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)
Objective To observe the effect of high glucose on the expression of activating transcription factor 4 (ATF4) in cultured retinal Muuml;ller glia cells. Methods The retinal tissue of Sprague-Dawley (SD) rats was collected, and Muuml;ller cells were isolated and cultured. The glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS) of Muuml;ller cells were identified by streptavidin-biotin-peroxidase complex. Cultured rat Muuml;ller cells were divided into control group (5.5 mmol/L glucose), group A (20 mmol/L glucose), group B (30 mmol/L glucose) and group C (40 mmol/L glucose). ATF4 protein expressions in Muuml;ller cells of four groups were measured by Western blot four days after cultured. Results GFAP and GS expressed in more than 95% of Muuml;ller cells. Over 95% of Muuml;ller cells of group A, B and C were positive for GFAP and GS. Western blots indicated that ATF4 protein in group A, B and C increased obviously compared with the control group (q=0.293, 0.754,0.484;P＜0.05). Conclusion High glucose can increase the expression of ATF4 protein and cause endoplasmic reticulum stress in retinal Muuml;ller glia cells in vitro.
Objective To demonstrate if apoptosis is one of the mechanisms of siderotic retinopathy. Methods Autoclaved iron particles were implanted in the vitreous cavities of 32 eyes of SD rats.Glass chips were implanted in 10 control eyes.The experimental eyes were enucleated at various time intervals from days 1 to 15.Retinal degeneration was examined using the TdT-mediated,dUTP-biotin nickend labeling(TUNEL)method.Electrophoresis on agarose gel was used to detect internucleosomal DNA fragmentation.Results TUNEL-positive nuclei were observed only in the outer nuclear layer beginning on day 2.The nuclei spread throughout the outer nuclear layer by the end of day 3.No TUNEL-positive nuclei were observed in other layers throughout the experimental perios.Analysis of DNA,extracted from the retinas by electrophoresis on agarose gel,revealed a typical ladder pattern of internucleosoma DNA cleavage in the experimental eyes.ConclusionApoptosis of photoreceptors occurs at the early phase of iron-induced retinopathy in the rats.
ObjectiveTo observe the effects of Rhodiola on the rat retinal tissue morphology and the hypoxia-inducible factor (HIF)-1α at simulated hypoxia at different altitudes. Methods Forty-eight adult female Sprague Dawley rats were randomly divided into the Rhodiola Intervention group (intervention group) and the control group, each group had 24 rats. The intervention group rats were treated with intraperitoneal injection of 10 ml/kg of large plants Rhodiola solution, and the control group rats were injected with same volume of saline. One hour after the injection, six rats were randomly selected from both of the two groups and reared in the plateau environment simulation laboratory modules with the oxygen partial pressure of 17.4, 14.6, 11.3 and 7.4 kPa, which simulated the altitudes of 1500, 3000, 5000 and 8000 meters indoor respectively. Six hours later the rat eyeballs were harvested for paraffin sections and analyzed by hematoxylin and eosin staining, and immunohistochemical staining to observe the expression of HIF-1α and p53. ResultsIn the control group, the rat retinal layers were edema and loose, the retinal thickness increased, the retinal structure was disorganized, the ganglion cells were swollen and degenerated, and some can observe the karyopyknosis, karyolysis and the reduced cells number. As the altitude increased, the pathological changes of retinal became more obvious. In the intervention group, the characteristics of rat retinal morphology were same with the control group, while the degree of morphology changes was lighter than the control group. HIF-1α and p53 expressed mainly in the ganglion cell layer and inner nuclear layer of rat retina in the control group. As altitude increased, the expression of HIF-1α and p53 were increased too, which was positive correlated (r=0.9846, P < 0.05). Compared with the control group, the rat retinal expression of HIF-1α increased, while expression of p53 decreased in the intervention group, and the differences were statistically significant (P < 0.05). ConclusionRhodiola can reduce the retinal tissue pathology damage caused by high altitude hypoxia, and its mechanism may be related to the increasing expression of HIF-1α and reducing expression of p53.
