Objective To observe the effects of Crumbs (Crb) proteins on different types of zebrafish photoreceptors. Methods The retinal cell population dynamics of adult wild-type zebrafish and Tg (RH2-2:Crb2b-sf-EX/RH2-2:GFP)pt108b transgenic zebrafish (called pt108b zebrafish for short) were evaluated by monitoring the densities of three categories of retinal photoreceptors (rod cells, UV cone cells and RGB cone cells) in different retinal regions, which were visualized by Feulgen nuclear staining histology technique. Results The wild-type zebrafish retinal photoreceptor cell densities are generally higher in the central region than the peripheral regions. Compared with wild-type zebrafish, pt108b zebrafish had much less RGB cone cells at the top of outer nuclear layer, and no RGB cone cells at the central and intermediate regions of retina. While pt108b zebrafish had normal density of UV cone cells at the top of rods and the bottom of outer limiting membrane, they had much higher density of rods. Conclusions Crb proteins may affect the zebrafish retinal cell densities of different photoreceptor types.
Objective To observe the effect of celecoxib on the expression vascular endothelial growth factors (VEGF) in diabetic rats. Methods Thirty-six wistar rats were used to establish the diabetic models by intraperitoneal injection with streptozotocin. The diabetic rats were divided into 2 groups: diabetic group (n=18) and celecoxib group (n=18). Celecoxib (50 mg/kg) was administered orally to the rats in celecoxib group and the physiological saline with the same volume was given orally to the rats in diabetic group. Eighteen else rats were in normal control group. All of the rats were executed 3 months later. The expression of VEGF protein was detected by immunohistochemistry method. Reverse transcription-polymerase chain reaction（RT-PCR） analysis was used to examine the expression of retinal VEGF mRNA and cyclooxygenase-2 mRNA. Results Lower positive expression of VEGF mRNA and cyclooxygenase-2 mRNA, weakly positive action of immunohistochemistry of VEGF, and lower expression of VEGF protein were detected in normal control group; in the diabetic group, the expression of VEGF mRNA and cyclooxygenase-2 mRNA increased obviously comparing with which in the control group (Plt;0.05), and the bly positive action of immunohistochemistry of VEGF and increased expression of VEGF protein were detected (Plt;0.01); in celecoxib group, the expression of VEGF mRNA was lower than that in the diabetic group (Plt;0.05), the expression of cyclooxygenase-2 mRNA didnprime;t decrease much (Pgt;0.05), the positive action of immunohistochemistry of VEGF decreased, and the expression of VEGF protein decreased (Plt;0.01). Conclusion By inhibiting the activation of cyclooxygenase-2, celecoxib can inhibit the expression of retinal VEGF mRNA and protein in diabetic rats induced by streptozotocin. (Chin J Ocul Fundus Dis,2007,23:265-268)
Objective To observe the effects of stromal cellderived factor 1alpha; (SDF-1alpha;) in secondary neovascular glaucoma (NVG) of proliferative diabetic retinopathy (PDR). Methods The vitreous specimens from 25 PDR patients (31 eyes) were collected with 13 NVG eyes and non-NVG 18 eyes. The concentrations of SDF-1alpha; and vascular endothelial growth factor (VEGF) in those specimens were measured by enzyme-linked immunosorbent assay （ELISA）. Human umbilical vein endothelial cells (HUVEC) were treated by different concentrations of SDF-1alpha;and vascular endothelial growth factor (VEGF) in vitro, and the formation of tube cavity-like structure, length of capillarylike structures and 5prime;-bromo-2prime;-deoxyuridine (BrdU) labeling of treated HUVEC were measured. Results The length of HUVEC tube-like and capillarylike structure formation in 10, 100, 1000 ng/ml SDF-1alpha; and 10 ng/ml VEGF groups were longer than that in the control group, the differences were statistically significant (P＜0.01). The A value of BrdU labeling of 10, 100, 1000 ng/ml SDF-1alpha; and 10 ng/ml VEGF groups were increased than that in the control group, the differences were statistically significant (P＜0.01). The vitreous levels of SDF-1alpha; and VEGF of NVG specimens were higher than those in the non-NVG group, the differences were statistically significant (P＜0.01). Conclusions SDF-1alpha; may promote the migration and proliferation of vascular endothelium cells, and participate in the neovascularization process in NVG patients with PDR.