Project 4
Biomarkers of Exposure to Pulmonary Toxicants

Alan R. Buckpitt, Project Leader
Charles G. Plopper, Senior Investigator
Dietmar Kueltz, Senior Investigator
Michelle Fanucchi, Senior Investigator
 
Specific Aims

This project focuses on two pulmonary cytotoxicants, naphthalene (NA) and 1-nitronaphthalene (NN). The work seeks to 1) demonstrate lung injury for NA at vapor concentrations well below the current occupational standard, 2) show that the nasal epithelium is a susceptible target for both compounds, 3) identify many of the proteins adducted by reactive metabolites from NA and NN, and 4) demonstrate substantial quantitative differences in rodent vs nonhuman primate lung metabolism of these substrates. Overall, this work will contribute important data for current assessments of the potential human health hazards of these compounds. New methods are being developed that will: 1) allow preservation of the lung for transcriptome analysis in well defined subcompartments, 2) allow selective sampling of proteins from airway epithelium facilitating analysis of changes in the airway proteome in response to toxicants and 3) improve analysis of alterations in protein expression by incorporation of a fluorescent internal standard. The foci of the studies are to: 1) delineate differences in cytotoxic injury associated administration of respirable particle/chemical mixtures, 2) understand the importance of protein/nonprotein thiol oxidation in injury, 3) determine whether proteins which are adducted in the lung by reactive NA and NN metabolites are also adducted in susceptible nasal epithelium, 4) determine whether protein profiles and alterations in the metabolome present in nasal and bronchiolar lavage samples reflect injury to nasal and airway epithelium, 5) determine whether the nasal epithelium (and associated lavage sampling) can act as a legitimate surrogate for more distal parts of the lung and 6) delineate the importance of adducts with antioxidant enzymes and proteins involved in protein folding in cytotoxicity. These studies will provide important baseline data for work on the toxicology of 'real world' combustion mixtures. These particulate samples, many of which contain heavy metals, will be evaluated using nasal epithelium in vitro and in respiratory and renal tissue using proteomics approaches in vivo.