Objective To observe the differentiation effect of rabbit amnion-derived stem cells (ADSC) induced into neural cells.Methods ADSC of New Zealand female rabbits were isolated and cultured. Its mRNA level of Fibronectin, Nestin and Vimentin were detected by real-time quantitative polymerase chain reaction. The selfreplication ability of ADSC was confirmed by monoclonal formation experiments. These ADSC were further induced into neural cells in vitro. Five days after induced differentiation, the expression of -tubulin and glial fibrillary acidic protein (GFAP) were detected by immunofluorescent staining. Results ADSC were separated from amnion tissue gradually after 24 hours. There were polygonal cells gathered around the amnion tissue at 72 hours, and were distributed compactly around the amnion at 120 hours. The morphology of cleavage daughter cells was basically the same as parent cells. ADSC has the ability of self-replication. The Nestin, Vimentin, Fibronectin mRNA expressions in ADSC were 15.79, 1.91, 7.65 times those in spleen cells. The differences were statistically significant(Z=-5.243, -3.972, -2.524; P＜0.05). The beta;-tubulin expression was found in cytoplasm of most cells. The GFAP expression was found in cytoplasm in some cells. Conclusions ADSC has self-replication ability. It can be induced into neurons and neuroglial cells under the right conditions.
Objective To observe the effect of visible light (white light, red light, blue light) on the expression of reactive oxygen species (ROS), 8-OHdG and hOGG1 in cultured human retinal pigment epithelial (RPE) cells. Methods Cultured human RPE-19 cells (4th-6th generations) were divided into white light, red light, blue light and control group. The illumination was 600 Lux. The cells of experimental groups were exposed to white light or red light for 6, 12, 24 and 48 hours, and exposed to blue light for 1, 3, 6 and 12 hours, while cells of the control group were cultured in foil packaged dishes to avoid light. The levels of ROS expression were detected by 2prime;,7-dichlorofluorescin-diacetate (DCFH-DA), the levels of 8-OHdG protein expression were observed by immunocytochemistry (ICC), and the levels of hOGG1 were measured by western blot. Results Compared to the control group, the ROS expression in RPE cells were increased in white and red light group after 12, 24 and 48 hours and in blue light group after 1, 3, 6 and 12 hours (Fwhite light=11.611, Fred light=6.706, Fblue light=23.259; P＜0.05 ). Additionally, the ROS expression had a tendency to increase gradually along with exposure time. Compared to the control group, the 8-OHdG expression in RPE cells were increased significantly in both white and red light group after 12, 24 and 48 hours and in blue light group after 1, 3, 6 and 12 hours (Fwhite light=16.032,Fred light=6.378, Fblue light=19.484;P＜0.05). Additionally, the 8-OHdG expression in white and red light group were increased gradually with exposure time but decreased when exposure time was up to 48 hours, while that in blue light group was increased firstly though it started to decrease when exposure time was up to 6 hours. Compared to the control group, the hOGG1 expression in RPE cells were increased in white and red light group after 12, 24 and 48 hours and in blue light group after 6 and 12 hours (Fwhite light=15.121,Fred lig=21.041,Fblue light=12.479;P＜0.05). Conclusions Exposure to white, red or blue light could induce ROS production and DNA oxidative damage in RPE cells in a time-dependent way. Exposure to visible light could switch on self-protection of RPE cells against DNA oxidative damage by up-regulating of the hOGG1 expression.
Objective To investigate the effect of peritoneal exudative cells as feeder cells on growth state of primary culture of adult rat retinal Muuml;ller cells. Methods Peritoneal exudative cells were gained from adult rats, which were identified with specifically biological marker of macrophage (CD68). The phagocytosis was evaluated by the ink particles experiment. Retinal Muuml;ller cells of adult rats were cultured by enzyme digestion method, and identified by GFAP and vimentin immunocytochemically. As the feeder cells, peritoneal exudative cells were cocultured with Muuml;ller cells. The proliferation cycle of Muuml;ller cells was assayed by flow cytometry. One-step TUNEL staining was employed to detect the apoptotic Muuml;ller cells. Results Over ninety-five percent of rat peritoneal exudative cells were macrophage, which have a favourable phagocytic ability for the ink particles. The primary cultured Muuml;ller cells adhered to the wall of flask and grew fast, with large applanate cell bodies. The third-generation cells grew slowly. After cocultured with feeder cells, the Muuml;ller cells showed more rapid growth rate with more cells in S and G2/M phase(S phase, t=4.172, Plt;0.001; G2/M phase, t=3.562, Plt;0.01） and less apoptotic rate (t=3.804, Plt;0.01). The growing cycle was cut down from 25-30 days to 1822 days for the firstgeneration cells, from 10-15 days to 7-10 days for the second-generation cells. Conclusion It is an effective method to use the peritoneal exudative cells as feeder cells cocultured with primary culture of retinal Muuml;ller cells, which can shorten the culture period of Muuml;ller cells in adult rats.
