Role of reactive oxygen species in inhibition of endothelial cell migration by oxidized low-density lipoprotein.
OBJECTIVE
Endothelial cell migration is inhibited by oxidized low-density lipoprotein (oxLDL) and lysophosphatidylcholine (lysoPC). The purpose of this study was to explore the mechanism of this inhibition, specifically the role of reactive oxygen species.


METHODS
The ability of oxLDL, lysoPC, and known superoxide generators to stimulate endothelial cell production of reactive oxygen species and inhibit endothelial cell migration under the same conditions was assessed. Reactive oxygen species production was assessed with dichlorofluorescein. Migration was studied with a razor scrape assay and measured after 24 hours. In addition, the ability of various antioxidants, added before initiation of the scrape assay, to restore endothelial cell migration in oxLDL was determined.


RESULTS
OxLDL and lysoPC, at concentrations that stimulated reactive oxygen species production, also inhibited endothelial cell migration. Other agents that generated superoxide also inhibited endothelial cell migration, but hydrogen peroxide did not. Of a variety of antioxidants assessed for their ability to preserve endothelial cell migration in the presence of oxLDL, only superoxide dismutase and reduced nicotinamide adenine dinucleotide (phosphate) oxidase inhibitors (diphenyleneiodonium, quinacrine, hydralazine) preserved endothelial cell migration.


CONCLUSIONS
These data suggest that oxLDL inhibits endothelial cell migration through a superoxide-dependent mechanism and that reduced nicotinamide adenine dinucleotide (phosphate) oxidase is the cellular source of the superoxide.


CONCLUSIONS
OxLDL inhibits endothelial cell migration, and may impair healing of arterial injuries. The mechanism of oxidized LDL inhibition is not known. Our in vitro studies show that the inhibitory properties are related to production of reactive oxygen species. Superoxide dismutase or inhibitors of reduced nicotinamide adenine dinucleotide phosphate oxidase can preserve endothelial migration in the presence of oxLDL. This might improve the healing of endothelial injuries at sites of arterial repair or angioplasty, especially in lipid-laden arterial walls.
van Aalst
John A
JA
Department of Surgery, Case Western Reserve University, Cleveland, Ohio, USA.
Zhang
Dong-Mei
DM
Miyazaki
Keiko
K
Colles
Scott M
SM
Fox
Paul L
PL
Graham
Linda M
LM
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002417:Cattle; D002465:Cell Movement / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects* / Q000502:physiology; D016166:Free Radical Scavengers / Q000494:pharmacology; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D008244:Lysophosphatidylcholines / Q000494:pharmacology; D016877:Oxidants / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism
D000975:Antioxidants; D016166:Free Radical Scavengers; D008077:Lipoproteins, LDL; D008244:Lysophosphatidylcholines; D016877:Oxidants; D017382:Reactive Oxygen Species; C099252:oxidized low density lipoprotein; D013481:Superoxides