This proposal will center on the hypothesis that the toxic effects of ozone are mediated by lipid ozonation products (LOP) formed during the reaction of ozone with pulmonary surfactant, which signal through Toll-Like Receptor 4 (TLR4). The theory that ozone toxicity results from signaling by LOP is well accepted, but cellular signaling by LOP remains to be shown. The observation by Kleeberger and colleagues that the inbred mouse strain CH3/HeJ, which has a mutation in TLR4, is resistant to ozone suggests that TLR4 may be the link between LOP and the toxic effects of ozone. Standard assays for TLR4 activation in human monocytes and mouse macrophages will be used to screen for biologically active LOP in ozonized Calf Lung Surfactant Extract (CLSE). Mass spectrometric techniques will be used to structurally identify LOP. Second, the genetic differences seen with ozone toxicity are most likely multifactorial. There have been past studies to suggest differences in phospholipid content of surfactant may play a role in differences in ozone responsiveness. These studies have focused on the major components of surfactant such as phosphatidylcholine species. Less abundant components such as sphingomyelin and cholesterol have not been studied, although these Iipids are susceptible to ozone attack as well. A complete study is thus warranted of the lipids in surfactant of mice of varying ozone susceptibility. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Individual Predoctoral NRSA for M.D./Ph.D. Fellowships (ADAMHA) (F30)
Project #
7F30ES012347-03
Application #
6861013
Study Section
Special Emphasis Panel (ZRG1-F10 (20))
Program Officer
Shreffler, Carol K
Project Start
2003-03-01
Project End
2007-02-28
Budget Start
2004-03-04
Budget End
2005-02-28
Support Year
3
Fiscal Year
2004
Total Cost
$26,848
Indirect Cost
Name
University of Colorado Denver
Department
Pharmacology
Type
Schools of Medicine
DUNS #
041096314
City
Aurora
State
CO
Country
United States
Zip Code
80045
Pulfer, Melissa K; Taube, Christian; Gelfand, Erwin et al. (2005) Ozone exposure in vivo and formation of biologically active oxysterols in the lung. J Pharmacol Exp Ther 312:256-64
Pulfer, Melissa K; Harrison, Kathleen; Murphy, Robert C (2004) Direct electrospray tandem mass spectrometry of the unstable hydroperoxy bishemiacetal product derived from cholesterol ozonolysis. J Am Soc Mass Spectrom 15:194-202
Pulfer, Melissa K; Murphy, Robert C (2004) Formation of biologically active oxysterols during ozonolysis of cholesterol present in lung surfactant. J Biol Chem 279:26331-8
Pulfer, Melissa; Murphy, Robert C (2003) Electrospray mass spectrometry of phospholipids. Mass Spectrom Rev 22:332-64