Loading…

Mice Deficient in Interleukin-1 Converting Enzyme Are Resistant to Neonatal Hypoxic-Ischemic Brain Damage

Interleukin-1 (IL-1) converting enzyme (ICE) is a cysteine protease that cleaves inactive pro-IL-1β to active IL-1β. The pro-inflammatory cytokine IL-1β is implicated as a mediator of hypoxic-ischemic (HI) brain injury, both in experimental models and in humans. ICE is a member of a family of ICE-li...

Full description

Saved in:
Bibliographic Details
Published in:Journal of cerebral blood flow and metabolism 1999-10, Vol.19 (10), p.1099-1108
Main Authors: Liu, Xiao-Hong, Kwon, Deborah, Schielke, Gerald P., Yang, Guo-Yuan, Silverstein, Faye S., Barks, John D. E.
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Interleukin-1 (IL-1) converting enzyme (ICE) is a cysteine protease that cleaves inactive pro-IL-1β to active IL-1β. The pro-inflammatory cytokine IL-1β is implicated as a mediator of hypoxic-ischemic (HI) brain injury, both in experimental models and in humans. ICE is a member of a family of ICE-like proteases (caspases) that mediate apoptotic cell death in diverse tissues. The authors hypothesized that in neonatal mice with a homozygous deletion of ICE (ICE-KO) the severity of brain injury elicited by a focal cerebral HI insult would be reduced, relativefto wild-type mice. Paired litters of 9- to 10-day-old ICE-KO and wild-type mice underwent right carotid ligation, followed by 70 or 120 minutes of exposure to 10% O2, In this neonatal model of transient focal cerebral ischemia followed by reperfusion, the duration of hypoxia exposure determines the duration of cerebral ischemia and the severity of tissue damage. Outcome was evaluated 5 or 21 days after lesioning; severity of injury was quantified by morphometric estimation of bilateral cortical; striatal, and dorsal hippocampal volumes. In animals that underwent the moderate HI insult (70-minute hypoxia), damage was attenuated in ICE-KO mice, when evaluated at 5 or 21 days post-lesioning. In contrast, in mice that underwent the more severe HI insult (120-minute hypoxia), injury severity was the same in both groups. Reductions in intra-HI CBF, measured by laser Doppler flowmetry, and intra- and post-HI temperatures did not differ between groups. These results show that ICE activity contributes to the progression of neonatal HI brain injury in this model. Whether these deleterious effects are mediated by proinflammatory actions of IL-lβ and/or by pro-apoptotic mechanisms is an important question for future studies.
ISSN:0271-678X
1559-7016
DOI:10.1097/00004647-199910000-00006