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1.
T-2 toxin, a member of the trichothecene mycotoxin family produced by the Fusarium fungi, has been shown to exert a variety of toxic effects on multiple targets in vivo. However, the embryonic toxicity of T-2 toxin in vitro remains unclear. In the present study, two permanent cell lines, embryonic stem cells (ES cells D3) and fibroblast 3T3 cells, were used to evaluate T-2 toxin toxicity. Differentiated mouse ES cells were cultivated as embryoid bodies along with T-2 toxin at different concentrations (0.5, 1, and 2 ng/ml) for 24 h. The increases in cellular reactive oxygen species (ROS), lipid and DNA oxidative damage, and loss of mitochondrial transmembrane potential were observed at 1 and 2 ng/ml concentrations. Flow cytometry showed that T-2 toxin induced cell cycle arrest and apoptosis. Furthermore, T-2 toxin opened the mitochondrial permeability transition pore, caused the release of cytochrome c from mitochondria and induced the upregulation of p53, caspase-9, caspase-3 expression and increased the ratio of Bax/Bcl-2. However, T-2 toxin-induced oxidative damage and apoptosis in differentiated ES cells decreased significantly in the presence of the antioxidant Trolox. Taken together, these results demonstrate that T-2 toxin induces oxidative stress and apoptosis in differentiated murine ES cells, and ROS-mediated mitochondrial pathway plays an important role in T-2 toxin induced apoptosis.  相似文献   

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3.
T-2 toxin, a mycotoxin produced by Fusarium species, has been shown to cause diverse toxic effects in animals and is also a possible pathogenic factor of Kashin–Beck disease (KBD). The role of mitochondria in KBD is recognized in our recent research. The aim of this study was to evaluate the role of mitochondria in T-2 toxin-induced human chondrocytes apoptosis to understand the pathogenesis of KBD. T-2 toxin decreased chondrocytes viabilities in concentration- and time-dependent manners. Exposure to T-2 toxin can reduce activities of mitochondrial complexes III, IV and V, ΔΨm and the cellular ATP, while intracellular ROS increased following treatment with T-2 toxin. Furthermore, mitochondrial cytochrome c release, caspase-9 and 3 activation and chondrocytes apoptosis were also obviously observed. Interestingly, Selenium (Se) can partly block T-2 toxin -induced mitochondria dysfunction, oxidative damage and chondrocytes apoptosis. These results suggest that the effect of T-2 toxin on human chondrocytes apoptosis may be mediated by a mitochondrial pathway, which is highly consistent with the chondrocytes changes in KBD.  相似文献   

4.
镉(cadmium,Cd)是一种生物累积性的有毒重金属元素,能够在肾组织大量蓄积并引起肾发生病变和功能损伤。前期研究证实,Cd处理能够引起猪肾PK-15细胞的活性氧(reactive oxygen species,ROS)水平升高和细胞死亡,但详细机制有待进一步研究。本研究以PK-15细胞为研究对象,通过CCK-8检测、透射电镜观察、DCFH-DA标记、JC-1染色、彗星实验和流式细胞术等研究手段,分别检测Cd处理后的细胞活性、形态变化、ROS生成、线粒体膜电位Δψm、DNA损伤及细胞凋亡情况。CCK-8实验结果显示,CdCl2处理后PK-15细胞活性下降,且呈时间和剂量依赖性;形态学观察发现,CdCl2处理引起PK-15细胞皱缩、变圆,细胞核固缩、染色质凝聚,线粒体肿胀、线粒体嵴减少或消失;荧光染色和流式细胞术检测结果显示,CdCl2处理引起PK-15细胞内ROS水平升高、线粒体膜电位Δψm下降和DNA损伤,最终导致细胞凋亡。Western印迹结果显示,CdCl2处理组中促凋亡蛋白质Bax表达量上调,抑凋亡蛋白质Bcl-2表达量下调,并且CdCl2处理组检测到了活化状态的裂解胱天蛋白酶3(cleaved caspase 3)。此外,ROS清除剂N-乙酰基-L-半胱氨酸(N-acetyl-L-cysteine,NAC)缓解了CdCl2引起的线粒体损伤、DNA损伤和细胞凋亡。综上所述,Cd通过引发氧化应激和线粒体损伤诱导PK-15细胞凋亡。  相似文献   