Objective To investigate the experimental condition and mechanism of differentiation of human umbilical cord blood derived mesenchymal stem cells（hUCB-MSC）into neuron-like cells induced by recombined human epidermal growth factor （rhEGF） and taurine in vitro.Methods hUCB-MSC were primary cultured in Dulbeccoprime;s modified Eagle's medium/F12 （DMEM/F-12）which supplemented with 105U/L penicillin G, 100 mg/L streptomycin sulfate, 10% fetal bovine serum (FBS),5% autologous plasma,4 mmol Lglutamine, 30 ng/ml rhEGF.The DMEM/F-12 medium was replaced by taurine medium after 3 passages.The expression of surface antigen CD90,CD29,CD34,CD44 and CD45 were detected by flow cytometry；the expression of neuron specific enolase,rhodopsin and nestin were investigated by immunocytochemistry. The statistical method was chi square test.Results Morphologically similar to bonemarrow MSC,hUCB-MSC became attached cells after the first 5 to 7 days in culture，and reached 80% to 90% confluent after 3 to 4 weeks. Growth accelerated after passage. hUCB-MSC were positive for CD29,CD44 and CD90 but negative for CD34 and CD45. After taurine induction, 2515/3120 cells expressed NSE, 1168/3175 cells expressed rhodopsin and 903/3050 cells expressed nestin while only 234/2965 cells expressed NSE in the control group(P＜0.01).Conclusion rhEGF and taurine can induce hUCB-MSC differentiating into neuronlike or rhodopsin positive cells.
Objective To isolate neural stem cells (NSCs) from rabbit retina and brain, and induce differentiation of those NSCs using different culture media. Methods Single-cell suspensions of retina and cerebral cortex were prepared from rabbit embryo, cultured in 5 types of different media to isolate the NSCs by continual passages. After 3 passages, NSCs were induced to differentiation in 2 types of different media for 8 to 10 days. NSCs and inducedretinal cells were examined by immunofluorescence and flow cytometry for the expression pattern of some specific antigens.Results Immunofluorescence showed that NSCs from retina and brain, cultured in serumfree media, both expressed Nestin partially. Flow cytometry showed that Nestin positive cells were significantly decreased while the Rhodopsin and Thy1.1 positive cells were increased after induction. Compared with the combined induction of alltrans retinoid acid (ATRA) and serum, 5%FBS (fetal bovine serum) led to higher expression of Rhodopsin（P＜0.01），but lower expression of Thy1.1（P=0.01）.Conclusion Serumfree media with N2, EGF, bFGF, LIF is the best for NSCs purification. Both induciton media can induce NSCs to differentiate.Retina NSCs have higher potentials to differentiate into retinal neuroepithelial cells than brain NSCs.
Objective To investigate the feasibility of differentiation of invitro induced rat bone marrowderived mesenchymal stem cells（rMSCs） into retinal pigment epithelial （RPE） cells.Methods The rMSCs from BrwonNorway (BN) rats were isolated and cultured by adherent screening method. RPE cells lysate made by repeated freezethawing was put into the rMSCs culture system to identify whether the induced cells could express characteristic label cytokeratin（CK）and S-100 simultaneously or not.Results The growth rate of rMSCs induced by RPE cells lysate was slower and protuberant burr surrounded the fusiform cells. The results of immunoblotting and double immunofluorescence showed that partial induced cells expressed CK and S-100 simultaneously. The result of flow cytometry indicated that 14.1% induced cells expressed CK and S-100 simultaneously.Conclusion Induced by RPE cells lysate, rMSCs can differentiate into RPE cells.
Objective To investigate the expression of Human leucocyte antigen(HLA)-DP, -DQ, -DR and CD40 in human retinal pigment epithelial (RPE) cells, to determine their molecule expression in immune response process, and their abilities to stimulate T lymphocyte activation. Methods Human RPE cells were cultured with or without (IFN respectively. Expression of HLA-DP, -DQ, -DR and CD40 was measured by immunohistochemical staining. Meanwhile, peripheral blood mononuclear cells (PBMC) were cocultured with RPE cells in vitro, and then the expression of activated lymphocytes CD69 was measured by fluorescence activated cell sorter(FACS). Results Expression of HLA-DP, -DQ, -DR and CD40 antigen were enhanced by gamma;-interferon inducement. Increasing amount of CD69 positive lymphocytes were found in the co-culture system of RPE cells and PBMC. Conclusion T-lymphocytes in the peripheral blood were activated by human RPE cells which is antigen presenting cells with immunological characteristics potential.
