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 observe the pathological and functional changes of retinal photochemical damages exposed to green flurescent light. Methods The Sprague Dawley rats were continually exposed to green fluorescent light with an illuminancem level of (1 900plusmn;106.9) Lx for 24 hours.The changes of retinal morphology and morphometrics and flash electroretinogram were studied before light exposure and at the 6th hour,6th day and 14th day after light exposure. Results At the 6th hours after light exposure,the outer nuclear layer(ONL)of retina becoma thinner compared with that bfore light exposure.The thickness of ONL decreased by 23.91% and the inner and outer segments appeared disorderly arranged.At the 6th day after light exposure the thickness of ONL is thinner than that at the6th hour,i.e.decreased by 46.6%. At the 14th day after light exposure the thickness of ONL decreased by 42.40%.Flash electroretinogram showed that the amplitudes of a and b wave decreased continuously at the 6th hour and 6th day and unrecovered at the 14th day after light exposure. Conclusion This model might be an ideal one for research on retinal photochemical damage. (Chin J Ocul Fundus Dis,1998,14:101-103)
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)
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)
Objective To evaluate the effect of vascular endothelial cell growth factor (VEGF) antisense oligodeoxynucleotides (ASODNs) on the expression of VEGF in rats with oxygen-induced retinopathy. Methods Thirty newborn Sprague-Dawley (SD) rats were randomly divided into 3 groups:normal control group, disposal group and non-disposed group, The animal models with oxygen-induced proliferative retinopathy were established by raising the rats in hyperoxic environment. Retrobulbar injection was performed with VEGF ASODNs or normal saline on the rats in 3 groups respectively. The intraocular tissues (all the tissues except the cornea, sclera, and lens) and serum were collected, and the expressions of VEGF were determined by using competitive enzyme immunoassay.Results The expressions of VEGF in intraocular tissues of rats in disposal group were significantly lower than those in non-disposed group (P＜0.05), and there was no statistical difference between the disposal and normal control group (P＞0.05). There was no significant difference of the expressions of VEGF in serum of rats between the disposal and non-disposed group (P＞0.05), which were both lower than those in the normal control group (P＜0.05). Conclusion VEGF ASODNs could significantly inhibit the expression of VEGF in intraocular tissues. (Chin J Ocul Fundus Dis，2003，19：172-174)
Objective To determine the effect of methimazole (MMI) on retinal vascular development in neonatal rats, and to investigate the relationship between the concentration of insulin-like growth factor-I (IGF-I) in serum and the development of normal blood vessels and between the concentration of IGF-I and the formation of abnormal blood vessels. Methods There were 75 neonatal SpragueDawley rats in experimental group whose mothers were raised with water with 0.1% MMI at the first day of parturition. Another 50 neonatal rats were in the control group whose mothers were raised with normal water. The rats in the two groups were sub-divided into 4day and 10day subgroup, respectively. The retinal flatmount of the right eyes were stained with adenosine diphosphatase (ADPase); with the paraffin section of the left eyes, the number of nucleolus breaking through retinal inner limiting membrane was counted and the retinal blood vessels were evaluated. Serum IGF-I levels were detected by radioimmunoassay, and the weight of the neonatal rats in each group were observed and recorded. Results The incidence of retinal neovascularization in 10 day MMI group was 27%, and 0% in 4-day MMI group and control group. The serum IGF-I level in 4-day and 10-day MMI group (73.07 ng/ml, 175.13 ng/ml) was obviously lower than which in the 4-day and 10-day control group (168.73 ng/ml,306.38 ng/ml) （P=0.00）. Obvious slow growth of the neonatal rats was found in MMI group compared with which in the control group. Conculsions MMI may inhibit the normal growth of retinal blood vessels and lead neovascularization, which may relate to the initial decrease of the serum IGF-I level. (Chin J Ocul Fundus Dis, 2007, 23: 198-201)
