[Inhibitory effect of insulin-like growth factor binding protein-related protein 1 on retinal angiogenesis via ERK signaling pathway].
Objective:To explore the inhibitory effect of insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1), a novel anti-angiogenic factor, on retinal angiogenesis and its underlying molecular mechanisms.Methods:Experimental study. C57BL/6J mice were classified into three groups: control group (n=24), oxygen-induced retinopathy (OIR) non-intervention group (n=24) and OIR intervention group (n=72). The OIR mouse model was established using improved Smith's methods (n=96). Twelve-day-old mice in the OIR intervention group were randomly assigned into three groups receiving intravitreal injection of recombinant mouse IGFBP-rP1 (50 μg/L, 100 μg/L and 200 μg/L, respectively). Five days later, the proliferative neovascular responses were estimated by quantifying the new vessel area relative to the total retinal area in flattening retinas stained by high molecular FITC-Dextran and counting the number of neovascular cell nuclei breaking through the internal limiting membrane (ILM) in cross-sections. Retinal phosphor-ERK1/2 (p-ERK1/2), ERK1/2 and vascular endothelial growth factor (VEGF) protein expression was assessed by Western blot.Results:In the fluorescence angiograms, irregular neovascularization and fluorescence leakage were observed in the OIR model. In the OIR non-intervention group, the expression of p-ERK1/2 and VEGF was significantly up-regulated in comparison with the control group (t=100.068,P=0.000.t=6.526,P=0.003). The area ratios of new retinal vessels and the number of neovascular cell nuclei in mice receiving intravitreal injection of recombinant mouse IGFBP-rP1 both decreased significantly (F=1920,P=0.000.F=852.387,P=0.000), following the down-regulation of retinal p-ERK1/2 protein expression (F=859.587,P=0.000) and VEGF protein expression (F=24.301,P=0.000) in a dose-dependent manner (P<0.05). There was no significant difference in ERK1/2 protein expression (P>0.05).Conclusions:IGFBP-rP1 inhibits retinal angiogenesis by blocking ERK signaling pathway and down-regulating VEGF expression. This highlights the potential importance of IGFBP-rP1 serving as a target of gene therapy for retinal neovascularization.(Chin J Ophthalmol, 2017, 53: 207-211).
Department of Ophthalmology, Shanghai General Hospital, Shanghai JiaoTong University; Shanghai Key Laboratory of Fundus Disease; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China.
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D000818:Animals; D003911:Dextrans; D004195:Disease Models, Animal; D015536:Down-Regulation; D005451:Fluorescein Angiography; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives; D018969:Insulin-Like Growth Factor Binding Proteins / Q000494:pharmacology*; D058449:Intravitreal Injections; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D009389:Neovascularization, Pathologic; D010100:Oxygen; D012160:Retina / Q000187:drug effects*; D012164:Retinal Diseases; D015861:Retinal Neovascularization; D012171:Retinal Vessels; D015398:Signal Transduction; D042461:Vascular Endothelial Growth Factor A
D003911:Dextrans; D018969:Insulin-Like Growth Factor Binding Proteins; D042461:Vascular Endothelial Growth Factor A; C015219:fluorescein isothiocyanate dextran; C102529:insulin-like growth factor binding protein-related protein 1; D016650:Fluorescein-5-isothiocyanate; D010100:Oxygen
Insulin-like growth factor binding proteins; MAP kinase signaling system; Retinal neovascularization; Vascular endothelial growth factor A