VEGF is major stimulator in model of choroidal neovascularization.
OBJECTIVE
Vascular endothelial growth factor (VEGF) is upregulated by hypoxia and is a major stimulatory factor for retinal neovascularization in ischemic retinopathies such as diabetic retinopathy. This study sought to determine if VEGF is a stimulatory factor in a murine model of choroidal neovascularization (CNV).


METHODS
Mice with laser-induced ruptures in Bruch's membrane were treated with vehicle alone; a drug that inhibits both VEGF and platelet-derived growth factor (PDGF) receptor kinases; a drug that inhibits PDGF, but not VEGF receptor kinase; or genistein, a nonspecific kinase inhibitor. After two weeks, CNV was quantified and compared.


RESULTS
Blockade of phosphorylation by VEGF and PDGF receptors caused dramatic, almost complete inhibition of CNV. Genistein also had an inhibitory effect, but less so than the VEGF/PDGF receptor blocker. Blockade of phosphorylation by PDGF receptors, but not VEGF receptors, had no significant effect on CNV.


CONCLUSIONS
These data and our previous study, which demonstrated that a kinase inhibitor that blocks VEGF and PDGF receptors and several isoforms of protein kinase C causing dramatic inhibition of CNV, suggest that VEGF signaling plays a critical role in the development of CNV in this model. If safety is established, the effect of inhibiting VEGF receptor kinase activity should be investigated in patients with CNV.
Kwak
N
N
Departments of Ophthalmology and Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-9277, USA.
Okamoto
N
N
Wood
J M
JM
Campochiaro
P A
PA
D000818:Animals; D020256:Choroidal Neovascularization / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control; D016228:Endothelial Growth Factors / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019833:Genistein / Q000494:pharmacology; D008222:Lymphokines / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010766:Phosphorylation; D010793:Phthalazines / Q000494:pharmacology; D010982:Platelet-Derived Growth Factor / Q000502:physiology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D011725:Pyridines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D017978:Receptors, Growth Factor / Q000037:antagonists & inhibitors; D017479:Receptors, Platelet-Derived Growth Factor / Q000037:antagonists & inhibitors; D040262:Receptors, Vascular Endothelial Growth Factor; D015398:Signal Transduction / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
C092972:CGP 53716; D016228:Endothelial Growth Factors; D004791:Enzyme Inhibitors; D008222:Lymphokines; D010793:Phthalazines; D010982:Platelet-Derived Growth Factor; D011725:Pyridines; D011743:Pyrimidines; D017978:Receptors, Growth Factor; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; C404768:vatalanib; D019833:Genistein; D020794:Receptor Protein-Tyrosine Kinases; D017479:Receptors, Platelet-Derived Growth Factor; D040262:Receptors, Vascular Endothelial Growth Factor; D011493:Protein Kinase C