Objective To investigate the molecular mechanism of apoptosis in cultured human retinal pigment epithelial (RPE) cells. Methods The growth media of confluency human RPE cells were replaced with a daunoblastinacontaining one at a dose of 180mu;g/L,and the cells were incubated for 12 hr at 37℃.After incubation with the drug,the medium was withdrawn,fresh medium was added and incubation was carried out for an additional 24 hr.Apoptosis was monitored by light microscopy,enzyme linked immunosorbent assay(ELISA)and terminal deoxynucleotidyl transferase mediated biotin-dUTP nick-end labelling(TUNEL)staining.The expression of bax and bcl-2 were evaluated by immuncoytochemical staining with anti-human bcl-2 and bax antibodies. Results After the RPE cells treated with daunoblastina,shrinkage of cytoplasm and nucleus was identified.The ratio of nucleus to cytoplasm was increased.TUNEL staining showed that many cells were positive staining.The amount of apoptotic cells was directly proportional to the drug dose.The integral optical desity values for expression of bax inereased by 22.0%(Plt;0.05), and that of bcl-2 did not change significantly(Pgt;0.05). Conclusions During human RPE cell apoptosis induced by daunoblastina,overexpression of bax or low bcl-2/bax ratio were demonstrated.The results suggest that bax and bcl-2 gene expression could play a role in regulation of RPE cell apoptosis. (Chin J Ocul Fundus Dis, 1999, 15: 153-156)
Objective:To study the effects of growth factor on the proliferation of the cultured huamn retinal glial cells. Methods:EGF(0.5～100.0ng/ml) and NGF (0.5～10.0ng/ml) were added to cultures of human retinal glial cells and the proliferation rates of the cells were measured by MTT method. Results:EGF at a dosage ranging from 0.5ng/ml to 100.0ng/ml and NGF (0.05～10.0ng/ml) stimulated the cellular proliferation effectively with their EC 50 of 17ng/ml and 0.7 ng/ml respectively. Conclusion:Both EGF and NGF NGF had an effective stimulation on human retinal glial cell proliferation.They may play a role in the formation of PVR. (Chin J Ocul Fundus Dis,1998,14:33-34)
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）
Objective To investigate the activation and role of signal transduction pathway of epidermal growth factor (EGF)-epidermal growth factor receptor (EGFR)-mitogen activated protein kinase (MAPK) in proliferation of human retinal pigment epithelial (RPE) cells. Methods Human RPE cells were stimulated with 0.1%，10% foetal calfserum (FCS) and EGF(0.1, 1, 10, 50 and 100 ng/ml)in 0.1% FCS Dulbeco′s modified Eagle′s medium (DMEM) and in 10% FCS DMEM for 3 days, respectively. Immunohistochemical staining and in situ hybridization were used to observe the expressions of EGFR protein and EGFR mRNA，respectively. Activation of MAPK was detected by immunohistochemical method with specific anti-phosphorylated ERK 1/2 antibody. Results The optimal concentrations of EGF were 10 ng/ml in 0.1% FCS DMEM and 1 ng/ml in 10% FCS DMEM. After 3 days of stimulation with EGF, phosphorylated ERK 1/2 staining was detectable in nucleus of RPE cells, whereas cells presented immunostaining for phosphorylated ERK 1/2 in the cytoplasm before stimulation. Conclusions EGF may improve the expression of EGFR protein and EGFR mRNA of RPE cells, and induced MAPK nuclear translocation in a concentration-dependent manner. EGF-EGFR-MAPK signal transduction pathway may play a key role in RPE cells proliferation, and serum exerts an important acceclerating function in the process. (Chin J Ocul Fundus Dis，2004，20：67-132)
