Increased vascular endothelial growth factor 165 binding to kinase insert domain-containing receptor after infection of human endothelial cells by recombinant adenovirus encoding the Vegf(165) gene.
BACKGROUND
The angiogenic effect of vascular endothelial growth factor (VEGF(165)) is mediated mainly through the high-affinity tyrosine kinase receptor VEGF-R2 (KDR/flk-1). This study examined the effects of VEGF overexpression by primary human endothelial cells (ECs), which do not express VEGF under physiological conditions, on cell proliferation, VEGF binding to the kinase insert domain-containing receptor (KDR), and KDR expression.


RESULTS
Human primary ECs and SMCs were infected by recombinant adenoviral vector encoding VEGF(165) (rAdVEGF). Proliferation rate, bromodeoxyuridine incorporation, (125)I-labeled VEGF(165) binding to the KDR receptor, and KDR expression were tested in the infected cells and in cells supplemented with VEGF protein. Enhanced proliferation and a significant increase in (125)I-VEGF(165) binding to the KDR receptor were induced by rAdVEGF infection of ECs (autocrine effect) as well as by addition of recombinant VEGF(165) to noninfected cells. Infection of ECs by rAdVEGF led to posttranscriptional upregulation of the KDR receptor, whereas KDR mRNA expression levels remained unchanged. Similar effects were observed with supplemented recombinant VEGF(165) to noninfected ECs; nevertheless, this phenomenon occurred only with high VEGF(165) concentrations (10 ng/mL).


CONCLUSIONS
The effect of VEGF(165) on proliferation and upregulation of KDR receptor expression demonstrated an autocrine phenomenon of EC sensitization. The fact that high concentrations of VEGF may be achieved in vivo by local continuous overexpression of VEGF(165) by gene transfer emphasizes the potential advantage of gene transfer over protein supplementation for therapeutic angiogenesis.
Weisz
A
A
Laboratory of Molecular and Cellular Cardiology, Department of Cardiology, Lady Davis Carmel Medical Center, Haifa, Israel.
Koren
B
B
Cohen
T
T
Neufeld
G
G
Kleinberger
T
T
Lewis
B S
BS
Flugelman
M Y
MY
D000256:Adenoviridae / Q000235:genetics; D001665:Binding Sites; D001667:Binding, Competitive; D002455:Cell Division / Q000235:genetics; D002460:Cell Line; D002478:Cells, Cultured; D016228:Endothelial Growth Factors / Q000235:genetics / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D007457:Iodine Radioisotopes; D008222:Lymphokines / Q000235:genetics / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D017978:Receptors, Growth Factor / Q000235:genetics / Q000378:metabolism*; D040262:Receptors, Vascular Endothelial Growth Factor; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D007457:Iodine Radioisotopes; D008222:Lymphokines; D012333:RNA, Messenger; D017978:Receptors, Growth Factor; D011993:Recombinant Fusion Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor