Dataset Information

Human Keratinocyte Responses to Woodsmoke

ABSTRACT: Air pollution consists of complex mixtures of chemicals with serious deleterious health effects from acute and chronic exposure. To help understand mechanisms by which adverse effects occur, present work examines responses of cultured human epidermal keratinocytes to specific chemicals commonly found in woodsmoke. Our earlier findings with liquid smoke flavoring (aqueous extract of charred wood) revealed that such extracts stimulated expression of genes associated with oxidative stress and proinflammatory response, activated the aryl hydrocarbon receptor, thereby inducing cytochrome P4501A1 activity, and induced cross-linked envelope formation, a lethal event ordinarily occurring during terminal differentiation. Present results showed that furfural produced transcriptional responses resembling those of liquid smoke, cyclohexanedione activated the aryl hydrocarbon receptor, and several chemicals induced envelope formation. Of these, syringol permeabilized the cells to egress of lactate dehydrogenase at a concentration close to that yielding envelope formation, while furfural induced envelope formation without permeabilization detectable in this way. Furfural (but not syringol) stimulated incorporation of amines into cell protein in extracts in the absence of transglutaminase activity. Nevertheless, both chemicals substantially increased the amount of cellular protein incorporated into envelopes and greatly altered the envelope protein profile. Moreover, the proportion of keratins in envelopes was dramatically increased. These findings are consistent with chemically induced protein cross-linking in the cells. Elucidating mechanisms by which this phenomenon occurs may help interpret bioassays of complex pollutant mixtures and suggest additional sensitive ways to monitor exposures.

INSTRUMENT(S): Q Exactive Plus

ORGANISM(S): Homo Sapiens (ncbitaxon:9606)

SUBMITTER: Robert H. Rice

PROVIDER: MSV000093227 | MassIVE | Wed Nov 01 11:06:00 GMT 2023

SECONDARY ACCESSION(S): PXD046590

REPOSITORIES: MassIVE

ACCESS DATA

Similar Datasets

Project description:The polycyclic aromatic hydrocarbon (PAH), benzo[a]pyrene (BaP), was compared to dibenzo[def,p]chrysene (DBC) and combinations of three environmental PAH mixtures (coal tar, diesel particulate and cigarette smoke condensate) using a two stage, FVB/N mouse skin tumor model. DBC (4 nmol) was most potent, reaching 100% tumor incidence with a shorter latency to tumor formation, less than 20 weeks of 12-O-tetradecanoylphorbol-13-acetate (TPA) promotion compared to all other treatments. Multiplicity was 4 times greater than BaP (400 nmol). Both PAHs produced primarily papillomas followed by squamous cell carcinoma and carcinoma in situ. Diesel particulate extract (1 mg SRM 1650b; mix 1 ) did not differ from toluene controls and failed to elicit a carcinogenic response. Addition of coal tar extract (1 mg SRM 1597a; mix 2) produced a response similar to BaP. Further addition of 2 mg of cigarette smoke condensate (mix 3) did not alter the response of mix 2. PAH-DNA adducts measured in epidermis 12 h post initiation and analyzed by 32P post- labeling, did not correlate with tumor incidence. PAH dependent alteration in transcriptome of skin 12 h post initiation was assessed by microarray. Principal component analysis (sum of all treatments) of the 922 significantly altered genes (p<0.05), showed DBC and BaP to cluster distinct from PAH mixtures and each other. BaP and mixtures up-regulated phase 1 and 2 metabolizing enzymes while DBC did not. The carcinogenicity with DBC and two of the mixtures was much greater than would be predicted based on published Relative Potency Factors (RPFs). Gene expression was measured in mouse skin 12 hours after initiation with PAH carcinogens. The following initiation treatments were applied to mice (N=4 or 5 per biological replicates treatment); toluene vehicle control (200 M-NM-<l), BaP 400 nmol (100 M-NM-<g), DBC 4 nmol (1.2 M-NM-<g), or to mixtures of environmental PAH mixtures containing diesel particulate extract, coal tar extract, or cigarette smoke condensate.

Project description:Exposure to cigarette smoke is a leading cause of lung diseases including chronic obstructive pulmonary disease and cancer. Cigarette smoke is a complex aerosol containing over 6000 chemicals, and thus it is difficult to determine individual contributions to overall toxicity, and the molecular mechanisms by which smoke constituents exert their effects. We selected three well-known harmful and potentially harmful constituents (HPHCs) in tobacco smoke: acrolein, formaldehyde and catechol and established a High Content Screening (HCS) method using normal human bronchial epithelial cells, which are the first bronchial cells in contact with cigarette smoke. The impact of each HPHC was investigated using 13 multi-parametric indicators of cellular toxicity and complemented with a microarray-based whole transcriptome analysis followed by a computational approach leveraging mechanistic network models to identify and quantify perturbed molecular pathways. HPHCs were evaluated over a wide range of concentrations and at different exposure time points (4 h, 8 h, and 24 h). By High Content Screening, the toxic effects of the three HPHCs could only be observed at the highest doses. Whole genome transcriptomics unraveled toxicity mechanisms at lower doses and earlier time points. The most prevalent toxicity mechanisms observed were: DNA damage/growth arrest, oxidative stress, mitochondrial stress and apoptosis/necrosis. In summary, combination of multiple toxicological endpoints with a systems-based impact assessment allows for a more robust scientific basis for the toxicological assessment of HPHCs that allows insight into time- and dose-dependent molecular perturbations of specific biological pathways. This approach allowed us to establish an in vitro Systems Toxicology platform that can be applied to a broader selection of HPHCs and their mixtures and can serve more generally as the basis for testing the impact of other environmental toxicants on normal bronchial epithelial cells.

Dataset Information

Human Keratinocyte Responses to Woodsmoke

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure