Ethanol has differential effects on rat neuron and thymocyte reactive oxygen species levels and cell viability

In rat thymocytes and cerebellar granule cells, reactive oxygen species (ROS) levels were increased and cell viability was decreased as a result of exposure to ethanol (up to 0.4%). Thymocytes showed larger increases in ROS levels, but neurons showed more pronounced decreases in cell viability. These parameters in neurons were relatively unaffected when the cells were incubated with ethanol in the presence of inhibitors of alcohol-oxidizing enzymes, but in thymocytes, the presence of diallyl sulfide (an inhibitor of alcohol-inducible cytochrome P450, CYP2E1) or 4-methylpyrazole (an inhibitor of CYP2E1 and alcohol dehydrogenase) caused decreases in ROS production from ethanol. In both cell types, the presence of 3-aminotriazole (an inhibitor of catalase) did not decrease ROS production from ethanol. These studies show that the cytotoxic effects of ethanol in neurons may not be the result of oxidative metabolism of ethanol, whereas in thymocytes, the cytotoxic effect of ethanol is principally a result of its oxidative metabolism.     

Protective effects of atypical antipsychotic drugs against MPP(+)-induced oxidative stress in PC12 cells

Recent studies have suggested that some atypical antipsychotic drugs may have protective properties against oxidative stress. To confirm these findings, we investigated the protective effects of atypical antipsychotic drugs such as olanzapine, aripiprazole, and ziprasidone on oxidative stress induced by the N-methyl-4-phenylpyridinium (MPP(+)) ion in PC12 cells. Haloperidol, a typical antipsychotic drug, was used for comparison. We determined the antioxidant effects of atypical antipsychotic drugs using a number of measures, including cell viability, the formation of reactive oxygen species (ROS), superoxide dismutase (SOD) activity and Bax levels. MPP(+) treatment induced significant loss of cell viability, the formation of ROS, reduction of SOD activity, and up-regulation of Bax expression. However, olanzapine, aripiprazole and ziprasidone reversed these effects caused by MPP(+) treatment, but ziprasidone did not influence cell viability. In contrast, haloperidol did not affect all these effects. Moreover, haloperidol strongly increased the expression of Bax under MPP(+)-free conditions. Olanzapine, aripiprazole, and ziprasidone, but not haloperidol, may exert antioxidant effects through modulating ROS levels, SOD activity, and Bax expression to provide protective effects against MPP(+)-induced oxidative stress in PC12 cells. These results suggest that some atypical antipsychotic drugs have a useful therapeutic effect by reducing oxidative stress in schizophrenic patients.     

白藜芦醇对氧化应激诱导的大鼠海马神经元损伤的影响

目的:研究不同剂量的白藜芦醇对大鼠海马神经元氧化损伤的影响。方法:通过体外原代培养获得大鼠海马神经元。实验分为对照(control,Con)组、三甲基氯化锡(trimethyltin chloride,TMT)组、溶剂对照(vehicle)组和白藜芦醇(resveratrol,Res)组。其中,Res设4个浓度:5μmol/L、10μmol/L、20μmol/L和40μmol/L;除对照组外,其它各组细胞均采用三甲基氯化锡(TMT)处理使细胞出现氧化应激状态。采用CCK-8法和荧光探针DCFH-DA法观察各组神经元的活力与细胞内活性氧(reactive oxygen species,ROS)含量的变化;TUNEL荧光染色法检测各组神经元的凋亡程度。结果:与TMT组相比,不同浓度的白藜芦醇均能提高神经元的活力,其中20μmol/L的作用最显著。20μmol/L白藜芦醇能抑制经TMT处理后神经元内的ROS水平以及凋亡程度的增加。结论:白藜芦醇具有抑制TMT诱导的大鼠海马神经元氧化损伤的作用。     

Increased susceptibility to oxidative stress in scrapie-infected neuroblastoma cells is associated with intracellular iron status

The molecular mechanism of neurodegeneration in prion diseases remains largely uncertain, but one of the features of infected cells is higher sensitivity to induced oxidative stress. In this study, we have investigated the role of iron in hydrogen peroxide (H(2)O(2))-induced toxicity in scrapie-infected mouse neuroblastoma N2a (ScN 2 a) cells. ScN 2 a cells were significantly more susceptible to H(2)O(2) toxicity than N2a cells as revealed by cell viability (MTT) assay. After 2h exposure, significant decrease in cell viability in ScN 2 a cells was observed at low concentrations of extracellular H(2)O(2) (5-10 microM), whereas N2a cells were not affected. The increased H(2)O(2) toxicity in ScN 2 a cells may be related to intracellular iron status since ferrous iron (Fe(2+)) chelator 2,2'-bipyridyl (BIP) prevented H(2)O(2)-induced decrease in cell viability. Further, the level of calcein-sensitive labile iron pool (LIP) was significantly increased in ScN 2 a cells after H(2)O(2) treatment. Finally, the production of reactive oxygen species (ROS) was inhibited by 30% by iron chelators desferrioxamine (DFO) and BIP in ScN 2 a cells, whereas no significant effect of iron chelators on basal ROS production was observed in N2a cells. This study indicates that cellular resistance to oxidative stress in ScN 2 a cells is associated with intracellular status of reactive iron.     

去甲肾上腺素减轻脂多糖所致内皮细胞损伤

目的:探讨去甲肾上腺素(norepinephrine,NE)减轻脂多糖(lipopolysaccharides,LPS)对内皮细胞损伤的作用。方法:用100 mg/L LPS诱导人脐静脉血管内皮细胞HUVEC-12损伤,用不同浓度NE处理后,使用realtime PCR及Western blot法检测各组内皮细胞血管内皮型钙黏素(VE-cadherin)表达的变化,ELISA法测定细胞培养上清液中TNF-α、IL-1β、IL-2和IL-10的浓度,活性氧簇(reactive oxygen species,ROS)检测试剂盒检测细胞内的ROS水平。结果:LPS可显著抑制内皮细胞中VE-cadherin m RNA和蛋白的表达水平,同时伴有TNF-α、IL-1β和IL-2升高及IL-10下降,ROS含量明显增加;不同浓度的NE呈剂量依赖性地上调VE-cadherin的m RNA和蛋白表达,减轻细胞内的氧化应激水平,并部分逆转TNF-α、IL-1β、IL-2和IL-10的变化。结论:不同浓度NE能明显逆转LPS造成的内皮细胞损伤,其机制可能与上调VE-cadherin、减轻细胞的氧化应激及炎性介质水平有关。     

Ethanol-induced oxidative stress is mediated by p38 MAPK pathway in mouse hippocampal cells

It has been known that ethanol causes neuronal cell death through oxidative stress. Ethanol itself and reactive oxygen species (ROS) produced by ethanol modulate intracellular signaling pathways including mitogen-activated protein kinase (MAPK) cascades. This study was conducted to examine the impact of ethanol on MAPK signaling in HT22 cells. Ethanol (100 and 400 mM) caused activation of ERK, p38 MAPK, and JNK. ERK activation occurred in early time and p38 MAPK activation was evident when ERK activation was diminished. Specific inhibitor of p38 MAPK (SB203580) protected HT22 cells against ethanol, which was accompanied by an inhibition of ROS accumulation. However, inhibitors of ERK (U0126) and JNK (SP600125) had no effects on ethanol-induced neuronal cell death when they are treated with ethanol for 24 h. These results suggest that p38 MAPK may have important roles in ROS accumulation during ethanol-induced oxidative stress in HT22 cells.     

