Recruited Inflammatory Cells Mediate Endotoxin-induced Lung Maturation in Preterm Fetal Lambs

Abstract

Rationale: Chorioamnionitis is paradoxically associated with a decreased incidence of respiratory distress syndrome in preterm infants. In preterm lambs, intraamniotic endotoxin and interleukin 1 (IL-1) induce lung inflammation followed by lung maturation. Keywords: bronchopulmonary dysplasia; CD18; chorioamnionitis; respiratory distress syndrome; surfactant Chorioamnionitis or infection/inflammation of the fetal membranes and amniotic fluid is a pregnancy complication associated with up to 70% of all preterm deliveries at less than 30-wk

Antenatal inflammation and lung injury: prenatal origin of neonatal disease

“…60 Similar findings have been obtained in lung explants in which the presence of macrophages was mandatory for lung maturation after endotoxin administration. 61 Our current understanding is that fetal lung responds to proinflammatory mediators in amniotic fluid with a recruitment of inflammatory cells, which may be the major source of IL-1b, which in turn initiates maturational signals.…”

Endotoxin-induced maturation of monocytes in preterm fetal sheep lung

“…However, these inflammation-induced changes in the fetal lung also were accompanied by delayed alveolar and lung vascular development, which are similar to the changes described in bronchopulmonary dysplasia (BPD) (5,19,47). Our group recently demonstrated that an influx of peripheral blood leukocytes to the fetal lung is required for intra-amniotic endotoxin-mediated effects on fetal lamb lungs (21).…”

Experimental amniotic fluid infection in sheep: Effects of Ureaplasma parvum serovars 3 and 6 on preterm or term fetal sheep

“…colonization of their airways (18). Our ongoing investigations with lipopolysaccharide demonstrate that preterm lung 'maturation' in sheep, apparently like that observed in response to ureaplasma colonization, is the consequence of pulmonary leukocyte-mediated lung inflammation (19).…”