Objective To cultivate human retinal capillary endothelial cells (HRECs) and establish two-dimensional model of human retinal vessels in vitro. Methods In a fibronectincoated raising pound, HRECs were cultured by non-serum human-endothelial-cells substrate and two-dimensional model of human retinal vessels was established. Horseradish peroxidase was used to detect the permeability. Some of the vascular models were cultivated with 5 ng/ml vascular endothelial growth factor (VEGF), whose changes of permeability was compared with which of the models without cultivation with VEGF. The effect of VEGF on vascular permeability was observed. Results Meshy vascular structure came into being due to the confluent HRECs after 2 to 4 days. Comparatively complete two-dimensional vascular model after about 6 days. VEGF increased vascular permeability and promoted the formation of blood vessels. Conclusion HRECs can be cultivated successfully with human-endothelial-cells substrate; standard retinal two-dimensional vascular model in vitro can be established by using cellular raising pound and non-serum human-endothelial-cells substrate. (Chin J Ocul Fundus Dis, 2006, 22: 110-112)
Objective To investigate the effects of heparanase and vascular endothelial growth factor (VEGF) and their correlation in CoCl2 induced human retinal microvascular endothelial cells (HRECs) in an hypoxia model. Methods Human eyes were selected to establish CoCl2induced HRECs hypoxia model in this study. Four experimental groups were studied: normal control group, hypoxia group (CoCl2 100 μmol/L, 48 hours),PI-88 group (specific competitive inhibitor of heparanase: phosphomannopentaose sulfate, PI-88,5 μg/ml, combined with CoCl2 100 μmol/L, 48 hours) and PBS control group. Heparanase, VEGF and Pol Ⅱ expression in HRECs of normal and hypoxia group were analyzed with immunofluorescence. Western blot was used to evaluate the expression of heparanase and VEGF in HRECs of normal, hypoxia, PI88 and PBS control groups. ResultsImmunofluorescence studies showed that the expression of heparanase and VEGF in cytoplasm was intense in hypoxia HRECs, but faint in normal group. Heparanase was also observed in the nucleus of hypoxia HRECs. Western blot results showed that the expression of Hpa and VEGF protein was increased significantly in hypoxia group compared with normal group (Hpa：F=-4。005, P＜0.05；VEGF：F=-4.063, P＜0.05), and VEGF was decreased in HRECs treated with PI-88(F=5。963, P＜0.05). ConclusionsHeparanase is upregulated that resulted in increase of VEGF expression, therefore enhanced angiogenesis in CoCl2 induced hypoxia HRECs.
ObjectiveTo observe the effect of complement receptor 1 (CR1) on barrier of cultured human retinal epithelial cells (hRPE) under complement-activated oxidative stress. MethodsThe third to fifth passage of hRPE cultured on Transwell insert were used to establish a stable hRPE monolayer barrier. The hRPE monolayer barrier was exposed to 500 μmol/L ten-butyl hydroperoxide and 10% normal human serum to establish the hRPE monolayer barrier model of complement-activated oxidative stress in vitro. hRPE monolayer barriers under complement-activated oxidative stress were divided into two groups including model group and CR1 treatment (1 μg/ml) group. Model group and CR1 treatment group were treated with 1 μl phosphate buffer solution (PBS) or CR1 for 4 hours. Normal hRPE monolayer barrier were used as control in transepithelial resistance (TER) measurement experiment. TER was measured to evaluate the barrier function of hRPE. The hRPE-secreted vascular endothelial growth factor (VEGF) and chemokine (C-C Motif) Ligand 2 (CCL2), together with complement bioactive fragments (C3a, C5a) and membrane-attack complex (MAC) in the supernatant were detected by enzyme-linked immune sorbent assay. ResultsStable hRPE monolayer barrier was established 3 weeks after hRPE seeded on Transwell insert. Complement-activated oxidative stress resulted in a sharp decrease of TER to 54.51% compared with normal hRPE barrier. CR1 treatment could significantly improve TER of barrier under complement-activated oxidative stress to 63.48% compared with normal hRPE barrier(t=21.60, P < 0.05). Compared with model group, CR1 treatment could significantly decrease the concentration of VEGF and CCL2 by 11.48% and 23.47% secreted by hRPE under complement-activated oxidative stress (t=3.26, 2.43; P < 0.05). Compared with model group, CR1 treatment could also decreased the concentration of C3a, C5a and MAC by 24.00%, 27.87%, 22.44%.The difference were statistically significant (t=9.86, 2.63, 6.94; P < 0.05). ConclusionsCR1 could protect the barrier function of hRPE cells against complement-activated oxidative stress. The underlying mechanism may involve inhibiting complement activation and down-regulating the expression of VEGF and CCL2.