ObjectiveTo analyze the regulative rule of mRNA of vascular endothelial growth factor (VEGF) in mice with oxygen-induced retinopathy, and to elucidate the possible mechanism of occurrence of neovascularization in retinopathy of prematurity (ROP).MethodsSixty 7-day-old C57BL/6J mice were divided into oxygen-induced retinopathy group and control group. In oxygen-induced retinopathy group, 36 mice were exposed to 75% oxygen for 5 days and then to room air for 5 days; in control group, 24 mice were raised in room air. Vascular perfusion of fluorescein and retinal stretched preparation were used to observe the morphologic changes of retinal vessels. Reversal transcriptionpolymerase chain reaction (RT-PCR) was used to observe changes of VEGF mRNA in each group. ResultsIn oxygen-induced retinopathy group, the morphologic characteristics of retinal vessels were the unperfused area at the center of superficial and deepseated vessels, and the neovascularization appeared at mid-peripheral retina after 2 days in relative hypoxia condition. The results of RT-PCR showed space-time corresponding relation between expression of VEGF and neovascularization, which meant that the transcription of VEGF mRNA decreased in hyperxia conditionand increased in relative hypoxia condition. ConclusionHypoxia is the main reason of occurrence of retinal neovascularization; increased expression of VEGF caused by relative hypoxia after hyperxia might be effective in reducing the occurrence of neovascularization in ROP.(Chin J Ocul Fundus Dis, 2005,21:292-295)
Objective To investigate the expression of T cell receptor (TCR) Vβ8.3 gene on CD4+ T lymphocytes in the rats with experimental autoimmune uveoretinitis (EAU). Methods Eighteen Lewis rats were divided into EAU, complete Freund′s adjuvant, and the control group. Inter photoreceptor retinoid-binding protein (IRBP) R16 peptide was synthesized using Fmoc procedure for induction of EAU. Magnetic absorption cell sorting (MACS) me thod was used to isolate the CD4+T lymphocytes from the spleen of the rats. Flow cytometry was used to monitor the efficiency of isolation. The expression of TCR Vβ8.3 gene segment on CD4+T lymphocytes was determined by fluorescent quantitative polymerase chain reaction. Results EAU was successfully induced in the Lewis rats immunized with IRBP R16 peptide. The proportion of CD4+T lymphocytes isolated by means of MACS was statistically higher than that before isolation (P＜0.001). The expression of TCR Vβ8.3 gene segment on CD4+ T lymphocytes in EAU rats was significantly higher than that in the control (P＜0.05). Conclusions There is a predominant usage of antigen-specific TCR Vβ 8.3 gene in EAU rats induced by IR BP R16 peptide, which may serve as a target for immunotherapy of EAU. (Chin J Ocul Fundus Dis，2004，20：165-167)
Purpose To determine the effect of exogenous interleukin-1alpha; (IL-1alpha;) on the retina and its vasculature and VEGF expression in SD rats． Methods IL-1alpha;2．0 ng (20 mu;l) were injected into the vitreous of 8 left eyes of 8 SD rats while steriled PBS were injected into 8 right contralateral eyes of the same rats as control． All eyes were assessed by direct ophthalmoscopy every day and enucleated on the 7 thpostoperative day． Histological examination (hemato xylineosin staining) and immunohistochemical staining with antibody against VEGF antigen were performed， and sections were observed and photographed under light microscopy． Results ①All 8 IL-1alpha; inject ed eyes developed epiretinal membranes and extraretinal neovascularization on the 3 rd postoperative days while none of the 8 control eyes exhibited any a bnormal retinal vascular changes and they were confirmed by HE staining;②Immuno staining identified VEGF express mainly in the inner layer of vessel walls， the epiretinal membranes， the neuroganglional layer and the photoreceptor layer of retina， while the control eyes showed only weak positive staining in the photo receptor layer． Conclusions IL-1alpha; is capable of inducing vitreo retinal neovascularization，and increasing the expression of VEGF in the retina and epiretinal membranes． (Chin J Ocul Fundus Dis, 2001,17:135-137)
Objective To investigate the effect of inducible nitric oxide synth ase (iNOS) or cyclooxygenase－2 (COX－2) on retinal neovascularization and its possible mechanism in oxygen－induced retinopathy （OIR） mouse model. Methods Retinal neovascularization was induced by oxygen with different concentration. The expression of iNOS, COX－2, matrix metalloproteinases 2 (MMP－2) and vascular end othelial growth factor (VEGF) in the retinae of experimental animals were analyzed by immunohistochemistry, realtime polymerase chain reaction and western blotting technologies. Results The inhibition of COX－2 or iNOS obviously attenuated retinal neovascularization and decreased the expression of VEGF and MMP－2. The iNOS inhibition decreased COX－2 expression, and vice versa. Conclusions COX－2 and iNOS may play a role in retinal neovascularization in OIR mouse model, which may act by regulating the expression of VEGF and MMP－2.