Objective To investigate the protective effect and mechanism of erythropoietin (EPO) on injury of human retinal pigment epithelial (hRPE) cell induced by hydrogen peroxide (H2O2). Methods Take subcultured hFRPE cells as study target. They were treated with 800 mu;mol/L of H2O2 for 3 hours to establish the cell injury model. The cultured cells were divided into three groups：control group, simply injury group and therapeutic group which again divided into 10 IU/ml, 20 IU/ml, 40 IU/ml,60 IU/ml subgroups according to the concentration of recombinant human erythropoietin(rhEPO). NF-kappa;B was measured by immunohistochemistry. The content of Malondialdehyde(MDA) which was the product of cellular lipid peroxidation and the releasing rate of lactate dehydrogenase（LDH）were estimated by chromatometry. Results H2O2 could elevate the level of MDA and the releasing rate of LDH, compared simply injury group with control group, the differences were significant.(tLDH＝29.746,tMDA＝20.426,Plt;0.05); Compared all of therapeutics groups with simply injury group, the releasing rate of MAD and LDH were decreased obviously, the differences were significant.（LDH t10IU＝5.770，t20IU＝12.774，t40IU＝19.818，t60IU＝24.833，Plt;0.05；MDA t10IU＝5.345，t20IU＝10.278，t40IU＝18.571，t60IU＝20.247，Plt;0.05）; The correlative analysis results of each therapeutic subgroup were: ①the concentration of rhEPO had negative correlation with the relation rate of LDH and the content of MDA(r=-0.976，P=0.024； r=-0.968，P=0.032) ; ②the concentration of rhEPO had positive correlation with the nuclear translative rate of NF-kappa;B(r=0.998，P=0.002); ③the nuclear translative rate of NF-kappa;B had negative correlation with the content of MDA(r=－0.954，P=0.046). Conclusion EPO can protect hFRPE cells from the injury of H2O2, the mechanism may be related to the activation of NF-kappa;B.
Objective To establish a rapid in vitro culture method of human choroidal endothelial cells (HCEC) and the cellular Characteristics to provide an in vitro model for researches of choroiretinal diseases which involved the HCEC. Methods The human choroidal tissues were digested in two steps by trypsin and collagenase, and the HCEC were obtained and cultured after the digested cell suspension was sorted and purified with magnetic beads of CD31 Dynabeads. The characteristics of HCMEC were observed by the morphologic observation method, transmission electron microscopy, and immunohistochemical staining with FⅧ factor, CD31, and CD34. Results The cultured HCEC were polygonal and oval, and after amalgamation, the cells had slabstone-like appearance. After the subculture, the configuration of HCEC remained the same, and represented cobblestone appearance with less magnetic beads attached on the cellular surface after HCEC converged into a single layer. The Weibel-Palade body which is the characteristic marker of endothelial cells was found. The staining of FⅧ fatcor, CD31, CD34 were positive. Conclusion HCEC can be cultured in vitro successfully with our method, which is easy to get sufficient number of highly purified HCEC. (Chin J Ocul Fundus Dis, 2007, 23: 126-129)
Objective：To investigate the role of 17beta; estradiol on th e expressi on of vascular endothelial growth factor (VEGF) and on the releasing rate of lac tate dehydrogenase (LDH) in cultured anoxiainjured human retinal pigment epit h eliual (RPE) cells. Methods:Established the anoxiainjuried m odel of human RPE c ells with Cobalt Chloride (CoCl2) after RPE cells were pretreated with 17beta;E 2 and tamoxife, 17beta;E2 antagonist. The expression of VEGF mRNA was detecte d by re v erse transcriptionpolymerase chain reaction technique (RTPCR). The cultured RP E cells were divided into four groups: normal control group, anoxiainjured gro u p, 17beta;E2 pretreatment group and 17beta;E2 with tamoxifen pretreatment grou p. The releasing rate of LDH was detected by chromatometry. The expression of VEGF pro tein were detected by cellular immunohistochemistry. Results:T he expression of VEGF and LDH releasing rate were higher in anoxiainjured grou p than that in nor m al control group (P＜0.05), and were lower in 17beta;E2 pretreatment group than th at in anoxiainjured group （P＜0.05）. When the effect of 17beta;E2 was o bstructe d by tamoxifen, the expression of VEGF and LDH releasing rate increased but didn prime;t differ much from which in anoxiainjured group (P＞0.05). Conc lusion:The ex pression of VEGF increases in anoxiainjured human RPE cells. 17beta;E2 can do wnr egulate the expression of VEGF and decrease the releasing rate of LDH, which can be blocked by tamoxifen.