Respiratory syncytial virus potentiates ABCA3 mutation-induced loss of lung epithelial cell differentiation

• Published in: Human molecular genetics 2012-06, Vol.21 (12), p.2793-2806
• Main Authors: KALTENBORN, Eva, KERN, Sunčana, FRIXEL, Sabrina, FRAGNET, Laetitia, CONZELMANN, Karl-Klaus, ZARBOCK, Ralf, GRIESE, Matthias
• Format: Article
• Language: English
• Subjects: ATP-Binding Cassette Transporters - genetics; ATP-Binding Cassette Transporters - metabolism; Biological and medical sciences; Blotting, Western; Cadherins - genetics; Cadherins - metabolism; Cell Differentiation - genetics; Cell differentiation, maturation, development, hematopoiesis; Cell Line, Tumor; Cell physiology; Child; Epithelial Cells - metabolism; Epithelial Cells - pathology; Epithelial Cells - virology; Fundamental and applied biological sciences. Psychology; Gene Expression; Genetics of eukaryotes. Biological and molecular evolution; Host-Pathogen Interactions; Human viral diseases; Humans; Infant, Newborn; Infectious diseases; Life Sciences; Lung - metabolism; Lung - pathology; Lung - virology; Lung Diseases, Interstitial - genetics; Lung Diseases, Interstitial - virology; Matrix Metalloproteinase 2 - genetics; Matrix Metalloproteinase 2 - metabolism; Medical sciences; Membrane Proteins - genetics; Membrane Proteins - metabolism; Mesoderm - metabolism; Mesoderm - pathology; Microbiology and Parasitology; Microscopy, Fluorescence; Molecular and cellular biology; Mutation; Phosphoproteins - genetics; Phosphoproteins - metabolism; Pulmonary Alveoli - metabolism; Pulmonary Alveoli - pathology; Pulmonary Alveoli - virology; Pulmonary Surfactant-Associated Protein C - genetics; Pulmonary Surfactant-Associated Protein C - metabolism; Respiratory Distress Syndrome, Newborn - genetics; Respiratory Distress Syndrome, Newborn - virology; Respiratory Syncytial Viruses - physiology; Reverse Transcriptase Polymerase Chain Reaction; Snail Family Transcription Factors; Transcription Factors - genetics; Transcription Factors - metabolism; Transforming Growth Factor beta1 - genetics; Transforming Growth Factor beta1 - metabolism; Viral diseases; Viral diseases of the respiratory system and ent viral diseases; Virology; Zonula Occludens-1 Protein
• ISSN: 0964-6906; 1460-2083
• DOI: 10.1093/hmg/dds107

ATP-binding cassette transporter A3 (ABCA3) is a lipid transporter active in lung alveolar epithelial type II cells (ATII) and is essential for their function as surfactant-producing cells. ABCA3 mutational defects cause respiratory distress in newborns and interstitial lung disease (ILD) in children. The molecular pathomechanisms are largely unknown; however, viral infections may initiate or aggravate ILDs. Here, we investigated the impact of the clinically relevant ABCA3 mutations, p.Q215K and p.E292V, by stable transfection of A549 lung epithelial cells. ABCA3 mutations strongly impaired expression of the ATII differentiation marker SP-C and the key epithelial cell adhesion proteins E-cadherin and zonula occludens-1. Concurrently, cells expressing ABCA3 mutation acquired mesenchymal features as observed by increased expression of SNAI1, MMP-2 and TGF-β1, and elevated phosphorylation of Src. Infection with respiratory syncytial virus (RSV), the most common viral respiratory pathogen in small children, potentiated the observed mutational effects on loss of epithelial and acquisition of mesenchymal characteristics. In addition, RSV infection of cells harboring ABCA3 mutations resulted in a morphologic shift to a mesenchymal phenotype. We conclude that ABCA3 mutations, potentiated by RSV infection, induce loss of epithelial cell differentiation in ATII. Loss of key epithelial features may disturb the integrity of the alveolar epithelium, thereby comprising its functionality. We suggest the impairment of epithelial function as a mechanism by which ABCA3 mutations cause ILD.