Peroxynitrite increases VEGF expression in vascular endothelial cells via STAT3.
Increased expression of vascular endothelial growth factor (VEGF) has been correlated with increased oxidative stress and formation of peroxynitrite in numerous disease conditions, including diabetic microangiopathy, tumor angiogenesis, and atherosclerosis. In this study we tested the hypothesis that peroxynitrite stimulates VEGF expression. Treatment of microvascular endothelial cells with exogenous peroxynitrite induced a time- and dose-dependent increase in VEGF mRNA, which peaked within 1 h of treatment at a concentration of 100 muM. The increase in VEGF mRNA was followed by a significant increase in VEGF protein. To define the molecular mechanisms involved, the effect of peroxynitrite was determined on the activation of two transcription factors known to regulate VEGF expression during hypoxia and tumor angiogenesis-signal transducer and activator of transcription 3 (STAT3) and hypoxia-inducible factor-1 (HIF-1). Peroxynitrite caused activation and nuclear translocation of STAT3, but not HIF-1. Moreover, transduction of endothelial cells with dominant-negative STAT3 abrogated the peroxynitrite-induced increase in VEGF mRNA. The increase in VEGF mRNA was also blocked by inhibitors of transcription and was unaffected by the inhibition of protein synthesis. These results indicate that peroxynitrite causes increased expression of VEGF in vascular endothelial cells by a process that requires the activation of STAT3.
Platt
Daniel H
DH
Vascular Biology Center, Medical College of Georgia, Augusta, GA 30912, USA.
Bartoli
Manuela
M
El-Remessy
Azza B
AB
Al-Shabrawey
Mohamed
M
Lemtalsi
Tahira
T
Fulton
David
D
Caldwell
Ruth B
RB
D021581:Active Transport, Cell Nucleus; D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D002465:Cell Movement; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005609:Free Radicals; D005786:Gene Expression Regulation; D005799:Genes, Dominant; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000378:metabolism; D051793:Hypoxia-Inducible Factor 1 / Q000378:metabolism; D015151:Immunoblotting; D008833:Microcirculation; D008856:Microscopy, Fluorescence; D009130:Muscle, Smooth / Q000166:cytology; D018384:Oxidative Stress; D030421:Peroxynitrous Acid / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D013997:Time Factors; D014158:Transcription, Genetic; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism
D005609:Free Radicals; D051793:Hypoxia-Inducible Factor 1; D012333:RNA, Messenger; D050796:STAT3 Transcription Factor; D042461:Vascular Endothelial Growth Factor A; D030421:Peroxynitrous Acid; D049452:Green Fluorescent Proteins