Obiective lt;brgt;To investigate the change of the activity of proliferation in cultivated Muuml;ller cells treated by advanced glycation endoproducts (AGEs), and the effect of these changes on expression of occludin in bovine retinal vascular endothelial cells (BREC). lt;brgt;Methods lt;brgt;The cultivated Muuml;ller cells were devided into normal growth group and cultured with AGEs group. The cultured BREC were devided into 4 groups:group 1, without any medium; group 2, with normal growth Muuml;ller cell medium (MCM); group 3,MCM treated by AGEs; group 4, without cell as the control. Enzyme-linked immuno sorbent assay was used to detect the content of occludin in the medium in the 4 groups. lt;brgt;Results lt;brgt;The content of expression of occludin was the most in group 2, less in group 1, and the least in group 3. lt;brgt;Conclusion lt;brgt;AGEs may promote the abnormal proliferation of Muuml;ller cells and inhibit the expression of occludin in BREC. lt;brgt;(Chin J Ocul Fundus Dis, 2006, 22: 28-30)
Objective To investigate the effects of advanced glycation endproducts (AGEs) on proliferation of pericytes of bovine retinal capillary vessels and expression of transforming growth factor beta;(TGF-beta;). Methods The proliferation of pericytes detected by methyl thiazolyl tetrazolium (MTT) colorimetric assay, cellular cycle of pericytes was analyzed by flow cytometry was used to analyze cell, and TGF-beta; protein expression of pericytes was observed by immunofluorescent staining. Results AGEs inhibited the proliferation of pericytes of bovine retinal capillary vessels, stopped the cellular cycle of pericytes in synthesis phase (S phase), increased the number of apoptotic cells obviously (Plt;0.01), and promoted the expression of TGF-beta; proteinof perycytes. Conclusions AGEs may promote the apoptosis of pericytes by inhibiting the proliferation of pericytes to lead the decrease of pericytes number, and may accelerate diabetic retinopathy by promoting the expression of TGF-beta; protein of pericytes. (Chin J Ocul Fundus Dis, 2006, 22: 20-23)
Objective To investigate the effect of advanced glycation end products (AGEs) on the catalase activity and the levels of malondialdehyde in cultured bovine retinal capillary pericytes (BRPs), and to investigate the relationship between oxidative stress and diabetic retinopathy. Methods Cultured BRPs were exposed to AGEs (0, 8, 32, 125, 500, 2 000 μg/ml) for four days. Activity and the levels of catalase and malondialdehyde in cultured BRPs were examined by spectrophotometry. Results AGEs decreased the catalase activity, whereas increased the levels of malondialdehyde of cultured BRPs in a dose-dependent manner (r=-0.714, r=0.748, P＜0.01).There were significant differences between BRPs cultured in 32 μg/ml AGEs and in control group (P＜0.01), while no significant differences between BRPs cultured in non-glycated bovine serum albumin and absence of bovine serum albumin were found. Conclusion Oxidative stress may be one of the reasons why the pericyte disappears in diabetic retinopathy. (Chin J Ocul Fundus Dis, 2002, 18: 143-145)
Objective To investigate the effects of glycation pro ducts on growth and cytosoic free calcium (［Ca2+］i) of bovine retinal capillary pericytes. Methods The changes of growth and ［Ca2+］i of bovine retinal pericytes,which were cultured in early glycation products of bovine serum albumin (EG-BSA) and advanced glycation end products of bovine serum albumin (AGE-BSA),were studied by counting cell numbers,MTT colorimetric assay,［3H］thymidine incorporating,and fluorescent indicator fura-2 acetoxymeth1 ester (Fura-2AM). Results The number of alive pericytes in groups of EG-BSA and AGE-BSA were 17.87plusmn;2.36 and 14.77plusmn;3.72 which comparing with their control groups (20.54plusmn;0.82 and 20.31plusmn;0.93)were de creased 13．00% and 27．00% (Plt;0.01) by counting cell numbers on a counting plate after four days.The results were 0.4619plusmn;0.0946 and 0.3884plusmn;0.1031 which comparing with their control groups (0.5236plusmn;0.0539 and 0.5227plusmn;0.0519)were decreased 12．00% and 25.70% (Plt;0.01) by MTT colorimetric assay.Amount of ［3H］thymidine incorporating in groups of EG-BSA and AGE-BSA were 39450.16plusmn;887 0.68 and 33667.85plusmn;10581.70 which comparing with their control groups (56373.63plusmn;2317.97 and 56542.04plusmn;1961.23)were decreased 30．00% and 40.40% (Plt;0.01).The ［Ca2+］i concentration of pericytes in groups of EG-BSA and AGE-BSA were (129.55plusmn;30.41) nmol/L and (179.71plusmn;56.69) nmo l/L which comparing with their control groups ［(79.70plusmn;6.94) nmol/L and (83.plusmn;6.39) nmo l/L］ were increased to 163．00% and 214．00%. Conclusion Both EG-BSA and AGE-BSA can inhibit the proliferation and DNA syntheses of retinal capillary pericytes,and increased ［Ca2+］i concentration in pericytes,especially the AGE-BSA. (Chin J Ocul Fundus Dis，2000，16：139-212)