Objective To explore the effect of ischemia-reperfusion injury on the retinal functions of rats. Methods Seventy Wistar rats were selected, 20 of which were selected randomly and divided into two groups (control group and single-irrigated group). The rats were anesthetized and their anterior chambers of the right eyes were cannulated with a 7-gauge needle connected to a reservoir containing ringers balanced salt solution, which was maintained at the same level o f the eye for 1 hour. After that, ERG was recorded in both eyes of all rats. All the left rats were divided randomly into 10 groups and they were treated as the single-irrigated group. Retinal ischemia was induced by raising the reservoir to a height of 150 mm Hg. One hour later except the single ischemia group, all o f t he groups resumed perfusion after 3,6,12,and 24 hours and 3,5,7,14,and 21 days s eparately. ERG was recorded in both eyes of all rats.Results There was no difference in the results of ERG between left and right eyes in either the control group or the single-irrigated group. All the waves of ERG vanished in the single-ischemia group after 1 hour. In the ischemia-reperfusion groups, the waves of ERG partly recovered and the amplitude reduced persistently and progressively.Conclusion Ischemia-reperfusion injury may affect the function of the retina persistently and progressively. (Chin J Ocul Fundus Dis，2003，19：201-268)
Objective To analyse the changes of nitric oxide and nitric oxide synthase in rat retina under acute high ocular pressure and study the effect of nitric oxide in rat retinal damage under hypertension. Methods Sixty Wistar rats were divided randomly into five groups:Ocular hypertension 30 min,60 min,90 min and 12 h,24 h after reperfusion．Elevation of the ocular pressure in the anterior chamber of the rat eye ca used retina ischemic damage．The changes of retinal nitric oxide content were ob served indirectly by measuring NO2－/NO3－ content in retina.The distribution and changes of neuronal constitutive nitric oxide synthase (ncNOS)were studied by immunocytochemical localization of ncNOS. Results ncNOS positive neurons were distributed in the inner nuclear layer (INL),ganglion cell layer (GCL) and the inner plexiform layer of the normal and ischemic rat retina.During acute high IOP 30 min,60 min and 90 min,NO content decreased gradually and ncNOS immune activity weakens.During reperfusion,NO content increased remarkably (Plt;0.05) as compared with the groups of hypertension 90 min and decreased remarkably as compared with the normal rat retina.But ncNOS positive neurons continue to decrease compared with the groups of hypertension 90 min. Conclusion NO participates the rat retinal injury by acute elevated intraocular pressure, and nitric oxide synthetized by ncNOS may play an important role in protecting the retina from ischemic and post-ischemic injury.
Objective To observe the expression of erythropoietin (EPO) and its receptor (EPOR) mRNA and protein levels in retinae of mice with oxygen-induced retinopathy, and to evaluate the effect of EPO and EPOR in retinal vascular develo pment and in the occurrence and development of oxygen-induced retinopathy. Methods One hundred and thirty-two 7-day-old C57BL/6J mice were divided into two g rou ps: normal control group (control group) and oxygen-induced retinopathy group (experimental group). The proliferative neovascular response was estimated by obse rving the vascular pattern in adenosine diphosphatease (ADPase) stained retina flat-mounts by executing 6 mice in each group at the 12th, 15th, and 17th day, respectively. The expression of EPO, EPOR mRNA was determined by reverse transcription-polym erase chain reaction (RT-PCR), and the protein levels of EPO and E PO R were determined by immunohistochemistry. RT-PCR and immunohistochemistry were done every other day from the 7th to the 21st day. Results In the control group, retinal vascularization was found. In the experimental group, the large vesse ls were constricted straight, the branches decreased, and alarge nonperfusion area was observed at the 12th day; the large vessels were dilated and tortuous and neovascularization occurred at the 15th day; a mass of neovascularization was found and the vascular net structure of the deep and shallow layer was destroye d at the 17th day. The expression of EPO mRNA decreased from the 7th day and kee p decreasing in the whole oxygen-breathing duration in the experimental group. A fter the mice were returned to room air, the expression increased obviously from the 15th day and kept the high level until the 21st day. The expression of EPO mRNA increased at the 7th day and reached the peak at the 11th day, and kept the high level until the 21st day. The changes of protein levels of these three fac tors were later than that of their mRNA, but had the same trend. The difference of the expression between the two groups at the different time point was signifi cant except for the 7thday point (Plt;0.05). Conclusion It 's suggested that EPO and EPOR played important roles on the development of normal retina vascularizati on and the pathogenesis of ROP, which may provide new conception and method for the prevention and treatment of the oxygen-induced retinopathy.