Objective To detect the changes of function of blood-aqueous barrier in different Syndrome stages of patients with Vogt-Koyanagi-Harada (VKH) syndrome in order to provide the appropriate therapy. Methods According to clinical manifestation, 77 patients (144 eyes) with VKH syndrome were divided into 4 groups: 10 cases in posterior uvietis stage group (20 eyes), 27 in anterior uveal involvement stage group (50 eyes), 23 in recurrent anterior uvitis stage group (41 eyes), and 17 in convalescent stage group (33 eyes). The other 50 cases (100 eyes) were in the control group. Flare and cells of anterior chamber in patient with VKH Syndrome at different stages were graded and measured by laser flare and cell meter (LFCM) and slitlamp microscope. Results According to the results of slitlamp biomicroscopy, anterior chamber flare and cells were at the 0 grade in the patients at posterior uvietis stage (20 eyes). The results of LFCM examination revealed that the flare value and cells were (9.7±3.4) pc/ms and (0.9±0.6)/0.5 mm3 in posterior uvietis stage group, and (5.3±2.3) pc/ms and (0.8±0.6)/0.5 mm3 in the control group. The differences between the two groups were significant (Plt;0.001) and insignificant (P=0.899), respectively. In anterior uveal involvement stage group, the cells in anterior chamber was at grade 1+ in 25 eyes, 2+ in 19, and 3+ in 6, respectively, while the flare was at grade 1+in 27 eyes and 2+ in 23; the number of cells in anterior chamber was (13.7±6.5)/0.5 mm3，(40.8±17.6)/0.5 mm3, and (75.7±25.5)/ 0.5 mm3 respectively, and the value of flare was (31.4±12.8) pc/ms and (133.4±59.5) pc/ms. In recurrent anterior uvitis stage group, the cells in anterior chamber was at grade 1+ in 19 eyes, 2+ in 15, and 3+ in 7, respectively, while the flare was at grade 1+ in 24 eyes and 2+ in 17; the number of cells in anterior chamber was (11.2±5.4)/0.5 mm3，(29.6±14.4 )/0.5 mm3,and (69.3±22.2)/0.5 mm3, respectively, and the value of flare was (34.94±14.3) pc/ms and (150.9±83.3) pc/ms. The flare and cells in anterior chamber both in anterior uveal involvement stage and recurrent anterior uvitis stage group were higher than that in the control group (Plt;0.001). In convalescent stage group, the cells was at grade 0 in 33 eyes and the flare was at grade 0 in 15 eyes and 1+ in 18; while the number of cells was (1.0±0.7)/0.5 mm3 which was insignificantly differed from that in the control group (P=0.310), and the value of flare was (9.5±4.8) pc/ms and (30.0±12.3) pc/ms which were both higher than that in the control group (Plt;0.001). Conclusions The breakdown of blood-aqueous barrier with different degrees occurs at each stage in VKH syndrome, whereas inflammatory cells appearing in anterior chamber are only noted at some certain stages. This is very significant to offer directional and effective treatment to the patients with VKH syndrome. (Chin J Ocul Fundus Dis, 2005, 21: 363-366)
Objective To investigate the correlation of microperimetric parameters, best-corrected visual acuity (BCVA) and central retinal thickness (CRT) in diabetic macular edema (DME) eyes. Methods It is a prospective, no controlled, open study. Twenty-four consecutive patients (40 eyes) with DME were included. There were 10 males (18 eyes),14 females (22 eyes); aged from 41 to 79 years, with the mean age of (56.84±8.96) years. All the patients were type 2 diabetes, the average duration of diabetes was 8 years. BCVA was evaluated using the international Snellen E vision test chart, and then recorded as logarithm of the minimum angle of resolution (logMAR). CRT was measured by Cirrus HD-OCT4000. MAIA microperimetric parameters were evaluated, including average threshold (AT) of retinal sensitivity, macular integrity index (MI), fixating points within a circle of 1° (P1) and 2° of radius (P2), bivariate contour ellipse area (BCEA) considering 63% and 95% of fixating points (A63,A95), and horizontal and vertical axes of that ellipse (H63,H95,V63,V95). Pearson correlation analysis was performed to evaluate the association between these variables. The independent factor influenced