alpha-Tocopheryl succinate inhibits monocytic cell adhesion to endothelial cells by suppressing NF-kappa B mobilization.
The adherence of monocytes to activated endothelium is an early event in atherogenesis. Because antioxidants have been considered to be of antiatherosclerotic potential, we investigated the effects of alpha-tocopherol (TCP) and its acetate and succinate esters on monocyte adhesion to cytokine-stimulated human umbilical vein endothelial cells (HUVEC). Endothelial cells were treated with TCP, alpha-tocopherol acetate (TCP acetate), or alpha-tocopheryl succinate (TCP succinate) before stimulation with tumor necrosis factor-alpha (TNF-alpha; 10 U/ml, 6 h) or interleukin-1 beta (IL-1 beta; 10 U/ml, 6 h). Cytokine-stimulated cell surface expression of vascular cell adhesion molecule-1 (VCAM-1, CD106) and E-selectin (ELAM-1, CD62E), but not of intercellular adhesion molecule-1 (ICAM-1, CD54), was time- and dose-dependently inhibited by TCP succinate but not by TCP or TCP acetate. TCP succinate (200 microM, 24 h) reduced TNF-induced VCAM-1 and E-selectin expression from a specific mean fluorescence intensity of 151 +/- 28 to 12 +/- 4 channels and from 225 +/- 38 to 79 +/- 21 channels, respectively. Succinate alone had no effect. Decreased adhesion molecule expression was associated with a reduction of monocytic cell adhesion. TCP succinate (20 microM, 72 h), but not TCP (200 microM, 72 h), reduced U-937 cell adhesion to TNF-alpha-stimulated (10 U/ml, 6 h) HUVEC by 30% (P < 0.025) and to IL-1 beta-stimulated HUVEC by 56% (P < 0.010). Electrophoretic mobility-shift assays of HUVEC nuclear proteins revealed a decrease in TNF-alpha-stimulated nuclear factor-kappa B (NF-kappa B) activation after pretreatment of HUVEC with TCP succinate but not with TCP, TCP acetate, or succinate alone. In conclusion, we demonstrate that the vitamin E derivative TCP succinate prevents monocytic cell adhesion to cytokine-stimulated endothelial cells by inhibiting the activation of NF-kappa B, further emphasizing the antiatherosclerotic potential of lipid soluble antioxidants.
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Institut für Prophylaxe und Epidemiologie der Kreislaufkrankheiten, Ludwig-Maximilians-Universität, Munich, Germany.
Weber
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Wardemann
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Weber
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D001692:Biological Transport / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D009000:Monocytes / Q000187:drug effects* / Q000502:physiology; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D024505:Tocopherols; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000494:pharmacology
D015815:Cell Adhesion Molecules; D016328:NF-kappa B; D014810:Vitamin E; D024505:Tocopherols