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 investigate the adhesiveness of osteoblasts and vascular endothel ial cells from rat BMSCs co-cultured on allogeneic freeze-dried partially bone in vitro. Methods The BMSCs were isolated from 4-week-old SD rats (weighing 100-110 g) and cultured in vitro. The third generation of BMSCs were induced into osteoblasts and vascular endothel ial cells. The osteoblasts and vascular endothel ial cells after being induced for 7 days in a ratio of 1 to 1 were directlyco-cultured (experimental group), while the second generation of uninduced BMSCs was used as a control (control group). The growth and prol iferation abil ity were analyzed by MTT examination and the growth curve was drawn at 1-8 days. The osteoblasts and vascular endothel ial cells after being induced for 14 days were implanted in the allogeneic freeze-dried partially bone coated by 20% Col I or not at different densities (0.25 × 106/mL、0.50 × 106/mL、1.00 × 106/mL、2.00 × 106/mL、4.00 × 106/mL), as modified group and unmodified group, the cell adherence rate was calculated after 24 hours. These two kinds of cells were implanted in the pre-disposal treated allogeneic freeze-dried partially bone and observed by scanning electron microscope. Results ALP staining of osteoblasts showed that there were blue grains in cytoplasm at 7 days. CD31 and CD34 immunocytochemical staining of vascular endothelial cell showed that there were positive signals in the cytoplasm at 14 days. The MTT test showed that the prol iferation level of the experimental group was lower than those of the control group. There were significant differences in absorbance value between two group from 3 days to 8 days (P lt; 0.05). The cell adherence rate increased with increasing seeding density when the seeding density was (0.25-1.00) × 106/mL. The cell adherence rate reached the peak when the seeding density was 1.00 × 106/mL. The cell adherence rate decreased when the seeding density was more than 2.00 × 106/mL. There were significant differences in cell adherence rate between modified group and unmodified group at different seeding densities (P lt; 0.05). The prol iferation of the osteoblasts and endothel ial cells presented better growth and histocompatibil ity under scanning electron microscope. Conclusion The growing behavior of two kinds of cells is good in the allogeneic freezedried partially bone coated by 20% Col I , which can be used in reconstrction of vascularized tissue engineered bone.
PURPOSE:In search of the mechanism for photic retinal injury. METHODS:A visible light damage model was established in the primary cultured healthy,adult human RPE cells by using intense fluorescence light (2 400 Lx). RESULTS:Electron microscopy revealed swelling of the mitochondria and obscurity of nuclear membranous structure in the light damaged cells. The decrease or dissolution of organelle,vacuolization of cytoplasm and myelinic degeneration were found in some severely damaged cells. The level of intracellular SOD was decreased to 41% of that of the controls (P＜0.05). CONCLUSION:The structure of the RPE was damaged by the light radiation and the level of intracellular SOD was decreased. These suggested the light damage might be associated with the production of free radicals and the lipid perioxide reaction in membranous structure of cell. （Chin J Ocul Fundus Dis,1996,12: 174-175 ）
Purpose:To evaluate the function of gap junction-mediated intercellular communication in cultured cells of retinal pigment epithelial(RPE) cells from porcine eyes. Methods:The cultured RPE cells were previously stained by a fluorescent probe 5, 6-carboxy fluorescein diacetate (CFDA) ,and then photobleach the fluorescent molecule in chosed cells. Using laser scanning confocal microscope (LSCM)to observe fluorescence recovery rate of the RPE cells which located in different condition. The function of gap junction communication was evaluated according to the fluorescence recovery rate. Results:The fluorescence recovered after photobleached and the fluorescent density of cells which touching to them descend. The recovery rate per minnte of the cells which the cell number it adjacent to was 1,2 and 3 respectively was 1. 997plusmn;0. 665, 4. 378plusmn;0. 811 and 8. 736plusmn;2. 084. Conclusion:The cultured porcine RPE cells have the function of gap junction communication,and its function proportion is associate to its adjoining cells number. （Chin J Ocul Fundus Dis,1996,12: 41-42）
