Suppression of choroidal neovascularization by Endostar in rats

Choroidal neovascularization (CNV) is common in various retinal and choroidal diseases, and may result in severe and irreversible loss of vision. Our previous studies suggested that Endostar, a novel recombinant endostatin, is able to inhibit the proliferation and migration of choroid-retinal endothelial cells. To further evaluate the effect of Endostar on the formation of CNV in vivo, a rat model of laser-induced CNV was constructed and Endostar or phosphate-buffered saline treatment was administered intravitreally every other day. Using fluorescein angiography (FA), reduced CNV incidence and leakage grade was observed in the Endostar group. In addition, CNV area and maximal thickness were prominently reduced in the Endostar group measured by choroid flat mounts and sections. Furthermore, vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1α and chemokine C-X-C motif ligand 1 were markedly reduced in the Endostar group as determined by quantitative polymerase chain reaction and downregulation of VEGF was also verified by western blot analysis at the protein level. This study demonstrates that Endostar suppressed CNV in a rat model, which may be largely mediated by the downregulation of VEGF and other angiogenic molecules.