5.
Transient adaptation to mild oxidative stress was induced in human osteosarcoma cells chronically grown in sub-toxic concentrations of diethylmaleate (DEM), a glutathione (GSH) depleting agent. The adapted cells, compared to untreated cells, contain increased concentrations of GSH (4-6 fold) which, upon DEM withdrawal from the culture medium, return to normal values and are more resistant to subsequent oxidizing stress induced either by toxic concentrations of the same agent or by (H2O2) treatment. To investigate the molecular mechanisms involved in the adaptive response to oxidative stress, we analyzed the gene expression profiles of DEM-adapted cells by differential display. The expression of adaptive response to oxidative stress (AROS)-29 gene, coding for a transmembrane protein of unknown function, as well as of some known genes involved in energy metabolism, protein folding and membrane traffic is up-regulated in adapted cells. The increased resistance to both DNA damage and apoptosis, in cells stably overexpressing AROS-29, demonstrated its functional role in the protection against oxidative stress.  相似文献   

6.
d -galactosamine ( d -GalN) toxicity is a useful experimental model of liver failure in human. It has been previously observed that PGE 1 treatment reduced necrosis and apoptosis induced by d -GalN in rats. Primary cultured rat hepatocytes were used to evaluate if intracellular oxidative stress was involved during the induction of apoptosis and necrosis by d -GalN (0-40 mM). Also, the present study investigated if PGE 1 (1 &#119 M) was equally potent reducing both types of cell death. The presence of hypodiploid cells, DNA fragmentation and caspase-3 activation were used as a marker of hepatocyte apoptosis. Necrosis was measured by lactate dehydrogenase (LDH) release. Oxidative stress was evaluated by the intracellular production of hydrogen peroxide (H 2 O 2 ), the disturbances on the mitochondrial transmembrane potential (MTP), thiobarbituric-reacting substances (TBARS) release and the GSH/GSSG ratio. Data showed that intermediate range of d -GalN concentrations (2.5-10 mM) induced apoptosis in association with a moderate oxidative stress. High d -GalN concentration (40 mM) induced a reduction of all parameters associated with apoptosis and enhanced all those related to necrosis and intracellular oxidative stress, including a reduction of GSH/GSSG ratio and MTP in comparison with d -GalN (2.5-10 mM)-treated cells. Although PGE 1 reduced apoptosis induced by d -GalN, it was not able to reduce the oxidative stress and cell necrosis induced by the hepatotoxin in spite to its ability to abolish the GSH depletion.  相似文献   

7.
The polymerizable antibacterial monomer methacryloxylethyl cetyl ammonium chloride (DMAE-CB) has provided an effective strategy to combat dental caries. However, the application of such material raises the question about the biological safety and the question remains open. The mechanism of this toxic action, however, is not yet clearly understood. The present study aims at providing novel insight into the possible causal link between cellular oxidative stress and DNA damage, as well as apoptosis in human dental pulp cells exposed to DMAE-CB. The enhanced formation of reactive oxygen species and depletion of glutathione, as well as differential changes in activities of superoxide dismutase, glutathione peroxidase, and catalase in DMAE-CB-treated cells indicated oxidative stress. By using substances that can alter GSH synthesis, we found that GSH was the key component in the regulation of cell response towards oxidative stress induced by DMAE-CB. The increase in oxidative stress-sensitive 8-Oxo-2''-deoxyguanosine (8-OHdG) content, formation of γ-H2AX and cell cycle G1 phase arrest indicated that DNA damage occurred as a result of the interaction between DNA base and ROS beyond the capacities of antioxidant mechanisms in cells exposed to DMAE-CB. Such oxidative DNA damage thus triggers the activation of ataxia telangiectasia-mutated (ATM) signaling, the intrinsic apoptotic pathway, and destruction of mitochondrial morphology and function.  相似文献   

