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 investigate the effect of dissociation of the human retinal pigment epithelium (RPE) cells by ficoll hypaque gradient centrifugation.Methods The primary human RPE cells and subcultured human RPE cells were dissociated with ficoll gradient centrifugation solution (d=1.077 g/ml)and the same divid ed cells as the control were dissociated with routine normal culture medium cent rifugation. The Trypan blue (0.4%) rejection staining was used, and the mouse anti-human monoclonal anti-body and fluorescein isothiocyanate (FITC) labeled rabbit anti-mouse IgG were utilized for indirect immunoreactivity for the test of human cytokeratin (CK) in active RPE cells cytoplasm. Flow cytometry assay was used to analyzed the percentages of CK positive staining RPE cells. simultaneously, the cells configuration, growth condition, the rate of clone formation, and the purifying result were observed under the fluorescent and confocal microscope.Results The survival rate and positive rate of CK of RPE cells in experimental group were higher than those in the control（P＜0.001）, but the number of the cells was reduced. The cells in the experimental group were integrated round with smooth border, symmetrical staining, homogeneous configuration and higher rate of clone formation （P＜0.001）. Conclusions RPE cells disas sociated with ficoll gradient centrifugation have the better dissociation effects. (Chin J Ocul Fundus Dis，2003，19：333-404)
Objective To evaluate the effects of inflammatory cytokines, including tumor necrosis factorTNF-alpha; and interleukins (IL-6 and IL-8), to the expression of pigment epithelium-derived factor (PEDF) in human retinal pigment epithelium (RPE)cells. Method Cultured primary human RPE cells were treated with 20，2，0.2 , and 0.02 ng/ml of TNF-alpha;, IL-6 and IL-8 separately. The levels of PEDF expression were determined by Western blot of the supernant after 6，12，24 and 48 hours of culture. Results PEDF secretion of RPE cells was inhibited by TNF-alpha;, IL-6 and IL-8 in a time- and dose-dependent fashion. Compared with the controls, the expression of PEDF decreased significantly in 0.02 ng/ml and 6 hours group (F＝7.14, P＜0.05）, 2.00 ng/ml and 48 hours group（F=14.05，P＜0.01) , and 20.00 ng/ml and 24 hours group（F=11.53，P＜0.01). TNF-alpha; was the most strength inhibitor (F＝14,P＜0.01）.Conclusion TNF-alpha;, IL-6, and IL-8 could suppress the expression of PEDF in the cultured human RPE cells.
Objective To detect the effects of cytokines on the expression of early growth response gene-1 (Egr-1) in cultured human retinal pigment epithelial (RPE) cells. Methods Immunofluorescence staining, Western blotting and reverse transcription polymerase chain reaction (RT-PCR) were used to detect and quantitatively analyze the expression of Egr-1 protein and mRNA in cultured human RPE cells which were exposed to stimulants, including 20 mu;g/ml lipopolysaccharide (LPS), 40 ng/ml tumor necrosis factor (TNF)-alpha;, 10 U/ml interferon (IFN)gamma;, 30% supernatant of monocyte/macrophage strain (THP1 cells) and the vitreous humor from healthy human eyeballs, for 0, 10, 20, 30, 40 and 60 minutes, respectively. Results The RPE cells stimulated for 0 minute revealed faint green fluorescence of Egr-1 in the cytoplasm. With exposure to the stimulants, the expressionof Egr-1 increased obviously and b green fluorescence was found in cytoplasm in some nuclei of RPE cells. Compared with the untreated RPE cells, after stimulated by 20 mu;g/ml LPS, 40 ng/ml TNFalpha;, 10 U/ml IFNgamma;, 30% supernatant of THP-1 cells and the vitreous humor, the approximate ultimate amplitudes of Egr-1 mRNA enhanced 1.9, 1.3, 14, 1.2, and 1.4 times, respectively; the greatest amplitudes of Egr-1 protein increased 3.4, 1.2, 1.7, 32, and 1.3 times, respectively. Conclusion LPS, TNF-alpha;, IFN-gamma;, supernatant of THP-1 cells and the vitreous humor can upregulate the expression of Egr-1 mRNA and protein in cultured human RPE cells, and induce its nuclear transposition, which suggests the activation of Egr-1.
