Objective To investigate the effect of hepatocyte growth factor (HGF) on the barrier function of retinal peigment epithelium (RPE) and to detect the pathological mechanism of retinal detachment (RD) induced by over expression of HGF in RPE. Methods Sub-retina injection of E1/E3deleted adenoviral vectors encoding HGF (Ad CMV.HGF) and green fluorescent protein (Ad CMV.GFP) in adult pigmented rabbits [5times;104 plaque-forming units (pfu)/eye] to set up the model of retinal detachment. The ocular fundus and pathological changes were observed 3, 7, 14, and 28 days after injection. The expression level of HGF in retina and vitreous body was detected by immunohistochemistry and enzyme linked immunosorbent assay (ELISA). Results In the control eyes injected with AdCMV.GFP, expression of GFP only detected in RPE monolayer. The eyes injected with AdCMV.HGF had b HGF immune positive action in RPE cells at the injection site. The expression level of HGF in vitreous body reached the peak 7 days after injection and decreased to the basic level 28 days after injection. Chronic RD and chronic choroidal inflammation were found in the eyes injected with AdCMV.HGF within the time frame of HGF expression. Proliferative RPE cells were found in subretinal space in the region of RD, and multilayered cellular membranes developed in some eyes. Conclusion Over expression of HGF in RPE may induce chronic serous RD with subretinal proliferation of RPE, which suggests that HGF should be further studied as a target for therapeutic intervention in RD. (Chin J Ocul Fundus Dis, 2007, 23: 193-197)
Objective To evaluate the expressive varieties of Nogo-A mRNA in injured optic nerves of rats. Methods Reverse transcription polymerase chain reaction (RT-PCR) method was used to hemi-quantitatively analyze the levels of Nogo-A mRNA in the optic nerves 3, 7, 9, 15, 21, and 25 days respectively after injury.Results The level of the expression of Nogo-A mRNA was low in the normal optic nerves, while it was significantly high in the optic nerves 3 days after in jury, and kept the high level still after 25 days.Conclusion The expression of Nogo-A mRNA in injured optic nerves is increased. (Chin J Ocul Fundus Dis,2003,19:201-268)
PURPOSE:To measure the concentration changes of tumor necrosis factor a (TNF-alpha;)in vitreous during the development of experimental PVR induced by macrophages and explore the initial and mediated factors which stimulate the cellular proliferation. METHODS:Rabbit PVR model was induced by macrophages and the vitreous was taken at the 7th,14th,21st and 28th day and 4 eyes in each group. The TNF-alpha; levels in vivreous of the above examinated and control eyes were measured with an ELISA kit. RESULTS:The TNF-alpha; level in the vitreous reached its peak 434mu;g/ml at 21st day in the mod-el, then rappidly decreased to 122mu;g/ml at 28th day. CONCLUSION:The changes of TNF-a in the vitreous of the PVR model were parallel to the natrual phases of the development of PVR,indicating TNF-alpha; may play an important role in initiating and mediating the inflammation and cellular proliferation in the vitreous. (Chin J Ocul Fundus Dis,1997,13: 231-233)
Objective To investigate the damage to the retinal cells and apoptosis of retinal cells of rats after ischemia-reperfusion insult. Methods The retinal ischemia-reperfusion model was developed by increasing intraocular pressure to 109725 mm Hg in rat eyes. Morphological changes of the rat eyes were observed by means of routine histopathology with HE staining. Apoptosis of the retina was assayed by both DNA fragmentation gel-electrophoresis and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL). Results Compared with the normal control, no histopathological changes were revealed in the rat retinas 30 min after the ischemia and then reperfued for 24 h or 48 h. Retinal ganglion cell layer (RGL) and inner plaxiform layer (IPL) of the retina were observed, however, to become significantly thinner 60 min after the ischemia and then reperfued for 24 h or 48 h. Together with the pathological changes DNA ladder pattern was detected in the same group of the rats. Further, immunochemical stain of the eye demonstrated that TUNEL positive cells were localized in RGL and IPL of the retina. Conclusion Ischemia-reperfusion insult of the eye may remarkably damage the retina of the rat eye. The damage to the retinal cells is mainly localized within RGL and IPL and apoptosis is the important mechanism of the retinal disorder. (Chin J Ocul Fundus Dis, 2002, 18: 296-298)
Objective To study the global and histological changes of myopia and explore its pathogenic mechanism. Methods Chicks were reared with monocular suture of eyelid. When myopia had been confirmed by optometry, eyeballs were removed and subjected subsequently to measurement and light and electron microscopies. Results Three dimensions in the eyeballs of suture group were all enlarged markedly and the mean diopter was -15.00D. Under the light microscope, rod outer segment elongated and connected With PREC in suture group. With micrometer measure, cartilaginous sclera thickened and retina became thinner. Under electron microscope, rod outer segment elongated and membrane disc was intact. In the cytoplasm of RPEC, the phagosomes containing fractions of the membrane disc of outer segment were remarkably decreased. Conclusion Early form deprivation may affect the drop of membrane disc and cause eyeball enlargement; thus, myopia forms. (Chin J Ocul Fundus Dis,1999,15:20-23)
