Project description:RationaleIdiopathic pulmonary fibrosis (IPF) is a fatal disease with a variable and unpredictable course.ObjectivesTo determine whether BAL cell gene expression is predictive of survival in IPF.MethodsThis retrospective study analyzed the BAL transcriptome of three independent IPF cohorts: Freiburg (Germany), Siena (Italy), and Leuven (Belgium) including 212 patients. BAL cells from 20 healthy volunteers, 26 patients with sarcoidosis stage III and IV, and 29 patients with chronic obstructive pulmonary disease were used as control subjects. Survival analysis was performed by Cox models and component-wise boosting. Presence of airway basal cells was tested by immunohistochemistry and flow cytometry.Measurements and main resultsA total of 1,582 genes were predictive of mortality in the IPF derivation cohort in univariate analyses adjusted for age and sex at false discovery rate less than 0.05. A nine-gene signature, derived from the discovery cohort (Freiburg), performed well in both replication cohorts, Siena (P < 0.0032) and Leuven (P = 0.0033). nCounter expression analysis confirmed the array results (P < 0.0001). The genes associated with mortality in BAL cells were significantly enriched for genes expressed in airway basal cells. Further analyses by gene expression, flow cytometry, and immunohistochemistry showed an increase in airway basal cells in BAL and tissues of IPF compared with control subjects, but not in chronic obstructive pulmonary disease or sarcoidosis.ConclusionsOur results identify and validate a BAL signature that predicts mortality in IPF and improves the accuracy of outcome prediction based on clinical parameters. The BAL signature associated with mortality unmasks a potential role for airway basal cells in IPF.
Project description:BackgroundGiven the plethora of pathophysiologic mechanisms described in idiopathic pulmonary fibrosis (IPF), we hypothesize that the mechanisms driving fibrosis in IPF may be different from one patient to another.Research questionDo IPF endotypes exist and are they associated with outcome?Study design and methodsUsing a publicly available gene expression dataset retrieved from BAL samples of patients with IPF and control participants (GSE70867), we clustered IPF samples based on a dimension reduction algorithm specifically designed for -omics data, called DDR Tree. After clustering, gene set enrichment analysis was performed for functional annotation, associations with clinical variables and prognosis were investigated, and differences in transcriptional regulation were determined using motif enrichment analysis. The findings were validated in three independent publicly available gene expression datasets retrieved from IPF blood samples.ResultsOne hundred seventy-six IPF samples from three centers were clustered in six IPF clusters, with distinct functional enrichment. Although clinical characteristics did not differ between the clusters, one cluster conferred worse sex-age-physiology score-corrected survival, whereas another showed a numeric trend toward worse survival (P = .08). The first was enriched for increased epithelial and innate and adaptive immunity signatures, whereas the other showed important telomere and mitochondrial dysfunction, loss of proteostasis, and increased myofibroblast signatures. The existence of these two endotypes, including the impact on survival of the immune endotype, was validated in three independent validation cohorts. Finally, we identified transcription factors regulating the expression of endotype-specific survival-associated genes.InterpretationGene expression-based endotyping in IPF is feasible and can inform clinical evolution. As endotype-specific pathways and survival-associated transcription factors are identified, endotyping may open up the possibility of endotype-tailored therapy.
Project description:Rationale: Declining lung function in patients with interstitial lung disease is accompanied by epithelial remodeling and progressive scarring of the gas-exchange region. There is a need to better understand the contribution of basal cell hyperplasia and associated mucosecretory dysfunction to the development of idiopathic pulmonary fibrosis (IPF).Objectives: We sought to decipher the transcriptome of freshly isolated epithelial cells from normal and IPF lungs to discern disease-dependent changes within basal stem cells.Methods: Single-cell RNA sequencing was used to map epithelial cell types of the normal and IPF human airways. Organoid and air-liquid interface cultures were used to investigate functional properties of basal cell subtypes.Measurements and Main Results: We found that basal cells included multipotent and secretory primed subsets in control adult lung tissue. Secretory primed basal cells include an overlapping molecular signature with basal cells obtained from the distal lung tissue of IPF lungs. We confirmed that NOTCH2 maintains undifferentiated basal cells and restricts basal-to-ciliated differentiation, and we present evidence that NOTCH3 functions to restrain secretory differentiation.Conclusions: Basal cells are dynamically regulated in disease and are specifically biased toward the expansion of the secretory primed basal cell subset in IPF. Modulation of basal cell plasticity may represent a relevant target for therapeutic intervention in IPF.
