Silencing of Rac1 expression via RNA interference inhibits retinal neovascularization in rats

PURPOSE: To investigate the inhibitory effect of Ras-related C3 botulinum toxin substrate 1-small interfering RNA (Rac1-siRNA) on retinal neovascularization in a rat model. METHODS: Rac1-short hairpin RNA (shRNA) was synthesized, constructed, and transfected into HeLa cells. Reverse transcription polymerase chain reaction was then conducted to test for Rac1 gene expression. Retinal vein obstruction was performed in 25 Sprague-Dawley rats using the retinal photodynamic method. The vitrea bulbus of the eye in the shRNA rats group was transfected with the Rac1-shRNA vector, the other eye in the blank control group was transfected with the blank vector, and the interference control group was prepared by transfecting the Rac1-shRNA vector. Two weeks after transfection, the neonatal vessels were tested using fluorescein isothiocyanate–dextran retinal angiography. The number of endothelial cells beyond the internal limiting membrane was counted with hematoxylin and eosin staining. RESULTS: A large area of neovascularization and fluorescein isothiocyanate leakage was found in the positive control group. However, a small area of neovascularization and a little fluorescence leakage were found in the shRNA group, whereas the retinal vessels were normal in the negative control interference group. In the shRNA interference group, the mean number of endothelial cells beyond the internal limiting membrane was significantly higher than that in the positive control group or the interference negative control group (p<0.05). CONCLUSIONS: Silencing Rac1 expression with RNA interference inhibits retinal neovascularization in rats.