8.
9.
d -galactosamine ( d -GalN) toxicity is a useful experimental model of liver failure in human. It has been previously observed that PGE 1 treatment reduced necrosis and apoptosis induced by d -GalN in rats. Primary cultured rat hepatocytes were used to evaluate if intracellular oxidative stress was involved during the induction of apoptosis and necrosis by d -GalN (0-40 mM). Also, the present study investigated if PGE 1 (1 μM) was equally potent reducing both types of cell death. The presence of hypodiploid cells, DNA fragmentation and caspase-3 activation were used as a marker of hepatocyte apoptosis. Necrosis was measured by lactate dehydrogenase (LDH) release. Oxidative stress was evaluated by the intracellular production of hydrogen peroxide (H 2 O 2 ), the disturbances on the mitochondrial transmembrane potential (MTP), thiobarbituric-reacting substances (TBARS) release and the GSH/GSSG ratio. Data showed that intermediate range of d -GalN concentrations (2.5-10 mM) induced apoptosis in association with a moderate oxidative stress. High d -GalN concentration (40 mM) induced a reduction of all parameters associated with apoptosis and enhanced all those related to necrosis and intracellular oxidative stress, including a reduction of GSH/GSSG ratio and MTP in comparison with d -GalN (2.5-10 mM)-treated cells. Although PGE 1 reduced apoptosis induced by d -GalN, it was not able to reduce the oxidative stress and cell necrosis induced by the hepatotoxin in spite to its ability to abolish the GSH depletion.  相似文献   

10.
为了探讨T-2毒素对于家畜的毒性机理及诱导凋亡的分子机制,用T-2毒素对猪的肝脏细胞进行暴露,暴露浓度分别为0、0.02mg/L、0.05mg/L、0.1mg/L,暴露时间为48h,然后用微阵列技术检测0.05mg/L处理组基因表达谱的变化。结果表明,氧化应激和细胞凋亡相关基因发生上调,药物和脂质代谢的基因发生下调,同时荧光定量PCR对细胞色素P450家族的CYP2D25和CYP51两个药物代谢基因的表达情况进行了进一步的验证。结果表明,T-2毒素对猪肝细胞的毒性机制可能是引起丝裂原活化蛋白激酶(MAPK)途径氧化应激,进而导致细胞凋亡。  相似文献   

11.
Cadmium is a strong mutagen that acts by inhibiting DNA mismatch repair, while its toxic effect seems to be related to an indirect oxidative stress that involves glutathione (GSH) mobilization. Among the roles of GSH is the protection of proteins against oxidative damage, by forming reversible mixed disulfides with cysteine residues, a process known as protein glutathionylation and catalyzed by glutaredoxins (Grx). In this current study, Saccharomyces cerevisiae cells deficient in GRX2, growing in 80 muM CdSO(4), showed high mitochondrial mutagenic rate, determined by frequency of mutants that had lost mitochondrial function (petite mutants), high tolerance and lower apoptosis induction. The mutant strain also showed decreased levels of glutathionylated-protein after cadmium exposure, which might difficult the signaling to apoptosis, leading to increased mutagenic rates. Taken together, these results suggest that Grx2 is involved with the apoptotic death induced by cadmium, a form of cellular suicide that might lead of removal of mutated cells.  相似文献   

