HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 291/2/C357    most recent 00365.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Li, Z. Articles by Huang, Y.-C. T. Search for Related Content PubMed PubMed Citation Articles by Li, Z. Articles by Huang, Y.-C. T.

VASCULAR BIOLOGY

Pollutant particles enhanced H₂O₂ production from NAD(P)H oxidase and mitochondria in human pulmonary artery endothelial cells

¹Center for Environmental Medicine, Asthma and Lung Biology, University of North Carolina, Chapel Hill; and ²National Health and Environmental Effects Research Laboratory, Office of Research and Development, Environmental Protection Agency, Research Triangle Park, North Carolina

Submitted 20 July 2005 ; accepted in final form 24 March 2006

Particulate matter (PM) induces oxidative stress and cardiovascular adverse health effects, but the mechanistic link between the two is unclear. We hypothesized that PM enhanced oxidative stress in vascular endothelial cells and investigated the enzymatic sources of reactive oxygen species and their effects on mitogen-activated protein kinase (MAPK) activation and vasoconstriction. We measured the production of extracellular H₂O₂, activation of extracellular signal-regulated kinases1/2 (ERK1/2) and p38 MAPKs in human pulmonary artery endothelial cells (HPAEC) treated with urban particles (UP; SRM1648), and assessed the effects of H₂O₂ on vasoconstriction in pulmonary artery ring and isolated perfused lung. Within minutes after UP treatment, HPAEC increased H₂O₂ production that could be inhibited by diphenyleneiodonium (DPI), apocynin (APO), and sodium azide (NaN₃). The water-soluble fraction of UP as well as its two transition metal components, Cu and V, also stimulated H₂O₂ production. NaN₃ inhibited H₂O₂ production stimulated by Cu and V, whereas DPI and APO inhibited only Cu-stimulated H₂O₂ production. Inhibitors of other H₂O₂-producing enzymes, including N-methyl-L-argnine, indomethacin, allopurinol, cimetidine, rotenone, and antimycin, had no effects. DPI but not NaN₃ attenuated UP-induced pulmonary vasoconstriction and phosphorylation of ERK1/2 and p38 MAPKs. Knockdown of p47phox gene expression by small interfering RNA attenuated UP-induced H₂O₂ production and phosphorylation of ERK1/2 and p38 MAPKs. Intravascular administration of H₂O₂ generated by glucose oxidase increased pulmonary artery pressure. We conclude that UP induce oxidative stress in vascular endothelial cells by activating NAD(P)H oxidase and the mitochondria. The endothelial oxidative stress may be an important mechanism for PM-induced acute cardiovascular health effects.

mitogen-activated protein kinase; extracellular signal-regulated kinase; p38; vasoconstriction

This article has been cited by other articles:

				M. Medhora, Y. Chen, S. Gruenloh, D. Harland, S. Bodiga, J. Zielonka, D. Gebremedhin, Y. Gao, J. R. Falck, S. Anjaiah, et al. 20-HETE increases superoxide production and activates NAPDH oxidase in pulmonary artery endothelial cells Am J Physiol Lung Cell Mol Physiol, May 1, 2008; 294(5): L902 - L911. [Abstract] [Full Text] [PDF]