Ghrelin通过核因子-κB抑制肿瘤坏死因子-α诱导的HepG2细胞PAI-1 mRNA表达

目的探讨Ghrelin对肿瘤坏死因子-α(TNF-α)诱导的HepG2细胞纤溶酶原激活物抑制剂-1(PAI-1)mRNA表达的影响及核因子-κB(NF-κB)在其中的作用.方法HepG2细胞培养,加入不同浓度TNF-α,采用逆转录-聚合酶链反应测定(RT-PCR)检测PAI-1 mRNA的水平;免疫印迹法检测胞浆胞核NF-κBp65和胞浆κB抑制蛋白(IκB)的表达.给予Ghrelin预处理1 h后,加入TNF-α检测NF-κKBp65和IκB表达的变化.结果TNF-α(0.1,1,10μg·L-1)浓度依赖地增高HepG2细胞PAI-1 mRNA的表达;Ghrelin组的PAI-1 mRNA表达减少.TNF-α组胞核NF-κBp65表达增加,胞浆IκBα的表达减少;Ghrelin组较TNF-α组胞核NF-κBp65减少,胞浆IκBα的表达增加.结论TNF-α通过NF-κB介导HepG2 PAl-1mRNA的表达;Ghrelin通过抑制NF-κB而抑制TNF-α诱导PAI-1mRNA的表达.     

Exendin-4体外通过抑制NF-κB-iNOS-NO信号减轻氧化应激诱导的小鼠MIN6胰岛β细胞凋亡

探讨胰高血糖素样肽-1受体激动剂Exendin-4(Ex-4)在氧化损伤诱导胰岛β细胞凋亡中的保护作用.培养的MIN6胰岛β细胞,通过AO-EB染色观察细胞凋亡形态,Annexin-V-PI染色流式技术测定凋亡率,Griess法检测细胞内一氧化氮水平,Western blotting检测胞浆iNOS蛋白、胞浆及胞核核因子-κBp65(NF-κBp65)蛋白表达水平.Ex-4可抑制叔丁基过氧化氢(t-BHP)诱导的β细胞凋亡,Ex-4(100nmol·L-1)预处理较单独t-BHP处理,其凋亡率减少约67%(P<0.001).Ex-4同时减少NO水平的增高,并抑制t-BHP诱导的β细胞NF-κBp65活化及iNOS蛋白表达水平.Ex-4可能通过抑制细胞内NF-κB活化、胞浆iNOS表达来抑制NO水平,最终减轻氧化损伤诱导的β细胞凋亡.     

穿心莲内酯对人肺腺癌A549细胞NF-κB通路的调控作用

目的探讨穿心莲内酯对肿瘤细胞生长的作用及机制。方法人肺腺癌A549细胞分别与穿心莲内酯1.5～30μmol·L-1作用24h,以及穿心莲内酯30μmol·L-1作用4～24h。用MTT法检测A549细胞存活率;Western印迹法检测在肿瘤坏死因子α(TNF-α)10μg·L-1刺激下,穿心莲内酯30μmol·L-1对NF-κB信号通路中的相关蛋白NF-κB抑制因子α(IκBα)、磷酸化IκBα、IκB激酶β(IKKβ)和磷酸化IKKβ表达的影响;ELISA法检测穿心莲内酯对A549细胞核内NF-κBDNA结合活性的影响。结果穿心莲内酯的浓度和作用时间与A549细胞的存活率密切相关,穿心莲内酯30μmo·lL-1作用24h,A549细胞的存活率下降到(22.0±1.2)%,而穿心莲内酯1.5μmol·L-1作用24h或者穿心莲内酯30μmol·L-1作用4h对A549细胞的存活率几乎无影响。Western印迹法显示,穿心莲内酯能够抑制TNF-α诱导的NF-κB信号通路中IKKβ的磷酸化,抑制IκBα的磷酸化,推迟IκBα的降解,对IKKβ的表达无影响。穿心莲内酯还能够抑制TNF-α诱导的A549细胞核内NF-κBp65蛋白的DNA结合活性,抑制率达32%。结论穿心莲内酯通过影响NF-κB信号通路抑制A549细胞的生长。     