Objective To observe the characteristics of fundus autofluorescence （AF） distribution at the posterior pole in normal subjects. Methods Seventy-nine normal subjects （156 eyes）were studied. Confocal scanning laser ophthalmoscope (cSLO) HRA2 was used to obtain the AF average image at the posterior pole. The distance was calibrated by Digimizer image analysis system. With umbo as the center, the macula was divided into foveola, fovea, parafovea and perifovea areas which with the radius 175, 750, 1250 and 2750 mu;m respectively. Each area was further divided into inferior, superior, temporal and nasal quadrants by two radial lines angle of 90deg;, except for foveola. The AF intensity in four quadrants of different macular regions and optic disc were measured. The AF intensity in vertical and horizontal direction of umbo was also measured. Then the effects of age, eyes, and gender on AF intensity in four quadrants of different macular regions were analyzed. Results There were statistically significant differences in AF intensity among optic disc and four quadrants of macular regions （F=528.648, P＜0.05）. AF distribution was V-type in vertical direction and M-type in horizontal direction. There were statistically significant differences between age groups in foveola, inferior parafovea, temporal parafovea, inferior perifovea, superior perifovea and temporal perifovea （P＜0.01）. There were no statistically significant differences between the two eyes （P＞0.05）. Between genders group, there were statistically significant differences in foveola, superior fovea, inferior fovea, nasal fovea and temporal perifovea （P＜0.05）; no statistically significant differences in the other quadrants （P＞0.05）. Conclusions The distribution of AF intensity is inhomogeneous in macular regions and four quadrants of each region in normal subjects. AF intensity increases with aging. AF distribution is symmetrical in both eyes. There is probably no correlation between gender and AF intensity distribution.
Objective To investigate the ingestion, metabolism and subcellular localization of indocyanine green (ICG) in human retinal epithelial (R PE) cells.Methods RPE cells were incubated with 0.25 mg/ml ICG under the condition of 37oC in the camera. The ICG granule and ultrastructure of RPE cells were observed under the electron microscopy after 1, 4, and 24hour incubation, and the ICG autofluorescence was detected by fluorescence microscopy after the incubation for 1, 2, 4, 8, 12, 24, and 48 hours, respectively. The ab sorbency (A value) of ICG solution was measured at 805 nm with ultraviol et/v isible specrtrometer. The standard curve of concentration of ICG was drawn and the related equation of concentration of ICG and the A value was calculated. After being incubated for 1, 2, 4, 8, 12, 24, 48, and 72 hours, respectively, the A value of supernatant fluid was calculated according to the equation. Aft er incubated with ICG for 24 hours, one sample was observed under electron microscope and fluorescence microscope per week to evaluate the metabolizable period of ICG .Results ICG granules were distributed evenly after entering the RPE cells. After incubated with 0.25 mg/ml ICG for 24 hours, no significant change of the ultrastructure of the RPE cells was found. ICG granules accu mulated in the cells as the time goes by and reached the peak after 24 hours, and then they decreased because of the slowdown of the metabolism. Few ICG was still remained in the cells 1 week later Conclusions RPE cells may take in ICG actively. ICG metabolizable period in RPE cells is long, which may be one of the mechanisms of the toxicity of ICG to the retina in the vitreous operation.(Chin J Ocul Fundus Dis，2004，20：179-181)
Fluorescein angiography(FA)was performed in 31 pigmented rebbits.The angiograms were evaluated as prints and as negative film under a light microscope.The patterns of retinal pigment epithelial(RPE)cells were studied by scaning electron microscopy and fluorescein light one,compared with other rabbits belonging to the same species.In 58 eyes,we observed the hexagonal pattern of RPE cell.It showed central hypofluorescent area surrounded by hyperfluorescent rim,which was easily seen away from the medullary rays by three or more disc diameters and became larger in the periphery than that in the posterior pole.There were no finding in four lightly pigmented eyes. （Chin J Ocul Fundus Dis,1994,10:226-228）