ObjectiveTo investigate the influence of Ataxia-telangiectasia mutated (ATM) activation on cellular oxidative stress induced by high glucose in bovine retinal capillary endothelial cells(BRECs). Methods The BRECs were treated by different culture medium with various glucose concentrations (5 mmol/L glucose, 30 mmol/L glucose, 30 mmol/L glucose+10 μmol/L KU55933) as normal glucose group, high glucose group and treatment group respectively.After the cells incubated for 48 hours, the protein expression of ATM, P-ATM, Mitogen-Activated Protein Kinase P38(P38), P-P38, Extracellular signal-regulated kinases(ERKs), P-ERKs was detected by Western blot; cellular ROS level was detected by Reactive Oxygen Species Assay Kit; propidium iodide/Hoechst staining was used for analysis of apoptosis; the expression of vascular endothelial growth factor (VEGF) in the supernatant was determined by Enzyme-Linked Immunosorbent Assay (ELISA); the paracellular permeability between endothelium cells was detected by FITC-dextran. ResultsCompared with the protein level of P-ATM, P-P38 and P-ERKs in high glucose group increased. Especially, P-P38, P-ERKs expressed much more than in high glucose group. The secretion of VEGF in high glucose group was higher than that in the normal glucose group but less than that in treatment group. The same tendency existed in ROS assay, apoptosis assay and paracellular permeability measuring. ConclusionsHigh glucose induced altered activation of ATM which might play a protective role in cellular oxidative stress. Deficiency of ATM might lead to ROS explosion, cell apoptosis and dysfunction of endothelial barrier. The mechanism might be associated with P38, ERKs and VEGF.
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)
ObjectiveTo observe the stoichiometry of vascular endothelial growth factor receptor 2 (VEGFR2) on the retinal vascular endothelial cell membrane by single-molecule fluorescence imaging.MethodsRhesus monkey retinal vascular endothelial cells (RF/6A) were divided into blank control group (normal culture) and plasmid transfection group [transfected with VEGFR2-green fluorescent protein (GFP) recombinant plasmid]. The expression of GFP in the plasmid transfected group was observed by confocal microscope, and the expression of VEGFR2 in the cells was detected by real-time fluorescent quantitative polymerase chain reaction (qPCR) and Western blot. The fluorescence intensity distribution and bleaching steps of single VEGFR2-GFP molecule on the cell membrane were recorded by single-molecule imaging. The distribution of fluorescence intensity and the number of fluorescence bleaching steps of GFP were recorded.ResultsGFP green fluorescence was observed in the transfected cells 12 hours after transfection. qPCR results showed that the expression of VEGFR2 and GFP mRNA in the plasmid transfected group was significantly higher than that in the blank control group (t=11.240, 12.330; P＜0.001, 0.001). Western blot results showed that the expression of VEGFR2 protein in the plasmid transfected group was significantly higher than that in the blank control group (t=8.346, P＜0.01). The results of single-molecule imaging showed that the fluorescence intensity distribution of VEGFR2-GFP on the surface of RF/6A cell membrane without ligand stimulation was bimodal, in which monomer and dimer were 86.0% and 14.0% respectively. By counting the steps of GFP fluorescence bleaching, the proportions of receptor monomer, dimer, trimer, and tetramer were 81.4%, 12.9%, 5.5%, and 0.3% respectively.ConclusionIn the absence of ligands, VEGFR2 coexists in the form of monomers and dimers on the surface of RF/6A cell membrane, and monomers are dominant.
ObjectiveTo explore repressive effects of transthyretitin (TTR) on the growth of human retinal endothelial cells (hREC) under high glucose and hypoxia environment.MethodshRECs were divided into 8 groups, including normal glucose group (5.5 mmol/L glucose), hypoxia group, high glucose group (25.0 mmol/L glucose), high glucose and hypoxia group, normal glucose group+TTR, normal glucose and hypoxia group+TTR, high glucose group+TTR, high glucose and hypoxia group+TTR. Flow cytometry was used to analyze cellular apoptosis. The expression level of Akt, p-Akt, eNOS, Bcl-2 and Bax protein were measured by Western blot.ResultsHypoxia could induce apoptosis as the apoptosis rate of normal and hypoxia group was higher than normal group (χ2=25.360, P＜0.05), high glucose and hypoxia group was higher that high glucose group (χ2=17.400, P＜0.05). The cell apoptosis rate of high glucose and hypoxia group+TTR were increased significantly as compared with high glucose and hypoxia group (χ2=9.900, P＜0.05). There was no statistically significant difference on the cell apoptosis rate between normal group and high glucose group, normal group+TTR and normal group, high glucose group+TTR and high glucose group, normal and hypoxia group+TTR and normal and hypoxia group (P＞0.05). Western blot showed that the expression of Akt did not change significantly in all eight groups（F=2.450, P＞0.05). Compared to normal group, the expression of p-Akt, eNOS, Bcl-2 in normal and hypoxia group were decreased (t=9.406, 5.306, 4.819), and the expression of Bax (t=?4.503) was increased (P＜0.05). Compared to high glucose group, same trend was found in high glucose and hypoxia group (t=8.877, 7.723, 6.500, ?14.646; P＜0.05). The expression of p-Akt in normal and hypoxia group+TTR was higher than normal and hypoxia group (t=?5.024, P＜0.05) , but there was no difference on the expression of eNOS, Bcl-2, Bax between these two groups (t=?2.235, ?2.656, ?0.272; P＞0.05). Compared to high glucose and hypoxia group, the expression of p-Akt and Bcl-2 in high glucose and hypoxia group+TTR were decreased (t=4.355, 4.308; P＜0.05), the expression of Bax was increased (t=?4.311, P＜0.05), and there was no difference on the expression of eNOS between these two groups (t=?1.590, P＞0.05). There was no statistically significant difference in the expression of p-Akt, eNOS, Bcl-2, Bax between high glucose group and normal group (t=?3.407, ?4.228, ?4.302, ?2.076; P＞0.05), normal group+TTR and normal group (t=?4.245, ?4.298, ?2.816, ?1.326; P＞0.05), high glucose group+TTR and high glucose group (t=4.016, ?0.784, 0.707, ?0.328; P＞0.05).ConclusionUnder high glucose and hypoxia, transthyretitin suppress the growth of hREC through Akt/Bcl-2/Bax, but not Akt/eNOS signaling pathway.