Increased iron-induced oxidative stress and toxicity in scrapie-infected neuroblastoma cells

The mechanisms behind the pathology of prion diseases are still unknown, but accumulating evidence suggests oxidative impairment along with metal imbalances in scrapie-infected brains. In this study, we have investigated iron-induced oxidative stress in scrapie-infected mouse neuroblastoma N2a (ScN2a) cells. Uninfected N2a and ScN2a cells were treated with ferric ammonium citrate (FAC) for 1-16 h, and the levels of labile iron pool (LIP), the formation of reactive oxygen species (ROS), cell viability and ferritin protein levels were measured. The increase in LIP in N2a cells was transient with a quick recovery to normal levels within 4h accompanied by a moderate increase of formation of ROS after 3h followed by the decrease to the basal level. In ScN2a cells, the increase in LIP was lower, but the process of recovery was prolonged and accompanied by high ROS formation and decreased cell viability. Ferritin protein levels were significantly lower in ScN2a cells than in wild-type cells in all iron treatments. These results suggest that ScN2a cells are more sensitive to iron treatment as compared to wild-type cells with respect to ROS formation and cell viability, and that ferritin deficiency in infected cells may contribute to iron-induced oxidative stress in scrapie-infected cells.     

京尼平抑制高糖诱导的大鼠心肌H9c2细胞氧化应激及凋亡损伤

目的:探讨京尼平(genipin,GEN)对高糖损伤的大鼠心肌H9c2细胞的抗氧化作用和抑制细胞凋亡的机制。方法:体外培养大鼠心肌H9c2细胞,高浓度(50 mmol/L)葡萄糖处理H9c2细胞建立细胞损伤模型,分为正常糖对照组(NC组,葡萄糖浓度为5.6 mmol/L)、高糖损伤组(HG组,葡萄糖浓度为50 mmol/L)、正常糖+京尼平组(NC+GEN组)和高糖+京尼平组(HG+GEN组,京尼平浓度为10μmol/L)。CCK-8法检测细胞活力;酶标法和WST-1法分别测定细胞内丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性;微板法检测细胞培养上清液中乳酸脱氢酶(LDH)活性;荧光探针DCF检测细胞内活性氧簇(ROS)水平;ELISA法检测核小体片段的聚集值;线粒体膜电位检测试剂盒(JC-1)检测细胞内线粒体膜电位变化;利用Western blot法检测线粒体内抗氧化酶锰超氧化物歧化酶(Mn-SOD),以及早期凋亡蛋白细胞色素C(Cyt C)、Bax和cleaved caspase-3的蛋白水平。结果:与HG组比较,HG+GEN组细胞活力显著升高(P 0.05),细胞内MDA的含量及细胞上清液中LDH的活性明显降低(P 0.05),细胞内SOD活性升高(P 0.05),细胞内线粒体膜电位明显升高(P 0.05),ROS水平降低(P 0.05),核小体片段聚集程度显著降低(P 0.05)。HG组线粒体内抗氧化酶Mn-SOD比NC组降低(P 0.05),但线粒体内凋亡蛋白Cyt C、Bax和cleaved caspase-3的蛋白水平比NC组显著升高(P 0.05),而HG+GEN组与HG组相比,Mn-SOD升高(P 0.05),Cyt C、Bax和cleaved caspase-3的蛋白水平显著降低(P 0.05)。结论:京尼平对高糖损伤的心肌H9c2细胞具有抗氧化保护作用和抑制细胞凋亡的作用。     

去泛素化酶USP14调控H_2O_2诱导的H9c2细胞氧化应激损伤

目的:观察抑制泛素特异性蛋白酶14(ubiquitin-specific protease 14,USP14)的活性对H_2O_2诱导的H9c2细胞氧化应激损伤的影响。方法:体外培养H9c2心肌细胞,用H_2O_2(25μmol/L)处理2 h,建立心肌细胞氧化应激损伤模型。将细胞分为对照(control,CON)组、模型组(H_2O_2组)、USP14抑制剂IU1处理组(IU1组)和IU1处理后建模组(IU1+H_2O_2组)。MTS法检测H9c2心肌细胞活力;流式细胞术检测细胞内活性氧簇(ROS)的产生和细胞存活率;Western blot法检测丝裂原活化蛋白激酶家族相关蛋白的表达变化。结果:与CON组相比,H_2O_2组细胞活力、细胞存活率显著降低,细胞内ROS含量、Bax/Bcl-2、P53、p-ERK1/2、p-JNK和p-P38的蛋白水平显著增加(P0.05);与H_2O_2组比较,IU1+H_2O_2组细胞活力、细胞存活率显著增加,细胞内ROS含量、Bax/Bcl-2、P53、p-ERK1/2、p-JNK和p-P38蛋白水平显著降低(P0.05)。结论:抑制USP14活性可以减轻氧化应激条件下H9c2心肌细胞的损伤,其机制可能与抑制丝裂原活化蛋白激酶信号活化和下调凋亡相关蛋白有关。     