Project description:Idiopathic pulmonary fibrosis (IPF) is a devastating fibrotic lung disease of unknown etiology and limited therapeutic options. In this report, we characterize what we believe is a novel CCR10+ epithelial cell population in IPF lungs. There was a significant increase in the percentage of CCR10+ epithelial cells in IPF relative to normal lung explants and their numbers significantly correlated to lung remodeling in humanized NSG mice. Cultured CCR10-enriched IPF epithelial cells promoted IPF lung fibroblast invasion and collagen 1 secretion. Single-cell RNA sequencing analysis showed distinct CCR10+ epithelial cell populations enriched for inflammatory and profibrotic transcripts. Consistently, cultured IPF but not normal epithelial cells induced lung remodeling in humanized NSG mice, where the number of CCR10+ IPF, but not normal, epithelial cells correlated with hydroxyproline concentration in the remodeled NSG lungs. A subset of IPF CCR10hi epithelial cells coexpress EphA3 and ephrin A signaling induces the expression of CCR10 by these cells. Finally, EphA3+CCR10hi epithelial cells induce more consistent lung remodeling in NSG mice relative to EphA3-CCR10lo epithelial cells. Our results suggest that targeting epithelial cells, highly expressing CCR10, may be beneficial in IPF.
Project description:Background: We got interested whether genes of airway basal cells are enriched in COPD. Methods: Bronchoscopy with bronchial brushes and bronchoalveolar lavage was performed in 28 patients with COPD and 29 healthy donors and isolated BAL cells.Transcriptome of BAL cells were studied by using Affymetrix Human Genome U133 Plus 2.0 array on an Affymetrix platform. Microarray data were normalized data were imported, log2-transformed and quantile normalized using robust multi-array average (RMA). We tested enrichment for airway basal cells by ROMER enrichment analysis. Results: we did not find enrichment of airway basal cell genes in COPD compared to healthy volunteers.
Project description:Background: We got interested whether genes of airway basal cells are enriched in sarcoidosis. Methods: Bronchoscopy with bronchoalveolar lavage (BAL) was performed in 26 patients with sarcoidosis, chest-x-ray type III and IV, and 20 healthy donors and isolated BAL cells.Transcriptome of BAL cells were studied by using Affymetrix Human Affymetrix Whole-Transcript Human Gene 1.0 ST array on an Affymetrix platform. Microarray data were imported, log2-transformed and quantile normalized using robust multi-array average (RMA). We tested enrichment for airway basal cells by global enrichment analysis. Results: we did not find enrichment of airway basal cell genes in sarcoidosis compared to healthy volunteers.
Project description: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.
Project description:Background: Idiopathic pulmonary fibrosis (IPF) is a fatal disease with variable outcome. Currently, there is little information whether changes in molecular pathways in the alveolar compartment of patients with IPF are indicative of disease progression. To address this question we analyzed gene expression signatures in cells obtained from bronchoalveolar lavage (BAL) of patients with IPF. Methods: BAL cells were harvested from 212 IPF patients and 20 healthy donors at the time of diagnosis. RNA was extracted, labeled and hybridized to Agilent gene expression arrays. Our study included a discovery cohort of 62 patients from Freiburg, Germany, and two independent validation cohorts, Siena, Italy (50 patients) and Leuven, Belgium (64 patients). Survival analysis was performed by applying Cox models and component-wise boosting. Results: We found 1582 genes predictive of mortality in the discovery cohort in univariate analyses adjusted for age and gender at FDR<0.05. A nine gene signature, developed by component-wise boosting in the Freiburg array dataset, performed well in both validation cohorts, Siena (p<0.0032) and Leuven (p=0.0033). The genes associated with mortality in BAL cells were significantly enriched for genes expressed in airway basal epithelial cells, airway progenitor cells recently implicated in fibrosis. Conclusions: Our results identify and validate a BAL cell gene expression signature that predicts mortality in IPF. This signature unmasks a potential novel role for airway basal epithelial cells in IPF.