阿司匹林抗氧化作用机制的探讨

目的 探讨阿司匹林（AS）抗氧化作用的机制。方法 观察不同浓度的AS在抗H2O2损伤内皮细胞过程中诱导铁蛋白（Fn）表达的情况,以及添加外源性FeCI3和细胞内铁螯合剂去铁胺时对AS诱导Fn表达的影响。结果 极低剂量（0．1mmol/L）的AS即可诱导内皮细胞Fn表达超过对照25％（P＜0．05）,使乳酸脱氢酶（LDH）释放率减少50％,保护74．4％的细胞避免H2O2的损伤,同时使氧自由基指标丙二醛明显下降。AS与Fn表达之间表现出剂量与时间依赖关系,且对细胞的保护作用逐渐增强。但使用去铁胺去除细胞内游离铁能明显降低AS诱导Fn表达的作用,而加入FeCI3后诱导Fn表达的作用增强。结论 初步证实AS的抗氧化作用是通过影响细胞内铁代谢变化,增加Fn表达实现的。     

阿司匹林诱导内皮细胞铁蛋白表达与抗氧化损伤作用的研究

目的探讨阿司匹林(aspirin,As)在抗H2O2损伤内皮细胞过程中对铁蛋白(ferritin,Fn)表达的作用.方法体外培养人血管内皮细胞,酶联免疫吸附法(ELISA)测定As在不同浓度(0.1～3mmol/L)、不同处理时间(4～24h)对细胞Fn表达的影响,以及消炎痛和水杨酸钠对Fn表达的作用;并观察经As预处理后的细胞加入H2O2(0.5mmol/L)后乳酸脱氢酶(lactatedehydrogenase,LDH)释放率、丙二醛(malondialdehyde,MDA)和细胞存活率的改变.用单因素方差分析对上述指标进行统计学处理.结果小剂量As(0.1mmol/L)即可明显诱导内皮细胞Fn表达(5.8ng/106细胞数±0.3ng/106细胞数),与正常对照组比较P<0.05;且As与Fn之间表现出剂量和时间依赖关系,0.5mmol/L、1mmol/L、2mmol/L、3mmol/L组Fn浓度分别为(6.4±0.4)ng/106细胞数、(7.0±0.7)ng/106细胞数、(7.4±0.4)ng/106细胞数和(7.7±0.5)ng/106细胞数;4h组Fn尚未明显增加(5.8ng/106细胞数±1.0ng/106细胞数,P>0.05),但8h组Fn浓度(6.5±1.0)ng/106细胞数与正常对照组比较P<0.05,24h组Fn浓度达最大值(7.8±0.8)ng/106细胞数.As诱导Fn表达后能明显增强细胞抗氧化的能力,0.1mmol/L的As可减少细胞50%的LDH释放率,保护74.4%的细胞避免H2O2的损伤,同时使氧自由基指标MDA明显下降.并随As剂量的增大保护作用逐渐增强,其结果与未饱和铁蛋白组相似.而水杨酸钠及消炎痛则无诱导Fn表达的作用.结论As在较小剂量(0.1mmol/L)时即可明显诱导内皮细胞Fn的表达,增强其抗氧化损伤的能力;但其他非甾体类抗炎药不具有这个作用.     

HSPA1L在H2O2诱导SH-SY5Y细胞损伤中的作用

目的 研究HSPA1L蛋白在H2O2诱导SH-SY5Y细胞损伤中的作用.方法 将SH-SY5Y细胞用不同浓度的H2O2(1 200、800、600、400、200、100、50、0μmol/L)处理24 h,倒置显微镜观察SH-SY5Y细胞形态学的变化,MTF法检测SH-SY5Y细胞存活率,Western-blot检测SH-SY5Y细胞HSPA1L蛋白表达水平的变化.结果 与0 μmol/L组比较,不同浓度H2O2处理后,细胞形态发生了剂量依赖性损伤;SH-SY5Y细胞的存活率随H2O2浓度升高,呈现剂量依赖性降低;HSPA1L蛋白的表达水平随H2O2浓度升高,呈现剂量依赖性升高.结论 HSPA1L在H2O2诱导的SH-SY5Y细胞损伤模型中,呈现剂量依赖性升高,这可能是细胞应对氧化应激损伤的一种补偿机制.     

