Double exposure to intra-amniotic lipopolysaccharide and maternal betamethasone induces sustained increase of neutrophils in the lungs and disrupts alveolarization in newborn rats

Hyun Ju Lee; Youn Jin Lee; Heui Seung Jo; Chang Won Choi; Ee-Kyung Kim; Han-Suk Kim; Beyong Il Kim; Jung-Hwan Choi

doi:10.1515/jpm-2013-0063

Article

Double exposure to intra-amniotic lipopolysaccharide and maternal betamethasone induces sustained increase of neutrophils in the lungs and disrupts alveolarization in newborn rats

Hyun Ju Lee , Youn Jin Lee , Heui Seung Jo , Chang Won Choi , Ee-Kyung Kim , Han-Suk Kim , Beyong Il Kim and Jung-Hwan Choi

Published/Copyright: August 9, 2013

Published by

Become an author with De Gruyter Brill

Submit Manuscript Author Information Explore this Subject

From the journal Journal of Perinatal Medicine Volume 41 Issue 6

Abstract

Aim: We investigated the combined effects of intra-amniotic lipopolysaccharide (LPS) and maternal betamethasone (BMZ) on alveolarization using a newborn rat model.

Methods: LPS (1.0 μg/sac) or vehicle was injected into the amniotic sacs of pregnant rats and BMZ (170 μg/kg) or vehicle was injected intramuscularly into the pregnant rats twice at 8-h intervals on gestation day 20. The rat pups were delivered spontaneously after 2–2.5 days and raised until the measurements were taken. Bronchoalveolar lavage was performed on days 2 and 5, and morphometric analyses of the lungs were performed on days 5 and 14.

Results: Intra-amniotic LPS significantly increased the neutrophils in the bronchoalveolar lavage fluid (BALF) on day 2, but double exposure to LPS and BMZ significantly alleviated the neutrophil increase in the BALF. On day 5, while the neutrophils in the BALF decreased in the animals exposed to LPS alone, the neutrophil numbers in the BALF were steady in the animals exposed to both LPS and BMZ. Morphometric analyses on days 5 and 14 revealed a significant disruption of alveolarization only in the animals exposed to both LPS and BMZ.

Conclusions: Our results suggested that double exposure to maternal BMZ and intra-amniotic LPS induces sustained increase of neutrophils in the lungs and disrupts alveolarization.

Keywords: Alveolarization; bronchopulmonary dysplasia; chorioamnionitis; corticosteroid

Corresponding author: Chang Won Choi, MD, PhD, Department of Pediatrics, Seoul National University Bundang Hospital, 82 Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, Korea, Tel.: +82-31-787-7286, Fax: +82-31-787-4054, E-mail: choicw@snu.ac.kr; Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Korea; and Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea

This study was supported by a grant of the Basic Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2010-0021644) and by the SNUBH Research Fund (grant no. 02-2011-057).

References

[1] Arnon S, Grigg J, Silverman M. Pulmonary inflammatory cells in ventilated preterm infants: effect of surfactant treatment. Arch Dis Child. 1993;69:44–8.10.1136/adc.69.1_Spec_No.44Search in Google Scholar

[2] Ballard PL, Ning Y, Polk D, Ikegami M, Jobe AH. Glucocorticoid regulation of surfactant components in immature lambs. Am J Physiol. 1997;273:L1048–57.10.1152/ajplung.1997.273.5.L1048Search in Google Scholar

[3] Bruschettini M, van den Hove DL, Gazzolo D, Steinbusch HW, Blanco CE. Lowering the dose of antenatal steroids: the effects of a single course of betamethasone on somatic growth and brain cell proliferation in the rat. Am J Obstet Gynecol. 2006;194:1341–6.10.1016/j.ajog.2005.11.044Search in Google Scholar

[4] Burri PH, Dbaly J, Weibel ER. The postnatal growth of the rat lung. I. Morphometry. Ana Rec. 1974;178:711–30.10.1002/ar.1091780405Search in Google Scholar