12.
The effect of endotoxin (lipopolysacharide, LPS) exposure on luteal cells was studied using an in vitro cell culture system. Buffalo luteal cells were isolated from corpora lutea of the late luteal phase (days 14-16 post estrus) and exposed to various LPS doses (5, 10 and 100 microg/ml) for different time periods (6, 12, 18 or 24 h). The cultured cells were subsequently evaluated for oxidative stress (super oxide, nitric oxide, inducible nitric oxide synthase activity, reduced glutathione depletion and lipid peroxidation) and apoptotic markers (mitochondrial membrane potential, DNA fragmentation, apoptotic cells and cell viability). LPS exposure significantly increased the production of super oxide (P<0.05) and nitric oxide (P<0.01) and increased inducible nitric oxide synthase activity (P<0.01). LPS exposure further depleted reduced glutathione (P<0.05) levels and induced lipid peroxidation (P<0.05). LPS exposure also induced the loss of mitochondrial membrane potential (P<0.05), increased DNA fragmentation (P<0.01) and apoptosis (P<0.01) and decreased cell viability (P<0.01). LPS mediated apoptotic pathway in luteal cells was further characterized using a selected LPS dose (10 microg/ml). It was observed that LPS exposure induced mitochondrial translocation of proapoptotic protein Bax, increased the total Bad expression and down regulated the expression of antiapoptotic proteins Bcl2 and BclXL. LPS exposure further induced cytochrome c release and increased Caspase-9 (P<0.01) and Caspase-3 (P<0.01) activities. LPS exposure also inhibited luteal progesterone secretion (P<0.01). It was evident that the LPS mediated apoptotic effects could be prevented by the coincubation of luteal cells with mitochondrial permeability transition pore blocker Cyclosporine A, inducible nitric oxide synthase inhibitor N-[3-(aminomethyl)benzyl]acetamidine and oxidative stress scavenger N-acetyl cysteine. Our study clearly indicates that LPS induces oxidative stress mediated apoptosis in luteal cells through the mitochondrial pathway.  相似文献   

13.
Oxidative stress has an important role in neurodegenerative diseases and cerebral ischemic injury. It is reported that d-β-hydroxybutyrate (DβHB), the major component of ketone bodies, is neuroprotective in recent studies. Therefore, in the present work the neuroprotective effects of DβHB on H2O2-induced apoptosis mediated by oxidative stress was investigated. PC12 cells were exposed to H2O2 with different concentrations of H2O2 for different times after DβHB pretreatment. MTT assay, apoptotic rates, intracellular reactive oxygen species (ROS) level, GSH content, mitochondrial membrane potential (MMP) and caspase-3 activity were determined. The results showed that DβHB inhibited the decrease of cell viability induced by H2O2 in PC12 cells. DβHB decreased the apoptotic rates induced by H2O2. The changes of intracellular ROS, GSH, MMP and caspase-3 activity due to H2O2 exposure were partially reversed in PC12 cells. So DβHB inhibited the apoptosis of PC12 cells induced by H2O2 via inhibiting oxidative stress.  相似文献   

14.
Cuccarolo P  Viaggi S  Degan P 《The FEBS journal》2012,279(14):2479-2494
Fanconi's anemia (FA) patients face severe pathological consequences. Bone marrow failure, the major cause of death in FA, accounting for as much as 80-90% of FA mortality, appears to be significantly linked to excessive apoptosis of hematopoietic cells induced by oxidative stress. However, 20-25% of FA patients develop malignancies of myeloid origin. A survival strategy for bone marrow and hematopoietic cells under selective pressure evidently exists. This study reports that lymphoblastoid cell lines derived from two FA patients displayed significant resistance to oxidative stress induced by treatments with H(2) O(2) and various glutathione (GSH) inhibitors that induce production of reactive oxygen species, GSH depletion and mitochondrial membrane depolarization. Among the various GSH inhibitors employed, FA cells appear particularly resistant to menadione (5 μm) and ethacrynic acid (ETA, 50 μm), two drugs that specifically target mitochondria. Even after pre-treatment with buthionine sulfoximine, a GSH synthesis inhibitor that induces enhanced induction of reactive oxygen species, FA cells maintain significant resistance to these drugs. These data suggest that the resistance to oxidative stress and the altered mitochondrial and metabolic functionality found in the FA mutant cells used in this study may indicate the survival strategy that is adopted in FA cells undergoing transformation. The study of redox and mitochondria regulation in FA may be of assistance in diagnosis of the disease and in the care of patients.  相似文献   

