BAL cell gene expression is predictive of Mortality in Idiopathic Pulmonary Fibrosis and enriched for Genes of Airway Basal Cells (I)

Background: Based on previous publication and our own data we became interested in the gene expression signature of airway basal cells. Methods: Bronchoscopy with bronchial brushes and bronchoalveolar lavage was performed in healthy donors. Airway basal cells were obtained by brushing segmental bronchi of the right lower lobe and outgrowth of cells in BEGM supplemented with growth factors according to the manufacturer’s instructions. Alveolar macrophages were sorted by flow cytometry. Microarray data of 11 airway basal cell samples, 7 alveolar macrophage samples and 4 samples of bronchial epithelial cells were obtained. The transcriptome of the three different cell types was compared using univariate ANOVA resulting in 8874 genes significantly differently expressed between the three cell types (p<0.0001). The data of these 8874 transcripts were used for a clustering approach applying Cluster 3.0 software. The samples were hierarchically clustered with median normalization of the genes and centroid linkage, and the similarity metric used was Pearson correlation. Results and Conclusion: we obtained an airway basal cell type specific signature consisting out of 961 genes which was used in further studies. Microarray data of 11 airway basal cell samples, 7 alveolar macrophage samples and 4 samples of bronchial epithelial cells were obtained. The transcriptome of the three different cell types was compared using univariate ANOVA resulting in 8874 genes significantly differently expressed between the three cell types (p<0.0001). The data of these 8874 transcripts were used for a clustering approach applying Cluster 3.0 software. The samples were hierarchically clustered with median normalization of the genes and centroid linkage, and the similarity metric used was Pearson correlation.