Objective To investigate the effects of epidermal growth factor (EGF)，fibroblast growth factor(FGF), and bovine serum on proliferation and apoptosis of the cultured fetal human retinal cells.Methods EGF and FGF were added or not to the medium of fetal human retinal cells cultured by bovine serum in vitro. The number of cells, bromodeoxyuridine(BrdU) incorporation and Tdt-mediated dUTP nick end labelling(TUNEL) were detected to determine the proliferation and apoptosis. Immunohistochemical staining of neuron specific enolase(NSE), Thy1.1, glial fibrillary acidic protein(GFAP) and scan electromicroscopy were performed to identify cell components. The expression of transcription factor c-fos, c-jun and apoptosis regulation factor bcl-2 and Bax were examined by immunohistochemical staining to explore the underlying mechanism.Results The increased number of NSE and Thy1.1 positive cells and BrdU incorporation, and decreased apoptotic cells were found in the groups treated with EGF and FGF. Meanwhile, the up-regulation of c-fos, c-jun and bcl-2 were also found. Conclusion EGF and FGF can promote the survival and proliferation of cultured retinal cells by up-regulating the expression of c-fos, c-jun and bcl-2. (Chin J Ocul Fundus Dis，2003，19：113-116)
ObjectiveTo investigate the protection and the corresponding molecular mechanisms of polypyramidine tract binding protein-associated splicing factor (PSF) overexpression on human retinal microvascular endothelial cells (hRMECs) induced by advanced glycation end-products (AGEs).MethodsThe hRMECs were divided into the normal group, the vector group, PSF group, zinc protoporphyrin (ZnPP) group and PSF+ZnPP group for experiment. Cells in the normal group were cultured in a DMEM medium containing 10% fetal calf serum, penicillin/streptomycin, and placed in a closed constant temperature incubator at 37 °C, 95% air, and 5% CO2. Cells in the vector group were infected with empty lentivirus. The cells in the PSF group were infected with overexpressing PSF lentivirus. Cells in the ZnPP group were treated with ZnPP (10 mol/L) for 2 h. The PSF+ZnPP group cells were infected with overexpressing PSF lentivirus, and then pretreated with ZnPP (10 mol/L) for 2 h. With the last four groups of cells stimulated with AGEs, HE, Hoechst33258 staining and flow cytometry were used to observe the protective effect of high expression of PSF on cell damage and the antagonistic effect of ZnPP on PSF. Western blot was used to detect the protein expression of heme oxygenase-1 (HO-1), phosphorylated (p) extracellular regulatory protein kinase (ERK), and Nrf2 in the cells. U0126, a specific antagonist of ERK pathway, was introduced, and Western blot verified the reversal effect of U0126 on the expression of HO-1 induced by PSF protein.ResultsHE staining and Hoechst33258 staining showed that the number of nuclei of damaged cells of PSF group were significantly increased compared with control group, while decreased compared with PSF+ZnPP group (F=27.5, 38.7; P＜0.05). The results of flow cytometry showed that the ROS produced by cells in the PSF group was significantly increased compared to the normal group, and significantly decreased compared to the PSF+ZnPP group, the difference was statistically significant (F=126.4, P＜0.05). Western blot results showed that HO-1 expression of PSF group was significantly increased compared with control and the vector group (F=70.1, P＜0.05). AGEs inducement of 30, 60, 120 and 240 min could significantly improve pERK expression compared with 15 min (F=474.0, P＜0.05). The expression of HO-1 and Nrf2 proteins in the PSF+/U0126－ group was significantly more than those in the PSF－/U0126－ group, the expression of HO-1 and Nrf2 proteins in the PSF+/U0126+ group was significantly lower than that in the PSF+/U0126－ group, and the differences were statistically significant (F=30.2, 489.4; P＜0.05).ConclusionOver expression of PSF can promote the HO-1 expression by activating ERK pathway and promoting the Nrf2 to the nucleus, thus protect hRMECs against AGEs-induced oxidative damage.