Inhibitory Effects On Retinal Neovascularization by Ranibizumab and sTie2-Fc in An Oxygen-Induced Retinopathy Mouse Model

ABSTRACTPurpose: To study retinal neovascularization (RNV) inhibition by intravitreal injections (IVs) of ranibizumab, sTie2 fusion protein (sTie2-Fc), and a combined therapy in an oxygen-induced retinopathy (OIR) model.Materials and methods: An OIR mouse model was used to simulate RNV in retinopathy of prematurity (ROP); and the effect of blocking the angiopoietin (Ang) and its receptor (Tie2) and the vascular endothelial growth factor (VEGF) and its receptor (VEGFR) signaling pathways was compared using an IV of sTie2-Fc (Ang inhibitor) and/or ranibizumab (aVEGF antagonist). The effects were assessed using fluorescein isothiocyanate (FITC)-dextran cardiac perfusion, isolectin B4 (IB4) staining with whole retinal mounting, and hematoxylin and eosin (HE) staining to count the endothelial cells (ECs) that broke through the internal limiting membrane (ILM). The mRNA and protein levels of VEGF-A, VEGFR-2, Ang1, Ang2, and Tie2 were also determined by reverse transcriptase polymerase chain reaction (RT-PCR) an...