丹参素对H2O2诱导的内皮细胞氧化损伤的保护作用研究

目的:探讨丹参素对H2O2诱导人脐静脉内皮细胞(HUVEC)氧化损伤的保护作用。方法:采用MTT法测定丹参素对正常和H2O2损伤HUVEC活性的影响,筛选出最低有效剂量,并确定丹参素保护HU-VEC氧化损伤的浓度。通过活体探针标记、流式细胞术定量分析丹参素对损伤HUVEC细胞内活性氧(ROS)和线粒体膜电位的影响。结果:丹参素对正常HUVEC的活性无影响;而丹参素(25、50、250μmol/L)能显著降低H2O2诱导的HUVEC活性,具有一定的剂量依赖性,细胞活性分别为H2O2损伤组的120.72%、177.48%和736.48%(P<0.01)。丹参素可明显降低H2O2诱导的HUVEC内ROS水平(P<0.01)和提高线粒体膜电位(P<0.05,P<0.01)。结论:丹参素对H2O2诱导HUVEC损伤的保护作用可能是通过抑制细胞内ROS产生、减少线粒体膜损伤而发挥抗氧化作用。     

齐墩果酸对损伤血管内皮细胞的保护作用及其机制探讨

目的:探讨齐墩果酸(oleanic acid,OA)对过氧化氢(hydrogen peroxide,H2O2)诱导人血管内皮细胞(human umbilical vein endothelial cells,HUVECs)损伤的保护作用及其机制?方法:培养HUVECs,分为正常组?H2O2模型组?H2O2+OA (0.25 ?滋mol/L)组?H2O2+OA (0.50 ?滋mol/L)组?H2O2+OA (1.00 ?滋mol/L)组?H2O2+维生素C(1.50 mmol/L)组?各组培养24 h后,通过MTT法检测细胞增殖能力,酶生化法测定上清液中的乳酸脱氢酶(lactate dehydrogenase,LDH)和一氧化氮(nitric oxide,NO)含量,酶生化法测定细胞裂解液中的丙二醛(malondialdehyde,MDA)含量?谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)和超氧化物歧化酶(superoxide dismutase,SOD)活力,流式细胞仪测细胞内活性氧(reactive oxygen species,ROS)和细胞凋亡率?结果:OA能够恢复H2O2损伤的细胞活力,减轻H2O2诱导的LDH释放,减少H2O2诱导的MDA生成,恢复H2O2损伤的GSH-Px和SOD活力,清除H2O2诱导的ROS,减轻H2O2诱导的细胞凋亡,提高HUVECs细胞NO的生成?结论:OA对损伤血管内皮细胞有保护作用,这与OA能够启动HUVECs细胞内抗氧化防御机制,清除细胞内的ROS,提高HUVECs细胞NO的生成,抑制H2O2诱导的HUVECs细胞凋亡有关?     

原花青素对过氧化氢损伤血管内皮细胞的保护作用

目的:探讨原花青素对氧化损伤的人脐静脉内皮细胞(HUVEC)的保护作用。方法:体外培养内皮细胞,将细胞分为6组,即空白对照组(Control组)、氧化损伤组(H2O2组)、氧化损伤加入VitC对照组(VC+H2O2组)、氧化损伤加入原花青素5μmol/L、25μmol/L、50μmol/L浓度组(procyanidin-L+H2O2组、procyanidin-M+H2O2组、procyanidin-H+H2O2组)。将750μmol/LH2O2作用于加入VitC及不同浓度原花青素预培养24h的内皮细胞,继续培养18h,以细胞毒四唑盐(MTT)比色试验、乳酸脱氢酶(LDH)、一氧化氮(NO)、丙二醛(MDA)作为检测指标。结果:原花青素呈剂量依赖性降低H2O2对内皮细胞的生长抑制率,降低MDA、LDH量,增加培养液中NO2-/NO3-含量,各指标比较差异有统计学意义(P0.01)。结论:原花青素可保护和修复过氧化氢诱导的血管内皮细胞的损伤,其作用可能与抗氧化、促进NO释放有关。     

