Oxidized low-density lipoprotein increases the production of intracellular reactive oxygen species in endothelial cells: inhibitory effect of lacidipine.
OBJECTIVE
The mechanisms by which oxidized low-density lipoprotein (ox-LDL) induces the expression of adhesion molecules on endothelial cells (HUVECs) are still not clear. The signal transduction pathways for these binding molecules include the translocation of the transcription factor NF-kB and the intracellular reactive oxygen species (ROS) are said to play a key role in this process. Aim of this study was (1) to evaluate the effect of ox-LDL on intracellular production of ROS in culture of HUVECs; (2) to evaluate if the intracellular increase of ROS induced by ox-LDL is mediated by the binding to a specific endothelial receptor; (3) to ascertain if lacidipine can decrease ox-LDL-induced ROS production in HUVECs.


METHODS
Five microM Cu2+ ox-LDL were incubated with HUVECs for 5 min. 2',7'-Dichlorofluorescein (DCF) as an expression of intracellular ROS production, was measured by flow cytometry.


RESULTS
ox-LDL induced a significant dose-dependent increase in DCF production (P < 0.001) through the binding to a specific receptor. The preincubation of HUVECs with radical scavengers compounds and lacidipine significantly reduced (P < 0.001) the ox-LDL-induced DCF production.


CONCLUSIONS
ox-LDL increased the intracellular formation of ROS through the ligation to a specific endothelial receptor. Preincubation of HUVECs with lacidipine, a calcium antagonist with antioxidant properties, significantly reduced the intracellular ROS formation induced by ox-LDL. We propose that the effect of lacidipine on adhesion molecule expression and on NF-kB activation can be explained by its effect on intracellular ROS formation.
Cominacini
L
L
Istituto di Semeiotica e Nefrologia Medica, Università di Verona, Italy.
Garbin
U
U
Pasini
A F
AF
Davoli
A
A
Campagnola
M
M
Pastorino
A M
AM
Gaviraghi
G
G
Lo Cascio
V
V
D000975:Antioxidants / Q000494:pharmacology; D001161:Arteriosclerosis / Q000209:etiology / Q000517:prevention & control; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002478:Cells, Cultured; D004095:Dihydropyridines / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism*; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006801:Humans; D007424:Intracellular Fluid / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000378:metabolism / Q000494:pharmacology*; D016328:NF-kappa B / Q000378:metabolism; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000378:metabolism*
D000975:Antioxidants; D002121:Calcium Channel Blockers; D015815:Cell Adhesion Molecules; D004095:Dihydropyridines; D005452:Fluoresceins; D005456:Fluorescent Dyes; D008077:Lipoproteins, LDL; D016328:NF-kappa B; D017382:Reactive Oxygen Species; C099252:oxidized low density lipoprotein; C029569:diacetyldichlorofluorescein; C060285:lacidipine