Purpose To investigate whether experimental autoimmune uveitis can be induced equally in different rats by urea soluble fraction of bovine melanin-associated antigen(USF-BMAA),and,if so,difference among them. Methods Lewis rats,F344 rats,Wistar rats were immunized with USF-BMAA emulsified with complete Freud is adijuvant and Bordelella pertussis to induce experimental autoimmune uveitis.The animal models were investigated clinically and histopathologically and compared with each other. Rusults Experimental autoimmune uveitis could be induced in Lewis rats,F344 rats and Wistar rats with US-BMAA.Clinical and histopathalogical examination showed that bilateral ocular inflammation developed after immunization 9-13 days.Although inflammation was mainly located in anterior uvea,a mild focal choroiditis was noted in those with severe anterior inflammation.No inflammation was observed in the retina and pineal gland.Experimental autoimmune uveieis induced with USF-BMAA was similar to experimental autoimmune anterior uveitis incited with BMAA presented by other authors.Inflammation induced with USF-BMAA in F344 rats and in Lewis rats was quite similar in the severity and course of the model.But the inflammation was less in Wistar rats compared with that in Lewis rats and F344 rats. Conclusion Experimental autoimmune anterior uveitis was successfully induced with USF-BMAA in Lewis rats,F344 rats and Wistar rats.The difference with regard to the severity among these aminals were propably attributed to their genetic bankground. (Chin J Ocul Fundus Dis,1998,14:149-152)
ObjectiveTo investigate the effect of nerve growth factor (NGF) on recuperate of optic nerve after contusion by clamping in adult rabbits. MethodsSixteen adult rabbits were randomly divided into NGF and the control group with 8 rabbits in each group. After the optic nerve of the right eyes was clamped，tissue engineering nerve containing 0.06 ml NGF（concentration: 5×10-4 g/L, NGF group） and 0.06 ml of PBS (control group) was immediately transplanted into the injured eyes respectively, and 0.02 ml NGF（concentration: 5×10-4 g/L, NGF group）and 0.02 ml of PBS (control group) were injected into the vitreous of right eyes respectively. Flash visual evoked potential (FVEP) test was performed on the eyes 1 day, 2 weeks and 8 weeks after the injury. The number of retinal ganglion cells (RGCs) and changes of optic nerves were observed by light microscopy and electron microscopy at the 8th week after contusion,and a computer-image-analysis system was used to count the optic nerve axons.ResultsThe ratio of amplitude of FVEP of the injured and healthy eyes was 0.765±0.150 in NGF group and 0.494±0.108 in the control at the 2th week after injury with a significant difference between the two groups (Plt;0.05); and was 0.581±0.138 and 0.409±0.119 respectively at the 8th week after contusion with statistical difference between the two groups (Plt;0.05). The results of light microscopy and electron microscopy showed that degeneration of RGCs and optic nerves in the NGF group was lighter than that in the control group 8 weeks after injury, while the amount of optic nerve axons was (10 955±608.7) axons/ mm2 in the NGF group and (7 898±608.8) axons/mm2 in the control with statistical difference between the two groups (Plt;0.05). ConclusionNGF may redound to the survival of RGCs and regeneration of the axons in some degree, which can promote the recuperation of optic nerve and visual function. (Chin J Ocul Fundus Dis, 2005,21:253-257)
Purpose To study an animal model of retinal sheets transplantation using excimer laser. Methods A layer of pure photoreceptors was got by the use of excimer laser.Then the photoreceptor layer was transplanted to the subretinal space of the adult RCS rats which were an animal model of inherited retinal degeneration.The globes were enucleated one month after transplantation.Sections were made for light microscopic examninations. Results A layer of pure and uniform photoreceptors can be got by the use of excimer laser.The transplanted photoreceptors survived well in the subretinal space. Conclusion Retinal sheets transplantation using excimer laser can provide us with well oriented retinal construction and more photoreceptors after transplantation. (Chin J Ocul Fundus Dis,1998,14:209-211)
