Líffræðifélag Íslands
Líffræðiráðstefnan 2015

Erindi/veggspjald / Talk/poster E45

Functional role of MUC5B polymorphism in airway epithelial differentiation and Idiopathic pulmonary fibrosis

Amaranta U. Armesto, Ari J. Arason, Thorarinn Gudjonsson, Magnus K. Magnusson.

Biomedical Center, University of Iceland

Kynnir / Presenter: Amaranta U. Armesto Jiménez

Tengiliður / Corresponding author: Magnus K. Magnusson. (magnuskm@hi.is)

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial fibrotic lung disease with high morbidity and mortality. Recent genome wide association studies have linked a common MUC5B promoter polymorphism (rs35705950) with an increased risk of IPF and the risk allele (C=>T) was shown to be associated with higher expression of MUC5B both in lungs of normal carriers and IPF patients. However, little is known about the mechanism underlying the links between the polymorphism and its potential involvement on IPF. We have established an air-liquid interphase (ALI) culture system where human basal cell lines with progenitor properties recreate in culture the histoarchitechture of the upper airways. In order to understand the molecular effects of the MUC5B promoter polymorphism (T-allele) we have cloned the MUC5B promoter area (4.1kb) into a luciferase reporter plasmid and using in vitro mutagenesis to generate the IPF-associated T-allele. Using two human bronchial cell lines, Bci-NS1.1 and VA-10, in monolayer and air-liquid interface (ALI) we have shown that the T-allele is associated with increased luciferase signal in the Bci_NS1.1 cell line compared to wildtype (WT) allele in monlolayer cultures. We are currently generating stable lentiviral luciferase cell lines carrying the WT and T-allele MUC5B promoters to carry out in ALI cultures. Using a bioinformatics approach we have identified candidate transcription factors (TFs) binding to the critical area involved in the polymorphism. Several TFs are now being studied to see if their expression is associated with MUC5B expression. Binding of these TFs will be assessed using chromatin immunoprecipitation. Finally, CRISPR technique is currently being employed to edit the MUC5B promoter in the Bci-NS1.1 and VA-10 human basal cell lines. Our preliminary data indicates that the rs35705950 MUC5B polymorphism positively affects MUC5B expression. Our airway epithelial cell model is a unique model that allows us to study the molecular understanding of the MUC5B promoter polymorhism associated with IPF.