Purpose To investigate retinoic acid (RA) induced apoptosis in retinal pigment epithelial (RPE) cells. Methods 10-5、10-6、10-7 mol/L were added to cultured PRE cells.Aridine orange fluorescence and TdT-mediated dUTP nick end labelling(TUNEL) techniques were used to observe apoptotic changes. Resultss 10-5、10-6、10-7 mol/L RA induced apoptosis in RPE cells.Cell shringkage,chromatin condensation and nuclear DNA fragmentation of RPE cells were observed by TUNEL technique.When 10-7、10-6、10-5mol/L RA treated RPE cells for 5 days,apoptotic index(AI)was 36.9%、4409% and 61.4% respectively,and 48.0%、59.9%、74.2% for 6 days.At the same concentration of RA,AI increased when time prolonged．At the same day,AI increased when the concentration of RA rose.There was significant difference in the results(Plt;0.05). Conclusion Our results showed that RA-induced apoptosis in RPE cells was detected with a good dose and time response. (Chin J Ocul Fundus Dis,1998,14:153-155)
Porpose To investigate the optimal concentration of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) on DNA synthesis and their synergism indensity arrested human retinal pigment epithelial (RPE) cells. Methods Growth factor effects in cultured human RPE of the 6th generation were assessed by [3 H]-thymidine incorporation and radioautography. Results EGF and bFGF were potent stimulators when used alone,and their optimal concentrations were 10ng/ml in DMEM and 1ng/ml in 2% serum DMEM.When used in combination (10ng/ml EGF and 10ng/ml bFGF),they caused a significant enhancement of [3 H]-thymidine incorporation about 2.96 times. Conclusion EGF and bFGF were potent stimulators in RPE cells,and demonstrated synergism in their action. (Chin J Ocul Fundus Dis,1998,14:98-100)
OBJECTIVE:To observe the effect of dexamethasone to intracellular free Ca2+ of frozen RPE cells. METHODS:The cultured human RPE cells were frozen for 30s at --70deg;C. The RPE cells were loaded with Fura-2/AM and analyzed using a digital imaging microscopy system,the effect of dexamethasone to intracellular free Ca2+ was measured at a serial concentration of 40, 60,100,150,200mu;g/ml. RESULTS:The concentration of intracellular free Ca in frozen human RPE cells was increased to 18.6%~29.8% by dexamethasone at concenlration of 40mu;g/ml~60mu;g/ml,while was decreased to 28.4%~35.2% at 150mu;g/ml~200mu;g/ml. CONCLUSIONS:Effect of dexamethasone showed two aspects of effect to frozen cultured human RPE ceils,that it was inhibitor at high concentration and stimulator at low concentration （Chin J Ocul Fundus Dis,1997,13: 86-88）
Purpose To identify matrix metalloproteinase (MMP) in human vitreous samples of diabetic vitreoretinopathy (DR) and other ocular diseases (non-DR) and to probe the related factors of MMP expression． Methods Thirty-one diabetic and 17 non-diabetic vitreous samples (nine macular hole and eight epiretinal membrane patients) were examined． Samples were concentrated and subjected to substrate zymography to conduct a quantitative analysis of MMP-2,9 activity． The technology of Western blotting against anti-human MMP-2,9 was performed to identify MMP in vitreous samples． Results Vitreous samples both from DR patients and from non-DR patients showed a single band at the position of 72 kDa, correspondin g to MMP-2． Quantitative analysis revealed that diabetic vitreous showed higher MMP-2 activity than non-DR, although the difference was not significant.45.2% of DR patients showed MMP-9, but no expression in non-DR．Among DR samples, the positive ratio of MMP-9 in partial posterior vitreous detachment (PVD)(66．7%) was significantly higher than that of complete PVD (15．4%)． Western blotting study confirmed the expression of MMP-2 and MMP-9． Conclusion There is no obvious difference of MMP-2 activity between DR and non-DR． MMP-9 may be involved in the pathogenesis of diabetic vitreor etinopathy and the deterioration of proliferative change． (Chin J Ocul Fundus Dis, 2001,17:195-197