乳酸链球菌素诱导氧化应激促进人骨肉瘤MG63细胞凋亡

目的:探讨乳酸链球菌素(nisin)对人骨肉瘤MG63细胞凋亡及其相关的氧化应激机制.方法:乳酸链球菌素单独或联合抗氧化剂N-乙酰-L-半胱氨酸(N-acetyl-L-cysteine,NAC)处理MG63细胞后,采用CCK-8法检测细胞活力;annexin-V/PI双染法检测细胞凋亡;2',7'-二氯荧光素二乙酸酯(...     

蜂胶醇提物通过抑制caspase-12减轻氧化低密度脂蛋白诱导的巨噬细胞凋亡

 目的: 研究蜂胶醇取物(ethanol extract of propolis,EEP)对氧化低密度脂蛋白(oxidized low-density lipoprotein,ox-LDL)诱导的巨噬细胞凋亡的抑制作用,并探讨可能的分子机制。 方法: 体外培养RAW264.7巨噬细胞,给予EEP(7.5、15和30 mg/L)、4-苯丁酸(4-phenylbutyric acid,PBA;5 mmol/L)或二亚苯基碘鎓(diphenyleneiodo-nium, DPI;5 μmol/L)预处理1 h,再加入ox-LDL(100 mg/L)或衣霉素(tunicamycin,TM;4 mg/L)继续培养24 h。分别采用MTT法和Annexin V-FITC双染法检测细胞活力和凋亡情况;试剂盒测定细胞内超氧化物歧化酶(superoxide dismutase,SOD)活性、活性氧簇(reactive oxygen species,ROS)和丙二醛(malondialdehyde,MDA)的水平。采用免疫印迹技术检测内质网应激(endoplasmic reticulum stress,ERS)凋亡途径关键蛋白caspase-12的表达变化。结果: 与ERS抑制剂PBA相似,EEP呈剂量依赖性减轻ox-LDL所致的巨噬细胞损伤,表现为细胞活力增加(P<0.01),凋亡率降低(P<0.05),且可抑制ERS诱导剂TM所引起的巨噬细胞活力下降和凋亡(P<0.05);与氧化应激抑制剂DPI相似,EEP可抑制ox-LDL诱导的氧化应激反应,表现为ROS和MDA生成减少(P<0.01),SOD活性增加(P<0.05);EEP显著抑制ox-LDL和TM所诱导的caspase-12活化(P<0.05);与ox-LDL组比较,PBA和DPI预处理组caspase-12活性也受到明显抑制(P<0.01)。结论: EEP可减轻 ox-LDL 所诱导的RAW264.7巨噬细胞凋亡,其机制可能与抑制氧化应激和caspase-12活化有关。     

Human α-Synuclein over-expression increases intracellular reactive oxygen species levels and susceptibility to dopamine

alpha-Synuclein is a major component of Lewy bodies found in the brains of patients with Parkinson's disease (PD). Two point mutations in alpha-synuclein (A53T and A30P) are identified in few families with dominantly inherited PD. Yet the mechanism by which this protein is involved in nigral cell death remains poorly understood. Mounting evidence suggests the importance of oxidative stress in the pathogenesis of PD. Here we investigated the effects of wild-type and two mutant forms of alpha-synuclein on intracellular reactive oxygen species (ROS) levels using clonal SH-SY5Y cells engineered to over-express these proteins. All three cell lines, and particularly mutant alpha-synuclein-expressing cells, had increased ROS levels relative to control LacZ-engineered cells. In addition, cell viability was significantly curtailed following the exposure of all three alpha-synuclein-engineered cells to dopamine, but more so with mutant alpha-synuclein. These results suggest that over-expression of alpha-synuclein, and especially its mutant forms, exaggerates the vulnerability of neurons to dopamine-induced cell death through excess intracellular ROS generation. Thus, these findings provide a link between mutations or over-expression of alpha-synuclein and apoptosis of dopaminergic neurons by lowering the threshold of these cells to oxidative damage.     