原花青素二聚体B_2对大鼠滑膜细胞NF-κB核转运及炎症因子表达的影响

目的通过观察原花青素二聚体B2(procyanidins di-mer B2,PCB2)对大鼠滑膜细胞NF-κB核转运及相关炎症因子表达的影响,探讨其抗炎的分子机制。方法免疫荧光法观察NF-κB/p65在细胞中的定位,RT-PCR检测PCB2对诱导细胞的COX-2 mRNA表达,Western blot分析COX-2蛋白含量变化,ELISA测定各处理组细胞上清液中IL-1β、VEGF的含量变化。结果 TNF-α(10μg.L-1)诱导RSC-364细胞NF-κB从细胞质转运至细胞核,50μmol.L-1 PCB2明显抑制NF-κB/P65核转运;PCB2剂量依赖性抑制COX-2基因和蛋白的表达;PCB2下调了TNF-α诱导的IL-1β、VEGF的水平。结论 PCB2能有效抑制COX-2、IL-1β及VEGF的表达,其机制可能与抑制TNF-α诱导的NF-κB核转运,抑制NF-κB活化有关。     

H_2O_2预处理对NF-κB的激活作用特征及其细胞保护作用

目的探讨H2O2预处理对核转录因子-κB(NF-κB)的激活作用,并观察NF-κB在H2O2预处理诱导的适应性细胞保护中的作用。方法在PC12细胞建立H2O2预处理对抗高浓度H2O2诱导细胞凋亡的实验模型,分组如下:(1)空白对照组;(2)预处理组;(3)损伤组;(4)预处理+损伤组;(5)TPCK+预处理+损伤组;(6)TPCK组。应用碘化丙啶(PI)染色流式细胞术检测细胞凋亡率,甲氮甲唑蓝(MTT)法检测细胞存活率,免疫印迹法(Westernblot)测定NF-κB的表达水平,电泳迁移实验(EMSA)检测NF-κBDNA结合活性。结果H2O2预处理PC12细胞上调NF-κBp65的表达,增强DNA结合活性,并能明显地增加高浓度H2O2引起的NF-κBp65的表达(与损伤组比较,P<0.01)。H2O2预处理能使PC12细胞对抗高浓度H2O2引起的损伤,提高细胞存活率,降低细胞凋亡率(与损伤组比较,P<0.01)。NF-κB抑制剂甲苯磺酰苯丙氨酰氯甲酮(TPCK)可拮抗H2O2预处理对NF-κBp65的激活作用,并减弱H2O2预处理诱导的适应性细胞保护作用(与预处理+损伤组比较,P<0.01)。结论H2O2预处理对NF-κB的激活作用可能是其引起的适应性细胞保护机制之一。     

川芎嗪对LPS致心肌细胞损伤的影响及机制研究

目的探讨川芎嗪对脂多糖(LPS)诱导的大鼠心肌细胞损伤及NF-κB核移位的影响。方法采用原代培养SD乳鼠心肌细胞,经终浓度分别为40、80、120μmol·L-1川芎嗪预处理后,用10 mg·L-1LPS处理6 h,处理完成后检测培养液乳酸脱氢酶(LDH)活性,四唑盐(MTT)比色法检测心肌细胞存活率,流式细胞法检测ROS生成,试剂盒检测细胞内丙二醛(MDA)含量及细胞内抗氧化酶(SOD、GSH-Px)活性、Western blot法检测核蛋白中NF-κB p65的变化情况。结果不同剂量川芎嗪(40、80、120μmol·L-1)预处理3 h后可明显降低LDH活性,增加细胞存活率,降低ROS生成,减少MDA含量,升高SOD、GSH-Px活性,抑制NF-κB p65在细胞核中的表达,且呈剂量依赖性。结论川芎嗪可抑制LPS所致的心肌损伤,其机制与减少脂质过氧化、增强抗氧化酶系、降低ROS生成、抑制NF-κB p65核移位有关。     