ObjectiveTo observe the expression of connective tissue growth factor (CTGF) in injured model of retinal pigment epithelial (RPE) cells and the promoting effect of CTGF on migration of RPE cells.MethodsCultured monolayer-confluent human RPE cells were scraped with a trephine and a cotton stick, and set up the injured model of RPE cells with round scraped area. Immunohistochemistry and in situ hybridization(ISH) were used to detect the expression of CTGF protein and mRNA in injured RPE cells at distinct time points after injury. The number of RPE cells migrated to injured area was measured and the effect of CTGF on migration of RPE cells and the effect of dexamethasone (DEX) on the promoting process of CTGF were observed.ResultsThe results of immunohstochemistry and ISH indicated the weak positive expression of CTGF in RPE cells at the edge of scrape 6 hours after injury, and the positive expression increased gradually as time goes by after the injury. Strong positive expression of CTGF in RPE cells at the edge of scrape was found 24 and 48 hours after injury. Rebuilt human CTGF stimulated migration of RPE cells in a dose-depended manner, and DEX significantly inhabited the migration.ConclusionCTGF involves in the procedure of repair of injury of RPE cells, which may play an important role in the pathogenesis of intraocular proliferative diseases such as proliferative vitreoretinaopathy.(Chin J Ocul Fundus Dis, 2005,21:306-309)
Objective To monitor the release of amino acids of the whole retina during and after experimental glaucoma by increasing the intraocular pressure (IOP). Methods Experimental glaucoma was induced in one of the two eyes of rabbits by increasing IOP at 120 mm Hg for 45 min under infusion of saline in anterior chamber;then the pressure was released and the needle inserted into the anterior chamber was removed,this state was maintained for another 45 min.Every 15 min during the experiment 5 rabbits were killed and experimental eyes were enucleated.Aliquots(20 μl)of the retinal extracts(see below)were mixed with ophthaldialdehyde reagent and analysed for amino acid content by the HPLC method of Wangwei,using a 150 mm×4.6 mm,5 μm C18 column. Results A large increase in the release of glutamate,but not of the other three amino acids monitored,occurred during initial experimental ocular hypertension.It reached peak value of(111.73±17.46)10-5 mmol/g at 15 min of hypertension.15 min after release of intraocular pressure,again,immediately large and specific increase in the concentration of glutamate was reached to(102.96±51.91)10-5 mmol/g.In eyes subjected to paracentesis of anterior chamber,no difference was found between experimental eyes and controls. Conclusion These results suggest that glutamate is triggered by increasing the IOP,and it releases not only during the period of experimental ocular hypertension,but also afterwards. (Chin J Ocul Fundus Dis, 2002, 18: 146-148)
ObjectiveTo explore the effect of estrogen on the permeability of retinal blood vessel by ovariectomy.MethodsTwenty-two healthy rats were divided into experimental and control group randomly. Estrogen level of rats decreased due to ovariectomy in the experimental group while stabilized by sham-ovariectomy in the control group. The results were confirmed by vaginal epithelium smearing. Retinal vein occlusion was established by photodynamic method, and leakage of Evan's blue in retina was determined by spectrophotometer.ResultsMature value of vaginal epithelium decreased significantly in ovariectomy rats(t=21.008,P=0.000) while not significantly in sham-ovariectomy ones (t=0.319,P=0.756); the mean leakage of Evans blue was (25.503 0±4.378 47) ng/mg in experimental group, and (17.830 0±4.265 69) ng/mg in the control group, and the difference between the two groups is significant(t=3.969 36,P=0.001).ConclusionOvariectomy is an useful method to study the effect of estrogen on ocular diseases, and when estrogen level decreases, the permeability of retinal blood vessel increases.(Chin J Ocul Fundus Dis, 2005,21:174-176)
Objective To detect expression of NF-κB in the inner retina and in vestigate the inhibitoryeffect of pyrrolidine dithiocarbamate on retinal neovascularization in rats. Methods The rat models with retinopathy were set up un der the hypoxia condition, and fluorescein fundus angiography (FFA) was used to observe the retinal neovascularization. The expressions of NF-κB in the inner retina in rats with and without neovascularization were detected by immunohisto chemical method. PDTC was intraperitoneally injected in rats with neovascularization to observe the expression of NF-κB in the inner retina and the effect on retinal neovascularization. Results Hypoxia induced NF-κB activation in the retinal glial cells and endothelial cells. But immuno-staining intensity for NF-κB and adhesion molecules were reduced by PDTC intraperitoneal injection. Retin al angiogenesis in rats were suppressed effectively (P<0.05). Conclusions NF-κB activation correlates with retinal neovascularization closely. PDTC may inhibit the NF-κB activation and prove beneficial in the treatment of ischemic neovascularization. (Chin J Ocul Fundus Dis,2003,19:201-268)
Objective It has been shown that pigment epitheliumderived factor (PEDF) is an effective anti-apoptosis agent on several kinds of cells of the central nervous system.This study aimed to evaluate the effect of PEDF on pressure induced retinal ischemia in a rat model. Methods Retinal ischemia was induced by increasing the intraocular pressure to 110 mm Hg for 45 minutes via an intracameral catheter.Ten microlit ers (0.1 mu;g/mu;l) PEDF was injected into the vitreous of 4 eyes of each group im mediately after reperfusion and 4 additional eyes received only normal saline as vehicle controls.The animals were euthanized at 2 or 7 days after reperfusion.T he effect of PEDF on retinal degeneration was assessed by measuring the thicknes s of the inner retinal layers (MTIRL) and counting the retinal ganglion cells (R GC) on plastic embedded retinal sections. Results The MTIRL and the RGC counting in eyes treated with intravitreal PEDF were significantly higher than those in vehicle controls (118.1plusmn;5.0) mu;m vs(94.9plusmn;3.0) mu;m (Plt;0.05);(6.0plusmn;1.0) cells/100 mu;m vs (4.5 plusmn;0.5) cells/100 mu;m (Plt;0.05) 7 days after reperfusion,respectively. Conclusion Intravitreal administration of PEDF can ameliorate an ischemiareperfusion retinal injury and may be useful to prevent neuronal degeneration in the inner retina. (Chin J Ocul Fundus Dis, 2001,17:138-140)