Research expression of Slit3 and Robo4 in corneal neovascularization of rats / 国际眼科杂志(Guoji Yanke Zazhi)

AlM: To explore the roles of neuronal axon-guidance molecules Slit3 and Robo4 receptor in corneal neovascularization ( CNV ) by study their expression in neovascularized cornea of rats. METHODS: CNV models were established by implantation pellets containing basic fibroblast growth factor ( bFGF ) into corneal stroma. CNV models were measured by biomicroscopy photography. lmmunohistochemical staining and imaging analysis system were used to detect the expression of Slit3 and Robo4 in the models after 1, 4, 7, 10 and 14d. RESULTS:The area of CNV and the expression of Slit3, Robo4 were increased in CNV models compared to that in normal cornea and reached highest level on 7d. And the expression level of Slit3 and Robo4 were significantly correlated with the size of CNV on every time point except 1d (r=0. 84-0. 91, all P CONCLUSlON: The expression of Slit3 and Robo4 may be related to the CNV development. They are potential therapeutical target for CNV.

Angiogenesis induced by micropocket assay on rat cornea / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To explore the skills and characteristics of corneal neovascular model in rat induced by micropocket assay. ·METHODS: Nine eyes of nine Sprague-Dawley rats were studied. Pellets made of vascular endothelial growth factor (VEGF), poly-2-hydroxylethylmethacrylate and sucralfate were implanted into the corneal stroma nocloser than 1mm from the limbus. Biomicroscopic features of corneal neovascular were observed on 1,3, 5, 7th day after the implantation. ·RESULTS: On day 1 after operation, the limbal vessels were dilated, with no angiogenesis appeared. On day 3, angiogenesis began to invade peri-cornea with a brush shape, the area of CNV was (2.23±0.59) mm2. On day 5, new vessels reached the lower margin of pellet densely, the area of CNVwas (6.81±1.35)mm2. On day 7, new vessels continued to elongate, parts of them extended as loops toward the pellet, the area of CNV was (8.92± 1.79)mm2. Neither hyphema or other complications occurred.·CONCLUSION: Corneal neovascular induced by micropocket assay in rat grows steadily, with no complication, and is suitable for quantitative researches.

Angiogenesis effects of nerve growth factor (NGF) on rat corneas

This study was performed to evaluate the effects of nerve growth factor (NGF) upon angiogenesis in the rat cornea, to examine its possible application as an alternative angiogenic inducer and to provide basic data for further studies. Angiogenesis was induced by cornea micropocket assay, as previously described. Eight of thirty two eyes of Sprague-Dawley rats were randomly assigned to one of four groups, namely, a non-NGF group (Group 0), a 0.5 ng of NGF group (Group 0.5), a 1.0 ng of NGF group (Group 1.0) and a 5.0 ng of NGF group (Group 5.0). Pellets made of poly-2-hydroxylethylmethacrylate and sucralfate were implanted into the corneal stroma no closer than 1 mm from the limbus. After the implantation, the number of new vessels, vessel length and circumferential neovascularization were examined daily under the surgical microscope over a period of 7 days. The area of neovascularization was determined using a mathematical formula. Although new vessels in Group 0 and Group 0.5 were first observed at day 5, those of Groups 1.0 and 5.0 were first noted on days 4 and 3, respectively. However, the growth rates of new vessels in Groups 1.0 and 5.0 were higher than those of Groups 0 and 0.5 with the passage of time. The number, length, circumferential neovascularization and areas covered by the vessels in Groups 1.0 and 5.0 were significantly more than in Group 0 and Group 0.5 (p<0.05). This study showed that NGF had a dose-dependent angiogenic effects on the rat cornea and that the minimal effective dose of NGF was 1.0 ng per cornea. Also, it showed that NGF would be useful in angiogenic studies as an alternative angiogenic inducer.

Inhibitory Effect of Antibody to alphavbeta5 in Corneal Angiogenesis

PURPOSE: This study investigated the importance of alphavbeta5 function during vascular endothelial growth factor (VEGF) induced corneal angiogenesis by examining the effects of antibody to alphavbeta5 that blocks alphav 5-mediated cell adhesion to vitronectin. METHODS: A hydrogel disk containing 500 ng of VEGF was implanted into the superior corneal stroma of each of sixteen New Zealand white rabbit eyes. Each eye also received a second hydrogel disk placed adjacent to the first, randomized to contain either 40 g of antibody to alphavbeta5 (n=8) or phosphate-buffered saline (PBS)(n=8). Both disks were positioned 1.2 mm apart from the superior limbus. Eyes were examined daily under a stereomicroscope by two observers and assigned an angiogenesis score based on number and length of new blood vessels. RESULTS: On days 3 through 7 postimplantation, angiogenesis scores were significantly lower in eyes treated with antibody to alphavbeta5 (averaged score=16.33) as compared to eyes treated with PBS (averaged score=26.52)(P<0.05, Wilcoxon signed rank test). CONCLUSIONS: In a rabbit corneal micropocket assay, antibody to alphavbeta5 inhibits corneal angiogenesis induced by VEGF. Substances that target the integrin alphavbeta5 subunit may have therapeutic potential in disorders characterized by ocular neovascularization.