Up-regulation of the Nedd2 gene encoding an ICE/Ced-3-like cysteine protease in the gerbil brain after transient global ischemia

We assessed the expression of several genes encoding pro-apoptotic cysteine proteases similar to interleukin-1 beta converting enzyme (ICE) and nematode Ced-3 in association with delayed neuronal death (DND) after transient forebrain ischemia in Mongolian gerbil. The levels of the two species of Nedd2 mRNA concomitantly increased about twofold in the whole forebrain at 3-6 h after 10-min ischemia and declined to the basal level by 24 h. In situ hybridization revealed that the Nedd2 gene was up-regulated in some neuronal populations in CA(1) and CA(3) regions of the hippocampus. In contrast, expression of ICE, CPP32/Yama/Apopain, and TX/ICErelII did not change within 48 h. These observations raise the possibility that up-regulation of Nedd2 in the vulnerable neurons may contribute to the proteolytic processes preceding the manifestation of apoptosis and/or necrosis after ischemic insult.