抗氧化剂2-吲哚啉酮衍生物对NF-κB信号通路的抑制作用

目的探讨2-吲哚啉酮衍生物(PMID)对NF-κB信号通路的调控作用。方法用PMID 2,5和10μmol·L-1预处理HEK293T细胞2 h,加入肿瘤坏死因子α(TNF-α)10μg·L-1刺激8 h。用双荧光素酶报告基因系统检测PMID对TNF-α诱导的NF-κB报告基因和ICAM启动子报告基因的影响;对照组HEK293T细胞单用TNF-α10μg·L-1处理,实验组用PMID 10μmol·L-1预处理细胞2 h,加入TNF-α10μg·L-1,分别在0,10,30,60 min后收取细胞,Western蛋白印迹法检测PMID对TNF-α诱导的IκBα降解和P65入核的影响;对照组用PMID 10μmol·L-1处理HEK293T细胞12 h,实验组用10μmol·L-1PMID处理4 h,后用TNF-α10μg·L-1刺激8 h。采用实时荧光定量PCR检测PMID对NF-κB信号通路下游靶基因白细胞介素6(IL-6)、单核细胞趋化因子(MCP)和干扰素γ(IFN-γ)表达的影响。结果 TNF-α单用组与正常对照组比较,NF-κB和IFN-β报告基因活性明显增加(P<0.01),ICAM报告基因活性增加(P<0.05)。PMID预处理细胞后再采用TNF-α刺激,与TNF-α单用组比较,PMID 2μmol·L-1时,NF-κB和IFN-β报告基因活性降低(P<0.05),ICAM报告基因活性无明显变化;PMID 5μmol·L-1时,NF-κB和IFN-β报告基因活性明显降低(P<0.01),ICAM报告基因活性降低(P<0.05);PMID 10μmol·L-1时,NF-κB,ICAM和IFN-β报告基因活性明显降低(P<0.01)。与TNF-α单用组比较,PMID预处理后再用TNF-α处理,在10,30和60 min 3个时间点,IκBα表达增高(P<0.05),细胞核中P65表达减弱(P<0.05),胞浆中的P65表达增加(P<0.05)。加入PMID后,与正常对照组相比,对NF-κB下游靶基因IL-6和MCP的表达明显抑制(P<0.01),对IFN-γ有一定的抑制作用(P<0.05);加入TNF-α刺激后,与正常对照组相比,IL-6,MCP和IFN-γ表达均显著增高(P<0.01);加入PMID处理后,与TNF-α单用组比较,IL-6,MCP和IFN-γ表达均明显下降(P<0.05)。结论 PMID作为抗氧化剂,可负调控NF-κB信号通路。     

文冠果壳苷诱导人恶性黑色素瘤A375.S2细胞的凋亡及机制

目的观察文冠果壳苷对人恶性黑色素瘤A375.S2细胞增殖抑制作用及诱导凋亡的机理。方法采用四甲基噻唑蓝法(MTT法)检测化合物对细胞的生长抑制作用,光学显微镜及荧光显微镜观察细胞形态学变化,免疫印迹法(Western blotting)检测p-p38、p38、核转录因子-κB(nuclear factor kappa B,NF-κB)p65及核转录抑制因子-κB(nuclear factor kappa B inhibitor,I-κB)蛋白表达水平,检测细胞核内NF-κB p65表达水平。结果文冠果壳苷可浓度依赖性地抑制A375.S2细胞增殖,并优于5-氟尿嘧啶(5-FU);10μmol·L-1文冠果壳苷作用于A375.S2细胞,形态学观察发现明显的凋亡小体和核固缩;Western blotting检测发现文冠果壳苷可时间依赖性地降低p-p38、p38、NF-κB p65及I-κB的蛋白表达水平;文冠果壳苷抑制NF-κB p65自细胞浆到细胞核的转位。结论文冠果壳苷可能通过抑制NF-κB和p38的活化诱导人恶性黑色素瘤A375.S2细胞凋亡。     

