Objective To construct specifically expressed vascular endothelial growth factor (VEGF)165 gene in retina. Methods Rho promoter, specifically expressed in retina, was amplified by polymerase chain reaction (PCR) from the genomic DNA of a BLAB/C rat, then it was cut with restriction enzymes and cloned into the plasmid pcDNA3.1+-VEGF165 to form recombinant plasmid pcDNA3.1+-rho-VEGF165. The correct recombinant plasmid pcDNA3.1+-rho-VEGF165 was identified by restriction enzymes and PCR, and was transferred by jetPEI into cultured human navel vein endothelial cells and human retinal pigment epithelial (RPE) cells. The expression of VEGF protein in human navel vein endothelial and RPE cells was detected by immunocytochemical staining and protraction of the growth curve of the cells. Results In human RPE cells, the expression of VEGF protein was more in recombinant plasmidpcDNA3.1+-rho-VEGF165 than that in plasmidpcDNA3.1+-rho-VEGF165 ; in human navel vein endothelial cells, no obvious difference of the expression of VEGF protein between recombinant plasmid pcDNA3.1+-rho-VEGF165 and plasmid pcDNA3.1+-rho-VEGF165 was found. Conclusions The construction of pcDNA3.1+-rho-VEGF165 carrier may provide the basic material for the study of the nosogenesis of VEGF in retinal neovascularization, and establish the foundation to set up the model of transgenic mice with VEGF specific expressing in retina. (Chin J Ocul Fundus Dis, 2005,21:106-108)
Objective To investigate the protective effect of blocking the signal path of p38 mitogen activated protein kinase on blood retinal barrier (BRB) and retinal ganglion cells (RGC) in early diabetic rats.Methods A total of 60 Wistar rats were divided into the control and diabetes group, with 30 rats in each group. Diabetes was induced in rats in diabetes group by peritoneal injection of streptozotocin (STZ);the plasma glucose level of ＞16.7 mmol/L indicated that the diabetes model was set up successfully.The rats in the control group underwent peritoneal injection of equivalent sodium citrate solution. IgG leakage method was used to measure the damage of BRB function and vascular leakage. The expression and localization of caspase-3 and vascular endothelial growth factor (VEGF) in retina of diabetic rats were examined by immunohistochemistry analyses.Two weeks after the establishment of the diabtes model, the rats in diabtes group underwent intravitreal injection with SB203580, a p38 inhibitor;six weeks after the injection, the expression of caspase-3 and VEGF was detected, and the number of apoptosis RGC was counted via immunofluorescence technique.Results In the contral group, IgG staining located in the blood vessels with little leakage; while the IgG leakage was much more obvious in the diabetes group eight weeks after the establishment of the model. Six weeks after intravitreal injection with SB203580, the leakage decreased in diabtes rats. The results of semiquantitative analysis and fluorescence immunohistochemistry showed that compared with the results in diabetes rats 8 weeks after intravitreal injection (2.9 times much more than that in the control group), the fluorescence expression of VEGF decreased in diabetes rats six weeks after intravitreal injection (1.8 times much more than that in the control group).The apoptisis RGC number in rats 6 weeks after intravitreal injection of SB203580 was much less than that in rats without intravitreal injection (t＝5.731, Plt;0.01). Conclusions SB203580 can alleviate the disruption of BRB and apoptosis of RGC in early diabetes rats, which suggests that p38 MAPK pathways appear to be directly involved in the pathogenesis of early diabetic retinopathy.