番茄红素对CHL细胞DNA氧化损伤的影响

目的研究番茄红素对CHL细胞氧化损伤的影响。方法在CHL细胞培养液中分别加入0.5、1、5及10μmol/L番茄红素,给予H2O2作用30min,用单细胞凝胶电泳方法测定细胞DNA损伤情况。结果加入不同剂量番茄红素的CHL细胞经过24h培养后自发性DNA损伤(拖尾率和DNA迁移长度)与溶剂对照组相比没有明显差异。而加入0.5、1、5μmol/L番茄红素后H2O2诱导的CHL细胞DNA损伤率明显低于H2O2组(P<0.05);但10μmol/L番茄红素对H2O2诱导的DNA损伤的保护作用丧失。结论0.5、1、5μmol/L番茄红素对H2O2诱导的细胞DNA损伤有保护作用,10μmol/L番茄红素的抗氧化能力丧失。     

当归红芪超滤膜提取物对过氧化氢致PC12细胞氧化损伤的影响

目的观察当归红芪超滤膜提取物对过氧化氢(H2O2)致PC12细胞氧化损伤的影响。方法 H2O2诱导PC12细胞构建氧化应激损伤模型;不同剂量当归红芪超滤膜提取物(0.38、0.75、1.5 g/L)干预;MTT法测定细胞存活率;生化法检测细胞内MDA、LDH、SOD含量;双氯荧光黄乙酸乙酯(DCF-DA)染色,检测细胞内ROS含量。结果 200μmol/L H2O2作用6 h成功诱导PC12细胞氧化应激损伤;与空白对照组比较,H2O2模型组细胞存活率下降,细胞内LDH、MDA、ROS含量增多,SOD含量下降(P0.05);与H2O2模型组相比,当归红芪超滤膜提取物各剂量组细胞存活率明显上升,细胞内LDH、MDA、ROS含量降低,SOD含量增加(P0.05)。结论当归红芪超滤膜提取物可修复H2O2诱导的PC12细胞氧化损伤。     

二苯乙烯苷对H2O2诱导损伤血管内皮

目的 研究二苯乙烯苷(TSG)对过氧化氢( H2O2)诱导损伤的人脐静脉内皮细胞单核细胞趋化蛋白1( MCP-1)表达的影响. 方法 体外培养人脐静脉内皮细胞,分为空白对照组、H2O2组(200 μmol/L H2O2)、辛伐他汀组(5 μmol/L辛伐他汀+200 μmol/L H2O2)、TSG组(1μmol/L TSG +200 μmol/L H2O2),按分组处理24h细胞后,运用逆转录聚合酶链式反应和酶联免疫吸附试验分别检测MCP-1 mRNA与其蛋白的表达. 结果 200 μmol/L的H2O2作用内皮细胞24h后,MCP-1的mRNA和蛋白水平均较空白对照组显著升高,P＜0.01.TSG预处理细胞后,MCP-1的mRNA和蛋白水平较H2O2组降低,差异有显著性(P＜0.05). 结论 TSG能抑制H2O2诱导损伤的人脐静脉内皮细胞MCP-1的表达.     

染料木黄酮对人血管内皮细胞氧化应激损伤的保护作用

目的 观察染料木黄酮(genistein, Gen)对人血管内皮细胞株EA hy.926氧化应激损伤保护效应并探讨其机制.方法 用H2O2建立氧化应激损伤模型,CCK-8法检测Gen对细胞活力的影响;流式细胞仪和TUNEL法检测Gen对氧化应激诱导细胞凋亡的影响;Western blot检测Gen对Bcl-2、Nrf2、HO-1表达的影响.结果 H2O2明显影响细胞活力和诱导凋亡(IC50为650 μmol/L),Gen(100～500 nmol/L)处理能显著抑制细胞活力下降,且细胞凋亡率由16.54%下降为6.18%;Gen对Bcl-2有上调作用;Gen能激活Nrf2/HO-1抗氧化途径.结论 Gen抑制血管内皮细胞的氧化应激损伤与对Bcl-2的调节和Nrf2/HO-1抗氧化途径的激活有关.     

