neurons induced by lack of neurotrophin signals.