[5] Choi CW, Kim BI, Hong JS, Kim EK, Kim HS, Choi JH. Bronchopulmonary dysplasia in a rat model induced by intra-amniotic inflammation and postnatal hyperoxia: morphometric aspects. Pediatr Res. 2009;65:323–7.10.1203/PDR.0b013e318193f165Search in Google Scholar

[6] Collins JJ, Kunzmann S, Kuypers E, Kemp MW, Speer CP, Newnham JP, et al. Antenatal glucocorticoids counteract LPS changes in TGF-β pathway and caveolin-1 in ovine fetal lung. Am J Physiol Lung Cell Mol Physiol. 2013;304:L438–44.10.1152/ajplung.00251.2012Search in Google Scholar

[7] Crowley PA. Antenatal corticosteroid therapy: a meta-analysis of the randomized trials, 1972 to 1994. Am J Obstet Gynecol. 1995;173:322–35.10.1016/0002-9378(95)90222-8Search in Google Scholar

[8] Hartling L, Liang Y, Lacaze-Masmonteil T. Chorioamnionitis as a risk factor for bronchopulmonary dysplasia: a systematic review and meta-analysis. Arch Dis Child Fetal Neonatal Ed. 2012;97:F8–17.10.1136/adc.2010.210187Search in Google Scholar PubMed

[9] Jobe AH. Glucocorticoids, inflammation and the perinatal lung. Semin Neonatol. 2001;6:331–42.10.1053/siny.2001.0068Search in Google Scholar PubMed

[10] Jobe AH, Newnham JP, Willet KE, Moss TJ, Gore Ervin M, Padbury JF, et al. Endotoxin-induced lung maturation in preterm lambs is not mediated by cortisol. Am J Respir Crit Care Med. 2000;162:1656–61.10.1164/ajrccm.162.5.2003044Search in Google Scholar PubMed

[11] Jobe AH, Newnham JP, Willet KE, Sly P, Ervin MG, Bachurski C, et al. Effects of antenatal endotoxin and glucocorticoids on the lungs of preterm lambs. Am J Obstet Gynecol. 2000;182:401–8.10.1016/S0002-9378(00)70231-6Search in Google Scholar

[12] Kallapur SG, Kramer BW, Moss TJ, Newnham JP, Jobe AH, Ikegami M, et al. Maternal glucocorticoids increase endotoxin-induced lung inflammation in preterm lambs. Am J Physiol Lung Cell Mol Physiol. 2003;284:L633–42.10.1152/ajplung.00344.2002Search in Google Scholar

[13] Kallapur SG, Moss TJ, Auten RL Jr, Nitsos I, Pillow JJ, Kramer BW, et al. IL-8 signaling does not mediate intra-amniotic LPS-induced inflammation and maturation in preterm fetal lamb lung. Am J Physiol Lung Cell Mol Physiol. 2009;297:L512–9.10.1152/ajplung.00105.2009Search in Google Scholar

[14] Kotecha S, Chan B, Azam N, Silverman M, Shaw RJ. Increase in interleukin-8 and soluble intercellular adhesion molecule-1 in bronchoalveolar lavage fluid from premature infants who develop chronic lung disease. Arch Dis Child Fetal Neonatal Ed. 1995;72:F90–6.10.1136/fn.72.2.F90Search in Google Scholar

[15] Kramer BW, Ikegami M, Moss TJ, Nitsos I, Newnham JP, Jobe AH. Antenatal betamethasone changes cord blood monocyte responses to endotoxin in preterm lambs. Pediatr Res. 2004;55:764–8.10.1203/01.PDR.0000120678.72485.19Search in Google Scholar

[16] Kuypers E, Collins JJ, Kramer BW, Ofman G, Nitsos I, Pillow JJ, et al. Intra-amniotic LPS and antenatal betamethasone: inflammation and maturation in preterm lamb lungs. Am J Physiol Lung Cell Mol Physiol. 2012;302:L380–9.10.1152/ajplung.00338.2011Search in Google Scholar