A comparative study on the enhancement efficacy of specific and non-specific iron chelators for protoporphyrin IX production and photosensitization in HaCat cells

The iron chelators can be utilized in target cells to improve 5-aminolaevulinic acid （ALA）-based photodynamic therapy （PDT）. The purpose of this study is to compare the effect of two kinds of iron chelators, desferrioxamine （DFO） and ethylenediaminetetraacetic acid （EDTA） on the enhancement of ALA-PDT. HaCat cells were cultured in medium containing 2.0 mmol/L of ALA and 0.5 mmol/L of DFO or EDTA. After 3-h incubation in the dark, the concentration of cellular pro-toporphyrin Ⅸ （PpⅨ） was detected by high performance liquid chromatography （HPLC）, and the fluorescence of PpⅨ was observed at 630 nm emission under confocal laser scanning microscope. For PDT, HaCat cells were irradiated using 632.8 nm laser, and the fractions of apoptotic and necrotic cells were flow cytometrically assayed. Related differences in morphology and ultrastructure of Ha-Cat cells were observed using optical microscope or transmission electron microscope. Compared to incubation with ALA alone, the addition of DFO or EDTA increased the concentration of cellular PpⅨ and the fluorescent density of PpⅨ, and also increased cell death ratio after PDT. PDT using ALA plus DFO produced the highest cellular PpⅨ level, greatest cell death ratio and most severe structural damage to the cells. It was concluded that both DFO and EDTA could enhance ALA-based PpⅨ production and PDT. Compared to the non-specific iron chelator of EDTA, the specific chelator, DFO, showed more potential for the enhancement.     

阿司匹林对胃癌细胞增殖及血管生成相关因子作用的研究

目的:从抗血管生成的角度研究阿司匹林抗肿瘤作用的机理。方法:采用MTT法检测不同浓度阿司匹林对胃癌细胞增殖的影响;免疫细胞化学法检测阿司匹林对胃癌细胞COX-2、VEGF蛋白表达的影响。结果:①阿斯匹林对胃癌细胞的增殖具有抑制作用,随着作用时间的延长(F=402.062P<0.01),浓度的增加(F=50.141P<0.01),其抑制作用也增加。②当阿司匹林浓度为0 mmol/L、0.1 mmol/L、1.0 mmol/L、8.0 mmol/L时,COX-2蛋白质表达的A值分别为0.675±0.031、0.660±0.023、0.597±0.016、0.578±0.014,与0 mmol/L阿司匹林组相比,阿司匹林浓度为1.0 mmol/L8、.0 mmol/L组可明显抑制COX-2蛋白表达(P<0.05)。③阿司匹林浓度为0 mmol/L0、.1 mmol/L1、.0 mmol/L8、.0 mmol/L时,VEGF蛋白质表达的A值分别为0.480±0.014、0.457±0.027、0.407±0.032、0.363±0.029,与0 mmol/L阿司匹林组相比,阿司匹林浓度为1.0 mmol/L8、.0 mmol/L组可明显抑制VEGF蛋白表达(P<0.05)。结论:阿斯匹林对胃癌细胞增殖具有一定的抑制作用,其作用可能是通过对COX-2和VEGF等血管生成相关因子的抑制起作用。     

阿司匹林对血管内皮细胞增殖及磷酸化p44／42 MAPK表达的抑制作用

OBJECTIVE: To observe the effects of aspirin on vascular endothelial cell proliferation in vitro and on the activity of p44/p42 mitogen-activated protein kinase (MAPK) phosphorylation. METHODS: ECV 304 cells cultured in vitro were treated with aspirin (1, 2, 5, and 10 mmol/L, respectively) and observed for their proliferation in comparison with the control group. The ratio of cell proliferation was determined by non-radioactive MTS/PES assay. The expression of phosphorylated p44/42 MAPK protein was evaluated by the immunoblotting technique using anti-p44/42 phospho-MAPK antibody. RESULTS: The proliferation rate of the endothelial cell was 1.533+/-0.286 in the control group, and 0.459+/-0.107, 0.708+/-0.125, 0.953+/-0.149 and 1.253+/-0.225 in aspirin-treated groups corresponding to aspirin concentrations of 10, 5, 2 and 1 mmol/L, respectively. It was shown that aspirin significantly inhibited the vascular endothelial cell proliferation at the concentration above 1 mmol/L (P<0.05), in a dose-dependent manner as compared with the control group (P<0.05). The expression of phosphorylated p44/42 MAPK protein was significantly inhibited by aspirin. CONCLUSIONS: Aspirin decreases vascular endothelial cell proliferation, and arrest of endothelial cell proliferation may be an important mechanism by which aspirin produces protective effect against acute coronary disease.     

