Proteomics in Nasal Lavage Fluids from Persulfate Challenged Hairdressers

Sammanfattning: Hairdressers have an increased risk for developing airway symptoms e.g. asthma and rhinitis. Persulfate salts, which are oxidizing agents present in bleaching powder, are considered to be important causal agents for these symptoms. The underlying mechanisms are unclear and efficient tools for risk assessment and diagnosis are scarce. The general aim of this thesis was to measure proteomic changes, both with respect to protein abundances and protein oxidation, in nasal lavage fluids (NLF) from hairdressers challenged with persulfates. Proteins regulate most biological processes in the human body. Changes in protein levels may therefore provide a better understanding of disease pathogenesis and/or candidate biomarkers for persulfate exposure, effect and/or oxidative stress. A high throughput screening method for quantification of 246 NLF proteins was developed using selected reaction monitoring (SRM). Also, a strategy for identification of multiple oxidative modifications was developed and applied on proteins oxidized in vitro by persulfate. SRM assays targeting the oxidized peptides were developed. NLF samples from a previous persulfate challenge study were analyzed. Hairdressers with bleaching powder associated rhinitis were compared to hairdressers without respiratory symptoms and with atopic subjects without work related exposure to persulfate. Protein abundances in the NLF samples were analyzed with two different proteomic approaches. Pooled samples were first analyzed with an untargeted approach using 2D-nanoLC-MS/MS combined with iTRAQ-labeling and then with the SRM method targeting 246 NLF proteins. Also, oxidized peptides were measured in the samples by SRM. Several proteins with biologically relevant functions were changed after the persulfate challenge. The exact role of these proteins in relation to persulfate-induced respiratory symptoms needs to be further studied as well as the usefulness of them as effect biomarkers. Persulfates oxidized tryptophan and methionine residues. It was concluded that oxidized peptides containing these modifications are not suitable as persulfate exposure biomarkers due to poor specificity. Peptides containing oxidized tryptophan may be useful as biomarkers for oxidative stress and should be further evaluated.