In Vitro Systems Toxicology Approach To Investigate The Effects Of Repeated Cigarette Smoke Exposure On Respiratory Tract Tissue Cultures
Presented at SYSTEMS TOXICOLOGY 2013 - FROM BASIC RESEARCH TO HUMAN RISK ASSESSMENT
Objective: The aim of this study is to develop assay systems that model in vitro the impact of Cigarette Smoke (CS) on different human organotypic respiratory tract tissue cultures (bronchial, nasal, buccal and gingival) which are in contact with CS upon inhalation in vivo. Such assay systems may have a role in the assessment of potential modified risk tobacco products. Methods: We intended to mimic the smoking behavior of a moderate smoker during one day by exposing repeatedly and in parallel four tissue cultures (bronchial, nasal, buccal and gingival) directly at the air/liquid interface (Vitrocell® System) to four cigarettes with one hour intervals between each cigarette. These organotypic cultures are generated from primary cells derived from non-smoking donors and contain fibroblasts and epithelial cells in order to reproduce as closely as possible the in vivo situation. Results: Firstly, we simultaneously exposed all tissues to various CS concentrations ranging from 8% to 35% (diluted Vol/Vol with humidified air) or to humidified air (control). We found that gingival tissue was more sensitive to CS exposure than the other tissues based on cell viability assay. Secondly, all tissues were exposed in parallel to two doses of whole CS (10% and 16% - doses inducing less than 20% cell death) or to humidified air and various endpoints (e.g., gene and microrna expression, CYP activity, pro-inflammatory markers release, differential cell counts, cytotoxicity measurement) were captured at different post-exposure times. Conclusion: The systems biology endpoints obtained were analyzed using computational approaches. This allowed the identification of biological perturbations similar to those seen in vivo in smokers. This suggests that these four human in vitro tissue cultures when exposed to whole CS may be valuable models which could be used to investigate the impact of CS on the respiratory tract.