Expression of interleukin-1 beta converting enzyme gene family and bcl-2 gene family in the rat brain following permanent occlusion of the middle cerebral artery.

Recent investigations have been suggesting that some neuronal subpopulations may die via programmed cell death after focal ischemic injury. To clarify the possible roles of the genes involved in the cell-death program, this study examined the expression of three members of the interleukin-1 beta converting enzyme (Ice) gene family (Ice, Nedd2, and Yama/CPP32) and two members of the bcl-2 gene family (bcl-2 and bcl-x) in the rat brain after permanent occlusion of the middle cerebral artery. Northern blot analysis revealed a transient induction of Nedd2 mRNA 8 h after the ischemic insult (3.8-fold) and an increase in Yama/CPP32 mRNA 16 to 24 h after the insult (5.8-fold at 24 h), whereas the expression of Ice remained constant. The expression of bcl-2 and bcl-x remained constant after the ischemic insult. Taking into account the key role of the Ice gene family in the execution of programmed cell death, the induction of Ice gene family might play a causative role in apoptotic cell death.