Regulation of blood vessel versus lymphatic vessel growth in the cornea.
OBJECTIVE
In the present study, the authors developed novel models to stimulate blood vessel formation (hemangiogenesis) versus lymphatic vessel formation (lymphangiogenesis) in the cornea.


METHODS
Micropellets loaded with high-dose (80 ng) or low-dose (12.5 ng) basic fibroblast growth factor (bFGF) were placed in BALB/c corneas. Angiogenic responses were analyzed by immunohistochemistry to quantify blood neovessels (BVs) and lymphatic neovessels (LVs) to 3 weeks after implantation. Areas covered by BV and LV were calculated and expressed as a percentage of the total corneal area (percentage BV and percentage LV). Hemangiogenesis (HA) and lymphangiogenesis (LA) were also assessed after antibody blockade of VEGFR-2 or VEGFR-3


RESULTS
Although high-dose bFGF stimulation induced a more potent angiogenic response, the relative LV (RLV=percentage LV/percentage BV x 100) was nearly identical with high- and low-doses of bFGF. Delayed LA responses induced 3 weeks after implantation of high-dose bFGF resulted in a lymphatic vessel-dominant phenotype. Interestingly, the blockade of VEGFR-2 significantly suppressed BV and LV. However, the blockade of VEGFR-3 inhibited only LV (P=0.0002) without concurrent inhibition of BV (P=0.79), thereby resulting in a blood vessel-dominant phenotype


CONCLUSIONS
An HA-dominant corneal phenotype can be obtained in BALB/c mice 2 weeks after implantation of an 80-ng bFGF micropellet with VEGFR-3 blockade. Alternatively, an LA-dominant corneal phenotype can be obtained 3 weeks after implantation of an 80-ng bFGF micropellet without supplementary modulating agents. These models will be useful in evaluating the differential contribution of BV and LV to a variety of corneal abnormalities, including transplant rejection, wound healing and microbial keratitis.
Chung
Eui-Sang
ES
Schepens Eye Research Institute, Boston, Massachusetts 02114, USA.
Saban
Daniel R
DR
Chauhan
Sunil K
SK
Dana
Reza
R
D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology; D001808:Blood Vessels / Q000502:physiology*; D003315:Cornea / Q000098:blood supply; D016510:Corneal Neovascularization / Q000378:metabolism* / Q000473:pathology; D003319:Corneal Stroma / Q000187:drug effects; D004195:Disease Models, Animal; D004343:Drug Implants; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage; D019084:Fluorescent Antibody Technique, Indirect; D042583:Lymphangiogenesis / Q000502:physiology*; D042601:Lymphatic Vessels / Q000502:physiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D020133:Reverse Transcriptase Polymerase Chain Reaction; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000037:antagonists & inhibitors; D040321:Vascular Endothelial Growth Factor Receptor-3 / Q000037:antagonists & inhibitors
D019138:Antibodies, Blocking; D004343:Drug Implants; D016222:Fibroblast Growth Factor 2; D040301:Vascular Endothelial Growth Factor Receptor-2; D040321:Vascular Endothelial Growth Factor Receptor-3