Objective To investigate the effect of surface propertyof different polyether-ester block copolymers［poly(ethylene glycol-terephthalate)/poly(butylene terephthalate), PEGT/PBT］ on the growth of smooth muscle cells (SMCs) and endothelial cells(ECs). Methods Three kinds of copolymers were synthesized, which were 1000-T20 (group A), 1000PEGT70/PBT30 (group B) and 600PEGT70/PBT30 (group C). The water-uptake and contact angle of three polyether-ester membranes were determined. The canine aorta smooth muscle cells and external jugular vein endothelial cells were primarily harvested, subcultured, and then identified. The proliferation of SMCs and ECs on the different polyether-ester membranes were investigated. Results The water-uptake of three copolymers arranged as the sequence of group C＜group A＜group B, and contact angle as the sequence of group C＞group A＞group B, indicating group B being more hydrophilic. However, smooth musclecells andendothelial cells grew poorly on the membrane of group B after low density seeding, but proliferated well on the membranes of group A and group C. Conclusion In contrast with more hydrophilic 1000PEGT70/PBT30, moderately hydrophilic 1000-T20 and 600PEGT70/PBT30 has better compatibility with vascular cells. The above results indicate that the vascular cells can grow well on moderately hydrophilic PEGT/PBT and that PEGT/PBT can be used in vascular tissue engineering.
Objective To observe the vascular endthelial cellular apoptosis induced by transpupillary thermotherapy (TTT). Methods Vascular endothelial cells (VEC) cultured in vitro were treated with TTT, hyperthermia and TTT combined with indocyanine green (ICG) pretreatment. The cellular apoptosis was detected by doublelabelled flow cytometer (annexin Vfluroescein isothiocyanate and propidium iodide) analysis, fluorescent microscopy, nucleolus stainned with DNA dye hoechst 33258, DNA ladder detection and electron microscopy. Results Without significant rising of the temperature, TTT couldnprime;t increase the apoptosis of VEC. Pure hyperthermia and TTT combined with ICG pretreatment could increase apoptosis of VEC significantly, and the effect of the latter method was more obvious. The higher power of TTT was used and the longer duration the cells were cultured, the higher apoptosis rate of VEC was. Conclusion The induction of apoptosis of VEC might play an important role in the mechanism of the occlusion of CNV by TTT, and combining with ICG may obviously enhance the apoptosis rate at the same temperature, which may supply a theoretical basis for promoting the clinical effect of TTT.
Objective To explore morphological recellularization level of bioprosthetic valve scaffold (BVS) and to provide researching means for fabricating tissue engineered heart valve in vitro.Methods The homograft bioprosthetic aortic tube valve was selected as BVS, which was conserved by liquid nitrogen, and its endothelial cells (ECs) were removed by 0.1% sodium dodecylsulphate (SDS). As implantation cells, the endothelial cells (ECs) differentiating from human bone marrow mesenchymal stem cells (MSCs) in vitro were implanted with high-density seeding (gt;10 5 cells/cm2) on the BVS, which was covered by fibronectin (80 μg/ml) in advance. The complex structure was statically cultured in DMEM (high glucose) with 20% FBS and VEGF (10 ng/ml) for about 20 days in vitro and stained by 0.5% AgNO3. The morphological structure was observed and photographed by stereomicroscope to detect the recellularization level. Results The ECs of the bioprosthetic valve were notonly removed completely, but also the collagen fiber and elastic fibers were reserved. The ECs differentiating from MSCs were successfully implanted on the HBS, whose recellularization levels on 7th, 14th and 20th day were 73%, 85%, and 92% respectively. Conclusion AgNO3 staining technique is effective, convenient, and economic in evaluating the recellularization level of BVS. It is an effective method in morphological observation for fabricating tissueengineered heart valve in vitro.