淫羊藿次苷Ⅱ通过调节IKK/IκB/NF-κB信号通路抑制脂多糖诱导的星形胶质细胞炎症反应

目的研究ICSⅡ对脂多糖(LPS)诱导的星形胶质细胞炎症反应的作用。方法体外分离新生SD大鼠脑皮质组织提取原代星形胶质细胞并进行培养。将星形胶质细胞分为空白组、空白+ICSⅡ高浓度组、模型组、模型+ICSⅡ低浓度组、模型+ICSⅡ中浓度组、模型+ICSⅡ高浓度组、模型+地塞米松组。ICSⅡ(5,10,20μmol·L-1)或DSMX(1μmol·L-1)预处理星形胶质细胞1 h后,继续与LPS共同作用24 h。采用MTT法检测ICSⅡ作用于星形胶质细胞的安全浓度范围,确定安全浓度后再观察ICSⅡ对LPS诱导的星形胶质细胞炎症反应的影响;采用ELISA法检测星形胶质细胞中TNF-α,IL-1β,NO,Aβ1-40和Aβ1-42的水平;采用Western蛋白免疫印迹技术检测COX-2,i NOS,IκB-α,NF-κB(p65)(胞核),NF-κB(p65)(胞质)和BACE1的蛋白表达,以及NF-κB(p65)、IKK-α和IKK-β磷酸化水平;采用分子对接技术模拟ICSⅡ与BACE1蛋白的结合。结果 ICSⅡ(0～50μmol·L-1)对星形胶质细胞无毒性作用。模型组较空白组星形胶质细胞中TNF-α,IL-1β和NO水平均显著上升(P<0.05);细胞炎症通路蛋白COX-2,i NOS,NF-κB(p65)(胞核)及BACE1表达升高(P<0.05);IκB-α和NF-κB(p65)(胞质)表达显著降低(P<0.05);NF-κB(p65),IKK-α和IKK-β的磷酸化水平明显上升(P<0.05)。给予ICSⅡ能够明显降低TNF-α,IL-1β和NO水平(P<0.05)。此外,ICSⅡ显著下调炎症相关蛋白COX-2,i NOS,NF-κB(胞核)及BACE1的表达(P<0.05),明显上调NF-κB(胞质)和IκB-α蛋白表达(P<0.05)。同时,明显降低NF-κB(p65),IKK-α和IKK-β的磷酸化水平(P<0.05),对LPS诱导的IκB-α降解、NF-κB活化及细胞核易位均具有显著的抑制作用。结论本研究条件下,ICSⅡ通过调节IKK/IκB/NF-κB信号通路发挥其对LPS诱导的星形胶质细胞炎症损伤的保护作用。     

FK228对HepG2细胞NF-κB活化及炎症因子转录的影响

目的:研究FK228对TNF-α诱导的人肝癌细胞HepG2核转录因子κB(nuclear factor-κB,NF-κB)活化及炎症因子IL-6、IL-8转录的影响。方法:培养的HepG2细胞分为对照组、TNF-α刺激组和FK228干预组。分别用TNF-α刺激和FK228+TNF-α共同作用,免疫印迹(Western blot)法分析细胞核中NF-κBp65及其细胞浆中抑制因子IκBα的表达;RT-PCR对炎症因子IL-6、IL-8 mRNA作半定量分析。结果:FK228(4～32μg·L~(-1))干预组与TNF-α刺激组比较,细胞核内NF-κB显著减少(P<0.01);FK228(8～32μg·L~(-1))减少胞浆中IκBα的降解且各组之间差异有统计学意义(P<0.01);FK228降低TNF-α诱导的IL-6、IL-8 mRNA表达,FK228干预组与TNF-α刺激组相比,差异具统计学意义(P<0.01)。结论:FK228减少胞浆中IκBα降解、阻碍NF-κB的过度活化可能是降低炎症因子释放、发挥抗炎作用的重要机制。     

