Dataset Information

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.

Objective

To test if inflammatory cells are required to mediate induced lung maturation.

Methods

Lung inflammation was induced by intraamniotic injection of endotoxin or IL-1. Inflammatory cell recruitment to the lung was inhibited by an anti-CD18 blocking antibody given intramuscularly to the fetus. Preterm lambs were delivered at 124-d gestation (term = 150 d) 2 or 7 d after exposure to endotoxin/IL-1 or endotoxin/IL-1 + anti-CD18 antibody.

Measurements

Lung inflammation was measured by bronchoalveolar lavage fluid cell count, inflammatory scoring of lung parenchyma, and expression of proinflammatory cytokines and inducible nitric oxide synthase. Lung maturation was quantitated by surfactant protein mRNA expression, saturated phosphatidylcholine pool size, and pressure-volume curves.

Main results

Inhibition of CD18 significantly reduced endotoxin-induced but not IL-1-induced fetal lung inflammatory cell recruitment and activation as well as expression of proinflammatory cytokines. Compared with control lungs, both endotoxin and IL-1 induced lung maturation. Anti-CD18 antibody administration inhibited only endotoxin-induced but not IL-1-induced increases in surfactant protein mRNA and surfactant saturated phosphatidylcholine. Exposure to anti-CD18 antibody moderated endotoxin-induced increases in lung volumes but had no effect on IL-1-induced increases in lung volumes.

Conclusions

(1) Endotoxin- but not IL-1-induced inflammatory cell recruitment in the preterm fetal lamb lung is CD18 dependent; (2) recruited inflammatory cells mediate some aspects of fetal lung maturation.

SUBMITTER: Kallapur SG

PROVIDER: S-EPMC2718417 | biostudies-literature | 2005 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Recruited inflammatory cells mediate endotoxin-induced lung maturation in preterm fetal lambs.

Kallapur Suhas G SG Moss Timothy J M TJ Ikegami Machiko M Jasman Richard L RL Newnham John P JP Jobe Alan H AH

American journal of respiratory and critical care medicine 20050818 10

<h4>Rationale</h4>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.<h4>Objective</h4>To test if inflammatory cells are required to mediate induced lung maturation.<h4>Methods</h4>Lung inflammation was induced by intraamniotic injection of endotoxin or IL-1. Inflammatory cell recruitment to the lung was ...[more]

PMID: 16109976

Similar Datasets

Project description:BackgroundBronchopulmonary dysplasia (BPD) is closely associated with ventilator-induced lung injury (VILI) in very preterm infants. The greatest risk of VILI may be in the immediate period after birth, when the lungs are surfactant deficient, still partially filled with liquid and not uniformly aerated. However, there have been very few studies that have examined this immediate post-birth period and identified the initial injury-related pathways that are activated. We aimed to determine if the early response genes; connective tissue growth factor (CTGF), cysteine rich-61 (CYR61) and early growth response 1 (EGR1), were rapidly induced by VILI in preterm lambs and whether ventilation with different tidal volumes caused different inflammatory cytokine and early response gene expression.MethodsTo identify early markers of VILI, preterm lambs (132 d gestational age; GA, term approximately 147 d) were resuscitated with an injurious ventilation strategy (V(T) 20 mL/kg for 15 min) then gently ventilated (5 mL/kg) for 15, 30, 60 or 120 min (n = 4 in each). To determine if early response genes and inflammatory cytokines were differentially regulated by different ventilation strategies, separate groups of preterm lambs (125 d GA; n = 5 in each) were ventilated from birth with a V(T) of 5 (VG5) or 10 mL/kg (VG10) for 135 minutes. Lung gene expression levels were compared to levels prior to ventilation in age-matched control fetuses.ResultsCTGF, CYR61 and EGR1 lung mRNA levels were increased approximately 25, 50 and 120-fold respectively (p < 0.05), within 30 minutes of injurious ventilation. VG5 and VG10 caused significant increases in CTGF, CYR61, EGR1, IL1- , IL-6 and IL-8 mRNA levels compared to control levels. CTGF, CYR61, IL-6 and IL-8 expression levels were higher in VG10 than VG5 lambs; although only the IL-6 and CYR61 mRNA levels reached significance.ConclusionCTGF, CYR61 and EGR1 may be novel early markers of lung injury and mechanical ventilation from birth using relatively low tidal volumes may be less injurious than using higher tidal volumes.

Dataset Information

Recruited inflammatory cells mediate endotoxin-induced lung maturation in preterm fetal lambs.

Rationale

Objective

Methods

Measurements

Main results

Conclusions

Publications

Recruited inflammatory cells mediate endotoxin-induced lung maturation in preterm fetal lambs.

Similar Datasets

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