title: Evaluating the Toxicity of Cigarette Whole Smoke Solutions in an Air-Liquid-Interface Human In Vitro Airway Tissue Model.
abstract: Exposure to cigarette smoke causes a multitude of pathological changes leading to tissue damage and disease. Quantifying such changes in highly differentiated in vitro human tissue models may assist in evaluating the toxicity of tobacco products. In this methods development study, well-differentiated human air-liquid-interface (ALI) in vitro airway tissue models were used to assess toxicological endpoints relevant to tobacco smoke exposure. Whole mainstream smoke solutions (WSSs) were prepared from 2 commercial cigarettes (R60 and S60) that differ in smoke constituents when machine-smoked under International Organization for Standardization conditions. The airway tissue models were exposed apically to WSSs 4-h per day for 1-5 days. Cytotoxicity, tissue barrier integrity, oxidative stress, mucin secretion, and matrix metalloproteinase (MMP) excretion were measured. The treatments were not cytotoxic and had marginal effects on tissue barrier properties; however, other endpoints responded in time- and dose-dependent manners, with the R60 resulting in higher levels of response than the S60 for many endpoints. Based on the lowest effect dose, differences in response to the WSSs were observed for mucin induction and MMP secretion. Mitigation of mucin induction by cotreatment of cultures with N-acetylcysteine suggests that oxidative stress contributes to mucus hypersecretion. Overall, these preliminary results suggest that quantifying disease-relevant endpoints using ALI airway models is a potential tool for tobacco product toxicity evaluation. Additional research using tobacco samples generated under smoking machine conditions that more closely approximate human smoking patterns will inform further methods development.
authors.affiliation: U.S. Food and Drug Administration/National Center for Toxicological Research, Jefferson, Arkansas 72079.
authors.forename: Xuefei
authors.initials: X
authors.lastname: Cao
authors.affiliation: Toxicologic Pathology Associates, Jefferson, Arkansas 72079.
authors.forename: Levan
authors.initials: L
authors.lastname: Muskhelishvili
authors.affiliation: Toxicologic Pathology Associates, Jefferson, Arkansas 72079.
authors.forename: John
authors.initials: J
authors.lastname: Latendresse
authors.affiliation: U.S. Food and Drug Administration/Center for Tobacco Products, Silver Spring, Maryland 20993.
authors.forename: Patricia
authors.initials: P
authors.lastname: Richter
authors.affiliation: U.S. Food and Drug Administration/National Center for Toxicological Research, Jefferson, Arkansas 72079.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Heflich
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D015415:Biomarkers / Q000378:metabolism; D001980:Bronchi / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D002478:Cells, Cultured; D045424:Complex Mixtures / Q000633:toxicity; D017097:Electric Impedance; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D020782:Matrix Metalloproteinases / Q000378:metabolism; D008856:Microscopy, Fluorescence; D055271:Mucin 5AC / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism; D016877:Oxidants / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D020545:Respiratory Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D012906:Smoke / Q000009:adverse effects*; D015208:Smoke Inhalation Injury / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control; D012995:Solubility; D062789:Tobacco Products / Q000633:toxicity*; D023382:Toxicity Tests, Acute / Q000379:methods*
chemical_list: D015415:Biomarkers; D045424:Complex Mixtures; D016166:Free Radical Scavengers; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D016877:Oxidants; D012906:Smoke; D020782:Matrix Metalloproteinases; D000111:Acetylcysteine
keywords: cigarette whole smoke solution (WSS); human air-liquid-interface (ALI) airway tissue model; matrix metalloproteinase (MMP).; mucin; oxidative stress