Vascular endothelial growth factor synergistically enhances induction of E-selectin by tumor necrosis factor-alpha.
OBJECTIVE
The regulation of endothelial cell adhesion molecules (CAMs) by vascular endothelial growth factor (VEGF) was investigated in cell cultures and in a rabbit model of atherogenic neointima formation.


RESULTS
VEGF regulation of vascular CAM-1 (vascular cell adhesion molecule), intercellular CAM-1 (intercellular adhesion molecule), and E-selectin were investigated in human umbilical vein endothelial cells using quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and flow cytometry, and in the rabbit collar model of atherogenic macrophage accumulation by immunostaining. VEGF alone caused no significant induction of vascular cell adhesion molecule-1, intercellular adhesion molecule-1, or E-selectin compared with tumor necrosis factor-alpha. In both hypercholesterolemic and normal rabbits, adenoviral VEGF-A165 expression caused no increase in endothelial vascular cell adhesion molecule-1 or E-selectin. In contrast, pretreatment of human umbilical vein endothelial cells with VEGF significantly increased E-selectin expression induced by tumor necrosis factor-alpha, compared with tumor necrosis factor-alpha alone, whereas vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 were unaffected. VEGF similarly enhanced IL-1beta-induced E-selectin upregulation. VEGF also synergistically increased tumor necrosis factor-alpha-induced E-selectin mRNA and shedding of soluble E-selectin. Synergistic upregulation of E-selectin expression by VEGF was mediated via VEGF receptor-2 and calcineurin signaling.


CONCLUSIONS
VEGF alone does not activate endothelium to induce CAM expression; instead, VEGF "primes" endothelial cells, sensitizing them to cytokines leading to heightened selective pro-inflammatory responses, including upregulation of E-selectin.
Stannard
Anita K
AK
BHF Laboratories, Department of Medicine, The Rayne Building, University College London, 5 University Street, London WC1E 6JJ, United Kingdom.
Khurana
Rohit
R
Evans
Ian M
IM
Sofra
Vassiliki
V
Holmes
David I R
DI
Zachary
Ian
I
D000818:Animals; D050197:Atherosclerosis / Q000378:metabolism; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004357:Drug Synergism; D019040:E-Selectin / Q000096:biosynthesis* / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D007150:Immunohistochemistry; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism* / Q000494:pharmacology; D015854:Up-Regulation; D019010:Vascular Cell Adhesion Molecule-1 / Q000187:drug effects / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism* / Q000494:pharmacology
D019040:E-Selectin; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D042461:Vascular Endothelial Growth Factor A