Vasculotropin-VEGF stimulates retinal capillary endothelial cells through an autocrine pathway.
OBJECTIVE
To determine whether bovine retinal endothelial cells (BRECs) bind, synthesize, and respond to vasculotropin-vascular endothelial growth factor (VAS-VEGF).


METHODS
Cultured BRECs were tested for their ability to bind 125I VAS-VEGF and their response to the growth and migration-promoting effect of VAS-VEGF. Total RNAs extracted from BRECs were reverse transcribed and amplified by polymerase chain reaction using VAS-VEGF primers. The translation was assessed by a Western blot analysis and a radioreceptor assay in the BREC-conditioned medium. Neutralization with anti-VAS-VEGF antibodies ascertained the autocrine role of VAS-VEGF.


RESULTS
BRECs bind VAS-VEGF on two high-affinity binding sites (apparent Kd of 2 and 56 pM) and can proliferate and migrate upon the addition of recombinant VAS-VEGF. Furthermore, BRECs synthesize and secrete into their own culture medium a mitogen related to VAS-VEGF as far as two factors are concerned: chromatographic behavior on heparin-affinity columns, and cross-reactivity with recombinant VAS-VEGF to the binding to its receptors or antibodies. Neutralization of the purified conditioned medium with anti-VAS-VEGF antibodies revealed that VAS-VEGF can act on BRECs through an autocrine pathway.


CONCLUSIONS
This is the first description of an autocrine regulation of endothelial cell growth by VAS-VEGF that could be involved in the pathogenesis of retinal neovascularization.
Simorre-Pinatel
V
V
Laboratoire de Biologie Moléculaire Eucaryote, Laboratoire d'Ophtalmologie, CHU, Toulouse, France.
Guerrin
M
M
Chollet
P
P
Penary
M
M
Clamens
S
S
Malecaze
F
F
Plouet
J
J
D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002196:Capillaries / Q000166:cytology / Q000187:drug effects; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D006133:Growth Substances / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D006706:Homeostasis / Q000502:physiology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D012171:Retinal Vessels / Q000166:cytology / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D017931:DNA Primers; D006133:Growth Substances; D012333:RNA, Messenger; D011994:Recombinant Proteins; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors