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Results 451 - 500 of 2521
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Starkenburg Shawn R - - 2008
The nitrite oxidizing Alphaproteobacterium, Nitrobacter winogradskyi, primarily conserves energy from the oxidation of nitrite (NO(2)(-))to nitrate (NO(3)(-)) through aerobic respiration. Almost 20 years ago, NO-dependent NADH formation was reported to occur in both aerobic and anaerobic cell suspensions of N. winogradskyi strain 'agilis', suggesting that NO oxidation might contribute to ...
Hassoun Ezdihar A - - 2008
Dichloroacetate (DCA) is used for different medical and industrial purposes and has been found to be a toxic by-product produced during the process of water chlorination. The DCA effects on superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) activities and glutathione (GSH) level were assessed and correlated with each other ...
Grande Sveva - - 2008
Signals attributable to amide protons and used in previous studies to measure intracellular pH were observed in the low-field region of the (1)H-MR spectra of four tumour cell lines: T98G, MCF-7, A172 and HeLa. The signals were more intense in the spectra of the two cell lines (T98G and MCF-7) ...
Haenold Ronny - - 2008
Methionine sulphoxide reductase A (MSRA) that reduces methionine-S-sulphoxide back to methionine constitutes a catalytic antioxidant mechanism to prevent oxidative damage at multiple sub-cellular loci. This study examined the relative importance of protection of the cytoplasm and mitochondria by MSRA using A-10 vascular smooth muscle cells, a cell type that requires ...
Bonfili Laura - - 2008
The purpose of this review is to discuss the effect of natural antioxidant compounds as modulators of the 20S proteasome, a multi-enzymatic multi-catalytic complex present in the cytoplasm and nucleus of eukaryotic cells and involved in several cellular activities such as cell-cycle progression, proliferation and the degradation of oxidized and ...
Panayiotidis Mihalis I - - 2009
The effects of low, moderate and severe oxidative stress on the steady-state levels of the metabolites involved in the transmethylation/transsulfuration pathway were studied in lung epithelial (A549) cells. When cells were exposed to low (0.1 mM) or moderate (1.0 mM) concentrations of hydrogen peroxide (H(2)O(2)) or tert-butylhydroperoxide (t-butOOH), intracellular levels ...
Sun Yu - - 2009
Chemopreventive agents generate oxidative stress, which culminates in cell death and may be part of a general mechanism of chemoprevention. The redox-responsive cyclooxygenase (COX)-2, overexpressed during carcinogenesis, has been a target for cancer prevention. To assess the potential link between chemopreventive agents, oxidative stress and COX-2, we studied the chemopreventive ...
Taki Kenji - - 2008
AIMS: In this study, we investigated the involvement of apoptosis signal-regulating kinase 1 (ASK1) in oxidative stress and osmotic stress-induced hepatocyte death. MAIN METHODS: Activation of ASK1-JNK/p38 cascade and resulting cell death induced by oxidative and osmotic stress was investigated by Western immunoblot analysis and cell toxicity assay using human ...
Di Benedetto Rita - - 2009
By using RNA interference (RNAi) in rat C6 glial cells, we previously generated the cell line abcd3kd in which the peroxisomal half-transporter PMP70 was stably knocked-down. The observations that abcd3kd cells had peroxisomal beta-oxidation impairment and an increase of hexacosenoic acid in cholesterol ester fraction, indicated an overlapping function of ...
Han Pei-pei - - 2009
Lipid signaling involved in mechanotransduction processes in response to shear stress in plants remained elusive. To understand the responses of phospholipids in shear stress-induced mechanotransduction, a lipidomic approach was employed to profile phospholipid species of Taxus cuspidata cells under laminar shear stress. A total of 99 phospholipid species were profiled ...
Luo Shen - - 2009
A variety of reactive oxygen species react readily with methionine residues in proteins to form methionine sulfoxide, thus scavenging the reactive species. Most cells contain methionine sulfoxide reductases, which catalyze a thioredoxin-dependent reduction of methionine sulfoxide back to methionine. Thus, methionine residues may act as catalytic antioxidants, protecting both the ...
Pulido Pablo - - 2009
Cereal seed cells contain different mechanisms for protection against the oxidative stress that occurs during maturation and germination. One such mechanism is based on the antioxidant activity of a 1-Cys peroxiredoxin (1-Cys Prx) localized in the nuclei of aleurone and scutellum cells. However, nothing is known about the mechanism of ...
Cooke Marcus S - - 2008
Thiopurine antimetabolites, such as azathioprine (Aza) and 6-thioguanine (6-TG), are widely used in the treatment of cancer, inflammatory conditions and organ transplantation patients. Recent work has shown that cells treated with 6-TG and UVA generate ROS, with implied oxidatively generated modification of DNA. In a study of urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) ...
Jin K B - - 2008
OBJECTIVES: After organ transplantation, some patients suffer from mild neurologic symptoms, ranging from tremor to severe complications, including seizures and encephalopathy. Among the immunosuppressants, tacrolimus can cause neurologic side effects. However, the mechanisms of encephalopathy by tacrolimus are not fully understood. We measured the antioxidant status, hydrogen peroxide level, and ...
Chafekar S M - - 2008
Alzheimer's disease (AD) is characterized by the aggregation and subsequent deposition of misfolded beta-amyloid (Abeta) peptide. The unfolded protein response (UPR) is activated by misfolded protein stress in the endoplasmic reticulum (ER). In previous studies we demonstrated mild activation of the UPR by extracellularly applied oligomeric but not fibrillar Abeta1-42. ...
Smith Paul J PJ Dept. of Pathology, Tenovus Bldg., School of Medicine, Cardiff Univ., Heath Park, Cardiff CF14 4XN, UK. - - 2008
Metallothioneins (MTs) have an important role in zinc homeostasis and may counteract the impact of oversupply. Both intracellular zinc and MT expression have been implicated in proliferation control and resistance to cellular stress, although the interdependency is unclear. The study addresses the consequences of a steady-state overexpression of MT-1 for ...
Mannarino Sérgio C - - 2008
Calorie restriction increases longevity of mammals and yeasts but this mechanism remains unclear. In this study, the role of glutathione on lifespan extension induced by calorie restriction was investigated by using a Saccharomyces cerevisiae strain deficient in glutathione synthesis (gsh1). We observed an increase in chronological lifespan of calorie-restricted gsh1 ...
Seiler Alexander - - 2008
Oxidative stress in conjunction with glutathione depletion has been linked with various acute and chronic degenerative disorders, yet the molecular mechanisms have remained unclear. In contrast to the belief that oxygen radicals are detrimental to cells and tissues by unspecific oxidation of essential biomolecules, we now demonstrate that oxidative stress ...
Ballatori Nazzareno - - 2009
Reduced glutathione (GSH) is critical for many cellular processes, and both its intracellular and extracellular concentrations are tightly regulated. Intracellular GSH levels are regulated by two main mechanisms: by adjusting the rates of synthesis and of export from cells. Some of the proteins responsible for GSH export from mammalian cells ...
Sekiya Mika - - 2008
SREBP1c (sterol regulatory element-binding protein 1c) is a metabolic-syndrome-associated transcription factor that controls fatty acid biosynthesis under glucose/insulin stimulation. Oxidative stress increases lipid accumulation, which promotes the generation of reactive oxygen species (ROS). However, we know little about the role of oxidative stress in fatty acid biosynthesis. To clarify the ...
Paixão Thiago R L C - - 2008
The uptake of ascorbate by neuroblastoma cells using a ruthenium oxide hexacyanoferrate (RuOHCF)-modified carbon fiber disc (CFD) microelectrode (r = 14.5 microm) was investigated. By use of the proposed electrochemical sensor the amperometric determination of ascorbate was performed at 0.0 V in minimum essential medium (MEM, pH = 7.2) with ...
Allagui M S - - 2009
SH-SY5Y cells, derived from a human neuroblastoma, were submitted to short- or long-term exposures to lithium carbonate concentrations ranging from 0.5 to 8 mM. Short-term exposures (4 days) to concentrations higher than 6 mM were found to reduce cell growth rate while exposure to 8 mM resulted in significant cell ...
Ramos-Márquez Martha E - - 2008
Oxidative cell damage is a natural occurring phenomenon due to the aerobic conditions where cells are embedded; however, such injury can efficiently be controlled and repaired by the inherent antioxidants of the cell. When the oxidant/antioxidant balance is disrupted towards the former by any chemical, biological or physical insult a ...
Seah Quee Ming - - 2008
We used immortalized human hepatocytes to study the bioactivation of leflunomide and the metabolic degradation to its major metabolite, A77 1726. Both leflunomide and A77 1726 caused a time- and concentration-dependent increase in LDH release. The cytotoxicity of leflunomide, but not that of A77 1726, was prevented by the pan-CYP ...
Rodriguez-Blanco Jezabel - - 2008
Oxidative stress has been shown to mediate neuron damage in Parkinson's disease (PD). In the present report, we intend to clarify the intracellular pathways mediating dopaminergic neuron death after oxidative stress production using post-mitotic PC12 cells treated with the neurotoxin 6-hydroxydopamine (6-OHDA). The use of post-mitotic cells is crucial, because ...