the type of fixation was analyzed by multiple linear regression analysis. Results Strong correlations of logMAR BCVA with CRT (r=0.58,P=0.000), V63 (r=0.44,P=0.004), V95 (r=0.41,P=0.008), MI (r=0.36,P=0.024), AT (r=−0.61,P=0.000), P1 (r=−0.41,P=0.009), P2 (r=−0.38,P=0.015) were found. AT was correlations with P1 (r=0.53,P=0.000), P2 (r=0.51,P=0.001), A63 (r=−0.39,P=0.012), A95 (r=−0.40,P=0.012), V63 (r=−0.53,P=0.000), V95 (r=−0.46,P=0.003), MI (r=−0.50,P=0.001). There was no correlation between AT and CRT (r=−0.21,P=0.190). Forty eyes were included in this study, 8 eyes (20%) had stable fixation,14 eyes (35%) had relatively unstable fixation,18 eyes (45%) had unstable fixation. Multiple linear regression analysis showed that fixation classification was independently affected by P1. Conclusions In DME eyes, logMAR BCVA was positively correlated with CRT, negatively correlated with AT, P1 and P2. There is no correlation between AT and CRT. The fixation classification was independently affected by P1.
Objective To observe the morphological changes of dendrite and soma in retinal ganglion cells (RGCs) which subsisted in early diabetic rats. Methods The RGCs of 3-months-course diabetic rats and coeval normal rats were marked by gene gun techniques. To collect RGCs photographs by Leica microscope with Z axis and CCD camera；to observe the changes of diameter, variance of structural features in dendritic field and somata after classification which according to the size and morphology. Thy-1 antibody marks on the retinal RGCs, taking a photograph under fluorescent microscope, counting the changes of retinal RGCs density in early diabetic rat. Results In three-month diabetic rats,the density of retinal RGCs was decreased obviously. Morphological changes of RGCs in the dendritic fields were observed with gene gun technique. There was no severe variation in all kinds of the bole of cell dendrite, in which some only showed crispation partially and sparseness also twisting in the dendritic ramus. The mean diameter of dendritic field and soma in class A of diabetic rats was (401plusmn;86) mu;m, the mean diameter of dendritic field in control group was (315plusmn;72) mu;m,compared with each other, there is statistically significant differences (t=21.249，Plt;0.001); the mean diameter of soma in class A of diabetic rats was (24plusmn;6) mu;m, the mean diameter of soma in control group was (22plusmn;5) mu;m, compared with each other, there is no statistically significant differences (t=0.927，Pgt;0.05); the mean diameter of dendritic field and soma in class B of diabetic rats were (170plusmn;36)、(14plusmn;2) mu;m respectively, in control group were (165plusmn;36)、(16plusmn;2) mu;m, the mean diameter of dendritic field and soma in class C of diabetic group were(265plusmn;78)、(17plusmn;5) mu;m respectively, in control group were (251plusmn;57)、(17plusmn;4) mu;m , compared with each other, there are on statistically significant differences(t=1.357，0.798，0.835，1.104，Pgt;0.05). Conclusions In short-term diabetes, the survived RGCs show good plasticity in adult diabetic rats, especially in class A. The changes of dendrites were more sensitive than the soma, which could be the leading index of the morphologic changes of RGCs in the early stage. The good plasticity showed by the RGCs and the time window from changing in dendrite to cell death provide us many evidences not only for the research but also for the nerve protection in clinic. (Chin J Ocul Fundus Dis,2008,24:249-254)