ObjectiveTo address the effect and mechanism of interleukin 17 (IL-17) on the proliferation, migration and apoptosis of human retinal vascular endothelial cells (HREC). MethodsIL-17 receptor (IL-17R) mRNA and protein expression in human retinal vascular endothelial cells (HREC) were quantified by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Cell proliferation of HREC was examined using CCK-8 assay in the presence of different concentrations of IL-17. Cell migration of HREC was detected using wound scratch assay. Flow cytometry was used to test the effect of IL-17 on the apoptosis of HREC. The effects of IL-17 on HREC expression of basic fibroblast growth factor (bFGF), Caspase-3 and thrombospondin-1 (TSP-1) were quantified by reverse transcriptase polymerase chain reaction (RT-PCR). The effect of IL-17 on HREC expression of Caspase-3 was examined using Western blot. ResultsIL-17 receptor (IL-17R) expressed in HREC as quantified by RT-PCR and Western blot. The proliferation of HREC in the presence of IL-17 was promoted in a dosage-dependent manner (t=-3.235, -6.276;P=0.032, 0.000). Wound scratch assay showed a significant increase in the migrated distance of HREC with IL-17 stimulation under the concentration of 100μg/L(t=-3.551, -2.849; P=0.006, 0.019), 200μg/L(t=-10.347, -4.519; P=0.000, 0.001) and 500μg/L (t=-3.541, -2.607; P=0.008, 0.036). The intervention of 200μg/L IL-17 can effectively inhibit the apoptosis of HREC, compared with the control group using flow cytometry (t=5.682, P=0.047). RT-PCR results showed that IL-17 can promote the expression of bFGF and inhibit the expression of Caspase-3 and TSP-1. Western blot result also showed that IL-17 can suppress the protein expression of Caspase-3. ConclusionThe mechanism of IL-17 promoting proliferation, migration but suppress apoptosis of HREC may via regulating the expression of bFGF and Caspase-3.
Intravitreal injection of anti-VEGF drugs has gradually become the first-line treatment for diabetic retinopathy (DR). However, diabetic macular edema (DME) caused by DR blood-retinal barrier damage is less sensitive to anti-VEGF drugs.Therefore, it is necessary to find supplementary drugs or alternative drugs that can effectively protect the structure of the blood vessel wall. Melatonin is a hormone mainly secreted by the pineal gland, which can play a number of functions in the human body such as regulating biological rhythms, scavenging free radicals, and anti-inflammatory. In recent years, studies have shown that melatonin can improve neuronal degeneration and protect blood vessel structure through multiple mechanisms in retinopathy. In terms of its protective effect on the retinal capillary structure, melatonin can improve the damage of early DR endothelial cells and pericytes through anti-oxidative stress, anti-inflammatory, and inhibiting cell apoptosis so as to protect the integrity of the blood-retinal barrier structure. It suggests that melatonin may provide new ideas for the prevention and treatment of DR, especially with DME.
ObjectiveTo observe the expression in vitro and the influence of adenovirus-mediated recombinant Tum5 gene to the proliferation, migration and tubing of Rhesus RF/6A cell under high glucose. MethodsTo construct the adenovirus vector of recombinant Tum5 gene (rAd-Tum5), and then infected RF/6A cell with it. The Flow Cytometry was used to detect the infection efficiency. RF/6A cells were divided into normal group, high glucose (HG)-control group (HG group), empty expression vector group (HG+rAd-GFP), and HG+rAd-Tum5 group. Western blot was used to detect the expression of Tum5. The CCK-8 test was applied to detect the proliferation of RF/6A cell, the Transwell test was applied to detect the migration and the Matrigel test was applied to detect the tubing of RF/6A cell under high glucose. The proliferation, migration and tubing of RF/6A were tested respectively by CCK-8 test, Transwell test and Matrigel test. ResultsThe adenovirus vector of recombinant Tum5 gene was successfully constructed. The infection efficiency of rAd-Tum5 in RF/6A cell was 50.31% and rAd-GFP was 55.13% by the Flow Cytometry. The results of Western blot indicated that Tum5 was successfully expressed in RF/6A cell. The result of CCK-8 test, Transwell test and Matrigel test indicated that there were statistical differences between all groups in proliferation, migration and tubing of the RF/6A cell (F=44.484, 772.666, 137.696;P < 0.05). The comparison of each group indicated that the HG group was higher than normal group (P < 0.05). There were no statistical differences between HG group and HG+rAd-GFP group (P > 0.05). However, the HG+rAd-Tum5 group was less than HG group (P < 0.05), and the same to HG+rAd-GFP (P < 0.05). ConclusionThe adenovirus vector of recombinant Tum5 gene can inhibit the proliferation, migration and tubing of RF/6A cell under high glucose.