Constitutive expression of VEGF, VEGFR-1, and VEGFR-2 in normal eyes.
OBJECTIVE
The expression of vascular endothelial growth factor (VEGF) and its high-affinity receptors VEGFR-1 and VEGFR-2 was investigated in normal eyes.


METHODS
Monkey and rat eyes were surgically removed in animals under deep anesthesia and immediately prepared for study. Ocular VEGF, VEGFR-1, and VEGFR-2 expression was studied using a combination of in situ hybridization, northern blot analysis, immunohistochemistry, immunoassay, and reverse transcription-polymerase chain reaction.


RESULTS
Steady state VEGF mRNA levels were detected in the normal vascularized ocular tissues of the monkey: the conjunctiva, iris, retina, and the choroid-retinal pigment epithelial complex. VEGF121 and VEGF165 were the major isoforms identified. VEGF protein was detected in the conjunctiva, retina, and the choroid-retinal pigment epithelial complex. Retinal VEGF mRNA localized to the ganglion, inner nuclear, and retinal pigment epithelial cell layers. VEGF protein localized to these same layers and to the cones of monkey retina. VEGFR-1 and VEGFR-2 mRNAs were detected in normal monkey iris, retina, and the choroid-retinal pigment epithelial complex. In both monkey and rat eyes, VEGFR-1 and VEGFR-2 mRNAs were localized to the inner nuclear layer of the retina.


CONCLUSIONS
VEGF, VEGFR-1, and VEGFR-2 are constitutively expressed in the vascularized tissues of normal eyes.
Kim
I
I
Children's Hospital, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA.
Ryan
A M
AM
Rohan
R
R
Amano
S
S
Agular
S
S
Miller
J W
JW
Adamis
A P
AP
D000818:Animals; D015152:Blotting, Northern; D017931:DNA Primers / Q000737:chemistry; D016228:Endothelial Growth Factors / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay; D005123:Eye / Q000378:metabolism*; D015870:Gene Expression; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D008222:Lymphokines / Q000235:genetics*; D008252:Macaca fascicularis; D008253:Macaca mulatta; D008297:Male; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D017978:Receptors, Growth Factor / Q000235:genetics*; D040262:Receptors, Vascular Endothelial Growth Factor; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A; D040281:Vascular Endothelial Growth Factor Receptor-1; D042442:Vascular Endothelial Growth Factors
D017931:DNA Primers; D016228:Endothelial Growth Factors; D008222:Lymphokines; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D017978:Receptors, Growth Factor; 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; D040281:Vascular Endothelial Growth Factor Receptor-1