Association of increased pulmonary interleukin-6 with the priming effect of intra-amniotic lipopolysaccharide on hyperoxic lung injury in a rat model of bronchopulmonary dysplasia.

Abstract

BACKGROUND:

The authors previously demonstrated the priming effect of intra-amniotic lipopolysaccharide (LPS) on hyperoxic lung injury in a rat model of bronchopulmonary dysplasia (BPD).

OBJECTIVES:

To investigate the mechanism underlying this priming effect by determining biochemical profiles in a rat model of BPD.

METHODS:

The rat model involved intra-amniotic LPS administration and postnatal hyperoxia (85%). The mRNA expressions of interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2), basic fibroblast growth factor (bFGF), and transforming growth factor beta(1) (TGF-beta(1)), as well as the protein levels of IL-6, VEGF, and protein carbonyl in lung tissue were compared between the LPS plus hyperoxia, the LPS only, the hyperoxia only, and the control groups.

RESULTS:

Morphometric analysis of lung tissues demonstrated that alveolarization was significantly inhibited only in the LPS plus hyperoxia group. IL-6 protein levels and its mRNA expression in the lungs were significantly increased only in the LPS plus hyperoxia group. Neither LPS nor hyperoxia increased IL-6 in the lungs independently. bFGF mRNA expression was significantly decreased in the LPS-treated groups. VEGF protein levels were significantly reduced by hyperoxia, whereas protein carbonyl levels were increased by intra-amniotic LPS or hyperoxia. No additional significant change to VEGF or protein carbonyl levels was produced by intra-amniotic LPS or hyperoxia. There were no significant differences in the mRNA expressions of VEGF, VEGFR-2, and TGF-beta(1).

CONCLUSIONS:

The priming effect of intra-amniotic LPS on hyperoxic lung injury may be associated with IL-6 elevation in the lungs.

• Authors: Do-Hyun Kim, Chang Won Choi, Ee-Kyung Kim, Han-Suk Kim, Beyong Il Kim, Jung-Hwan Choi, Myong Jin Lee, Eun Gyeong Yang
• Journal: Neonatology (Neonatology) Vol. 98 Issue 1 Pg. 23-32 (Jun 2010) ISSN: 1661-7819 [Electronic] Switzerland
• PMID: 19955834 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Interleukin-6
• Lipopolysaccharides
• Transforming Growth Factor beta1
• Vascular Endothelial Growth Factor A
• Fibroblast Growth Factors
• Vascular Endothelial Growth Factor Receptor-2

Topics

• Amnion (chemistry, metabolism)
• Animals
• Animals, Newborn
• Bronchopulmonary Dysplasia (etiology, metabolism)
• Disease Models, Animal
• Fibroblast Growth Factors (analysis, metabolism)
• Humans
• Hyperoxia (complications)
• Infant, Newborn
• Interleukin-6 (analysis, metabolism)
• Lipopolysaccharides (toxicity)
• Lung (chemistry, metabolism)
• Protein Carbonylation
• Pulmonary Alveoli (growth & development, metabolism)
• Rats
• Rats, Sprague-Dawley
• Transforming Growth Factor beta1 (metabolism)
• Vascular Endothelial Growth Factor A (analysis, metabolism)
• Vascular Endothelial Growth Factor Receptor-2 (analysis, metabolism)