Objective To examine the influence of retinal pigment epithelium(RPE) cells on antigen-specific activatedlymphocytes in vitro,and to explore the role of RPE cells in the immune privilege of the eye. Methods Co-culture systems of RPE cells with antigen-specific T lymphocyte lines and resting T lymphocytes were established in vitro．Induction of apoptosis was detected by genomic DNA electrophoresis,DNA in situ end-labelling and flow cytometry. Results RPE cells induced apoptosis in antigen-specific activated T lymphocytes. 24 hours after culture,the signs of apoptosis appeared in lymphocytes co-incubated with RPE cells．As time of co-culture went on,the number of apoptosic cells increased．Quantitative analysis of apoptosic cells showed that apoptosic cells accounted for 5.95% after 24 hours, 9.38% after 48 hours,and 17.95% after 72 hours．In contrast,RPE cells induced few apoptosis in resting T lymphocytes. Conclusions These results suggest that RPE cells possess the ability to induce the apoptosis of invading lymphocytes. This phenomenon serves as a restrain mechanism of immune response and may be of vital importance in the maintenance of immune privilege in posterior segment of eye and in the protection of eye from the damage of immunogenic inflammation. (Chin J Ocul Fundus Dis, 1999, 15: 241-244)
Purpose To investigate bax expression and induction of apoptosis in normal cultured retinal pigment epithelium (RPE) cells ． Methods Cultured human RPE cells were transfected by PMDNA3-hbax，which incoded the whole bax gene and may be induced by Zn2+ under the MTII promoter， through lepofectin mediated protocol．The tested RPE cells were divided into three groups of A，PMDNA3-hbax transfected ;B，PMDNA3 (nude vector) transfected and C ，normal RPE cells．After transfection， DNA gel electrophoreses were perform ed ，the tested RPE cell cycles were analyzed with flow cytometry (FCM)． Results The gel electrophoretogram showed DNA ladder phenomenon，FCM confirmed the apoptosis of RPE cells PMDNA3-hbaxtransfected ， consisting of significant apoptotic peak sited before the G 1 phase and the apoptotic rate was 36%． Conclusion The foreign bax gene can be effectively conducted in to the RPE cell through lepofectinmediated protocol and induced expression ． The foreign bax overexpression may induce the cultured human RPE cell susceptibi lity to apoptosis． (Chin J Ocul Fundus Dis, 2001,17:132-134)
ObjectiveTo investigate the expression of costimulatory molecules( B7，CD28, and CTLA-4) of peripheral blood lymphocytes in patients with Behcet′s disease(BD).MethodsLymphocytes were obtained in 24 patients with BD and 20 healthy individuals, and the expression of CD80(B7-1), CD86(B7-2), CD28 and CTLA-4 on T and B cells were detected by direct three-color immunofluorescence flow cytometry.ResultsSignificantly increased expression of CTLA-4 on CD 4+ T cells[(3.18±1.18)%]was found in BD patients compared with that in controls[(1.73±0.66) %](t=－3.722,P＜0.01). The expression of CD86 on CD19+B cells was also significantly increased in BD patients[(4.49±1.73)%]compared with that in controls[(2.40±1.49) %] (t=-2.071,P＜0.05). No significant difference in the expression of the other costimulatory molecules was found.ConclusionsInteraction of B7 and CD28 on peripheral lymphocytes promote the occurrence of uveitis in BD patients. Intervention with these costimulatory signals may lead to a new prevention or treatment for uveitis patients.(Chin J Ocul Fundus Dis, 2003,19:357-359)
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.