Magwere Tapiwanashe - - 2008
Ewing's sarcoma family of tumours (ESFT) are childhood cancers whose aggressive behaviour and propensity to relapse prompts the need for new treatment approaches. In this study, the role of cellular antioxidants in determining the sensitivity of ESFT cell lines to the cytotoxicity of the antineoplasic agent fenretinide was investigated with ...
T.K. Basak, T. Ramanujam, ...
In malignant cells, capacitance relaxation phenomena has been observed. This capacitance relaxation phenomena has been correlated with &#945; dispersion and VEGF. It is interesting to note that, in the process of pH homeostasis, cell signalling pathway is modulated by NRF2 which reduces oxidative stress on cells. This reduction of oxidative ...
Michard Q - - 2008
We previously reported that melanogenic enzyme TRP-2 (or DCT for DOPAchrome tautomerase) expression in WM35 melanoma cells resulted in increased intracellular GSH levels, reduction in DNA damage induced by free radicals, and decreased cell sensitivity to oxidative stress. These effects seemed to depend on a particular cellular context, because none ...
Park Eun-Jung - - 2008
As the applications of industrial nanoparticles are being developed, the concerns on the environmental health are increasing. Cytotoxicities of titanium dioxide nanoparticles of different concentrations (5, 10, 20 and 40 microg/ml) were evaluated in this study using a cultured human bronchial epithelial cell line, BEAS-2B. Exposure of the cultured cells ...
Kitagawa Rodrigo R - - 2008
The interaction of ascorbic acid with 5-methoxy-3,4-dehydroxanthomegnin, an 1,4-naphthoquinone, was investigated using the cytotoxic index for McCoy cells by neutral red assay. The synergistic effect was observed when such compounds were added simultaneously, most probably due to hydrogen peroxide being generated by ascorbate-driven 5-methoxy-3,4-dehydroxanthomegnin redox cycling. Incubation of cells in ...
Chang Mun-Seog - - 2008
AIM: To investigate the antioxidant effects of Morinda officinalis (Morindae radix, MR) on H(2)O(2)-induced oxidative stress in cultured mouse TM3 Leydig cells. METHODS: We carried out 2,2-diphenyl-1-picrylhydrazyl free radical scavenging, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, lipid peroxidation, testosterone enzyme immunoassay, superoxide dismutase (SOD), and catalase (CAT) assays in Leydig TM3 cells. RESULTS: MR ...
Han Yong Hwan - - 2008
Arsenic trioxide (ATO) affects many biological functions such as cell proliferation, apoptosis, differentiation and angiogenesis in various cells. We investigated the in vitro effects of ATO as a reactive oxygen species (ROS) generator or a glutathione (GSH) depletor on apoptosis in HeLa cells. ATO decreased the viability of HeLa cells ...
Poli G - - 2008
A comprehensive focus on 4-hydroxynonenal (HNE) as candidate molecule in a variety of pathophysiological conditions occurring in humans is here provided. Despite an active, now well characterized, metabolism in most cells and tissues, HNE can be easily detected and quantified by means of several methods, although with different sensitivity. Measurements ...
Zhang Da-Lei - - 2008
The attenuating effect of daidzein (DAI) on oxidative toxicity induced by Aroclor 1254 (A1254) was investigated in mouse testicular cells. Cells were exposed to A1254 alone or with DAI. The oxidative damage was estimated by measuring malondialdehyde (MDA) formation, superoxide dismutase (SOD) activity and glutathione (GSH) content. Results show that ...
Lee Hyang-Rim - - 2008
Pharmacological depletion of L-gamma-glutamyl-L-cysteinyl-glycine (GSH) has been implicated in the sensitization of cancer cells to alkylating agents and apoptosis. However, some types of cells do not induce apoptotic response following chemical depletion of GSH. In the present study, we report that murine embryonic fibroblasts (MEFs) can survive in the presence ...
Gales Grégoire - - 2008
The resistance of Saccharomyces cerevisiae to oxidative stress (H(2)O(2) and Cd(2+)) was compared in biofilms and planktonic cells, with the help of yeast mutants deleted of genes related to glutathione metabolism and oxidative stress. Biofilm-forming cells were found predominantly in the G1 stage of the cell cycle. This might explain ...
Löfgren Stefan - - 2008
PURPOSE: To examine the physiological function of the thioltransferase (TTase)/glutathione (GSH) system in the lens using TTase knockout mouse (TTase(-/-)) lens epithelial cells (LECs) as a model. METHODS: Primary LEC cultures were obtained from wild-type (TTase(+/+)) and TTase(-/-) mice. Characterization and validation of the cells were determined by immunoblotting for ...
