Eur J Pediatr Surg 2019; 29(01): 102-107
DOI: 10.1055/s-0038-1675772
Original Article
Georg Thieme Verlag KG Stuttgart · New York

Expression of Nitric Oxide Synthase Interacting Protein (NOSIP) is Decreased in the Pulmonary Vasculature of Nitrofen-Induced Congenital Diaphragmatic Hernia

Hiroki Nakamura
1   Our Lady's Children's Hospital, National Children's Research Centre, Crumlin, Dublin, Ireland
,
Julia Zimmer
1   Our Lady's Children's Hospital, National Children's Research Centre, Crumlin, Dublin, Ireland
2   Department of Pediatric Surgery, Hannover Medical School, Hannover, Germany
,
Florian Friedmacher
1   Our Lady's Children's Hospital, National Children's Research Centre, Crumlin, Dublin, Ireland
3   Department of Pediatric Surgery, The Royal London Hospital, London, United Kingdom
,
Prem Puri
1   Our Lady's Children's Hospital, National Children's Research Centre, Crumlin, Dublin, Ireland
4   Conway Institute of Biomolecular and Biomedical Research, School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
› Author Affiliations
Funding This research was supported by the National Children's Research Centre and the Children's Medical and Research Foundation.
Further Information

Publication History

14 May 2018

23 September 2018

Publication Date:
10 December 2018 (online)

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Abstract

Introduction Persistent pulmonary hypertension (PPH) is a major cause of morbidity and mortality in newborns with congenital diaphragmatic hernia (CDH). PPH is characterized by increased vascular resistance and smooth muscle cell (SMC) proliferation, leading to obstructive changes in the pulmonary vasculature. Nitric oxide (NO), generated by endothelial NO synthase (eNOS), is an important regulator of vascular tone and plays a key role in pulmonary vasodilatation. NO synthase interacting protein (NOSIP), which is strongly expressed by pulmonary SMCs, has recently been identified to reduce the endogenous NO production by interacting with eNOS. We designed this study to investigate the pulmonary vascular expression of NOSIP in the nitrofen-induced CDH model.

Materials and Methods Time-mated Sprague Dawley rats received nitrofen or vehicle on gestational day 9 (D9). Fetuses were sacrificed on D21 and lung specimens divided into CDH and control (n = 6 for each group). Quantitative real-time polymerase chain reaction and Western blotting were performed to analyze pulmonary gene and protein expression of NOSIP. Immunofluorescence double staining for NOSIP was combined with a specific SMC marker to evaluate protein expression in the pulmonary vasculature.

Results Relative messenger ribonucleic acid and protein expression of NOSIP was significantly decreased in nitrofen-exposed CDH lungs compared with controls. Confocal laser scanning microscopy revealed markedly diminished NOSIP immunofluorescence in nitrofen-exposed CDH lungs compared with controls, mainly in the muscular and endothelial components of the pulmonary vasculature.

Conclusion This study demonstrates for the first time decreased NOSIP expression in the pulmonary vasculature of the nitrofen-induced CDH. These findings suggest that NOSIP underexpression may interfere with NO production, contributing to abnormal vascular remodeling and PPH.