阿司匹林对肿瘤坏死因子-α诱导的大鼠平滑肌细胞syndecan-4蛋白及p44/42丝裂原活化蛋白激酶表达的影响

目的观察阿司匹林(ASA)对肿瘤坏死因子-α(TNF-α)诱导的离体大鼠血管平滑肌细胞(VSMCs)syndecan-4蛋白及磷酸化p44/42丝裂原活化蛋白激酶(MAPK)表达的影响。方法体外培养大鼠胸主动脉VSMCs,分别用20 ng/mL TNF-α、1 mmol/L ASA、2 mmol/L ASA、20 ng/mL TNF-α+1 mmol/L ASA、20 ng/mL TNF-α+2 mmol/L ASA作用24 h,并设立相关对照组进行比较。采用MTS/PMS法确定VSMCs的增殖状态,Western blot蛋白免疫印迹法测定VSMCs中syndecan-4蛋白及磷酸化p44/42MAPK表达。结果 (1)与对照组比较,TNF-α组能显著刺激大鼠VSMCs的增殖(P<0.01),单独应用ASA对大鼠VSMCs的增殖无明显作用(P>0.05)。TNF-α联合ASA组与TNF-α组比较,联用能明显抑制TNF-α诱导的大鼠VSMCs增殖(P<0.01)。(2)与对照组比较,TNF-α组能显著刺激大鼠VSMCs中syndecan-4蛋白及磷酸化p44/42MAPK的表达(P<0.01),单独应用ASA对二者的表达无明显作用(P>0.05)。TNF-α联合ASA组与TNF-α组比较,联用可显著降低这两种蛋白的表达水平(P<0.05)。结论一定剂量的ASA可明显抑制TNF-α诱导的大鼠血管平滑肌细胞syndecan-4蛋白及磷酸化p44/42MAPK蛋白的表达。     

Effective chelation of iron in beta thalassaemia with the oral chelator 1,2-dimethyl-3-hydroxypyrid-4-one

The main iron chelator used for transfusional iron overload is desferrioxamine, which is expensive, has toxic side effects, and has to be given subcutaneously. An orally active iron chelator is therefore required. The effects of oral 1,2-dimethyl-3-hydroxypyrid-4-one on urinary iron excretion were studied in eight patients who had received multiple transfusions: four had myelodysplasia and four beta thalassaemia major. Different daily doses of the drug up to 100 mg/kg/day, alone or in combination with ascorbic acid, were used. In three patients with thalassaemia the effect of the drug was compared with that of subcutaneous desferrioxamine at the same daily dose. In all eight patients a single dose of oral 1,2-dimethyl-3-hydroxypyrid-4-one resulted in substantial urinary iron excretion, mainly in the first 12 hours. Urinary iron excretion increased with the dose and with the degree of iron loading of the patient. Giving two or three divided doses over 24 hours resulted in higher urinary iron excretion than a single dose of the same amount over the same time. In most patients coadministration of oral ascorbic acid further increased urinary iron excretion. 1,2-Dimethyl-3-hydroxypyrid-4-one caused similar iron excretion to that achieved with subcutaneous desferrioxamine at a comparable dose. In some cases the iron excretion was sufficiently high (maximum 99 mg/day) to suggest that a negative iron balance could be easily achieved with these protocols in patients receiving regular transfusions. No evidence of toxicity was observed on thorough clinical examination or haematological and biochemical testing in any of the patients. None of the patients had any symptoms that could be ascribed to the drug. These results suggest that the oral chelator 1,2-dimethyl-3-hydroxypyrid-4-one is as effective as subcutaneous desferrioxamine in increasing urinary iron excretion in patients loaded with iron. Its cheap synthesis, oral activity, and lack of obvious toxicity at effective doses suggest that it should be developed quickly and thoroughly tested for the management of transfusional iron overload.     

