E-cigarette Vapor - Understanding Pulmonary Response on the Molecular Level.

With the advent of E-cigarettes and the potential lung damage that has been initially attributed to these devices, a better understanding of the molecular response to the vapor is clearly needed. Observing the early oxidative/nitrative damage in lung cells and tissue was our focus in order to understand the body's response to chemicals found in the vapors released from heating propylene glycol (PG), vegetable glycerol (VG) and nicotine. Performing quantitative redox proteomics on rat lung tissues exposed to PG/VG (50/50) + nicotine (15 mg/mL) vs air allowed elucidation of protein modifications that will be used as markers to evaluate the relative hazards of different e-cigarette aerosol/vapor constituents in future studies. Bronchoalveolar lavage (BAL) fluid was also assessed using proteomic and lipidomic analysis to identify inflammatory cells and processes that are present during PG/VG as well as PG/VG + nicotine exposure compared to air. With the data we obtained we were able to determine several potential genetic and metabolic pathways that are modified due to the inflammatory response to the vapors. The modified peptide information obtained from both the redox proteomics and the BAL fluid analysis will be used in the future experimental design of Selected Reaction Monitoring (SRM) assays. These assays will be used to quantify oxidative damage and inflammatory responses among treatment groups that vary in e-cig main components to evaluate the relative hazards of different e-liquid constituents. These studies are critical to identify the health hazards potentially posed by inhaling these chemicals on a routine basis.