Objective To investigate the effect of subretinal fluid (SRF) with different grades of proliferative vitreoretinopathy (PVR) on bcl-2 oncoprotein expression in retinal pigment epithelium (RPE) cells and fib roblast (FB)． Methods Using immunohistological staining technique and Western-blotting method to detect the expression of bcl-2 protein in RPE cells and FB under the stimulation of SRF． Results The expression levels of bcl-2 increased in both types of cells to a certain extent compared with those of the control group 4 hours after the cells subjected to SRF； 36 hours later, the expression levels of bcl-2 of experimental groups decreased more quickly than those of the control group， and the control group showed relatively higher bcl-2 protein levels at the end of observation． Conclusions SRF may stimulate the e xpression of bcl-2 in RPE cells and FB under culture at early stage, but accel arate the declining of bcl-2 protein levels a certain time after subjected to SRF． (Chin J Ocul Fundus Dis, 2001,17:58-60)
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