Genotoxicity of acrylamide in human hepatoma G2 (HepG2) cells

The recent finding that acrylamide (AA), a carcinogen in animal experiments and a probable human carcinogen, is formed in foods during cooking raises human health concerns. The relevance of dietary exposure for humans is still under debate. The purpose of the study was to evaluate the possible genotoxicity of acrylamide in human hepatoma G2 (HepG2) cells, a cell line of great relevance to detect genotoxic/antigenotoxic substances, using single cell gel electrophoresis (SCGE) assay and micronucleus test (MNT). In order to clarify the underlying mechanism(s) we evaluated the intracellular generation of reactive oxygen species (ROS) and the level of oxidative DNA damage by immunocytochemical analysis of 8-hydroxydeoxyguanosine (8-OHdG). The involvement of glutathione (GSH) in the AA-induced oxidative stress was examined through treatment with buthionine sulfoximine (BSO) to deplete GSH. The results indicate that AA caused DNA strand breaks and increase in frequency of MN in HepG2 cells in a dose-dependent manner. The possible mechanism underlies the increased levels of ROS, depletion of GSH and increase of 8-OHdG formation in HepG2 cells treated with AA. We conclude that AA exerts genotoxic effects in HepG2 cells, probably through oxidative DNA damage induced by intracellular ROS and depletion of GSH.     

氯沙坦抑制AngⅡ诱导的内皮单核细胞黏附涉及下调CXCR2受体表达

目的探讨氯沙坦对血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导的内皮单核细胞黏附的影响及可能分子机制。方法 AngⅡ(10-6mol.L-1)培养人脐静脉内皮细胞4 h或24 h,并加入不同浓度的氯沙坦(1、3、10μmol.L-1)预处理1 h。检测细胞内活性氧(reactive oxygen species,ROS)水平、内皮单核细胞黏附、上清液中白介素-8(interleukin-8,IL-8)水平、IL-8受体CXCR2 mRNA表达以及核转录因子(nuclear factor kappaB,NF-κB)活性。结果 AngⅡ(10-6mol.L-1)培养内皮细胞后显著增加细胞内ROS水平,上清液中IL-8水平,激活NF-κB,增加内皮单核细胞间黏附,上调IL-8受体CXCR2mRNA表达。氯沙坦呈剂量依赖性地抑制AngⅡ诱导的ROS水平的增加,抑制NF-κB的激活,减少IL-8的释放,下调CXCR2 mRNA表达,从而抑制内皮单核细胞黏附。结论氯沙坦可能通过抑制氧化应激-NF-κB-IL-8/CXCR2通路抑制AngⅡ诱导的内皮单核细胞黏附。     

拮抗Toll样受体4对于溶血磷脂酸诱导的THP-1细胞Toll样受体4／核因子-κB信号通路的影响

目的：通过拮抗Toll样受体4（TLR4）观察其对于溶血磷脂酸（lysophosphatidic acid,LPA）诱导的人单核细胞株THP-1细胞的核因子-κB（nuclear factor-kappaB,NF-κB）p65表达的影响以及肿瘤坏死因子-α（TNF-α）水平的变化。方法取THP-1细胞,LPA以不同浓度水平（0～10μmol·L－1）刺激4 h,或1μmol·L－1浓度刺激不同时间（0～8 h）,酶联免疫吸附法（ELISA）测定细胞因子TNF-α,随后在LPA （1μmol·L－1）条件下分别予不同浓度TLR4单克隆抗体（TLR4 mAb）（5,20,30 mg·L－1）干预THP-1细胞,观察其对LPA诱导的核蛋白NF-κB p65表达及TNF-α分泌水平的影响。结果 LPA以剂量依赖方式促进TNF-α分泌,并可诱导THP-1细胞NF-κB p65活化,予TLR4 mAb阻断TLR4后,可显著抑制NF-κB p65表达及TNF-α分泌。结论 LPA可经由Toll4／NF-κB信号途径激活单核细胞,最终引起TNF-α等炎性因子的分泌,参与动脉粥样硬化进程。     

