Abstract
Caspase-11 is an inducible protease that plays an important role in both inflammation and apoptosis. Inflammatory stimuli induce and activate caspase-11, which is required for the activation of caspase-1 or interleukin-1β (IL-1β) converting enzyme (ICE). Caspase-1 in turn mediates the maturation of proinflammatory cytokines such as IL-1β, which is one of the crucial mediators of neurodegeneration in the central nervous system. Here, we report that hypoxic exposure of cultured brain microglia (BV-2 mouse microglia cells and rat primary microglial cultures) induces expression and activation of caspase-11, which is accompanied by activation of caspase-1 and secretion of mature IL-1β and IL-18. Hypoxic induction of caspase-11 was observed in both mRNA and protein levels, and was mediated through p38 mitogen-activated protein kinase pathway. Transient global ischemia in rats also induced caspase-11 expression and IL-1β production in hippocampus supporting our in vitro findings. Caspase-11-expressing cells in hippocampus were morphologically identified as microglia. Taken together, our results indicate that hypoxia induces a sequential event - caspase-11 induction, caspase-1 activation, and IL-1β release - in brain microglia, and point out the importance of initial caspase-11 induction in hypoxia-induced inflammatory activation of microglia.
Original language | English |
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Pages (from-to) | 107-114 |
Number of pages | 8 |
Journal | Molecular Brain Research |
Volume | 114 |
Issue number | 2 |
DOIs | |
State | Published - 10 Jun 2003 |
Keywords
- Hypoxia
- Inflammation
- Ischemia
- Mitogen-activated protein kinase