Induction of vascular endothelial growth factor in balloon-injured baboon arteries. A novel role for reactive oxygen species in atherosclerosis.
Neovascularization is a hallmark of neointimal formation in atherosclerotic plaques and restenotic lesions. Vascular endothelial growth factor (VEGF) promotes neovascular growth, whereas oxidative stress is a potent factor in vascular cell proliferation. To investigate the mechanisms of neovascular formation, we treated human and rat vascular smooth muscle cells (VSMCs) with H2O2. Northern blot analysis demonstrated a dose- and time-dependent increase in VEGF mRNA, with a maximum of 4-fold at 3 hours (200 mumol/L). As determined by immunoblotting and enzyme-linked immunosorbent assay, VEGF protein expression and secretion were similarly increased. Human umbilical vein endothelial cells were treated with conditioned medium from VSMCs incubated with 200 mumol/L H2O2. DNA synthesis, measured by thymidine incorporation, was increased 4-fold compared with control, an effect that was blocked by a neutralizing anti-VEGF antibody. The lipid peroxidation product 4-hydroxynonenal (1 mumol/L), an endogenous reactive oxygen species present in human atherosclerotic lesions, also increased VEGF secretion in VSMCs in a similar time-dependent fashion. Immunohistochemical staining and in situ hybridization of aortic sections from balloon-injured baboons demonstrated increased VEGF expression in discrete areas of the neointima and media compared with control sections, and expression correlated with the generation of 4-hydroxynonenal. Regulators of VEGF expression, such as reactive oxygen species, may enhance neovascularization of atherosclerotic and restenotic arteries.
Ruef
J
J
Division of Cardiology, University of Texas Medical Branch at Galveston, USA.
Hu
Z Y
ZY
Yin
L Y
LY
Wu
Y
Y
Hanson
S R
SR
Kelly
A B
AB
Harker
L A
LA
Rao
G N
GN
Runge
M S
MS
Patterson
C
C
D000818:Animals; D001158:Arteries / Q000293:injuries / Q000378:metabolism*; D001161:Arteriosclerosis / Q000209:etiology*; D015152:Blotting, Northern; D002455:Cell Division; D002478:Cells, Cultured; D016228:Endothelial Growth Factors / Q000235:genetics / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D017403:In Situ Hybridization; D008222:Lymphokines / Q000235:genetics / Q000378:metabolism*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D010215:Papio; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000502:physiology*; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D008222:Lymphokines; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D006861:Hydrogen Peroxide