Vitamins C and E prevent endothelial VEGF and VEGFR-2 overexpression induced by porcine hypercholesterolemic LDL.
OBJECTIVE
Vascular endothelial growth factor (VEGF) is believed to play a role in the development of atherosclerosis and has been found to be increased in hypercholesterolemia. We examined the hypothesis that endothelial VEGF and VEGF receptor-2 (VEGFR-2) expression is upregulated by hypercholesterolemic low-density lipoprotein (LDL) and, because it could be driven by oxidative stress, we tested whether vitamin C and E supplementation could modulate it.


METHODS
Native LDL were characterized after isolation from adult normal (C-LDL), hypercholesterolemic (HC-LDL) and hypercholesterolemic mini-pigs receiving vitamins C and E (HCV-LDL). VEGF, VEGFR-2, HIF-1 alpha and superoxide anion (O(2)(-)) productions were measured in porcine coronary endothelial cells (ECs) incubated for 48 h with native LDL. The effect of exogenous ascorbic acid and alpha- or beta-tocopherol was also studied.


RESULTS
HC-LDL, with high cholesterol (P<0.05) and reduced tocopherol/cholesterol ratio (P<0.05), increased significantly VEGF and VEGFR-2 (p<0.001) in EC, associated with higher O(2)(-) and HIF-1 alpha expression, in comparison with C-LDL and HCV-LDL. The addition of vitamin C and alpha- or beta-tocopherol to the culture medium prevented the induction of VEGF and VEGFR-2 expression by HC-LDL, both at mRNA and protein levels.


CONCLUSIONS
Our data suggest HC-LDL induce endothelial VEGF and VEGFR-2 overexpression at least by increasing oxidative stress, and HIF-1 alpha is one of the signaling mechanisms involved. Prevention of VEGF and VEGFR-2 upregulation could help explain the beneficial effects of vitamins C and E in hypercholesterolemia-induced experimental atherosclerosis.
Rodríguez
José A
JA
Atherosclerosis Research Laboratory, Division of Cardiovascular Pathophysiology, School of Medicine, Foundation for Applied Medical Research, University of Navarra, Pamplona Navarra E-31008, Spain. josean@unav.es
Nespereira
Beatriz
B
Pérez-Ilzarbe
Maitane
M
Eguinoa
Ezequiel
E
Páramo
José A
JA
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology*; D002478:Cells, Cultured; D008078:Cholesterol, LDL / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000378:metabolism; D006937:Hypercholesterolemia / Q000097:blood*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008297:Male; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013552:Swine; D013556:Swine, Miniature; D014157:Transcription Factors / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis* / Q000235:genetics; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000096:biosynthesis / Q000235:genetics; D014810:Vitamin E / Q000494:pharmacology*
D000975:Antioxidants; D008078:Cholesterol, LDL; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D017382:Reactive Oxygen Species; D014157:Transcription Factors; D042461:Vascular Endothelial Growth Factor A; D014810:Vitamin E; D040301:Vascular Endothelial Growth Factor Receptor-2; D001205:Ascorbic Acid