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Early NFκB activation is inhibited during focal cerebral ischemia in interleukin‐1β‐converting enzyme deficient mice
Author(s) -
Huang FengPeng,
Wang ZhiQiu,
Wu DuChu,
Schielke Gerald P.,
Sun Yi,
Yang GuoYuan
Publication year - 2003
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.10654
Subject(s) - western blot , ischemia , immunohistochemistry , phosphorylation , immunostaining , endocrinology , microbiology and biotechnology , blot , electrophoretic mobility shift assay , medicine , biology , chemistry , gene expression , biochemistry , gene
Our previous study demonstrated that the inhibition of interleukin‐1β (IL‐1β) reduces ischemic brain injury; however, the molecular mechanism of the action of IL‐1 in cerebral ischemia is unclear. We are investigating currently the role of NFκB during focal cerebral ischemia, using mutant mice deficient in the interleukin‐1 converting enzyme gene (ICE KO) in a middle cerebral artery occlusion (MCAO) model. Adult male ICE KO and wild‐type mice ( n = 120) underwent up to 24 hr of permanent MCAO. Cytoplasmic phospho‐NFκB/p65 expression in ischemic brain was examined using Western blot analysis and immunohistochemistry. NFκB DNA‐binding activity was detected using electrophoretic mobility shift assay (EMSA). Furthermore, ICAM‐1 expression was examined in both the ICE KO and wild‐type mice (WT). Western blot analysis and immunostaining showed that the level of cytosolic phosphorylated NFκB/p65 increased after 2 and 4 hr of MCAO in WT mice; however, NFκB/p65 was significantly reduced after MCAO in the ICE KO mice ( P < 0.05). EMSA showed that NFκB DNA‐binding activity increased after MCAO in WT mice; but this effect was reduced in the ICE KO mice. The number of ICAM‐1‐positive vessels in the ischemic hemisphere was greatly attenuated in the ICE KO mice ( P < 0.05), which paralleled the results of immunohistochemistry. Our results demonstrate that NFκB phosphorylation is reduced in ICE KO mice, suggesting that ICE or IL‐1 are involved in early NFκB phosphorylation. Because cerebral ischemia induced infarction is significantly reduced in ICE KO mice, we conclude that early NFκB phosphorylation plays a disruptive role in the ischemic process. © 2003 Wiley‐Liss, Inc.