Combined oral and parenteral iron chelation in beta thalassaemia major

Thalassaemics in Malaysia are poorly chelated because desferrioxamine is too expensive and cumbersome for long term compliance. The efficacy and tolerability of the oral chelator deferiprone, and the effects of using a combination therapy in our patients were studied. Ten patients completed the study and the mean serum ferritin reduced from 7066.11 ug/L (2577-12,896 ug/L) to 3242.24 ug/L (955-6120 ug/L). The liver iron concentration did not show a significant drop (19.6 vs 18.2 mg/g dry weight) although 3 patients showed reductions ranging from 30-40%. Concomitant use of desferrioxamine increased the urinary excretion from a mean of 13.66 mg/day to 27.38 mg/day. Main side effects seen were nausea and rashes.     

心血管病患者阿司匹林抵抗的临床特征

目的　探讨心血管病患者阿司匹林抵抗(AR)的临床特征。方法　对326例病情稳定的心血管病患者,采用血小板聚集仪分别测定花生四烯酸(AA)、二磷酸腺苷(ADP)诱导的血小板聚集率。阿司匹林抵抗即用0.5 mmol/L花生四烯酸使血小板平均聚集率≥20%,用10μmol/L二磷酸腺苷使血小板平均聚集率≥70%。阿司匹林半抵抗(ASR)即符合阿司匹林抵抗条件之一者。结果　阿司匹林抵抗发生率为4.9%(16/326),半抵抗发生率为27.6%(90/326)。与阿司匹林敏感(AS)者相比,AR的临床特征有:1)老年患者居多;2)女性患者居多;3)糖尿病患者居多;4)与高血压、高脂血症、红细胞计数、血红蛋白、血小板计数无关;5) 较少见于吸烟者。结论　阿司匹林抵抗发生率和国外报道相似,除老年、女性患者外,糖尿病也是阿司匹林抵抗的一个危险因素。     

Effect of aspirin on high glucose-induced senescence of endothelial cells

Background Endothelial cell senescence is accelerated under high glucose condition, which may contribute to the vascular complications in the diabetics, tt has been proved that aspirin has multiple cytoprotective effects. This study aimed to investigate the effect of aspirin on high glucose-induced endothelial cell senescence and its possible mechanism. Methods Human umbilical venous endothelial cells were cultured in Dulbecco＇s modified Eagle＇s medium （DMEM） with different treatments including the normal glucose （5.5 mmol/L）, high glucose （33 mmol/L） and aspirin （0.01-1.00 mmol/L） with high glucose. And 300 umol/L L-NAME was added to the culture medium when needed. After 48 hours, SA-13-gal staining was used to evaluate the senescence. Total nitric oxide （NO） production and NO synthase （NOS） activity were measured using Griess reaction and molecular probes of 3-amino-4-aminomethyl-2＇, 7＇- difluorescein, diacetate. The level of intracellular reactive oxygen species was monitored by flow cytometry using 2＇, 7＇-dichlorofluorescein diacetate. Endothelial NOS （eNOS）, caveolin-1 protein expressions and caveolin-1/eNOS interaction were analyzed by immunoblotting and immunoprecipitation respectively. Asymmetric dimethylarginine （ADMA） concentration was determined by high-performance liquid chromatography. Results Exposure to 33 mmol/L glucose for 48 hours significantly increased the number of SA-13-gal positive cells. Co-incubation with aspirin markedly inhibited SA-13-gal activity dose-dependently. Aspirin increased NOS activity with eNOS protein expression unchanged and increased NO levels and alleviated oxidative stress. Consistent with these findings, caveolin-1 expression, caveolin-1/eNOS interaction and ADMA accumulation were also decreased. All the inhibitory effects of aspirin on senescence were completely obliterated by L-NAME, the NOS inhibitor. Conclusion The anti-senescent effects of aspirin are fulfilled by increasing NO production via the up-regulation of NOS activity and preventing caveolin-1 expression, caveolin-1/eNOS interaction and ADMA accumulation.