Carnosine and taurine protect rat cerebellar granular cells from free radical damage

Carnosine and taurine have been suggested to protect excitable tissues against oxidative stress. We have investigated the protection of cerebellar granule cells (neurons) by these compounds against free radicals generated by kainic acid (KA), and 3-morpholinosydnonimine hydrochloride (SIN-1) treatment. Carnosine decreased free radical levels in KA and SIN-1 treated cells, and increased cell viability. The KA effect, but not that of SIN-1, was dependent on the presence of external Ca2+ ions. Taurine increased cell viability, but did not decrease free radical levels. These results suggest that there are multiple pathways leading to cell death, not all of which involve decreases in intracellular free radical levels, and also indicate that multiple mechanisms of cellular defense exist against oxidative stress.     

PM2.5对血管内皮细胞氧化应激和凋亡的影响及机制

目的:从大气细颗粒物PM2.5对血管内皮细胞氧化应激和凋亡的影响,研究PM2.5对血管内皮细胞的毒性。方法:体外培养血管内皮细胞株EA.hy926,用不同浓度的PM2.5染毒24 h后,用CCK-8法测细胞的活性,用DCFH-DA荧光标记法检测细胞内氧自由基生成情况,用流式细胞术检测细胞凋亡率,然后用Western blot法检测凋亡相关蛋白细胞色素C、cleaved caspase-9和cleaved caspase-3的表达变化。结果:CCK-8法结果显示PM2.5对血管内皮细胞有明显的毒性,在浓度大于25 mg/L时可使EA.hy926细胞活性显著下降;PM2.5染毒24 h后可见DCFH-DA荧光染色增强,说明细胞内有大量的氧自由基形成;流式细胞术和Western blot检测证实PM2.5可以通过上调细胞色素C表达和活化cleaved caspase-9和cleaved caspase-3而诱导EA.hy926细胞凋亡。此外,用N-乙酰半胱氨酸抑制氧自由基生成可以抑制血管内皮细胞凋亡,提示PM2.5引起的细胞凋亡与氧化应激有关。结论:PM2.5可导致血管内皮细胞氧化应激水平增强和凋亡增加,这可能是其影响心血管系统功能的机制之一。     

Human alpha-synuclein over-expression increases intracellular reactive oxygen species levels and susceptibility to dopamine

alpha-Synuclein is a major component of Lewy bodies found in the brains of patients with Parkinson's disease (PD). Two point mutations in alpha-synuclein (A53T and A30P) are identified in few families with dominantly inherited PD. Yet the mechanism by which this protein is involved in nigral cell death remains poorly understood. Mounting evidence suggests the importance of oxidative stress in the pathogenesis of PD. Here we investigated the effects of wild-type and two mutant forms of alpha-synuclein on intracellular reactive oxygen species (ROS) levels using clonal SH-SY5Y cells engineered to over-express these proteins. All three cell lines, and particularly mutant alpha-synuclein-expressing cells, had increased ROS levels relative to control LacZ-engineered cells. In addition, cell viability was significantly curtailed following the exposure of all three alpha-synuclein-engineered cells to dopamine, but more so with mutant alpha-synuclein. These results suggest that over-expression of alpha-synuclein, and especially its mutant forms, exaggerates the vulnerability of neurons to dopamine-induced cell death through excess intracellular ROS generation. Thus, these findings provide a link between mutations or over-expression of alpha-synuclein and apoptosis of dopaminergic neurons by lowering the threshold of these cells to oxidative damage.     

