Description
Smoking-induced lung disease is one of the most prevalent forms of lung disease but also one of the more diverse. Based on the phenotypic diversity caused by the same environmental stress, we hypothesized that smoking may induce changes in lung cell expression of genes that, with specific variants, are causative of monogenic lung disease, i.e., not that smoking induces a phenocopy of a genetic disease, but smoking may subtly modify the expression of genes known to be associated with genetic disorders with distinct lung disease phenotypes. To assess this hypothesis, and based on the knowledge that most smoking-related disease phenotypes start in the small airway epithelium, we asked: are the genes associated with the monogenic lung disorders expressed in the small airway epithelium, and if so, does smoking alter the expression of these genes? To accomplish this, we examined small airway epithelium expression of 92 genes known to be associated with 17 monogenic lung disorders in 230 samples of small airway epithelium (SAE) obtained from healthy nonsmokers and healthy smokers without any clinical evidence of disease. Of the 86 monogenic disorder-related genes we found expressed in the SAE, strikingly, 37 were significantly differentially expressed in normal smokers compared to normal nonsmokers (p<0.05, Benjamini-Hochberg correction for multiple comparisons). The data demonstrates that the effect of smoking on the transcriptome of small airway epithelium includes significantly altered regulation of the genes responsible for known monogenic disorders.