Interaction of electrophilic lipid oxidation products with mitochondria in endothelial cells and formation of reactive oxygen species.
Electrophilic lipids, such as 4-hydroxynonenal (HNE), and the cyclopentenones 15-deoxy-Delta12,14 -prostaglandin J2 (15d-PGJ2) and 15-J2-isoprostane induce both reactive oxygen species (ROS) formation and cellular antioxidant defenses, such as heme oxygenase-1 (HO-1) and glutathione (GSH). When we compared the ability of these distinct electrophiles to stimulate GSH and HO-1 production, the cyclopentenone electrophiles were somewhat more potent than HNE. Over the concentration range required to observe equivalent induction of GSH, dichlorofluorescein fluorescence was used to determine both the location and amounts of electrophilic lipid-dependent ROS formation in endothelial cells. The origin of the ROS on exposure to these compounds was largely mitochondrial. To investigate the possibility that the increased ROS formation was due to mitochondrial localization of the lipids, we prepared a novel fluorescently labeled form of the electrophilic lipid 15d-PGJ2. The lipid demonstrated strong colocalization with the mitochondria, an effect which was not observed by using a fluorescently labeled nonelectrophilic lipid. The role of mitochondria was confirmed by using cells deficient in functional mitochondria. On the basis of these data, we propose that ROS formation in endothelial cells is due to the direct interaction of these lipids with the organelle.
Landar
Aimee
A
Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
Zmijewski
Jaroslaw W
JW
Dickinson
Dale A
DA
Le Goffe
Claire
C
Johnson
Michelle S
MS
Milne
Ginger L
GL
Zanoni
Giuseppe
G
Vidari
Giovanni
G
Morrow
Jason D
JD
Darley-Usmar
Victor M
VM
D000447:Aldehydes / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D050356:Lipid Metabolism / Q000502:physiology; D015227:Lipid Peroxidation / Q000187:drug effects / Q000502:physiology*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D015230:Prostaglandin D2 / Q000031:analogs & derivatives / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology
C477819:15-deoxyprostaglandin J2; D000447:Aldehydes; D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species; C027576:4-hydroxy-2-nonenal; D015230:Prostaglandin D2