ABSTRACT
Background Antagonists against vascular endothelial growth factor (VECF) play key roles in treating and preventing neovascular ophthalmopathy. As a novel anti-angiogenic factor, insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) might be an antagonist against VEGF in eye. Objective This study was to explore the inhibitory effect of IGFBP-rP1, a novel anti-angiogenic factor, on VEGF-induced retinal angiogenesis in vitro. Methods The retina-choroid endothelial cell line ( RF/6A ) was cultured in DMEM containing 10% fetal bovine serum. Culture cells were divided into control group(free-serum culture group) ,10mg/L VEGF culture group and different concentrations of IGFBP-rP1 (50,100,200 mg/L) +10 mg/L VEGF group. The expression of IGFBP-rP1 in the cells was detected by immunofluorescence assay. The proliferation and migration of RF/6A cells were evaluated using MTS colorimetric assay and the chemotactic motility assay, respectively. Flow cytometry was used to detect the apoptosis of RF/6A cells. Results The immunofluorescence assay RF/6A cells showed the green fluorescence in cytoplasm and red fluorescence in nuclei after cells were exposed to any concentration of IGFBP-rP1 ,but only red fluorescence was seen in nuclei in control cells. After stimulation of 10 mg/L VEGF,the proliferation value (A490) was elevated and the numbers of cell migration were increased in comparison with control group (t = -15. 191, P = 0. 000; t = -21. 274, P = 0. 000 ) , but the cellular apoptosis rate was lower than the control group (t - 10. 228, P = 0. 000 ) . After treated with various concentrations of IGFBP-rP +10% VEGF, the proliferation and migration of RF/6A cells were significantly decreased in comparison with only 10% VEGF group (F = 534. 158,P = 0. 000;F = 2742. 323,P = 0.000,respectively) ,and the inhibitory effects were gradually enhanced with the increase of IGFBP-rP1 levels (P<0. 05). The apoptosis rate of RF/6A cells in 50,100 and 200 mg/L + 10 mg/L VEGF groups increased by ( 1. 26±0. 04)% ,( 1. 50±0. 07)% and ( 1. 93±0. 27)% respectively,showing significant differences among different groups ( F = 274. 273, P = 0. 000). Conclusion IGFBP-rP1 inhibits the proliferation and activity of retina and choroid endothelial cells induced by VEGF at a concentration-independent manner. It appears to be as a novel endogenous inhibitory factor in retinal angiogenesis.
ABSTRACT
Objective To investigate the efficacy of recombinant human erythropoietin(rhEPO)in preventing and reversing dys- function of retinal neurons in streptozotocin(STZ)-induced diabetes in rats.Design Experimental study.Participants The early stage of diabetic rats.Method Two weeks after STZ(60 mg/kg,i.p.),diabetic rats were administered rhEPO(5000IU/kg)injection three times weekly for 2 weeks.Retinal samples of STZ-induced diabetic rats with or without rhEPO and controls were prepared for ultrathin sec- tions and subsequently photography by transmission electron microscope.Also the content of glutamate in retina of the rats was detected with high-performance liquid chromatography.Main Outcome Measures The ultrastructure of rat retinas and the content of retinal glutamate.Results Mitochondrial metamorphosis in ganglion cells occurred in STZ-induced diabetic rats without rhEPO.Obvious mito- chondrial metamorphosis couldn′t be found in STZ-induced diabetic rats with rhEPO treatment.Retinal glutamate at the end of the 4th week of STZ-induced diabetic rats had increased obviously comparing with the normal rats(P