Purpose To study changes of cell cycle of vascular endothelial cell in non-proliferative diabetic retinopathy. Methods Alloxan induced Wistar-rats were employed and immunohistochemistry,Western blotting methods were used. Results The vascular endothelial cells of retinas of 8～20 weeks diabetic rats were observe to be cyclinD1,cyclinD3,cyclinB1,p21 and p27 positive stained with light and electronmicroscopies.CyclinE immuno-stained vascular endothelial cells was observed occasionally.Meanwhile,the evidences of morphologic changes of the vascular en dothelial cells were proved:less plasma,thinner cell,more bubble organelles than those of controls.But,the ultra-structures of pericytes and other type of retinal cells did not change and they also immunostain negative.Komas blue and Western blotting methods also proved that the vascular endothelial cells of retina of 20th week diabetic rats expressed cyclinD1,cyclinB1,p21 and p27 protein. Conclusion Glucose induced retinal vascular endothelial cells of 8～20th weeks diabetic rats enter cell cycle and were arrested at G1/S restriction point.This study also suggested that retinal vascular endothelial cells may possess the ability to resist glucose damage and mechanism of selfstability during very early stage of diabetes. (Chin J Ocul Fundus Dis,2000,16:173-176)
ObjectiveTo observe the expression of Caspase-3, Caspase-8, Bcl-2, Bax in the rat retina of ocular ischemic syndrome (OIS). Methods30 Brown Norway rats were randomly divided into experimental group and control group, 15 rats in each group. The rats in experimental group were established a model through ligating the bilateral common carotid artery. At 3 months after modeling, the retinal thickness and ganglion cell (RGC) density were measured by hematoxylin eosin staining; the expression of Caspase 3, Caspase 8, Bax and Bcl-2 in the retina was measured by quantitative real-time reverse transcription polymerase chain reaction. ResultsThe RGC density in control group and experimental group was 61.97±9.07 and 38.1±5.98, respectively. Compared to the control group, the RGC density was diminished in the experimental group (t=3.059, P < 0.01). A significant decrease was found in the total retina (t=3.036), inner plexiform (t=3.715), inner nuclear (t=3.339) and outer plexiform (t=3.341) thickness (P < 0.05). However, no change of the thickness was evident in the outer nuclear layers (t=2.000, P > 0.05). The levels of protein and RNA expression of Caspase 3, Caspase 8 and Bax in the retina were increased in experimental group (F=17.036, 7.787, 11.431, 11.162, 17.763, 12.183; P < 0.05), while the Bcl-2 expression were decreased (F=10.298, 12.047; P < 0.05). ConclusionsThere is obvious expression of apoptosis-associated proteins in the rat retina of OIS. Caspase 3, Caspase 8 and Bax expression are increased, while Bcl-2 expression are decreased.
Objective To observe whether theograde axial flow of retinal ganglion cells (RGC) in diabetic rats at the early stage was damaged. Methods Diabetic model was induced by streptozotocin in 6 adult male Sprague-Dawley (SD)rats. Fluorogold (FG) was injected to the superior colliculi 4 weeks later.Streched preparation of retina was made 12 and 72 hours after the injection, and was stained after photographed by fluorescent microscope. The proportion of RGC with different sizes labeled by FG was calculated. Other 6 normal adult male SD rats were in the control group. Results Twelve hours after injection with FG, there was no difference of the total number of RGC in experimental and control group, but the ratio of small RGC was lower in experimental group than that in the control group; 72 hours after injection with FG, The number of RGC, especially the small RGC, decreased obviously in experimental group compared with the control group. Conclusion The speed of the retrograde axial flow of RGC in diabetic rats at the early stage is affected, and the small RGC are damageable. (Chin J Ocul Fundus Dis, 2006, 22: 4-6)
ObjectiveTo predict as well as bioinformatically analyze the target genes of has-miR-451. MethodsmiRBase, miRanda, TargetScan and PicTar were used to predict the target genes of hsa-miRNA-451. The functions of the target genes were demonstrated by Gene Ontology and pathway enrichment analysis. P < 0.05 was set as statistically significant. Results18 target spots of hsa-miRNA-451 were predicted by 3 databases or prediction software at least. The functions of the target genes were enriched in proliferation and development of epithelial cells and regulation of kinase activity (P < 0.05). Pathway analysis showed that transforming growth factor-beta signaling pathway, mitogen-activated protein kinase signaling pathway, epidermal growth factor signaling pathway, Wnt signaling pathway and mammalian target of rapamycin signaling pathway were significantly enriched (P < 0.05). Conclusionhsa-miRNA-451 might be involved in various signaling pathways related to proliferation and development of epithelial cells.
