In vitro systems toxicology approach to investigate the effects of repeated cigarette smoke exposure on human buccal and gingival organotypic epithelial tissue cultures

Smoking has been associated with diseases of the lung, pulmonary airways and oral cavity. Cytologic, genomic and transcriptomic changes in oral mucosa correlate with oral preneoplasia, cancer and inflammation (e.g. periodontitis). Alteration of smoking-related gene expression changes in oral epithelial cells is similar to that in bronchial and nasal epithelial cells. Using a systems toxicology approach, we have previously assessed the impact of cigarette smoke (CS) seen as perturbations of biological processes in human nasal and bronchial organotypic epithelial culture models. Here, we report our further assessment using in vitro human oral organotypic epithelium models. We exposed the buccal and gingival organotypic epithelial tissue cultures to CS at the air–liquid interface. CS exposure was associated with increased secretion of inflammatory mediators, induction of cytochrome P450s activity and overall weak toxicity in both tissues. Using microarray technology, gene-set analysis and a novel computational modeling approach leveraging causal biological network models, we identified
CS impact on xenobiotic metabolism-related pathways accompanied by a more subtle alteration in inflammatory processes. Gene-set analysis further indicated that the CS-induced pathways in the in vitro buccal tissue models resembled those in the in vivo buccal biopsies of smokers from a published dataset. These findings support the translatability of systems responses from in vitro to in vivo and demonstrate the applicability of oral organotypical tissue models for an impact assessment of CS on various tissues exposed during smoking, as well as for impact assessment of reduced-risk products.

ORL-300-FT-LC, GIN-300-FT, Lactate dehydrogenase assay, Transepithelial electrical resistance (TEER), p63, Ki-67, HLA-DR, cytochrome P450 CYP1A1/CYP1B1, transcriptomic analysis, MMP−9, MMP−1, VEGF, RANTES, MCP−1, IP−10, IL−8, IL−6, IL−1b, IL−1a, GM−CSF, G−CSF, Eotaxin, CCL-11, CSF3, CSF2, CXCL10, CCL2, CCL5, , gene-set analysis, microarray analysis, transcriptomics, histological analysis, tumor necrosis factor receptor 1 (TNFR1), receptor-interacting serine/threonine protein kinase-reactive oxygen species (RIPK-ROS), Database for Annotation, Visualization and Integrated Discovery (DAVID) analysis, reduced-risk products

cigarette smoke, 3R4F reference cigarettes, Triton X-100