Baigi Mojgan Ghavam - - 2008
Depending on the strength of oxidative stress, cells exhibit proliferative, apoptotic or necrotic responses. We have investigated whether the severity of glutathione (GSH) depletion could determine the type of cell death using 1,4-benzoquinone (BQ) and H(2)O(2) in two different tumor cell lines (human mammary gland carcinoma MCF-7 and rat hepatoma ...
Gupte Anshul - - 2008
D-Penicillamine (D-pen) is an established copper chelator. We have recently shown that the copper-catalyzed D-pen oxidation generates concentration-dependent hydrogen peroxide (H 2O 2). Additionally, D-pen coincubated with cupric sulfate resulted in cytotoxicity in human leukemia and breast cancer cells due to the extracellular generation of reactive oxygen species (ROS). The ...
Onaran Ilhan - - 2008
The purpose of this study was to test the hypothesis that warfarin may enhance free radical production and oxidative damage on cancer cells. We examined the possible concentration-dependent effect of warfarin on cytotoxicity with respect to oxidative stress on leukemia cell lines (K562 and HL-60) and normal human peripheral blood ...
Kaur Parvinder - - 2008
The ability of docosahexaenoic acid (DHA) to modulate methylmercury (MeHg)-induced neurotoxicity was investigated in primary astrocytes and neurons from the cerebellum. Gas chromatography measurements indicated increased DHA content in both cell types after 24h supplementation. After individual or combined treatment with MeHg (10microM) and DHA (30 and 90microM), the cell-associated ...
Auchère Françoise - - 2008
Friedreich's ataxia is a neurodegenerative disease caused by reduced expression of the mitochondrial protein frataxin. The main phenotypic features of frataxin-deficient human and yeast cells include iron accumulation in mitochondria, iron-sulphur cluster defects and high sensitivity to oxidative stress. Glutathione is a major protective agent against oxidative damage and glutathione-related ...
Xiao Xianghua - - 2008
Calcium and lipid peroxidation play important roles in oxidative stress-induced cellular injury and apoptosis, which ultimately cause cell death. In this study we examined whether protopine had a neuroprotection against H(2)O(2)-induced injury in PC12 cells. Pretreatment of PC12 cells with protopine improved the cell viability, enhanced activities of superoxide dismutase, ...
Reddy N M - - 2008
Genetic disruption of Nrf2 greatly enhances susceptibility to prooxidant- and carcinogen-induced experimental models of various human disorders; but the mechanisms by which this transcription factor confers protection are unclear. Using Nrf2-proficient (Nrf2(+/+)) and Nrf2-deficient (Nrf2(-/-)) primary epithelial cultures as a model, we now show that Nrf2 deficiency leads to oxidative ...
Helbig Kerstin - - 2008
Glutathione (GSH) and its derivative phytochelatin are important binding factors in transition-metal homeostasis in many eukaryotes. Here, we demonstrate that GSH is also involved in chromate, Zn(II), Cd(II), and Cu(II) homeostasis and resistance in Escherichia coli. While the loss of the ability to synthesize GSH influenced metal tolerance in wild-type ...
Numazawa Satoshi - - 2008
Pancreatic beta-cells are susceptible to oxidative stress, which is related closely to the islet dysfunction. In the present study, using the pancreatic cell lines HIT-T15 and RINm5F as known in vitro models of impaired beta-cell function as well as primary rat islet beta-cells, we observed a relationship between intracellular glutathione ...
Chen Helen H W - - 2008
Previous studies have demonstrated that treating cultured cells with cisplatin (CDDP) up-regulated the expression of glutathione (GSH) and its de novo rate-limiting enzyme glutamate-cysteine ligase (GCL), which consists of a catalytic (GCLC) and a modifier (GCLM) subunit. It has also been shown that many CDDP-resistant cell lines exhibit high levels ...
Han Yong Hwan - - 2008
Arsenic trioxide has been known to regulate many biological functions such as cell proliferation, apoptosis, differentiation, and angiogenesis in various cell lines. We investigated the involvement of GSH and ROS such as H(2)O(2) and O(2)(*-) in the death of As4.1 cells by arsenic trioxide. The intracellular ROS levels were changed ...
Koháryová M - - 2008
Oxidative stress plays an important role in the modulation of several important physiological functions. On the other side, oxidative stress is accountable for development of many unphysiological changes, which can be deleterious for cells. Consequently, at the present time there is increased interest about study mechanisms and changes evocated by ...
del V Cano Marisol - - 2008
PURPOSE: To quantify the effects of oxidant challenge on the redox state of adult human retinal pigment epithelial cells using microscopic autofluorescence spectroscopy and to determine whether treatment with the isothiocyanate sulforaphane protects these cells against oxidative stress. METHODS: Oxidative stress was evoked in ARPE-19 cells by H2O2 and tert-butyl ...
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