ObjectiveTo explore the effect of the serum high mobility group box-1 (HMGB1) on oncosis of pancreatic acinar cells in the rat with severe acute pancreatitis (SAP). MethodsThirty-two healthy SD rats were randomly divided into 2 groups:sham operation group (SO group, n=8) and SAP group (n=24). Rats of SO group were only flipped the intestinal canal after laparotomy, but rats of SAP group were induced by retrograde injection of 3% sodium taurocholate into bilio-pancreatic duct in addition. Rats of SO group were sacrificed at 6 hours after operation, and rats of SAP group were sacrificed at 6 (SAP-6 hour group, n=8), 12 (SAP-12 hour group, n=8), and 24 hours (SAP-24 hour group, n=8) after operation respectively. Pancreatic tissues were stained by HE to observe pathological changes. Serum HMGB1 was measured by ELISA, and the oncosis percentage of pancreatic acinar cells was examined by flowcytometry. ResultsPathological results showed that structural integrity was observed in pancreatic acinar, and occasionally a single inflammatory cell infiltration was observed in rats of SO group. Swelling, interstitial edema, and inflammatory cell infiltration were observed in rats of SAP-6 hour group. Some necrosis of pancreatic acinar cell, stromal vascular congestion, and focal necrosis were observed in rats of SAP-12 hour group and SAP-24 hour group, which the pathological damage were worse over time. Levels of serum HMGB1 and oncosis percentages of pancreatic acinar cells in rats of 3 SAP subgroups were all higher than those of SO group (P < 0.01), and the 2 kinds of indexes both increased over time (P < 0.05). There was positive correlation between concentration of serum HMGB1 and oncosis percentages of pancreatic acinar cells in SAP rat during 24 hours after operation (r=0.846, P < 0.01). ConclusionsHMGB1 seems to play an important role in SAP by inducing oncosis of pancreatic acinar cells when inducing inflammatory reaction in rat with SAP.
Human SW480 colonic cancer cell line was evaluated for its growth response to pentagastrin, gastrin receptor antagonist proglumide (PGL) in vitro by MTT assay and flow cytometry. The results showed that gastrin possessed a proliferative effect on SW480 cell, PGL alone had no obvious effect on SW480 cell, but it inhibited gastrin-induced growth of SW480 cell with dosage dependent when it was used with gastrin, its inhibitive effect did not steadly increase at a dose＞32μg/ml. This suggests that effect of gastrin is achieved via gastrin receptor. Gastrin promoted the sythesis of DNA, protein and triggered the cancer cell shifting from phase G0/G1 to phase S, G2M. PLG inhibited the effect of gastrin, it suggests that gastrin possessed a proliferation on SW480 cell at post receptor is achieved by the effect of gastrin on cell cycle.
Objective To investigate the changes of CD4 + CD25 + Foxp3 + regulatory T cells( Treg) in peripheral blood of patients with acute exacerbation of COPD( AECOPD) , and analyze the relationship of CD4 + CD25 + Foxp3 + Treg with insulin resistance. Methods A total of 79 patients with AECOPD were divided into four groups according to disease severity( 11 cases in stage Ⅰ,31 cases in stage Ⅱ,28 cases in stage Ⅲ, an 9 cases in stage Ⅳ) .42 healthy volunteers were recruited as control. Fast blood glucose( FBG) and fast insulin( FINS) were measured for calculating the insulin resistance index. The CD4 + CD25 + Foxp3 + Treg were detected by flow cytometry. The relationship between the proportion and number of CD4 + CD25 + Foxp3 + Treg with insulin resistance was statistically analyzed. Results Compared with the healthy control group, the levels of FBG, FINS, and insulin resistance index in the AECOPD patients were significantly higher ( P lt; 0. 01, P lt; 0. 05) . The proportion and number of CD4 + CD25 + Foxp3 + Treg in peripheral blood decreased significantly( P lt; 0. 01, P lt; 0. 05) . The insulin resistance index increased with the severity of AECOPD while the proportion and number of CD4 + CD25 + Foxp3 + Treg in peripheral blood decreased. The insulin resistance index in the AECOPD patients of stage Ⅲ and Ⅳ were higher than those of stage Ⅰ and Ⅱ. The proportion and number of CD4 + CD25 + Foxp3 + Treg in the AECOPD patients of stage Ⅲ and Ⅳ were significantly lower than those of stage Ⅰ and Ⅱ. Both the proportion and number of CD4 + CD25 + Foxp3 + Treg were negatively correlated with insulin resistance ( r = - 0. 633, - 0. 871, P lt; 0. 01) . Conclusions CD4 + CD25 + Foxp3 + Treg cells might may play important role in modulating insulin resistance in AECOPD. The more serious the disease, the lower the CD4 + CD25 + Foxp3 + Treg and the worse insulin resistance.