Objective To investigate the relationship between expression of retinal intercellular adhesion molecule-1 (ICAM-1) and blood-retinal barrier (BRB) rupture and therapeutic effect of intravitreous injection with triamcinolone acetonide (TA) on blood-retinal barrier rupture in rats with diabetes mellitus (DM). Methods Diabetic model of Wistar rats was induced and were divided into normal control group, DM-4-month group and DM-6-month group. Each group was subdivided into immunohistochemcial staining and BRB measurement groups. BRB measurement group was further divided into non-TA treatment group, 1-week-TA treatment group, and 2-week-TA treatment group. The rats were intravitreously injected with 5 mu;l TA. The digested retinal preparation was stained by immunohistochemcial method to observe the expression of retinal ICAM-1 and morphological changes. The mean optic density (A) value of endothelial cells was measured by image-analyzing software to quantify the expression of ICAM-1. BRB changes were measured by content test of retinal Evans blue (EB). Results In the immunohistochemcial staining groups, there was no significant positive expression of ICAM-1 in retinal capillary in control group. Compared with the control, there was significant positive expression of ICAM-1 in DM-4-month group (P＜0.001) with some morphological changes such as irregular width of capillary caliber, and there was enhanced positive expression of ICAM-1 in DM-6-month group (P＜0.001) with aggravated morphological changes and even acellular capillary. In the BRB measurement groups, there was no significant difference of EB content(P＞0.05) among control groups. The EB content in two DM groups significantly increased compared with that in the controls (Plt;0.001), and higher in DM-6-month group than that in DM-4-month group (Plt;0.01). In TA treatment groups, the EB content in all the DM groups significantly decreased (Plt;0.001) but with no significant difference among the groups(P＞0.05). EB content in DM-4-month group after 2-week treatment almost reached to normal value (P＞0.05) while was higher in the rest of TA treatment groups than that in the control group (Plt;0.05). Rectilinear correlation between A value of endothelial cells and the retinal EB content(r=－0.959)was found. Conclusion There is a positive relation between the expression of ICAM-1 and BRB rupture in retina of DM rats, and intravitreous injection with TA can effectively alleviate BRB rupture. (Chin J Ocul Fundus Dis, 2006, 22: 24-27)
PURPOSE:To investigate and changes of the retina and the chorid induced by lipopolysaccharide (LPS)in Lewis rats and to compare the results obtained on tissue wholemounts and sections. METHODS:Immunohistochemistry was carried out both on wholemounts of the retina and the chorid-sclera complex and on ocular sections from normal Lewis rats and those after LPS injection. RESULTS:It was shown on the tissue wholemounts that monocytes were attached to retinal blood vessels and emigrated into the choroid as early as 4hrs after LPS injection. Severe involvement of the retina and macrophages into whole area of these tissues.Furthermore increasing number of major histocompatibility complex classⅡ(MHC classⅡ)positive cells was observed in the choroid.The results on tissue sections revealed that the retina and the choroid were both involved as videnced by infiltration of these cells at some time points after LPS injection. CONCLUSION:Wholemount technique provides undoubtful evidences to show that the retina and choroid are primarily and severely involuted after LPS injection.The endotoxin induced uveitis is,for the first time,presumed to be model for human generalized uveitis. （Chin J Ocul Fundus Dis,1996,12:33-36）
Objective To further investigate pathologic mechanism of retinal phototrauma. Methods Twenty Wistar rats were divided into control and experimental groups.Their eyes were extracted in 12，24 and 36 hours after light exposure.HE stained retina samples were examined and TDT-mediated dUTP nick end labelling(TUNEL)method was employed to distinguish apoptotic cells. Results After 12-hour light exposure,slight vesiculation was observed in the rod outer segment of the retinas.After 24-hour light exposure,the outer nuclear layer showed predominant fractured and condensed nuclei and fragmented DNA.After 36-hour light exposure,the rod outer and inner segments were lysed and most of the nuclei in the outer nuclear layer were disappeared. Conclusions Apoptosis of photoreceptor cell is one of the important mechanisms which cause experimental retinal photoinjury of rats. (Chin J Ocul Fundus Dis, 1999, 15: 167-169)