Abstract
In vitro toxicology approaches have evolved from a focus on molecular changes within a cell to understanding of toxicity-related mechanisms in systems that can mimic the in vivo environment. The recent development of three dimensional (3-D) organotypic nasal epithelial culture models offers a physiologically robust system for studying the effects of exposure through inhalation. Exposure to cigarette smoke (CS) is associated with nasal inflammation; thus, the nasal epithelium is relevant for evaluating the pathophysiological impact of CS exposure. The present study investigated further the application of in vitro human 3-D nasal epithelial culture models for toxicological assessment of inhalation exposure. Aligned with 3Rs strategy, this study aimed to explore the relevance of a human 3-D nasal culture model to assess the toxicological impact of aerosols generated from a candidate modified risk tobacco product (cMRTP), the Tobacco Heating System (THS) 2.2, as compared with smoke generated from reference cigarette 3R4F. A series of experimental repetitions, where multiple concentrations of THS2.2 aerosol and 3R4F smoke were applied, were conducted to obtain reproducible measurements to understand the cellular/molecular changes that occur following exposure. In agreement with "Toxicity Testing in the 21st Century - a Vision and a Strategy", this study implemented a systems toxicology approach and found that for all tested concentrations the impact of 3R4F smoke was substantially greater than that of THS2.2 aerosol in terms of cytotoxicity levels, alterations in tissue morphology, secretion of pro-inflammatory mediators, impaired ciliary function, and increased perturbed transcriptomes and miRNA expression profiles.
Highlights
Mechanistic investigation of the impact of exposure on the lower airway remains challenging because access to lung tissues is limited
To circumvent the interspecies translatability, the aim of the current study was to explore the relevance of a human 3-D nasal culture model to detect toxicologically relevant findings to assess the biological impact of aerosols generated from a candidate modified risk tobacco product, the Tobacco Heating System (THS) 2.2, as compared with smoke generated from reference cigarette 3R4F
3.1 3R4F smoke and THS2.2 aerosol exposure characterization To assess the biological impact of 3R4F smoke and THS2.2 aerosols, a series of five experimental repetitions was conducted to increase the robustness of the assessment
Summary
Mechanistic investigation of the impact of exposure on the lower airway remains challenging because access to lung tissues is limited. Alternatives to animal testing have been proposed to overcome these drawbacks, including the 3Rs strategy – reduction, refinement, and replacement of laboratory animals – to reduce the number of animals, to refine the design of procedures such that pain and distress are minimized, and to replace animal models with alternative methods and lower organisms when possible (Doke and Dhawale, 2015). In this regard, the capability to preserve human respiratory cells in culture provides a tool to generate mechanistic data, and to improve the predicted effects of exposure hazard through inhalation in humans. An emphasis on assessment studies using human-derived in vitro culture systems will reduce the problems that are inherent to interspecies translatability (Manuppello and Sullivan, 2015)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