ObjectiveTo observe the protective effect of Zhicao Tea Mixture on Müller cells and the expression of inflammatory factors in mice with diabetic retinopathy.MethodsSeventy-five C57BL/6J mice were randomly divided into the normal control group, diabetes mellitus (DM) group, low concentrations group, medium concentrations group and high concentrations group, with 16 mice in each group. The diabetes model of mice in all groups except the normal control group were established by intraperitoneal injection of STZ (60 mg/kg). Four weeks after the successful modeling, the Zhicao Tea Mixture with low (30 ml/kg), medium (60 ml/kg) and high concentrations (120 ml/kg) were respectively administered by gavage. Weight and blood glucose of mice in each group were measured every two weeks. After 8 weeks, Western blot method was used to detect the mice retina Müller cells activation marker gelatinous fibrous acidic protein (GFAP). Immunofluorescence was performed to detect the expression GFAP and glutamine synthetase (GS). Real-time quantitative PCR (RT-qPCR) and ELISA were used to determine the mRNA and protein expression levels of mouse retinal VEGF, TNF-α, IL-1β and IL-6 respectively.ResultsThe weight of mice in the DM group was lower than that of the normal control group, and the blood glucose was increased. Zhicao Tea Mixture had no effect on the weight of DM mice, but had a significant hypoglycemic effect. The GFAP expression (t=38.318, P＜0.001) in the retina of mice in the DM group was increased and GS expression (t=29.737, P＜0.001) was decreased compared with the control group. The GFAP expression (t=13.677, 19.387, 16.305; P＜0.05) in the retina of mice in the low, medium and high concentrations group were decreased and GS expression (t=5.170, 19.399, 6.705; P＜0.05) were increased compared with the DM group. The expressions of retinal inflammatory factors VEGF, TNF-α, IL-1β and IL-6 in DM group all increased, while the expressions of the above-mentioned inflammatory factors in the retina of mice decreased in the low, medium and high concentrations group.ConclusionZhicao Tea Mixture can decrease the blood glucose of DM mice and reduces the diabetic retinal inflammatory response.
OBJECTIVE :To investigale effect of subretinal fluld(SRF)on proliferalion of the cellular elements of PVR. METHOD:The effect of SRF of 28 patients with rhegmatogenous retinal detachment proliferation of the cultured human retinal pigment epithelial cells(RPE),retinal glial cells (RG),and fibroblast (FB)was observed and detected by the methods of cell-counting and 3H-TdR in DNA synthesis. RESULTS:The range of proliferatinn-stimulating activity was 52.5%~233.3%, 36.4% ~ 177.8%，55.4% ~277.8% above the baseline in 1:10 dilution of these 3 kinds ,of cellular elements,and there was no significant difference among them. CONCLUSION ;The stimulating effect of SRF on the cellular proliferation was thougt to be due to the actions from certain growth factors. （Chin J Ocul Fundus Dis,1996,12: 233-235）
ObjectiveTo observe the influence of down-regulation of HtrA1 expression by small interfering RNA on light-injured human retinal pigment epithelium (RPE) cells. MethodsCultured human RPE cells(8th-12th generations)were exposed to the blue light at the intensity of (2000±500) Lux for 6 hours to establish the light injured model. Light injured cells were divided into HtrA1 siRNA group, negative control group and blank control group. HtrA1 siRNA group and negative control group were transfected with HtrA1 siRNA and control siRNA respectively. The proliferation of cells was assayed by CCK-8 method. Transwell test was used to detect the invasion ability of these three groups. Flow cytometry was used to detect the cell cycle and apoptosis. The expression of HtrA1 and vascular endothelial growth factor (VEGF)-A was detected by real time-polymerase chain reaction and Western blot respectively. ResultsThe mRNA and protein level of HtrA1 in the light injured cells increased significantly compared to that in normal RPE cells (t=17.62, 15.09; P<0.05). Compared with negative control group and blank control group, the knockdown of HtrA1 in HtrA1 siRNA group was associated with reduced cellular proliferation (t=6.37, 4.52), migration (t=9.56, 12.13), apoptosis (t=23.37, 29.08) and decreased mRNA (t=17.36, 11.32, 7.29, 4.05) and protein levels (t=12.02, 15.28, 4.98, 6.24) of HtrA1 and VEGF-A. Cells of HtrA1 siRNA group mainly remained in G0/G1 phase, the difference was statistically significant (t=6.24, 4.93; P<0.05). ConclusionKnockdown of HtrA1 gene may reduce the proliferation, migration capability and apoptosis of light-injured RPE cells, and decrease the expression of VEGF-A.