[17] Lee HJ, Choi CW, Kim BI, Kim EK, Kim HS, Choi JH, et al. Serial changes of lung morphometry and biochemical profiles in a rat model of bronchopulmonary dysplasia induced by intra-amniotic lipopolysaccharide and postnatal hyperoxia. J Perinat Med. 2010;38:675–81.10.1515/jpm.2010.091Search in Google Scholar

[18] Massaro GD, Massaro D. Development of bronchiolar epithelium in rats. Am J Physiol. 1986;250:R783–8.10.1152/ajpregu.1986.250.5.R783Search in Google Scholar

[19] Massaro D, Teich N, Maxwell S, Massaro GD, Whitney P. Postnatal development of alveoli. Regulation and evidence for a critical period in rats. J Clin Invest. 1985;76:1297–305.10.1172/JCI112103Search in Google Scholar

[20] Newnham JP, Kallapur SG, Kramer BW, Moss TJ, Nitsos I, Ikegami M, et al. Betamethasone effects on chorioamnionitis induced by intra-amniotic endotoxin in sheep. Am J Obstet Gynecol. 2003;189:1458–66.10.1067/S0002-9378(03)00758-0Search in Google Scholar

[21] Newnham JP, Moss TJ, Padbury JF, Willet KE, Ikegami M, Ervin MG, et al. The interactive effects of endotoxin with prenatal glucocorticoids on short-term lung function in sheep. Am J Obstet Gynecol. 2001;185:190–7.10.1067/mob.2001.114500Search in Google Scholar

[22] Pinkerton KE, Willet KE, Peake JL, Sly PD, Jobe AH, Ikegami M. Prenatal glucocorticoid and T4 effects on lung morphology in preterm lambs. Am J Respir Crit Care Med. 1997;156:624–30.10.1164/ajrccm.156.2.9701018Search in Google Scholar

[23] Polk DH, Ikegami M, Jobe AH, Sly P, Kohan R, Newnham J. Preterm lung function after retreatment with antenatal betamethasone in preterm lambs. Am J Obstet Gynecol. 1997;176:308–15.10.1016/S0002-9378(97)70490-3Search in Google Scholar

[24] Tigani B, Cannet C, Zurbrugg S, Schaeublin E, Mazzoni L, Fozard JR, et al. Resolution of the oedema associated with allergic pulmonary inflammation in rats assessed noninvasively by magnetic resonance imaging. Br J Pharmacol. 2003;140:239–46.10.1038/sj.bjp.0705429Search in Google Scholar PubMed PubMed Central

[25] Willet KE, Jobe AH, Ikegami M, Kovar J, Sly PD. Lung morphometry after repetitive antenatal glucocorticoid treatment in preterm sheep. Am J Respir Crit Care Med. 2001;163:1437–43.10.1164/ajrccm.163.6.2003098Search in Google Scholar PubMed

[26] Willet KE, Jobe AH, Ikegami M, Newnham J, Brennan S, Sly PD. Antenatal endotoxin and glucocorticoid effects on lung morphometry in preterm lambs. Pediatr Res. 2000;48:782–8.10.1203/00006450-200012000-00014Search in Google Scholar PubMed

[27] Willet KE, Jobe AH, Ikegami M, Polk D, Newnham J, Kohan R, et al. Postnatal lung function after prenatal steroid treatment in sheep: effect of gender. Pediatr Res. 1997;42:885–92.10.1203/00006450-199712000-00027Search in Google Scholar PubMed

[28] Willet KE, Kramer BW, Kallapur SG, Ikegami M, Newnham JP, Moss TJ, et al. Intra-amniotic injection of IL-1 induces inflammation and maturation in fetal sheep lung. Am J Physiol Lung Cell Mol Physiol. 2002;282:L411–20.10.1152/ajplung.00097.2001Search in Google Scholar PubMed

The authors stated that there are no conflicts of interest regarding the publication of this article.

Received: 2013-3-24

Accepted: 2013-7-8

Published Online: 2013-08-09

Published in Print: 2013-11-01

You are currently not able to access this content.

Articles in the same Issue

https://doi.org/10.1515/jpm-2013-0063

Keywords for this article

Alveolarization; bronchopulmonary dysplasia; chorioamnionitis; corticosteroid