Altered gene expression profiles in the lungs of benzo[a]pyrene-exposed mice in the presence of lipopolysaccharide-induced pulmonary inflammation

TitleAltered gene expression profiles in the lungs of benzo[a]pyrene-exposed mice in the presence of lipopolysaccharide-induced pulmonary inflammation
Publication TypeJournal Article
Year of Publication2017
AuthorsShi Q., Fijten R.R, Spina D., Y. Vasquez R, Arlt V.M, Godschalk R.W, Van Schooten F.J
JournalToxicology and Applied Pharmacology
Date PublishedDec 1
ISBN Number0041-008x
Accession Number28987381
Keywords*Benzo[a]pyrene (B[a]P), *Lipopolysaccharide (LPS), *Lipopolysaccharides, *Mouse lung, *RNA microarray, Animals, Benzo(a)pyrene/metabolism/*toxicity, Disease Models, Animal, DNA Adducts/genetics/metabolism, Gene Expression Profiling/methods, Gene Regulatory Networks, Inflammation Mediators/metabolism, Lung/*drug effects/metabolism, Male, Metabolic Detoxication, Phase I, Metabolic Detoxication, Phase II, Mice, Inbred C57BL, Oligonucleotide Array Sequence Analysis, Pneumonia/chemically induced/*genetics/metabolism, Principal Component Analysis, Transcriptome/*drug effects

Patients with inflammatory lung diseases are often additionally exposed to polycyclic aromatic hydrocarbons like B[a]P and B[a]P-induced alterations in gene expression in these patients may contribute to the development of lung cancer. Mice were intra-nasally treated with lipopolysaccharide (LPS, 20mug/mouse) to induce pulmonary inflammation and subsequently exposed to B[a]P (0.5mg/mouse) by intratracheal instillation. Gene expression changes were analyzed in mouse lungs by RNA microarrays. Analysis of genes that are known to be involved in the cellular response to B[a]P indicated that LPS significantly inhibited gene expression of various enzymes linked to B[a]P metabolism, which was confirmed by phenotypic analyses of enzyme activity. Ultimately, these changes resulted in higher levels of B[a]P-DNA adducts in the lungs of mice exposed to B[a]P with prior LPS treatment compared to the lungs of mice exposed to B[a]P alone. Using principle component analysis (PCA), we found that of all the genes that were significantly altered in their expression, those that were able to separate the different exposure conditions were predominantly related to immune-response. Moreover, an overall analysis of differentially expressed genes indicated that cell-cell adhesion and cell-cell communication was inhibited in lungs of mice that received both B[a]P and LPS. Our results indicate that pulmonary inflammation increased the genotoxicity of B[a]P via inhibition of both phase I and II metabolism. Therefore, inflammation could be a critical contributor to B[a]P-induced carcinogenesis in humans.

Short TitleToxicol Appl PharmacolToxicol. Appl. Pharmacol.
Alternate JournalToxicology and applied pharmacology