15.
The Nrf2-Keap1 pathway is believed to be a critical regulator of the phase II defense system against oxidative stress. By activation of Nrf2, cytoprotective genes such as heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase (NQO-1) and γ-glutamyl-cysteine ligase (GCL) are induced. GCL-induced glutathione (GSH) production is believed to affect redox signaling, cell proliferation and death. We here report that tert-butyl hydroperoxide (t-BHP)-induced GSH reduction led to mitochondrial membrane potential loss and apoptosis in cultured human retinal pigment epithelial cells from the ARPE-19 cell line. Hydroxytyrosol (HT), a natural phytochemical from olive leaves and oil, was found to induce phase II enzymes and GSH, thus protect t-BHP-induced mitochondrial dysfunction and apoptosis. Depletion of GSH by buthionine-[S,R]-sulfoximine enhanced t-BHP toxicity and abolished HT protection. Overexpression of Nrf2 increased GSH content and efficiently protected t-BHP-induced mitochondrial membrane potential loss. Meanwhile, HT-induced GSH enhancement and induction of Nrf2 target gene (GCLc, GCLm, HO-1, NQO-1) messenger RNA (mRNA) were inhibited by Nrf2 knockdown, suggesting that HT increases GSH through Nrf2 activation. In addition, we found that HT was able to activate the PI3/Akt and mTOR/p70S6-kinase pathways, both of which contribute to survival signaling in stressed cells. However, the effect of HT was not inhibited by the PI3K inhibitor LY294002. Rather, c-Jun N-terminal kinase (JNK) activation was found to induce p62/SQSTM1 expression, which is involved in Nrf2 activation. Our study demonstrates that Nrf2 activation induced by the JNK pathway plays an essential role in the mechanism behind HT's strengthening of the antiapoptotic actions of the endogenous antioxidant system.  相似文献   

16.
A dominant-negative, active-site mutant (C93S-Trx2) of mitochondrial thioredoxin-2 (Trx2) was expressed in cells to study the function of the thioredoxin system in protection against mitochondrial oxidative stress. C93S-Trx2 was detected as a disulfide with mitochondrial peroxiredoxin-3 (Prx3) but not peroxiredoxin-5 (Prx5). C93S-Trx2 enhanced sensitivity to cell death induced by tert-butylhydroperoxide or by tumor necrosis factor-alpha (TNF-alpha). In cells treated with buthionine sulfoximine (BSO) to deplete glutathione (GSH), endogenous Trx2 was oxidized, C93S-Trx2 potentiated toxicity, and overexpression of Trx2 protected against toxicity. Thus, the results show that Trx2 interacts with Prx3 in vivo and that the Trx2/Prx3 system functions in parallel with the GSH system to protect mitochondria from oxidative stress. The additive protection by Trx2 and GSH shows that Trx2 and GSH systems are both functionally important at low oxidative stress conditions.  相似文献   

17.
Role of mitochondria in toxic oxidative stress   总被引:17,自引:0,他引:17  
Oxidative stress and mitochondrial oxidative damage have been implicated in the etiology of numerous common diseases. The critical mitochondrial events responsible for oxidative stress-mediated cell death (toxic oxidative stress), however, have yet to be defined. Several oxidative events implicated in toxic oxidative stress include alterations in mitochondrial lipids (e.g., cardiolipin), mitochondrial DNA, and mitochondrial proteins (eg. aconitase and uncoupling protein 2). Furthermore, recent findings indicate the enrichment of mitochondrial membranes with vitamin E protects cells against the toxic effects of oxidative stress. This review briefly summarizes the role of these mitochondrial events in toxic oxidative stress, including: 1) the protective role of mitochondrial vitamin E in toxic oxidative stress, 2) the role of mitochondrial DNA in toxic oxidative stress, 3) the interaction between cardiolipin and cytochrome c in mitochondrial regulation of apoptosis, 4) the role of mitochondrial aconitase in oxidative neurodegeneration, and 5) the role of mitochondrial uncoupling protein 2 in the pathogenesis of type 2 diabetes.  相似文献   

