Proteome response of upper respiratory system following particle exposure

Airborne particles can be emitted from both occupational and environmental sources especially during combustion, fume alteration processes and other dust forming tasks. Exposure to airborne particles has been associated with several diseases, e.g. cancer, cardiovascular disease as well as lung diseases such as asthma, bronchitis and COPD. Airborne particles from occupational and environmental sources contain a complex mixture of agents that can differ in physical, chemical and biological properties that may be closely related to the induced health effects. A major part of the underlying induced mechanisms causing the health effects are not fully understood and additional knowledge needs to be gathered by associating the different occupational and environmental airborne exposure sources with the induced biological response. The general aim of this thesis is to measure protein changes, with respect to both protein abundance and the absolute quantity of specific proteins in nasal lavage fluids following three different exposures; persulfate, welding fume particles and diesel exhaust. Changes in the protein composition of the upper airways could provide a better understanding of the underlying pathogenesis. The general aim was also to clarify the role of different particle parameters affecting the dose metric. Protein-particle coronas were studied in an in vitro test carried out for two welding fume particle fractions; fine fraction (0.12.5 μm) and ultrafine fraction (<0.1 μm) and two types of iron oxides; Fe2O3 (20-40 nm) and Fe3O4 (8 nm) at different particle mass concentrations by adding them to nasal lavage proteins. The proteins that bound to the different particles at different mass concentrations were further analyzed with two different mass spectrometry approaches; a targeted SRM LC-MS/MS and 2DEMALDI-TOF-MS. Proteomic analyses were performed on nasal lavage proteins sampled from hairdressers with and without bleaching powder associated rhinitis and an atopic group experimentally exposed to persulfate. Samples were collected before, 20 min, 2h and 5h after the persulfate challenge. The protein composition was determined with a targeted SRM method for 247 proteins. In an exposure chamber, 11 welders with work-related symptoms in the lower airways were exposed to mild-steel welding fume particles (1 mg/m 3 ) and to filtered air, respectively. Nasal lavage samples were collected before, immediately after, and the day after exposure. The proteins in the nasal lavage were analyzed with two different mass spectrometry approaches, label-free discovery shotgun LC-MS/MS and a targeted, selected reaction monitoring (SRM) LC-MS/MS analyzing 130 proteins and four in vivo peptide degradation products. In an exposure chamber, 19 healthy volunteers were exposed to diesel exhaust (300 μg/m 3 ) and to filtered air, respectively. Nasal lavage samples were collected before, immediately after, and the day after exposure. The proteins in the nasal lavage were analyzed with two different mass spectrometry approaches, label-free discovery shotgun LC-MS/MS and a targeted selected reaction monitoring (SRM) LC-MS/MS analyzing 144 proteins and two in vivo peptide degradation products. Several proteins with biological relevance were altered after the respective exposures in the different study groups. This thesis suggests that the balance between proteases and antiproteases, disruption of the extracellular matrix, inflammation and immunosuppression are important induced effects by occupational and environmental particle exposure.It was also demonstrated that different particle parameters such as chemical composition, agglomerated particle size along with the primary particle size could determine the type of proteins that interact with them, and that such binding could cause an inhibitory effect of the bound protein, and cause an excessive effect on the downstream activity.