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Influence of chemical and ischemic preconditioning on cytokine expression after focal brain ischemia
Author(s) -
Pera Joanna,
Zawadzka Malgorzata,
Kaminska Bozena,
Szczudlik Andrzej
Publication year - 2004
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.20232
Subject(s) - ischemic preconditioning , ischemia , medicine , fas ligand , tumor necrosis factor alpha , downregulation and upregulation , cytokine , apoptosis , brain ischemia , brain damage , messenger rna , pharmacology , endocrinology , anesthesia , chemistry , programmed cell death , biochemistry , gene
Inflammation, upregulation of cytokines, proapoptotic molecules, and apoptosis are accepted widely as crucial players in stroke‐induced brain damage. Induction of brain tolerance against ischemia by pretreatment with nonlethal stressors (preconditioning) has been found to influence expression of different molecules, in addition to reduction of infarct size. It remains unclear, however, whether and how preconditioning changes expression of cytokines after subsequent brain ischemia. We sought to analyze cortical expression of interleukin (IL)‐1β, IL‐6, tumor necrosis factor (TNF)‐α, transforming growth factor (TGF)‐β, Fas, and Fas ligand (FasL) mRNA after a transient, focal brain ischemia in rats subjected to preconditioning. The mRNA levels were determined using a semiquantitative RT‐PCR in the ischemic and contralateral cortex, separately. Transient ischemia was induced by 90‐min middle cerebral artery occlusion (MCAo) and neurologic deficits as well as infarct size were quantified. Preconditioning was carried out by a short‐term MCAo or an injection of 3‐nitropropionic acid 3 days before MCAo. In both preconditioning paradigms, similar effects on investigated mRNA levels were observed. IL‐1β and IL‐6 levels were decreased in tolerant rats compared to those in nontolerant ones. Changes in TNF‐α, TGF‐β, and Fas levels were comparable independently of tolerance state. FasL mRNA was at similar level in rats subjected to chemical preconditioning but lower after ischemic preconditioning. Our findings demonstrate that both preconditioning methods exert a very similar effect on the expression of investigated cytokines. Interestingly, we observed a selective effect of preconditioning on IL‐1β and IL‐6 expression that suggests different functional properties as well as different regulation of analyzed molecules during an induction of the brain tolerance against ischemia. © 2004 Wiley‐Liss, Inc.