Objective To clarify the relationship between inhibition of proliferation and cxpression of Ki-67 in cultured human retinal pigment epithelial(RPE) cells. Methods The cultured human RPE cells were treated with daunoblastina at a dose of 180 mu;g/L for 12h.Twenty-four hours later,DNA inhibiting rate was studied by using tritium-labelled thymidine deoxyribose(3H-TdR)incorporation assay.The expression of Ki-67 was evaluated by immunocytochemical staining technique and image analysis system.Flow cytometry was used to analyse cell cycle. Results DNA inhibiting rate was directly proportional to the dosage of daunoblastina.The proportion of the cells positive staining to Ki-67 in the control and the daunoblastina-treated group were 89.3% and 45.6%(Plt;0. 01),and the integral optical density values for expression of Ki-67 in the two groups were 68.1plusmn;6.2 and 27.3plusmn;5.5(Plt;0.01),respectively.The percen tage of cells in G2 phase of cell cycle increased from 8.9% to 29.5%. Conclusion G2 block was induced and poliferation was inhibited by daunoblastina in cultured human RPE cells.There is a relatively good correlation between Ki-67 immunostaining and inhibition of RPE cell proliferation. (Chin J Ocul Fundus Dis，2000，16：1-70)
【Abstract】 Objective To investigate the effect of IGF-1 on the growth of primary human embryonicmyoblasts. Methods The method of incorporation of 3H-TdR was used to evaluate the abil ity of prol iferation of myoblasts.The count per minute (CPM) values of myoblasts at different concentrations(1, 2, 4, 8, 16 and 32 ng/mL) of IGF-1 were measured,and dose-effect curves were drawn to choose the optional concentration of IGF-1 to promote the prol iferation. Then theexperimental group of myoblasts received the addition of the optional concentration of IGF-1 in the growth medium, the controlgroup just received the growth medium. The flow cytometry was used to detect the cell cycle . The method of incorporation of3H-TdR was used to measure the peak-CPM. The myotube fusion rate was measured in myoblasts with different concentrations(0, 5,10, 15, 20, 25 and 30 ng/ mL) of IGF-1 in fusion medium, the dose-effect curves were also drawn, so as to decided the optional concentrationof IGF-1 in stimulating differentiation. Fusion medium with optional concentration of IGF-1 was used in experimentalgroup, and the control group just with fusion medium. The fusion rate of myotube and the synthesis of creatine kinase(CK) weredetected in both groups. Results The optional concentration of 5 ng/mL IGF-1 was chosen for stimulating prol iferation . It was shown that the time of cell cycle of control was 96 hours, but that of the experimental group was reduced to 60 hours. The results of flow cytometry showed that the time of G1 phase, S phase and G2M phase was 70.03, 25.01 and 0.96 hoursrespectively in control group, and were 22.66, 16.47 and 20.87 hours respectively in experimental group. The time-CPM value curves showed that the peak-CPM emerged at 96 hours in control group and 48 hours in experimental group, which was in agreementwith the results of the flow cytometry. The optional concentration stimulating prol iferation was 20 ng/mL IGF-1. Compared with control, the quantity of CK was increased by 2 000 mU/mL and the fusion rate was elevated by 30% in experimental group. Conclusion The concentrations of 20 ng/mL IGF-1 can elevat obviously the fusion rate and the quantity of CK. IGF-1 can enhance the prol iferation and differentiation of myoblasts via inducing the number of myoblasts at G1 phase and increasing the number of myoblasts at S and G2M phases.