Polyamines reduce oxidative stress in Escherichia coli cells exposed to bactericidal antibiotics

Bactericidal antibiotics (fluoroquinolones, aminoglycosides and cephalosporins) at their sublethal concentrations were able to produce hydroxyl radicals, hydrogen peroxide and superoxide anions (ROS) in Escherichia coli cells, which resulted in damage to proteins and DNA. The cells responded to oxidative stress by a 2-3-fold increase in cell polyamines (putrescine, spermidine) produced as a consequence of upregulation of ornithine decarboxylase (ODC). Relief of oxidative stress by cessation of culture aeration or addition of antioxidants substantially diminished or even completely abolished polyamine accumulation observed in response to antibiotics. Alternatively, inhibition of polyamine synthesis resulted in enhancement of oxidative stress in antibiotic-processed cells. When added to antibiotic-inhibited culture, polyamines reduced intracellular ROS production and thereby prevented damage to proteins and DNA. These effects eventually resulted in a substantial increase in cell viability, growth recovery and antibiotic resistance that were more strongly expressed in polyamine-deficient mutants.     

HO-1在造影剂所致肾小管上皮细胞损伤中的作用

目的:探讨血红素加氧酶-1(Heme oxygenase-1,HO-1)在造影剂所致肾小管上皮细胞损伤中的作用.方法:体外培养的HK-2细胞,分为正常对照组、甘露醇对照组、造影剂损伤组、钴原卟啉(CoPP)处理组、锌原卟啉(ZnPP)处理组.比色法测定细胞培养上清液乳酸脱氢酶(LDH)水平,四甲基偶氮唑(methyl ...     

波动性葡萄糖对胰岛细胞凋亡及PTEN表达的影响

目的:研究细胞凋亡是否与PTEN表达升高相关,并探讨PTEN表达升高是否通过活性氧簇(ROS)进行调控。方法:细胞分为5组:恒定低糖组(L组)、恒定高糖组(H组)、葡萄糖波动组(F组)、高糖后低糖组(HL组)及波动后低糖组(FL组)。检测各组ROS水平、细胞凋亡率、细胞内钙离子浓度、胰岛素水平和PTEN蛋白的表达。结果:F组较H、L组钙离子浓度升高,胰岛素分泌减少,ROS水平升高,PTEN蛋白表达增加,细胞凋亡增多(P0.05)。HL组较H组钙离子浓度、ROS水平、PTEN蛋白表达和凋亡率有所下降,但仍高于L组(P0.05)。FL组较F组钙离子浓度、ROS水平、PTEN蛋白表达和凋亡率有所下降,但仍高于低糖组(P0.05)。结论:波动性葡萄糖较恒定高糖更易导致胰岛细胞凋亡,可能与细胞内钙离子浓度变化,加重氧化应激促进PTEN表达增加有关。葡萄糖浓度恢复可一定程度解除氧化应激,使PTEN表达减少,细胞损伤减轻。     

Possible involvement of 12-lipoxygenase activation in glucose-deprivation/reload-treated neurons

The aim of this study was to clarify whether 12-lipoxygenase (12-LOX) activation was involved in reactive oxygen species (ROS) generation, extensive poly(ADP-ribose) polymerase (PARP) activation and neuronal death induced by glucose-deprivation, followed by glucose-reload (GD/R). The decrease of neuronal viability and accumulation of poly(ADP-ribose) induced by GD/R were prevented 3-aminobenzamide, a representative PARP inhibitor, demonstrating this treatment protocol caused the same oxidative stress with the previously reported one. The PARP activation, ROS generation and decrease of neuron viability induced by GD/R treatment were almost completely abolished by an extracellular zinc chelator, CaEDTA. p47(phox), a cytosolic component of NADPH oxidase was translocated the membrane fraction by GD/R, indicating its activation, but it did not generate detectable ROS. Surprisingly, pharmacological inhibition of NADPH oxidase with apocynin and AEBSF further decreased the decreased neuron viability induced by GD/R. On the other hand, AA861, a 12-LOX inhibitor, prevented ROS generation and decrease of neuron viability caused by GD/R. Interestingly, an antioxidant, N-acetyl-l-cysteine rescued the neurons from GD/R-induced oxidative stress, implying effectiveness of antioxidant administration. These findings suggested that activation of 12-LOX, but not NADPH oxidase, following to zinc release might play an important role in ROS generation and decrease of viability in GD/R-treated neurons.