IL-1alpha causes lung inflammation and maturation by direct effects on preterm fetal lamb lungs

Ilene Sosenko, Suhas Kallapur, Ilias Nitsos, Timothy Moss, John Newnham, Machiko Ikegami, Alan Jobe

Research output: Contribution to journalArticleResearchpeer-review

29 Citations (Scopus)

Abstract

Intra-amniotic endotoxin induces IL-1, causes chorioamnionitis, lung inflammation, lung injury and lung maturation in preterm lambs. Intra-amniotic IL-1alpha also causes chorioamnionitis, lung inflammation and lung maturation. We asked if IL-1alpha effects on the preterm lung are mediated by direct signaling to the lung rather than by indirect effects from the chorioamnionitis. To study IL-1 effects independently of chorioamnionitis, the lungs and the amniotic fluid were surgically separated in fetal sheep by diverting fetal lung fluid via a tracheostomy tube to a sialastic bag. A mini-osmotic pump delivered an intratracheal infusion of recombinant sheep IL-1alpha (10 microg) or saline (control) over 24 h. Preterm lambs were delivered 1d or 7d after the start of the infusion at 124d gestational age (Term = 150d). IL-1alpha recruited inflammatory cells and increased pro-inflammatory cytokine mRNA expression in the fetal lungs. Compared with controls, IL-1alpha did not alter lung antioxidant enzyme activity or alveolar numbers. IL-1alpha had minimal effects on the mRNA or protein expression of proteins essential for vascular development. IL-1alpha induced large increases in alveolar surfactant saturated phosphatidylcholine and increased lung gas volumes. Lung inflammation and maturation result from direct exposure of the fetal lung to a single cytokine - IL-1alpha.
Original languageEnglish
Pages (from-to)294 - 298
Number of pages5
JournalPediatric Research
Volume60
Issue number3
DOIs
Publication statusPublished - 2006
Externally publishedYes

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