Interleukin-1α expression precedes IL-1β after ischemic brain injury and is localised to areas of focal neuronal loss and penumbral tissues

<p>Abstract</p> <p>Background</p> <p>Cerebral ischemia is a devastating condition in which the outcome is heavily influenced by inflammatory processes, which can augment primary injury caused by reduced blood supply. The cytokines interleukin-1α (IL-1α) and IL-1β are ke...

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Bibliographic Details
Main Authors: Luheshi Nadia M, Kovács Krisztina J, Lopez-Castejon Gloria, Brough David, Denes Adam
Format: Article
Language:English
Published: BMC 2011-12-01
Series:Journal of Neuroinflammation
Online Access:http://www.jneuroinflammation.com/content/8/1/186
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Summary:<p>Abstract</p> <p>Background</p> <p>Cerebral ischemia is a devastating condition in which the outcome is heavily influenced by inflammatory processes, which can augment primary injury caused by reduced blood supply. The cytokines interleukin-1α (IL-1α) and IL-1β are key contributors to ischemic brain injury. However, there is very little evidence that IL-1 expression occurs at the protein level early enough (within hours) to influence brain damage after stroke. In order to determine this we investigated the temporal and spatial profiles of IL-1α and IL-1β expression after cerebral ischemia.</p> <p>Findings</p> <p>We report here that in mice, as early as 4 h after reperfusion following ischemia induced by occlusion of the middle cerebral artery, IL-1α, but not IL-1β, is expressed by microglia-like cells in the ischemic hemisphere, which parallels an upregulation of IL-1α mRNA. 24 h after ischemia IL-1α expression is closely associated with areas of focal blood brain barrier breakdown and neuronal death, mostly near the penumbra surrounding the infarct. The sub-cellular distribution of IL-1α in injured areas is not uniform suggesting that it is regulated.</p> <p>Conclusions</p> <p>The early expression of IL-1α in areas of focal neuronal injury suggests that it is the major form of IL-1 contributing to inflammation early after cerebral ischemia. This adds to the growing body of evidence that IL-1α is a key mediator of the sterile inflammatory response.</p>
ISSN:1742-2094