title: DMBT1 promotes basal and meconium-induced nitric oxide production in human lung epithelial cells in vitro.
abstract: Meconium aspiration syndrome (MAS) is characterized by surfactant inactivation and inflammation. As lung epithelial cells up-regulate nitric oxide (NO) in response to inflammation, the NO production following meconium exposition was examined in relation to expression of Deleted in Malignant Brain Tumors 1 (DMBT1), a protein with functions in innate immunity and inflammatory regulation. Here, DMBT1 expression was analyzed by immunohistochemistry in postmortem lung sections from patients with MAS. The lung epithelial cell line A549, stably transfected with a DMBT1 (DMBT1+ cells) expression plasmid or with an empty expression plasmid (DMBT1- cells), was exposed to meconium. NO was determined in dependence of aminoguanidine (inducible NO synthase inhibitor), steroids and lipopolysaccharide (LPS). DMBT1 is highly expressed in lungs with MAS. In the absence of meconium, DMBT1+ cells showed a higher NO production than the DMBT1- cells (p = 0.0090). Meconium led in DMBT1- and DMBT1+ cells to elevated NO levels (p < 0.0001), but with a higher NO level in DMBT1+ cells (p < 0.0001). Aminoguanidine, an iNOS inhibitor, reduced the higher NO production in DMBT1+ cells (p = 0.0476), but NO levels remained above NO production from DMBT1- cells (p = 0.0289). Dexamethasone diminished NO production in DMBT1+ cells after meconium exposition (p = 0.0076). Combined addition of LPS and meconium significantly increased NO production in both cell types (p < 0.0001). In comparison to exposure with only meconium, the combined addition of LPS and meconium to the cells increased NO levels in both DMBT1- cells (p = 0.0030) and DMBT1+ cells (p = 0.0028). In conclusion, basal and meconium-induced NO production in lung epithelial cells is positively regulated by DMBT1.
authors.affiliation: Department of Pediatrics I, Neonatology, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45147, Essen, Germany. Hanna.Mueller@uk-essen.de.|Division of Neonatology, Department of Pediatrics, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany. Hanna.Mueller@uk-essen.de.
authors.forename: Hanna
authors.identifier: http://orcid.org/0000-0003-1901-865X
authors.initials: H
authors.lastname: Müller
authors.affiliation: Institute of Medical Statistics and Biomathematics, Medical Faculty Mannheim, University of Heidelberg, Ludolf-Krehl-Straße 13-17D, 68167, Mannheim, Germany.
authors.forename: Christel
authors.initials: C
authors.lastname: Weiss
authors.affiliation: Institute of Pathology, University of Heidelberg, Im Neuenheimer Feld 224, 69120, Heidelberg, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Renner
authors.affiliation: Department of Pediatrics I, Neonatology, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45147, Essen, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Felderhoff-Müser
authors.affiliation: Lundbeckfonden Center of Excellence NanoCAN and Molecular Oncology, Institute for Molecular Medicine, University of Southern Denmark, JB Winsloews Vej 25, 5000, Odense C, Denmark.
authors.forename: Jan
authors.initials: J
authors.lastname: Mollenhauer
mesh_terms: D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007231:Infant, Newborn; D008168:Lung / Q000166:cytology*; D008470:Meconium / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis*; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000378:metabolism*; D025521:Tumor Suppressor Proteins
chemical_list: D002135:Calcium-Binding Proteins; C108174:DMBT1 protein, human; D004268:DNA-Binding Proteins; D011956:Receptors, Cell Surface; D025521:Tumor Suppressor Proteins; D009569:Nitric Oxide
keywords: DMBT1; Inflammation; Meconium aspiration; Nitric oxide