The Study Of Cordycepin Inhibition Diabetic Retinal Angiogenesis And VEGF Protein Expression

Purpose: To investigate the inhibition effete of cordycepin on the the angiogenesis and the expression of VEGF,VEGFR2 in high glucose-treated rhesus macaque choroid-retinal endothelial(RF/6A) cell and diabetic retinopathy(DR) rat and further to study the possible mechanism,in order to Provide experimental basis for cordycepin used in clinic to Preventing and curing DR.Methods: RF/6A cells cultured in high glucose conditions were treated with 0,10,50 and 100 ug/ml of cordycepin respectively. The CCK8, Transwell migration assay and Matrigel angiogenesis assay were used to detect cell proliferation,migration and tube formation influenced by cordycepin in RF/6A cells respectively.Western blot were used to measure the expressions of VEGF,VEGFR2; Sprague Dawley rats were randomly divided into three groups:normal control group(NC),diabetic retinopathy group(DR) and diabetes treated with cordycepin group(DR+C).Besides the normal group, the rats of other groups were induced by strptozotocin(STZ) once intraperitoeal injection,60mg/kg. After the models successfully established for16 weeks,the rats of cordycepin group were given the cordycepin by intraperitoneal injection of 20mg/kg perday lasting 4 weeks, the normal group and the model group were given corresponding quantity’s physiological saline by intraperitoneal injection. The morphologica and pathological changes of retina were investigated through HE staining, retinal stretched preparation with Evans blue(EB) and retinal EB contant caculation.In additon,VEGF and VEGFR2 protein expression in retina were caculated through Western-blot.RESULTS: cordycepin could inhibit proliferation,migration, tube formation and decrease VEGF,VEGFR2 protein expression of RF/6A in high glucose conditions. HE staining and the retinal stretched preparation with EB of CN group showed that morphologica and pathological changes of retina was normal.Compared with the NCgroup, retinal nerve fiber and nerve cell layer of DR group arranged in haphazard and loosly,and cavity structure is obvious, The retinal vascular became highly irregular and had a lot of leakage of fluoresced. The retinal morphologica and pathological damage of retina in DR+C group were slighter than that in DR group.Retinal EB contant of DR group was significantly more than NC and DR+C group(P<0.05),.In addition,the relative expressionl evels of VEGF and VEGFR2 protein were significantly elevated in DR group compared with the DR+C group group and the NC group(P<0.05).Conclusion: Cordycepin can inhibits the increased protein levels of VEGFand VEGFR2 in RF/6A cells cultured in high glucose and the retinas of diabetic to prevent the formation of neovascularization, which slowing the progress of diabetic retinopathy development.