First Author | Xu H | Year | 2001 |
Journal | Brain Res Mol Brain Res | Volume | 90 |
Issue | 1 | Pages | 57-67 |
PubMed ID | 11376856 | Mgi Jnum | J:69589 |
Mgi Id | MGI:1934965 | Doi | 10.1016/s0169-328x(01)00087-0 |
Citation | Xu H, et al. (2001) Attenuation of hypoxia-ischemia-induced monocyte chemoattractant protein-1 expression in brain of neonatal mice deficient in interleukin-1 converting enzyme. Brain Res Mol Brain Res 90(1):57-67 |
abstractText | Interleukin-1beta (IL-1beta) upregulates expression of the chemokine monocyte chemoattractant protein-1 (MCP-1) in many experimental models. In neonatal rodent brain, hypoxia-ischemia rapidly stimulates expression of this chemokine, although the role of IL-1beta in regulating this response is unknown. Interleukin-1 converting enzyme (ICE) is a cysteine protease that cleaves inactive pro-IL-1beta to generate mature IL-1beta. Neonatal mice with a homozygous deletion of ICE (ICE -/-) are resistant to moderate, but not to severe cerebral hypoxic-ischemic insults, relative to their wild-type controls. We hypothesized that their resistance to moderate hypoxic-ischemic insults is mediated by suppression of the acute inflammatory response to brain injury in the absence of IL-1beta, and that hypoxia-ischemia induced MCP-1 expression would be attenuated in ICE -/- animals. To test this hypothesis, paired litters of 9-10-day-old ICE -/- and wild-type mice underwent right carotid ligation, followed by 40, 70 or 120 min exposure to 10% O(2) and ischemia-induced changes in MCP-1 mRNA and protein were compared, using a semi-quantitative reverse-transcription polymerase chain reaction assay and an ELISA, respectively. With a lesioning protocol that elicits minimal injury in wild-types (ligation+40 min 10% O(2)), there was an attenuation of hypoxia-ischemia-induced MCP-1 production at 8 h post-hypoxia; in contrast, in animals that underwent longer periods of hypoxia-ischemia the magnitude of injury-induced induced MCP-1 production did not differ between wild-type and ICE -/- animals. These results demonstrate both that the acute inflammatory response to hypoxia-ischemia is attenuated in ICE -/- animals, and also that hypoxic-ischemic brain injury stimulates MCP-1 expression even in the absence of IL-1beta activity. |