Use of rat liver slices for the study of oxidative DNA damage in comparison with isolated rat liver nuclei and HepG2 human hepatoma cells.

Tissue slices are a useful biological system for lipid peroxidation studies but their use for DNA damage studies is not well characterized. Hence, the present study investigates DNA damage in rat liver slices, in comparison with isolated rat liver nuclei and HepG2 human hepatoma cells, incubated with ferric nitrilotriacetate (Fe(III)-NTA), bromotrichloromethane (BrCCl(3)), bromobenzene (BrB) or 2-nitropropane (2-NP) at 37 degrees C for 2 hr. DNA damage was measured in slices, cells or nuclei after centrifugation as formation of as 8-hydroxy-2'-deoxyguanosine (8-OH-dGu) and loss of double-stranded (dsDNA) due to strand breakage using a fluorometric analysis of DNA unwinding (FADU). Lipid peroxidation was measured as thiobarbituric acid-reactive substances (TBARS) released into the medium. The results show that in liver slices and isolated nuclei, Fe/NTA (1 mM/4 mM) induced high levels of TBARS but low levels of 8-OH-dGu, whereas the oxidant induced low levels of TBARS and no formation of 8-OH-dGu in HepG2 cells. In all three systems, inclusion of ascorbate caused dose-dependent formation of 8-OH-dGu, and the levels were similar between liver slices and HepG2 cells but were far higher in isolated nuclei. In liver slices the FADU assay was not applicable due to limited solubilization of DNA from the slice, whereas the assay detected significant loss of dsDNA in HepG2 cells and slight loss in isolated nuclei induced by Fe/NTA with or without ascorbate. Liver slices incubated with 1 mm BrCCl(3), BrB or 2-NP had elevated TBARS but had little or no formation of 8-OH-dGu; none of these oxidants induced lipid peroxidation or DNA damage in HepG2 cells. When liver slices obtained from rats injected with diethylmaleate (to deplete GSH) were incubated with BrCCl(3), BrB or 2-NP, levels of TBARS and 8-OH-dGu increased markedly. Similarly, HepG2 cells with decreased GSH showed marked elevation of TBARS and loss of dsDNA induced by these oxidants, although no formation of 8-OH-dGu was detected. The present study demonstrates the usefulness and limitations of liver slices for DNA damage studies and the importance of cellular GSH in the protection of DNA against environmental toxicants.     

The role of oxidative stress in Sudan IV‐induced DNA damage in human liver‐derived HepG2 cells

Objectives: We evaluated the role of oxidative stress in Sudan IV‐induced DNA damage, using human liver‐derived HepG2 cells. Methods: The DNA damaging effects of Sudan IV in HepG2 cells were evaluated by alkaline single cell gel electrophoresis assay and micronucleus test (MNT). To clarify the underlying mechanisms, we monitored the intracellular generation of reactive oxygen species (ROS) by 2, 7‐dichlorofluorescein diacetate assay and the level of oxidative DNA damage by immunoperoxidase staining for 8‐hydroxydeoxyguanosine (8‐OHdG). Furthermore, the intracellular glutathione (GSH) level was moderated by pretreatment with buthionine‐(S,R)‐sulfoximine (BSO), a specific GSH synthesis inhibitor. Results: A significant dose‐dependent increment in DNA migration was detected at all tested concentrations (25–100 μM) of Sudan IV. And in the MNT, a significant increase of the frequency of micronuclei was found at higher tested concentrations (50–100 μM). The data suggested that Sudan IV caused DNA strand breaks and chromosome breaks. In addition, significantly increased levels of ROS, 8‐OHdG formation were observed in HepG2 cells. It was also found that depletion of GSH in HepG2 cells with BSO dramatically increased the susceptibility of HepG2 cells to Sudan IV‐induced DNA damage. Conclusions: Based on these data we believe that Sudan IV exerts toxic effects in HepG2 cells, probably through oxidative DNA damage induced by intracellular ROS and depletion of GSH. © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2011.     

