The long-term objective of the proposed research is to determine the molecular mechanisms by which asbestos, a well recognized lung pathogen, interacts with cells in vitro and in vivo to stimulate the release of mediators of inflammation and fibrosis. To this end, the interaction of crocidolite asbestos and rabbit pleural mesothelial cells will be studied as a paradigm of asbestos-cell interactions. In recent work the applicant found that exposure of rabbit pleural mesothelial cells to crocidolite asbestos in vitro induced message for interleukin-8 (IL-8), a cytokine with potent chemotactic activity for neutrophils. How asbestos interacts with the cell to regulate IL-8 or other gene expression is not clear. Asbestos fibers may signal changes in IL-8 gene expression through intermediaries such as active oxygen species (produced by asbestos), or proteins (produced by mesothelial cells), or through interaction with the cells' external environment (extracellular matrix proteins), or internal environment (the cytoskeleton). To test the hypothesis that the interaction of asbestos fibers with the extracellular matrix and cytoskeleton is necessary for asbestos induced gene expression, the effect of extracellular matrix proteins and cytoskeletal toxins, on asbestos-induction of IL-8 MRNA will be analyzed. To test the hypothesis that the interaction of asbestos fibers and the pleural mesothelial cell stimulates the mesothelial production of mediators of inflammation and fibrosis, TGF-beta and fibronectin protein production and MRNA induction will be assessed, members of the family of IL-8 related proteins will be identified, and a series of in vivo experiments will be performed. The work supported by this award will not only yield information about the pathogenesis of asbestos-induced pleural disease, but win also provide the applicant with the tools necessary to achieve her goal of becoming an independent investigator. A rigorous training program has been planned by her sponsors including a series of courses and conferences. Space, facilities, and protected time for research have been made available to establish her independence.
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|Broaddus, V C; Yang, L; Scavo, L M et al. (1996) Asbestos induces apoptosis of human and rabbit pleural mesothelial cells via reactive oxygen species. J Clin Invest 98:2050-9|
|Boylan, A M; Hebert, C A; Sadick, M et al. (1994) Interleukin-8 is a major component of pleural liquid chemotactic activity in a rabbit model of endotoxin pleurisy. Am J Physiol 267:L137-44|
|Broaddus, V C; Boylan, A M; Hoeffel, J M et al. (1994) Neutralization of IL-8 inhibits neutrophil influx in a rabbit model of endotoxin-induced pleurisy. J Immunol 152:2960-7|