【摘要】 目的 观察晚期糖基化终产物（advanced glycosylation end prodrcts，AGE）对人结肠癌细胞株SW-480增殖的影响，并探讨其可能机制。 方法 不同浓度AGE干预SW-480细胞，噻唑蓝（MTT）法比较各组细胞活力，流式细胞术观察AGE对SW-480细胞周期的影响，蛋白质印迹法观察AGE对SW-480细胞CyclinD1表达的影响，端粒重复序列扩增法（telomeric repeat amplification protocol，TRAP）银染法观察AGE对SW-480细胞端粒酶活性的影响。MTT测细胞活力的检测设置空白对照组、100 μg/mL小牛血清白蛋白（bovine serum albumin，BSA）组及50、100、500 μg/mL AGE组，其余检测只设置100 μg/mL BSA组和100 μg/mL AGE组。 结果 MTT结果示AGE促进SW-480细胞的增殖，且呈浓度依赖性。100 μg/mL BSA组与100 μg/mL AGE组72 h后的细胞G0/G1期所占百分比分别为56.02%±0.58%、51.93%±1.01%，差异有统计学意义（Plt;0.05）。蛋白质印迹法示100 μg/mL AGE组72 h后CyclinD1的表达较100 μg/mL BSA组增加，差异有统计学意义（Plt;0.05）。TRAP银染法检测示100 μg/mL AGE干预SW-480细胞72 h后可以增加端粒酶活性（Plt;0.05）。 结论 AGE可促进人结肠癌细胞SW-480生长，呈剂量依赖性。其作用机制可能与AGE上调CyclinD1的表达加速G1/S期转换及增加端粒酶活性有关。【Abstract】 Objective To observe the effects of advanced glycosylation end products (AGE) on proliferation of SW-480 cells and study the possible mechanism. Methods Various concentrations of AGE were designed to have impact on SW-480 cells. Proliferation of SW-480 cells was assessed by thiazolyl blue tetrazolium bromide (MTT) assay; The impact of AGE on the cell cycle of SW-480 cells was analyzed by flow cytometry (FCM); the influence of AGE on expression of CyclinD1 was checked by Western blotting; and the impact of AGE on telomerase activity was examined by telomeric repeat amplification proctol (TRAP) sliver staining. For the MTT assay, blank control group, 100 μg/mL bovine serum albumin (BSA) group, 50, 100 and 500 μg/mL AGE groups were designed, while for other examinations, there were only 100 μg/mL BSA group and 100 μg/mL AGE group. Results MTT result showed that AGE increased the proliferation of SW-480 cells in a dose-dependent mode. The proportion of the cells at G0/G1 stage of the 100 μg/mL BSA group and the 100 μg/mL AGE experimental group were (56.02±0.58)% and (51.93±1.01)% respectively after 72 hours, with a significant difference (Plt;0.05); western blotting showed that the expression of CyclinD1 in the 100 μg/mL AGE group was significantly higher than that in the 100 μg/mL BSA group after 72 hours; TRAP silver staining demonstrated that telomerase activity increased significantly after treated with 100 μg/mL AGE for 72 hours. Conclusions AGE can promote the growth of SW-480 cells in a dose-dependent mode. Its mechanism is mainly by up-regulating the expression of CyclinD1 to shorten G0/G1 and increasing the telomerase activity significantly.
Objective To study the expression of receptor of advanced glycation end products (RAGE) in autogenous vein graft of streptozotocin induced diabetic rats and the inhibitory effects of aminoguanidine on intimal hyperplasia. Methods Sixty male Sprague-Dawley rats were randomly divided into three groups: aminoguanidine group, distilled water group and control group. Autogenous vein graft models were established in all groups. Streptozotocin was injected into abdominal cavity to induce diabetes in both aminoguanidine group and distilled water group, and they were intragastric administrated with aminoguanidine or distilled water, respectively before and after transplantation. Specimens were collected from autogenous vein graft 7 days and 14 days after surgery to undergo histological examination. At the same time, the level of serum advanced glycation end products (AGE) was tested. Western blotting and immunohistochemistry were used to detect the protein expression of RAGE and NF-κB p65. RAGE and NF-κB p65 mRNA were measured by reverse transcription-PCR. Results The mRNA and protein expressions of RAGE, NF-κB p65, the level of serum AGE and the intimal thickness of vein graft in distilled water group increased in comparison with those in control group 7 days and 14 days after surgery （P＜0.05). The level of serum AGE, mRNA and protein expressions of NF-κB p65 and the intimal thickness of vein graft in aminoguanidine group were lower than those in distilled water group （P＜0.05), and showed no significant difference compared with control group （P＞0.05). Conclusion The over-expression of RAGE in vein graft activats NF-κB in streptozotocin-induced diabetic rat, which has a close relation with intimal hyperplasia. Aminoguanidine can block the binding of AGE and RAGE by inhibiting the production of AGE, which will prevent intimal hyperplasia of vein graft.