硼替佐米对人胃癌SGC-7901细胞uPA、NF-κB表达的影响及与其侵袭力关系

目的硼替佐米对人胃癌SGC-7901细胞uPA、NF-κB表达的影响及与其侵袭力关系。方法 Brdu ELISA法测细胞增殖活性;Boyden小室培养测细胞的迁移率;Western blot测细胞uPA、NF-κB的蛋白水平;细胞免疫化学测NF-κB细胞表达及细胞定位。结果 (1)与对照组(无血清培养基组)相比,10%FCS组细胞增殖活性与迁移率明显增高(P<0.05);与10%FCS组相比,硼替佐米呈浓度依赖性抑制人胃癌SGC-7901细胞增殖及迁移,硼替佐米浓度为(4μg.L-1),人胃癌SGC-7901细胞增殖活性与迁移率均明显降低(P<0.05);与PDTC组(10μmol.L-1)相比,两者无明显差别;(2)与10%FCS组相比,硼替佐米呈浓度依赖性抑制胃癌SGC-7901细胞uPA、NF-κB蛋白表达,硼替佐米浓度为(4μg.L-1)时uPA、NF-κB蛋白表达均明显降低(P<0.05);与NF-κB特异性抑制剂PDTC组相比,两组uPA、NF-κB表达均无明显差别;硼替佐米浓度为(4μg.L-1)能明显降低NF-κB核蛋白含量,与PDTC组相比,两者无显著差异(P>0.05);(4)细胞免疫化学结果示:硼替佐米(4μg.L-1)抑制10%FCS诱导人胃癌SGC-7901细胞NF-κB核移位。结论①硼替佐米抑制血清诱导胃癌SGC-7901细胞增殖迁移及uPA、NF-κB蛋白表达,②硼替佐米降低胃癌SGC-7901细胞侵袭力可能与其抑制NF-κB活性,降低UPA水平有关。     

Genotoxic and oxidative stress effects of 2-amino-9H-pyrido[2,3-b]indole in human hepatoma G2 (HepG2) and human lung alveolar epithelial (A549) cells

Abstract

2-Amino-9H-pyrido[2,3-b]indole (AαC), which is present in high quantities in cigarette smoke and also in fried food, has been reported to be a probable human carcinogen. However, few studies have reported on the genotoxicity and oxidative stress induced by AαC. This study investigated the genotoxic effects of AαC in human hepatoma G2 (HepG2) and human lung alveolar epithelial (A549) cells using the comet assay. Significant increases in DNA fragment migration indicated that AαC causes serious DNA damage in HepG2 and A549 cells. The role of oxidative stress in the mechanism of AαC-induced genotoxicity was clarified by measuring the level of intracellular reactive oxygen species (ROS), the GSH/GSSG ratio and the formation of 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative DNA damage. The results showed that the levels of ROS and 8-OHdG increased, whereas the GSH/GSSG ratio decreased. The concentration of 8-OHdG was positively related to DNA damage. Taken together, these results indicate that AαC can induce genotoxicity and oxidative stress and that AαC likely exerts genotoxicity in HepG2 and A549 cells through ROS-induced oxidative DNA damage. This is the first report to describe AαC-induced genotoxic and oxidative stress in HepG2 and A549 cells.