Dome-shaped macula (DSM) of high myopia has been described as an inward convexity or bulge of the macular within the concavity of the posterior staphyloma in highly myopic eyes, with the bulge height over than 50 μm, which can be observed by optical coherence tomography. There are three patterns of DSM, including the typical round dome, the horizontally oriented oval-shaped dome and the vertically oriented oval-shaped dome. The pathogenesis of DSM development remains unclear, several hypotheses have been suggested, such as localized choroidal thickening in the macular area, relatively localized thickness variation of the sclera under the macula, resistance to deformation of sclera staphyloma, ocular hypotony and tangential vitreoretinal traction. Vision-threatening macular complications of DSM including serous retinal detachment, choroidal neovascularization, foveoschisis and retinal pigment epithelial atrophy. Clinically, asymptomatic patients with DSM mainly take regular follow-up observation. Appears serous retinal detachment and significant visual impairment, treatment with half-dose photodynamic therapy, supplementary of laser photocoagulation or oral spironolactone may have a beneficial effect. However, more large clinical studies are required to confirm the exact efficacy of these treatments.
Objective To observe apoptotic and proliferative characteristics of the retinal vascular end othelial cells (RVECs) of the 1～16 weeks diabetic rats and p53 and bcl-2 expressions of the rats,in order to probe the pathogenic mechanism of diabetic retinopathy(DR). Methods Models of diabetic Wistar rats were made by alloxan venous injection.The retinal blood vessels were filled by ink,the wholemounts and paraffin-embedded sections of the retinas were made,TUNEL staining and Immunohistochemical ABC staining were used,and light microscopy was taken,in succession. Results Apoptosis of the RVECs was not found.Compared with control group,the morphologic features of the RVECs and the structure of the retinal blood vessels remained unchanged.In the period from the 10th to the 16th week,the immunohistochemical stain of PCNA,BrdU,p53,and bcl-2 for RVECs revealed positive results,but there was no any sign of the RVECs stacking and proliferating or new blood vessels forming in the retinas.In control group,the reaction of immunological stain of the aforementioned parameters was negative. Conclusions No accelerated apoptosis and proliferation of the RVECs in the 1～16 week diabetic rats happen after alloxan injection.Almost all of the RVECs were stimulated to enter the cell cycle in the 10th week.Expression of p53 and bcl-2 might play an important role in stabilizing the RVECs in early stage of diabetes. (Chin J Ocul Fundus Dis, 1999, 15: 157-159)
OBJECTIVE: To investigate the changes of regeneration and conduction function for peripheral nerve after neurolysis by nerve special staining and electrophysiology. METHODS: Sixty Sprague-Dawley male rats were randomly divided into four groups(n = 15), four methods were designed on rats models of sciatic nerve compression. There were simple decompression as group A, internal neurolysis after decompression as group B, lemithason(0.5 mg/kg) injected in the epineurium after decompression as group C, and lemithason(0.5 mg/kg) injected around the epineurium after decompression and internal neurolysis as group D. Motor nerve conduction velocity(MNCV) and motor latency (Lan) were monitored at 1,2,3,4,5 weeks after decompression, sections were regularly taken from the previously compressed area to perform morphometric analysis. RESULTS: After 2 weeks of decompression, the significant recovery were observed in both MNCV and Lan of four groups. Up to the 5th week of decompression, recovery of electrophysiology was significantly faster in group C and D than that of group A and B, particular in group C(P lt; 0.05), while group A compared with group B, there was no statistical difference in both MNCV and Lan(P gt; 0.05). Morphometric analysis showed that a lot of neural regeneration fibers were observed in group C and D after 3 weeks of decompression. CONCLUSION: Decompression can improve nerve conduction function significantly, while injection of lemithason in epineurium after decompression can promote the structure and function recovery of injured nerve.