Inflammatory Effects of Inhaled Organic Diesel Exhaust Particles

Andre Nel
University of California at Los Angeles
R01ES10553

Background: Numerous epidemiologic studies have demonstrated an association between exposure to ambient particulate matter (PM) and adverse cardiorespiratory effects. These effects include asthma exacerbations and allergic inflammation. Previous research by this group using diesel exhaust particles (DEP) as a model air pollutant have shown that organic chemical compounds play an important role in the pro-oxidative and proinflammatory effects of DEP in the respiratory tract.

Advance: By extracting organic chemicals from DEP and applying them to bronchial epithelial cells in culture, this group demonstrated an induction of oxidative stress by inducing the formation of heme oxygenase and other markers. Macrophages responded in a similar manner; however, epithelial cells produced more superoxide radicals and were more susceptible to cytotoxic effects. The cytotoxicity was determined to be the result of mitochondrial damage, superoxide production, and energy depletion.

Implication: These findings show that organic DEP chemicals induce a range of biological responses in epithelial cells and macrophages that depend on the generation of oxidative stress. This study also sheds light on the mechanisms by which exposure to DEP has adverse effects on the respiratory system.

Citation: Li N, Wang M, Oberley TD, Sempf JM, Nel AE. Comparison of the pro-oxidative and proinflammatory effects of organic diesel exhaust particle chemicals in bronchial epithelial cells and macrophages. J Immunol. 2002 Oct 15;169(8):4531-41.