18.
Humans are exposed to dietary acrylamide (AA) during their lifetime; it is therefore necessary to investigate the mechanisms associated with AA induced toxic effects. Accumulating evidence indicates that oxidative stress may contribute to AA cytotoxicity, but the link between oxidative stress and AA cytotoxicity in the gastrointestinal tract, the primary organ in contact with dietary AA, has not been described. In this study, we evaluate the alterations of the redox balance induced by AA in Caco-2 intestinal cells as well as the potential protective role of natural antioxidants such as a well-standardized cocoa polyphenolic extract (CPE) and its main polyphenol components epicatechin (EC) and procyanidin B2 (PB2). We found that AA-induced oxidative stress in Caco-2 cells is evidenced by glutathione (GSH) depletion and reactive oxygen species (ROS) overproduction. AA also activated the extracellular-regulated kinases and the c-Jun N-amino terminal kinases (JNKs) leading to an increase in caspase-3 activity and cell death. Studies with appropriate inhibitors confirmed the implication of oxidative stress and JNKs activation in AA-induced apoptosis. Additionally, AA cytotoxicity was counteracted by CPE or PB2 by inhibiting GSH consumption and ROS generation, increasing the levels of gamma-glutamyl cysteine synthase and glutathione-S-transferase and blocking the apoptotic pathways activated by AA. Therefore, AA-induced cytotoxicity and apoptosis are closely related to oxidative stress in Caco-2 cells. Interestingly, natural dietary antioxidant such as PB2 and CPE were able to suppress AA toxicity by improving the redox status of Caco-2 cells and by blocking the apoptotic pathway activated by AA.  相似文献   

19.
Costunolide (CE) is a sesquiterpene lactone well-known for its antihepatotoxic, antiulcer, and anticancer activities. The present study focused on the evaluation of the cytogenetic toxicity and cellular death-inducing potential of CE in CHO cells, an epithelial cell line derived from normal ovary cells of Chinese hamster. The cytotoxic effect denoting MTT assay has shown an IC50 value of 7.56 μM CE, where 50% proliferation inhibition occurs. The oxidative stress caused by CE was confirmed based on GSH depletion induced cell death, conspicuously absent in N-acetylcysteine (GSH precursor) pretreated cells. The evaluation of genotoxic effects of CE using cytokinesis block micronucleus assay and chromosomal aberration test has shown prominent induction of binucleated micronucleated cells and aberrant metaphases bearing chromatid and chromosomal breaks, indicating CE’s clastogenic and aneugenic potential. The apoptotic death in CE treated cells was confirmed by an increase in the number of cells in subG1 phase, exhibiting chromatin condensation and membranous phosphatidylserine translocation. The apoptosis induction follows mitochondrial mediation, evident from an increase in the BAX/Bcl-2 ratio, caspase-3/7 activity, and mitochondrial membrane permeability. CE also induces cytostasis in addition to apoptosis, substantiated by the reduced cytokinetic (replicative indices) and mitotic (mitotic indices and histone H3 Ser-10 phosphorylation) activities. Overall, the cellular GSH depletion and potential genotoxic effects by CE led the CHO cells to commit apoptosis and lowered cell division. The observed sensitivity of CHO cells doubts unintended adverse effects of CE on normal healthy cells, suggesting higher essentiality of further studies in order to establish its safety efficacy in therapeutic explorations.  相似文献   

20.
探索九香虫血淋巴诱导肿瘤细胞凋亡的作用通路。利用Bradford法检测九香虫血淋巴浓度并将其作用于体外培养的人乳腺癌MCF-7细胞、人胃癌SGC-7901细胞,Western blot法检测经九香虫血淋巴干预后肿瘤细胞凋亡相关蛋白Caspase-3、Caspase-8、Caspase-9、Bcl-2、Bax等的表达。结果显示,九香虫血淋巴作用的SGC-7901、MCF-7细胞中Caspase-3、Caspase-9、Bax蛋白的表达较对照组细胞明显上调;两种细胞的Bcl-2蛋白,较对照组细胞表达明显下调;两种细胞的Caspase-8蛋白,较对照组细胞表达无明显差异。结果表明,经九香虫血淋巴诱导的SGC-7901、MCF-7细胞可能通过触发其线粒体凋亡途径使肿瘤细胞发生不可逆的凋亡。  相似文献   

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